Carbonate and Bicarbonate Ion Transport in Alkaline Anion Exchange Membranes

DTIC Science & Technology

2013-06-25

membranes (AEMs) are being developed for potential use in fuel cell systems which include portable power applications. In a fuel cell , these membranes...Alkaline Anion Exchange Membranes Report Title ABSTRACT Anion exchange membranes (AEMs) are being developed for potential use in fuel cell systems which...include portable power applications. In a fuel cell , these membranes transport hydroxide ions from the cathode to the anode. If carbon dioxide is

Fuel cell system with interconnect

DOEpatents

Liu, Zhien; Goettler, Richard

2016-12-20

The present invention includes an integrated planar, series connected fuel cell system having electrochemical cells electrically connected via interconnects, wherein the anodes of the electrochemical cells are protected against Ni loss and migration via an engineered porous anode barrier layer.

Lithium battery management system

DOEpatents

Dougherty, Thomas J [Waukesha, WI

2012-05-08

Provided is a system for managing a lithium battery system having a plurality of cells. The battery system comprises a variable-resistance element electrically connected to a cell and located proximate a portion of the cell; and a device for determining, utilizing the variable-resistance element, whether the temperature of the cell has exceeded a predetermined threshold. A method of managing the temperature of a lithium battery system is also included.

Design of biomimetic cellular scaffolds for co-culture system and their application.

PubMed

Kook, Yun-Min; Jeong, Yoon; Lee, Kangwon; Koh, Won-Gun

2017-01-01

The extracellular matrix of most natural tissues comprises various types of cells, including fibroblasts, stem cells, and endothelial cells, which communicate with each other directly or indirectly to regulate matrix production and cell functionality. To engineer multicellular interactions in vitro, co-culture systems have achieved tremendous success achieving a more realistic microenvironment of in vivo metabolism than monoculture system in the past several decades. Recently, the fields of tissue engineering and regenerative medicine have primarily focused on three-dimensional co-culture systems using cellular scaffolds, because of their physical and biological relevance to the extracellular matrix of actual tissues. This review discusses several materials and methods to create co-culture systems, including hydrogels, electrospun fibers, microfluidic devices, and patterning for biomimetic co-culture system and their applications for specific tissue regeneration. Consequently, we believe that culture systems with appropriate physical and biochemical properties should be developed, and direct or indirect cell-cell interactions in the remodeled tissue must be considered to obtain an optimal tissue-specific microenvironment.

Cascade redox flow battery systems

DOEpatents

Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

2014-07-22

A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

B cell biology: implications for treatment of systemic lupus erythematosus.

PubMed

Anolik, J H

2013-04-01

B cells are critical players in the orchestration of properly regulated immune responses, normally providing protective immunity without autoimmunity. Balance in the B cell compartment is achieved through the finely regulated participation of multiple B cell populations with different antibody-dependent and independent functions. Both types of functions allow B cells to modulate other components of the innate and adaptive immune system. Autoantibody-independent B cell functions include antigen presentation, T cell activation and polarization, and dendritic cell modulation. Several of these functions are mediated by the ability of B cells to produce immunoregulatory cytokines and chemokines and by their critical contribution to lymphoid tissue development and organization including the development of ectopic tertiary lymphoid tissue. Additionally, the functional versatility of B cells enables them to play either protective or pathogenic roles in autoimmunity. In turn, B cell dysfunction has been critically implicated in the pathophysiology of systemic lupus erythematosus (SLE), a complex disease characterized by the production of autoantibodies and heterogeneous clinical involvement. Thus, the breakdown of B cell tolerance is a defining and early event in the disease process and may occur by multiple pathways, including alterations in factors that affect B cell activation thresholds, B cell longevity, and apoptotic cell processing. Once tolerance is broken, autoantibodies contribute to autoimmunity by multiple mechanisms including immune-complex mediated Type III hypersensitivity reactions, type II antibody-dependent cytotoxicity, and by instructing innate immune cells to produce pathogenic cytokines including IFNα, TNF and IL-1. The complexity of B cell functions has been highlighted by the variable success of B cell-targeted therapies in multiple autoimmune diseases, including those conventionally viewed as T cell-mediated conditions. Given the widespread utilization of B cell depletion therapy in autoimmune diseases and the need for new therapeutic approaches in SLE, a better understanding of human B cell subsets and the balance of pathogenic and regulatory functions is of the essence.

Fuel cell system with combustor-heated reformer

DOEpatents

Pettit, William Henry

2000-01-01

A fuel cell system including a fuel reformer heated by a catalytic combustor fired by anode effluent and/or fuel from a liquid fuel supply providing fuel for the fuel cell. The combustor includes a vaporizer section heated by the combustor exhaust gases for vaporizing the fuel before feeding it into the combustor. Cathode effluent is used as the principle oxidant for the combustor.

Evolution of taste and solitary chemoreceptor cell systems.

PubMed

Finger, T E

1997-01-01

Vertebrates possess four distinct chemosensory systems distinguishable on the basis of structure, innervation and utilization: olfaction, taste, solitary chemoreceptor cells (SCC) and the common chemical sense (free nerve endings). Of these, taste and the SCC sense rely on secondary receptor cells situated in the epidermis and synapsing on sensory nerve fibers innervating them near their base. The SCC sense occurs in anamniote aquatic craniates, including hagfish, and may be used for feeding or predator avoidance. The sense of taste occurs only in vertebrates and is always utilized for feeding. The SCC system achieves a high degree of specialization in two teleosts: sea robins (Prionotus) and rocklings (Ciliata). In sea robins, SCCs are abundant on the three anterior fin rays of the pectoral fin which are free of fin webbing and are used in active exploration of the substrate. Behavioral and physiological studies show that this SCC system responds to feeding cues and drives feeding behavior. It is connected centrally like a somatosensory system. In contrast, the specialized SCC system of rocklings occurs on the anterior dorsal fin which actively samples the surrounding water. This system responds to mucus substances and may serve as a predator detector. The SCC system in rocklings is connected centrally like a gustatory system. Taste buds contain multiple receptor cell types, including a serotonergic Merkel-like cell. Taste receptor cells respond to nutritionally relevant substances. Due to similarities between SCCs and one type of taste receptor cell, the suggestion is made that taste buds may be compound sensory organs that include some cells related to SCCs and others related to cutaneous Merkel cells. The lack of taste buds in hagfish and their presence in all vertebrates may indicate that the phylogenetic development of taste buds coincided with the elaboration of head structures at the craniate-vertebrate transition.

Long-term maintenance of human induced pluripotent stem cells by automated cell culture system.

PubMed

Konagaya, Shuhei; Ando, Takeshi; Yamauchi, Toshiaki; Suemori, Hirofumi; Iwata, Hiroo

2015-11-17

Pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem (iPS) cells, are regarded as new sources for cell replacement therapy. These cells can unlimitedly expand under undifferentiated conditions and be differentiated into multiple cell types. Automated culture systems enable the large-scale production of cells. In addition to reducing the time and effort of researchers, an automated culture system improves the reproducibility of cell cultures. In the present study, we newly designed a fully automated cell culture system for human iPS maintenance. Using an automated culture system, hiPS cells maintained their undifferentiated state for 60 days. Automatically prepared hiPS cells had a potency of differentiation into three germ layer cells including dopaminergic neurons and pancreatic cells.

Pressure Regulator With Internal Ejector Circulation Pump, Flow and Pressure Measurement Porting, and Fuel Cell System Integration Options

NASA Technical Reports Server (NTRS)

Vasquez, Arturo

2011-01-01

An advanced reactant pressure regulator with an internal ejector reactant circulation pump has been developed to support NASA's future fuel cell power systems needs. These needs include reliable and safe operation in variable-gravity environments, and for exploration activities with both manned and un manned vehicles. This product was developed for use in Proton Exchange Membrane Fuel Cell (PEMFC) power plant reactant circulation systems, but the design could also be applied to other fuel cell system types, (e.g., solid-oxide or alkaline) or for other gas pressure regulation and circulation needs. The regulator design includes porting for measurement of flow and pressure at key points in the system, and also includes several fuel cell system integration options. NASA has recognized ejectors as a viable alternative to mechanical pumps for use in spacecraft fuel cell power systems. The ejector motive force is provided by a variable, high-pressure supply gas that travels through the ejector s jet nozzle, whereby the pressure energy of the fluid stream is converted to kinetic energy in the gas jet. The ejector can produce circulation-to-consumption-flow ratios that are relatively high (2-3 times), and this phenomenon can potentially (with proper consideration of the remainder of the fuel cell system s design) be used to provide completely for reactant pre-humidification and product water removal in a fuel cell system. Specifically, a custom pressure regulator has been developed that includes: (1) an ejector reactant circulation pump (with interchangeable jet nozzles and mixer sections, gas-tight sliding and static seals in required locations, and internal fluid porting for pressure-sensing at the regulator's control elements) and (2) internal fluid porting to allow for flow rate and system pressure measurements. The fluid porting also allows for inclusion of purge, relief, and vacuum-breaker check valves on the regulator assembly. In addition, this regulator could also be used with NASA's advanced nonflow-through fuel cell power systems by simply incorporating a jet nozzle with an appropriate nozzle diameter.

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results. Fourth Report

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

Eudy, Leslie; Post, Matthew

This report presents results of a demonstration of fuel cell electric buses (FCEB) operating in Oakland, California. Alameda-Contra Costa Transit District (AC Transit) leads the Zero Emission Bay Area (ZEBA) demonstration, which includes 12 advanced-design fuel cell buses and two hydrogen fueling stations. The FCEBs in service at AC Transit are 40-foot, low-floor buses built by Van Hool with a hybrid electric propulsion system that includes a US Hybrid fuel cell power system and EnerDel lithium-based energy storage system. The buses began revenue service in May 2010.

Thermal Design for Extra-Terrestrial Regenerative Fuel Cell System

NASA Technical Reports Server (NTRS)

Gilligan, R.; Guzik, M.; Jakupca, I.; Bennett, W.; Smith, P.; Fincannon, J.

2017-01-01

The Advanced Exploration Systems (AES) Advanced Modular Power Systems (AMPS) Project is investigating different power systems for various lunar and Martian mission concepts. The AMPS Fuel Cell (FC) team has created two system-level models to evaluate the performance of regenerative fuel cell (RFC) systems employing different fuel cell chemistries. Proton Exchange Membrane fuel cells PEMFCs contain a polymer electrolyte membrane that separates the hydrogen and oxygen cavities and conducts hydrogen cations (protons) across the cell. Solid Oxide fuel cells (SOFCs) operate at high temperatures, using a zirconia-based solid ceramic electrolyte to conduct oxygen anions across the cell. The purpose of the modeling effort is to down select one fuel cell chemistry for a more detailed design effort. Figures of merit include the system mass, volume, round trip efficiency, and electrolyzer charge power required. PEMFCs operate at around 60 C versus SOFCs which operate at temperatures greater than 700 C. Due to the drastically different operating temperatures of the two chemistries the thermal control systems (TCS) differ. The PEM TCS is less complex and is characterized by a single pump cooling loop that uses deionized water coolant and rejects heat generated by the system to the environment via a radiator. The solid oxide TCS has its own unique challenges including the requirement to reject high quality heat and to condense the steam produced in the reaction. This paper discusses the modeling of thermal control systems for an extraterrestrial RFC that utilizes either a PEM or solid oxide fuel cell.

Direct methanol feed fuel cell and system

NASA Technical Reports Server (NTRS)

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

Involvement of autophagy in T cell biology.

PubMed

Oral, Ozlem; Yedier, Ozlem; Kilic, Seval; Gozuacik, Devrim

2017-01-01

Autophagy is an essential cellular pathway that sequesters various cytoplasmic components, including accumulated proteins, damaged organelles or invading microorganisms and delivers them to lysosomes for degradation. The function of autophagy has been reported in various tissues and systems, including its role in the regulation of cellular immunity. Autophagy plays a fundamental role at various stages of T cell maturation. It regulates the thymocyte selection and the generation of T cell repertoire by presenting intracellular antigens to MHC class molecules. Autophagy is crucial for metabolic regulation of T cells, and therefore supports cell survival and homeostasis, particularly in activated mature T cells. Furthermore, deletion of specific autophagy-related genes induces several immunological alterations including differentiation of activated T cells into regulatory, memory or natural killer T cells. In this review, we emphasize the impact of autophagy on T cell development, activation and differentiation, which is pivotal for the adaptive immune system.

Water reactive hydrogen fuel cell power system

DOEpatents

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.

Water reactive hydrogen fuel cell power system

DOEpatents

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

2014-11-25

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 the fuel cartridge to generate hydrogen for the fuel cell which then produces power for the user.

Fuel cell membrane hydration and fluid metering

DOEpatents

Jones, Daniel O.; Walsh, Michael M.

2003-01-01

A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

DOEpatents

Dane, C Brent [Livermore, CA; Hackel, Lloyd [Livermore, CA; Harris, Fritz B [Rocklin, CA

2007-04-24

A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

Fuel cell gas management system

DOEpatents

DuBose, Ronald Arthur

2000-01-11

A fuel cell gas management system including a cathode humidification system for 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 equal 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.

Energy Storage Technology Development for Space Exploration

NASA Technical Reports Server (NTRS)

Mercer, Carolyn R.; Jankovsky, Amy L.; Reid, Concha M.; Miller, Thomas B.; Hoberecht, Mark A.

2011-01-01

The National Aeronautics and Space Administration is developing battery and fuel cell technology to meet the expected energy storage needs of human exploration systems. Improving battery performance and safety for human missions enhances a number of exploration systems, including un-tethered extravehicular activity suits and transportation systems including landers and rovers. Similarly, improved fuel cell and electrolyzer systems can reduce mass and increase the reliability of electrical power, oxygen, and water generation for crewed vehicles, depots and outposts. To achieve this, NASA is developing non-flow-through proton-exchange-membrane fuel cell stacks, and electrolyzers coupled with low permeability membranes for high pressure operation. The primary advantage of this technology set is the reduction of ancillary parts in the balance-of-plant fewer pumps, separators and related components should result in fewer failure modes and hence a higher probability of achieving very reliable operation, and reduced parasitic power losses enable smaller reactant tanks and therefore systems with lower mass and volume. Key accomplishments over the past year include the fabrication and testing of several robust, small-scale non-flow-through fuel cell stacks that have demonstrated proof-of-concept. NASA is also developing advanced lithium-ion battery cells, targeting cell-level safety and very high specific energy and energy density. Key accomplishments include the development of silicon composite anodes, lithiatedmixed- metal-oxide cathodes, low-flammability electrolytes, and cell-incorporated safety devices that promise to substantially improve battery performance while providing a high level of safety.

Design of biomimetic cellular scaffolds for co-culture system and their application

PubMed Central

Kook, Yun-Min; Jeong, Yoon; Lee, Kangwon; Koh, Won-Gun

2017-01-01

The extracellular matrix of most natural tissues comprises various types of cells, including fibroblasts, stem cells, and endothelial cells, which communicate with each other directly or indirectly to regulate matrix production and cell functionality. To engineer multicellular interactions in vitro, co-culture systems have achieved tremendous success achieving a more realistic microenvironment of in vivo metabolism than monoculture system in the past several decades. Recently, the fields of tissue engineering and regenerative medicine have primarily focused on three-dimensional co-culture systems using cellular scaffolds, because of their physical and biological relevance to the extracellular matrix of actual tissues. This review discusses several materials and methods to create co-culture systems, including hydrogels, electrospun fibers, microfluidic devices, and patterning for biomimetic co-culture system and their applications for specific tissue regeneration. Consequently, we believe that culture systems with appropriate physical and biochemical properties should be developed, and direct or indirect cell–cell interactions in the remodeled tissue must be considered to obtain an optimal tissue-specific microenvironment. PMID:29081966

Study terrestrial applications of solar cell powered systems

NASA Technical Reports Server (NTRS)

Ravin, J. W.

1973-01-01

Terrestrial applications of solar cells and design systems are considered for those applications that show the most promise for becoming practical and accepted by users within the next five years. The study includes the definition, categorization, evaluation and screening of the most attractive potential terrestrial applications for solar cells. Potential markets are initially grouped and categorized in a general sense and are weighted in priority by their business volume, present and future. From a categorized list including marine, transportation, security, communication, meteorological and others, 66 potential solar cell applications have been cataloged. A methodology was formulated to include the criteria for evaluation and screening. The evaluation process covers all parts and components of the complete system required for each application and gives consideration to all factors, such as engineering, economic, production, marketing and other factors that may have an influence on the acceptance of the system.

Bioreactor concepts for cell culture-based viral vaccine production.

PubMed

Gallo-Ramírez, Lilí Esmeralda; Nikolay, Alexander; Genzel, Yvonne; Reichl, Udo

2015-01-01

Vaccine manufacturing processes are designed to meet present and upcoming challenges associated with a growing vaccine market and to include multi-use facilities offering a broad portfolio and faster reaction times in case of pandemics and emerging diseases. The final products, from whole viruses to recombinant viral proteins, are very diverse, making standard process strategies hardly universally applicable. Numerous factors such as cell substrate, virus strain or expression system, medium, cultivation system, cultivation method, and scale need consideration. Reviewing options for efficient and economical production of human vaccines, this paper discusses basic factors relevant for viral antigen production in mammalian cells, avian cells and insect cells. In addition, bioreactor concepts, including static systems, single-use systems, stirred tanks and packed-beds are addressed. On this basis, methods towards process intensification, in particular operational strategies, the use of perfusion systems for high product yields, and steps to establish continuous processes are introduced.

Thermal System Modeling for Lunar and Martian Surface Regenerative Fuel Cell Systems

NASA Technical Reports Server (NTRS)

Gilligan, Ryan Patrick; Smith, Phillip James; Jakupca, Ian Joseph; Bennett, William Raymond; Guzik, Monica Christine; Fincannon, Homer J.

2017-01-01

The Advanced Exploration Systems (AES) Advanced Modular Power Systems (AMPS) Project is investigating different power systems for various lunar and Martian mission concepts. The AMPS Fuel Cell (FC) team has created two system-level models to evaluate the performance of regenerative fuel cell (RFC) systems employing different fuel cell chemistries. Proton Exchange Membrane fuel cells PEMFCs contain a polymer electrolyte membrane that separates the hydrogen and oxygen cavities and conducts hydrogen cations (protons) across the cell. Solid Oxide fuel cells (SOFCs) operate at high temperatures, using a zirconia-based solid ceramic electrolyte to conduct oxygen anions across the cell. The purpose of the modeling effort is to down select one fuel cell chemistry for a more detailed design effort. Figures of merit include the system mass, volume, round trip efficiency, and electrolyzer charge power required. PEMFCs operate at around 60 degrees Celsius versus SOFCs which operate at temperatures greater than 700 degrees Celsius. Due to the drastically different operating temperatures of the two chemistries the thermal control systems (TCS) differ. The PEM TCS is less complex and is characterized by a single pump cooling loop that uses deionized water coolant and rejects heat generated by the system to the environment via a radiator. The solid oxide TCS has its own unique challenges including the requirement to reject high quality heat and to condense the steam produced in the reaction. This paper discusses the modeling of thermal control systems for an extraterrestrial RFC that utilizes either a PEM or solid oxide fuel cell.

Microfluidic devices, systems, and methods for quantifying particles using centrifugal force

DOEpatents

Schaff, Ulrich Y.; Sommer, Gregory J.; Singh, Anup K.

2015-11-17

Embodiments of the present invention are directed toward microfluidic systems, apparatus, and methods for measuring a quantity of cells in a fluid. Examples include a differential white blood cell measurement using a centrifugal microfluidic system. A method may include introducing a fluid sample containing a quantity of cells into a microfluidic channel defined in part by a substrate. The quantity of cells may be transported toward a detection region defined in part by the substrate, wherein the detection region contains a density media, and wherein the density media has a density lower than a density of the cells and higher than a density of the fluid sample. The substrate may be spun such that at least a portion of the quantity of cells are transported through the density media. Signals may be detected from label moieties affixed to the cells.

Develop and test fuel cell powered on-site integrated total energy system. Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

Kaufman, A.

1981-01-01

An integrated 5 kW power system based upon methanol fuel and a phosphoric acid fuel cell operating at about 473 K is described. Description includes test results of advanced fuel cell catalysts, a semiautomatic acid replenishment system and a completed 5 kW methanol/system reformer. The results of a preliminary system test on a reformer/stack/inverter combination are reported. An initial design for a 25 kW stack is presented. Experimental plans are outlined for data acquisition necessary for design of a 50 kW methanol/steam reformer. Activities related to complete mathematical modelling of the integrated power system, including wasteheat utilization, are described.

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

PubMed

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

Description and modelling of the solar-hydrogen-biogas-fuel cell system in GlashusEtt

NASA Astrophysics Data System (ADS)

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.

Measurement of wood/plant cell or composite material attributes with computer assisted tomography

DOEpatents

West, Darrell C.; Paulus, Michael J.; Tuskan, Gerald A.; Wimmer, Rupert

2004-06-08

A method for obtaining wood-cell attributes from cellulose containing samples includes the steps of radiating a cellulose containing sample with a beam of radiation. Radiation attenuation information is collected from radiation which passes through the sample. The source is rotated relative to the sample and the radiation and collecting steps repeated. A projected image of the sample is formed from the collected radiation attenuation information, the projected image including resolvable features of the cellulose containing sample. Cell wall thickness, cell diameter (length) and cell vacoule diameter can be determined. A system for obtaining physical measures from cellulose containing samples includes a radiation source, a radiation detector, and structure for rotating the source relative to said sample. The system forms an image of the sample from the radiation attenuation information, the image including resolvable features of the sample.

Development of a Space-Rated Proton Exchange Membrane Fuel Cell

NASA Technical Reports Server (NTRS)

Hoffman, William C., III; Vasquez, Arturo; Lazaroff, Scott M.; Downey, Michael G.

1999-01-01

Power systems for human spacecraft have historically included fuel cells due to the superior energy density they offer over battery systems depending on mission length and power consumption. As space exploration focuses on the evolution of reusable spacecraft and also considers planetary exploration power system requirements, fuel cells continue to be a factor in the potential system solutions.

Radioisotope powered AMTEC systems

NASA Astrophysics Data System (ADS)

Ivanenok, Joseph F., III; Sievers, Robert K.

1994-11-01

Alkali metal thermal to electric converter (AMTEC) systems are being developed for high performance spacecraft power systems, including small, general purpose heat source (GPHS) powered systems. Several design concepts have been evaluated for the power range from 75 W to 1 kW. The specific power for these concepts has been found to be as high as 18-20 W/kg and 22 kW/m(exp 3). The projected area, including radiators, has been as low as 0.4 m(exp 2)/kW. AMTEC power systems are extremely attractive, relative to other current and projected power systems, because AMTEC offers high power density, low projected area, and low volume. Two AMTEC cell design types have been identified. A single-tube cell is already under development and a multitube cell design, to provide additional power system gains, has undergone proof-of-principle testing. Solar powered AMTEC (SAMTEC) systems are also being developed, and numerous terrestrial applications have been identified for which the same basic AMTEC cells being developed for radioisotope systems are also suitable.

A single cell penetration system by ultrasonic driving

NASA Astrophysics Data System (ADS)

Zhou, Zhaoying; Xiao, Mingfei; Yang, Xing; Wu, Ting

2008-12-01

The researches of single cell's control and operation are the hotspots in whole world. Among the various technologies, the transmission of ectogenic genetic materials between cell membrane is very significant. Imitating the Chinese traditional acupuncture therapy, a new ultrasonic resonance driving method, is imported to drive a cell's penetration probe. A set of the single cell penetration system was established to perform this function. This system includes four subsystems: driving part, micromanipulation part, observation and measurement part, and actuation part. Some fish egg experiments indicate that this system is workable and effective.

Advances in Materials and System Technology for Portable Fuel Cells

NASA Technical Reports Server (NTRS)

Narayanan, Sekharipuram R.

2007-01-01

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

Exclusive Liquid Repellency: An Open Multi-Liquid-Phase Technology for Rare Cell Culture and Single-Cell Processing.

PubMed

Li, Chao; Yu, Jiaquan; Schehr, Jennifer; Berry, Scott M; Leal, Ticiana A; Lang, Joshua M; Beebe, David J

2018-05-23

The concept of high liquid repellency in multi-liquid-phase systems (e.g., aqueous droplets in an oil background) has been applied to areas of biomedical research to realize intrinsic advantages not available in single-liquid-phase systems. Such advantages have included minimizing analyte loss, facile manipulation of single-cell samples, elimination of biofouling, and ease of use regarding loading and retrieving of the sample. In this paper, we present generalized design rules for predicting the wettability of solid-liquid-liquid systems (especially for discrimination between exclusive liquid repellency (ELR) and finite liquid repellency) to extend the applications of ELR. We then apply ELR to two model systems with open microfluidic design in cell biology: (1) in situ underoil culture and combinatorial coculture of mammalian cells in order to demonstrate directed single-cell multiencapsulation with minimal waste of samples as compared to stochastic cell seeding and (2) isolation of a pure population of circulating tumor cells, which is required for certain downstream analyses including sequencing and gene expression profiling.

7 CFR 457.162 - Nursery crop insurance provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... inch in diameter (including trays containing 200 or fewer individual cells, unless specifically... or cell interior, have an established root system, and meet all other conditions specified in the... container interior (including trays that contain 200 or fewer individual cells, unless specifically provided...

7 CFR 457.162 - Nursery crop insurance provisions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... inch in diameter (including trays containing 200 or fewer individual cells, unless specifically... or cell interior, have an established root system, and meet all other conditions specified in the... container interior (including trays that contain 200 or fewer individual cells, unless specifically provided...

7 CFR 457.162 - Nursery crop insurance provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... inch in diameter (including trays containing 200 or fewer individual cells, unless specifically... or cell interior, have an established root system, and meet all other conditions specified in the... container interior (including trays that contain 200 or fewer individual cells, unless specifically provided...

7 CFR 457.162 - Nursery crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... inch in diameter (including trays containing 200 or fewer individual cells, unless specifically... or cell interior, have an established root system, and meet all other conditions specified in the... container interior (including trays that contain 200 or fewer individual cells, unless specifically provided...

Identification Of Cells With A Compact Microscope Imaging System With Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2006-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking mic?oscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to autofocus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously.

Tracking of Cells with a Compact Microscope Imaging System with Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2007-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking microscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to autofocus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously

Tracking of cells with a compact microscope imaging system with intelligent controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2007-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking microscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to auto-focus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously.

Organic solvents, electrolytes, and lithium ion cells with good low temperature performance

NASA Technical Reports Server (NTRS)

Huang, Chen-Kuo (Inventor); Smart, Marshall C. (Inventor); Surampudi, Subbarao (Inventor); Bugga, Ratnakumar V. (Inventor)

2002-01-01

Multi-component organic solvent systems, electrolytes and electrochemical cells characterized by good low temperature performance are provided. In one embodiment, an improved organic solvent system contains a ternary mixture of ethylene carbonate, dimethyl carbonate and diethyl carbonate. In other embodiments, quaternary systems include a fourth component, i.e, an aliphatic ester, an asymmetric alkyl carbonate or a compound of the formula LiOX, where X is R, COOR, or COR, where R is alkyl or fluoroalkyl. Electrolytes based on such organic solvent systems are also provided and contain therein a lithium salt of high ionic mobility, such as LiPF.sub.6. Reversible electrochemical cells, particularly lithium ion cells, are constructed with the improved electrolytes, and preferably include a carbonaceous anode, an insertion type cathode, and an electrolyte interspersed therebetween.

Marshall Space Flight Center battery activity

NASA Technical Reports Server (NTRS)

Lowery, Eric

1993-01-01

The topics covered are presented in viewgraph form and include a flight program history and in-house activities. Some of the in-house activities addressed include secondary battery/cell testing and Hubble Space Telescope Test data updates involving the NiCd type 40 test - battery 1 and 2, the NiCd type 41 test battery, the general electric battery, the NiCd six-battery system, the six four-cell packs, fourteen-cell pack, three four-cell packs, the NiH2 six-battery system, and the flight spare battery. A general test data update is also presented for the twelve-cell pack, the four four-cell packs, the reconditioning test, and planned Ni-MH testing.

A flexible and qualitatively stable model for cell cycle dynamics including DNA damage effects.

PubMed

Jeffries, Clark D; Johnson, Charles R; Zhou, Tong; Simpson, Dennis A; Kaufmann, William K

2012-01-01

This paper includes a conceptual framework for cell cycle modeling into which the experimenter can map observed data and evaluate mechanisms of cell cycle control. The basic model exhibits qualitative stability, meaning that regardless of magnitudes of system parameters its instances are guaranteed to be stable in the sense that all feasible trajectories converge to a certain trajectory. Qualitative stability can also be described by the signs of real parts of eigenvalues of the system matrix. On the biological side, the resulting model can be tuned to approximate experimental data pertaining to human fibroblast cell lines treated with ionizing radiation, with or without disabled DNA damage checkpoints. Together these properties validate a fundamental, first order systems view of cell dynamics. Classification Codes: 15A68.

Dynamic model of a micro-tubular solid oxide fuel cell stack including an integrated cooling system

NASA Astrophysics Data System (ADS)

Hering, Martin; Brouwer, Jacob; Winkler, Wolfgang

2017-02-01

A novel dynamic micro-tubular solid oxide fuel cell (MT-SOFC) and stack model including an integrated cooling system is developed using a quasi three-dimensional, spatially resolved, transient thermodynamic, physical and electrochemical model that accounts for the complex geometrical relations between the cells and cooling-tubes. The modeling approach includes a simplified tubular geometry and stack design including an integrated cooling structure, detailed pressure drop and gas property calculations, the electrical and physical constraints of the stack design that determine the current, as well as control strategies for the temperature. Moreover, an advanced heat transfer balance with detailed radiative heat transfer between the cells and the integrated cooling-tubes, convective heat transfer between the gas flows and the surrounding structures and conductive heat transfer between the solid structures inside of the stack, is included. The detailed model can be used as a design basis for the novel MT-SOFC stack assembly including an integrated cooling system, as well as for the development of a dynamic system control strategy. The evaluated best-case design achieves very high electrical efficiency between around 75 and 55% in the entire power density range between 50 and 550 mW /cm2 due to the novel stack design comprising an integrated cooling structure.

APOPTOSIS DURING DEVELOPMENT AND AGING AND IN RESPONSE TO MERCURY EXPOSURE.

EPA Science Inventory

In the central nervous system from embryogenesis through senescence, cell number is regulated, in part, by apoptosis. Each region of the nervous system has a characteristic temporal pattern of programmed cell death, which includes far greater numbers of cells undergoing apop...

Childhood Central Nervous System Germ Cell Tumors Treatment (PDQ®)—Health Professional Version

Cancer.gov

Treatment for children with central nervous system germ cell tumors (GCT) depend upon the specific tumor type. Options include radiation therapy, chemotherapy, surgery (in various combinations) and stem cell rescue. Get detailed information about GCTs in this clinician summary.

Electrochemical cell for rebalancing REDOX flow system

NASA Technical Reports Server (NTRS)

Thaller, L. H. (Inventor)

1979-01-01

An electrically rechargeable REDOX cell or battery system including one of more rebalancing cells is described. Each rebalancing cell is divided into two chambers by an ion permeable membrane. The first chamber is fed with gaseous hydrogen and a cathode fluid which is circulated through the cathode chamber of the REDOX cell is also passed through the second chamber of the rebalancing cell. Electrochemical reactions take place on the surface of insert electrodes in the first and second chambers to rebalance the electrochemical capacity of the anode and cathode fluids of the REDOX system.

Systems, methods and computer readable media for estimating capacity loss in rechargeable electrochemical cells

DOEpatents

Gering, Kevin L.

2013-06-18

A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples charge characteristics of the electrochemical cell. The computing system periodically determines cell information from the charge characteristics of the electrochemical cell. The computing system also periodically adds a first degradation characteristic from the cell information to a first sigmoid expression, periodically adds a second degradation characteristic from the cell information to a second sigmoid expression and combines the first sigmoid expression and the second sigmoid expression to develop or augment a multiple sigmoid model (MSM) of the electrochemical cell. The MSM may be used to estimate a capacity loss of the electrochemical cell at a desired point in time and analyze other characteristics of the electrochemical cell. The first and second degradation characteristics may be loss of active host sites and loss of free lithium for Li-ion cells.

High throughput solar cell ablation system

DOEpatents

Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

2014-10-14

A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

High throughput solar cell ablation system

DOEpatents

Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

2012-09-11

A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

Fuel-cell engine stream conditioning system

DOEpatents

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.

Conservation and Evolutionary Dynamics of the agr Cell-to-Cell Communication System across Firmicutes▿ †

PubMed Central

Wuster, Arthur; Babu, M. Madan

2008-01-01

We present evidence that the agr cell-to-cell communication system is present across firmicutes, including the human pathogen Clostridium perfringens. Although we find that the agr system is evolutionarily conserved and that the general functions which it regulates are similar in different species, the individual regulated genes are not the same. This suggests that the regulatory network controlled by agr is dynamic and evolves rapidly. PMID:17933897

Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death

NASA Astrophysics Data System (ADS)

Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.

2018-05-01

Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.

Lipid Rafts in Mast Cell Biology

PubMed Central

Silveira e Souza, Adriana Maria Mariano; Mazucato, Vivian Marino; Jamur, Maria Célia; Oliver, Constance

2011-01-01

Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization. PMID:21490812

Photovoltaics and solar thermal conversion to electricity - Status and prospects

NASA Technical Reports Server (NTRS)

Alper, M. E.

1979-01-01

Photovoltaic power system technology development includes flat-plate silicon solar arrays and concentrating solar cell systems, which use silicon and other cell materials such as gallium arsenide. System designs and applications include small remote power systems ranging in size from tens of watts to tens of kilowatts, intermediate load-center applications ranging in size from tens to hundreds of kilowatts, and large central plant installations, as well as grid-connected rooftop applications. The thermal conversion program is concerned with large central power systems and small power applications.

Fuel cell on-site integrated energy system parametric analysis of a residential complex

NASA Technical Reports Server (NTRS)

Simons, S. N.

1977-01-01

A parametric energy-use analysis was performed for a large apartment complex served by a fuel cell on-site integrated energy system (OS/IES). The variables parameterized include operating characteristics for four phosphoric acid fuel cells, eight OS/IES energy recovery systems, and four climatic locations. The annual fuel consumption for selected parametric combinations are presented and a breakeven economic analysis is presented for one parametric combination. The results show fuel cell electrical efficiency and system component choice have the greatest effect on annual fuel consumption; fuel cell thermal efficiency and geographic location have less of an effect.

A fast solution switching system with temperature control for single cell measurements

PubMed Central

Koh, Duk-Su; Chen, Liangyi; Ufret-Vincenty, Carmen A.; Jung, Seung-Ryoung

2011-01-01

This article describes a perfusion system for biophysical single cell experiments at the physiological temperature. Our system regulates temperature of test solutions using a small heat exchanger that includes several capillaries. Water circulating inside the heat exchanger warms or cools test solutions flowing inside the capillaries. Temperature-controlled solutions are delivered directly to a single cell(s) through a multibarreled manifold that switches solutions bathing a cell in less than 1 s. This solution exchange is optimal for patch clamp, single-cell microamperometry, and microfluorometry experiments. Using this system, we demonstrate that exocytosis from pancreatic β cells and activation of TRPV1 channels are temperature sensitive. We also discuss how to measure local temperature near a single cell under investigation. PMID:21536068

Novel Therapeutic Strategies for Solid Tumor Based on Body's Intrinsic Antitumor Immune System.

PubMed

Duan, Haifeng

2018-05-22

The accumulation of mutated somatic cells due to the incompetency of body's immune system may lead to tumor onset. Therefore, enhancing the ability of the system to eliminate such cells should be the core of tumor therapy. The intrinsic antitumor immunity is triggered by tumor-specific antigens (TSA) or TSA-sensitized dendritic cells (DC). Once initiated, specific anti-tumor antibodies are produced and tumor-specific killer immune cells, including cytotoxic T lymphocytes (CTL), NK cells, and macrophages, are raised or induced. Several strategies may enhance antitumor action of immune system, such as supplying tumor-targeted antibody, activating T cells, enhancing the activity and tumor recognition of NK cells, promoting tumor-targeted phagocytosis of macrophages, and eliminating the immunosuppressive myeloid-derived suppressor cells (MDSCs) and Treg cells. Apart from the immune system, the removal of tumor burden still needs to be assisted by drugs, surgery or radiation. And the body's internal environment and tumor microenvironment should be improved to recover immune cell function and prevent tumor growth. Multiple microenvironment modulatory therapies may be applied, including addressing hypoxia and oxidative stress, correcting metabolic disorders, and controlling chronic inflammation. Finally, to cure tumor and prevent tumor recurrence, repairing or supporting therapy that consist of tissue repair and nutritional supplement should be applied properly. © 2018 The Author(s). Published by S. Karger AG, Basel.

Systems, methods and computer-readable media for modeling cell performance fade of rechargeable electrochemical devices

DOEpatents

Gering, Kevin L

2013-08-27

A system includes an electrochemical cell, monitoring hardware, and a computing system. The monitoring hardware periodically samples performance characteristics of the electrochemical cell. The computing system determines cell information from the performance characteristics of the electrochemical cell. The computing system also develops a mechanistic level model of the electrochemical cell to determine performance fade characteristics of the electrochemical cell and analyzing the mechanistic level model to estimate performance fade characteristics over aging of a similar electrochemical cell. The mechanistic level model uses first constant-current pulses applied to the electrochemical cell at a first aging period and at three or more current values bracketing a first exchange current density. The mechanistic level model also is based on second constant-current pulses applied to the electrochemical cell at a second aging period and at three or more current values bracketing the second exchange current density.

Bioreactors to Influence Stem Cell Fate: Augmentation of Mesenchymal Stem Cell Signaling Pathways via Dynamic Culture Systems

PubMed Central

Yeatts, Andrew B.; Choquette, Daniel T.; Fisher, John P.

2012-01-01

Background Mesenchymal stem cells (MSCs) are a promising cell source for bone and cartilage tissue engineering as they can be easily isolated from the body and differentiated into osteoblasts and chondrocytes. A cell based tissue engineering strategy using MSCs often involves the culture of these cells on three-dimensional scaffolds; however the size of these scaffolds and the cell population they can support can be restricted in traditional static culture. Thus dynamic culture in bioreactor systems provides a promising means to culture and differentiate MSCs in vitro. Scope of Review This review seeks to characterize key MSC differentiation signaling pathways and provides evidence as to how dynamic culture is augmenting these pathways. Following an overview of dynamic culture systems, discussion will be provided on how these systems can effectively modify and maintain important culture parameters including oxygen content and shear stress. Literature is reviewed for both a highlight of key signaling pathways and evidence for regulation of these signaling pathways via dynamic culture systems. Major Conclusions The ability to understand how these culture systems are affecting MSC signaling pathways could lead to a shear or oxygen regime to direct stem cell differentiation. In this way the efficacy of in vitro culture and differentiation of MSCs on three-dimensional scaffolds could be greatly increased. General Significance Bioreactor systems have the ability to control many key differentiation stimuli including mechanical stress and oxygen content. The further integration of cell signaling investigations within dynamic culture systems will lead to a quicker realization of the promise of tissue engineering and regenerative medicine. PMID:22705676

Radioisotope powered AMTEC systems

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

Ivanenok, J.F. III; Sievers, R.K.

1994-11-01

Alkali metal thermal to electric converter (AMTEC) systems are being developed for high performance spacecraft power systems, including small, general purpose heat source (GPHS) powered systems. Several design concepts have been evaluated for the power range from 75 W to 1 kW. The specific power for these concepts has been found to be as high as 18-20 W/kg and 22 kW/m(exp 3). The projected area, including radiators, has been as low as 0.4 m(exp 2)/kW. AMTEC power systems are extremely attractive, relative to other current and projected power systems, because AMTEC offers high power density, low projected area, and lowmore » volume. Two AMTEC cell design types have been identified. A single-tube cell is already under development and a multitube cell design, to provide additional power system gains, has undergone proof-of-principle testing. Solar powered AMTEC (SAMTEC) systems are also being developed, and numerous terrestrial applications have been identified for which the same basic AMTEC cells being developed for radioisotope systems are also suitable. 35 refs.« less

Advances of blood cell-based drug delivery systems.

PubMed

Sun, Yanan; Su, Jing; Liu, Geyi; Chen, Jianjun; Zhang, Xiumei; Zhang, Ran; Jiang, Minhan; Qiu, Mingfeng

2017-01-01

Blood cells, including erythrocytes, leukocytes and platelets are used as drug carriers in a wide range of applications. They have many unique advantages such as long life-span in circulation (especially erythrocytes), target release capacities (especially platelets), and natural adhesive properties (leukocytes and platelets). These properties make blood cell based delivery systems, as well as their membrane-derived carriers, far superior to other drug delivery systems. Despite the advantages, the further development of blood cell-based delivery systems was hindered by limitations in the source, storage, and mass production. To overcome these problems, synthetic biomaterials that mimic blood cell and nanocrystallization of blood cells have been developed and may represent the future direction for blood cell membrane-based delivery systems. In this paper, we review recent progress of the rising blood cell-based drug delivery systems, and also discuss their challenges and future tendency of development. Copyright © 2016. Published by Elsevier B.V.

Fuel cell membrane hydration and fluid metering

DOEpatents

Jones, Daniel O.; Walsh, Michael M.

1999-01-01

A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

Engineering model system study for a regenerative fuel cell: Study report

NASA Technical Reports Server (NTRS)

Chang, B. J.; Schubert, F. H.; Kovach, A. J.; Wynveen, R. A.

1984-01-01

Key design issues of the regenerative fuel cell system concept were studied and a design definition of an alkaline electrolyte based engineering model system or low Earth orbit missions was completed. Definition of key design issues for a regenerative fuel cell system include gaseous reactant storage, shared heat exchangers and high pressure pumps. A power flow diagram for the 75 kW initial space station and the impact of different regenerative fuel cell modular sizes on the total 5 year to orbit weight and volume are determined. System characteristics, an isometric drawing, component sizes and mass and energy balances are determined for the 10 kW engineering model system. An open loop regenerative fuel cell concept is considered for integration of the energy storage system with the life support system of the space station. Technical problems and their solutions, pacing technologies and required developments and demonstrations for the regenerative fuel cell system are defined.

Ex vivo gut culture for studying differentiation and migration of small intestinal epithelial cells

PubMed Central

Fu, Xing; Du, Min

2018-01-01

Epithelial cultures are commonly used for studying gut health. However, due to the absence of mesenchymal cells and gut structure, epithelial culture systems including recently developed three-dimensional organoid culture cannot accurately represent in vivo gut development, which requires intense cross-regulation of the epithelial layer with the underlying mesenchymal tissue. In addition, organoid culture is costly. To overcome this, a new culture system was developed using mouse embryonic small intestine. Cultured intestine showed spontaneous peristalsis, indicating the maintenance of the normal gut physiological structure. During 10 days of ex vivo culture, epithelial cells moved along the gut surface and differentiated into different epithelial cell types, including enterocytes, Paneth cells, goblet cells and enteroendocrine cells. We further used the established ex vivo system to examine the role of AMP-activated protein kinase (AMPK) on gut epithelial health. Tamoxifen-induced AMPKα1 knockout vastly impaired epithelial migration and differentiation of the developing ex vivo gut, showing the crucial regulatory function of AMPK α1 in intestinal health. PMID:29643147

Vorinostat and Bortezomib in Treating Young Patients With Refractory or Recurrent Solid Tumors, Including Central Nervous System Tumors and Lymphoma

ClinicalTrials.gov

2013-07-01

Childhood Burkitt Lymphoma; Childhood Central Nervous System Choriocarcinoma; Childhood Central Nervous System Germ Cell Tumor; Childhood Central Nervous System Germinoma; Childhood Central Nervous System Mixed Germ Cell Tumor; Childhood Central Nervous System Teratoma; Childhood Central Nervous System Yolk Sac Tumor; Childhood Choroid Plexus Tumor; Childhood Craniopharyngioma; Childhood Diffuse Large Cell Lymphoma; Childhood Immunoblastic Large Cell Lymphoma; Childhood Medulloepithelioma; Childhood Meningioma; Childhood Mixed Glioma; Childhood Nasal Type Extranodal NK/T-cell Lymphoma; Childhood Oligodendroglioma; Recurrent Childhood Anaplastic Large Cell Lymphoma; Recurrent Childhood Brain Stem Glioma; Recurrent Childhood Central Nervous System Embryonal Tumor; Recurrent Childhood Cerebellar Astrocytoma; Recurrent Childhood Cerebral Astrocytoma; Recurrent Childhood Ependymoma; Recurrent Childhood Grade III Lymphomatoid Granulomatosis; Recurrent Childhood Large Cell Lymphoma; Recurrent Childhood Lymphoblastic Lymphoma; Recurrent Childhood Malignant Germ Cell Tumor; Recurrent Childhood Medulloblastoma; Recurrent Childhood Pineoblastoma; Recurrent Childhood Small Noncleaved Cell Lymphoma; Recurrent Childhood Subependymal Giant Cell Astrocytoma; Recurrent Childhood Supratentorial Primitive Neuroectodermal Tumor; Recurrent Childhood Visual Pathway and Hypothalamic Glioma; Recurrent Childhood Visual Pathway Glioma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Unspecified Childhood Solid Tumor, Protocol Specific

iCELLigence real-time cell analysis system for examining the cytotoxicity of drugs to cancer cell lines

PubMed Central

Türker Şener, Leyla; Albeni̇z, Gürcan; Di̇nç, Bi̇rcan; Albeni̇z, Işil

2017-01-01

The recently developed iCELLigence™ real-time cell analyzer (RTCA) can be used for the label-free real-time monitoring of cancer cell proliferation, viability, invasion and cytotoxicity. The RTCA system uses 16-well microtiter plates with a gold microelectrode biosensor array that measures impedance when cells adhere to the microelectrodes causing an alternating current. By measuring the electric field generated in this process, the RTCA system can be used for the analysis of cell proliferation, viability, morphology and migration. The present review aimed to summarize the working method of the RTCA system, in addition to discussing the research performed using the system for various applications, including cancer drug discovery via measuring cytotoxicity. PMID:28962095

The pathogenesis of oligoarticular/polyarticular vs systemic juvenile idiopathic arthritis.

PubMed

Lin, Yu-Tsan; Wang, Chen-Ti; Gershwin, M Eric; Chiang, Bor-Luen

2011-06-01

Juvenile idiopathic arthritis (JIA) has had a long and difficult problem with classification. It is clearly a heterogeneous and multi-factorial autoimmune disease but all too often the distinctions among subtypes were unclear. In fact, there is now increasing evidence of a distinct pathogenesis of oligo/polyarticular JIA compared to systemic JIA. Oligo/polyarticular JIA is an antigen-driven lymphocyte-mediated autoimmune disease with abnormality in the adaptive immune system. Cartilage-derived auto-antigens activate autoreactive T cells including Th1 and Th17 cells with production of pro-inflammatory cytokines IFN-γ and IL-17. On the other hand, the inhibition of regulatory T (Treg) cells including natural Foxp3(+) Treg and self-heat shock protein-induced Treg cells with decreased anti-inflammatory cytokine IL-10 results in the loss of immune tolerance. Imbalance between autoreactive Th1/Th17 and Treg cells leads to the failure of T cell tolerance to self-antigens, which contributes to the synovial inflammation of oligo/polyarticular JIA. By contrast, systemic JIA is an autoinflammatory disease with abnormality in the innate immune system. A loss of control of the alternative secretory pathway leading to aberrant activation of phagocytes including monocytes, macrophages and neutrophils seems to be involved in the release of pro-inflammatory cytokines IL-1, IL-6, IL-18 and pro-inflammatory S100-proteins, which contribute to the multisystem inflammation of systemic JIA. Markedly distinct pathogenesis of oligo/polyarticular JIA and systemic JIA implies that they might need different treatment strategies. Copyright © 2011 Elsevier B.V. All rights reserved.

Osteoimmunology: The Conceptual Framework Unifying the Immune and Skeletal Systems.

PubMed

Okamoto, Kazuo; Nakashima, Tomoki; Shinohara, Masahiro; Negishi-Koga, Takako; Komatsu, Noriko; Terashima, Asuka; Sawa, Shinichiro; Nitta, Takeshi; Takayanagi, Hiroshi

2017-10-01

The immune and skeletal systems share a variety of molecules, including cytokines, chemokines, hormones, receptors, and transcription factors. Bone cells interact with immune cells under physiological and pathological conditions. Osteoimmunology was created as a new interdisciplinary field in large part to highlight the shared molecules and reciprocal interactions between the two systems in both heath and disease. Receptor activator of NF-κB ligand (RANKL) plays an essential role not only in the development of immune organs and bones, but also in autoimmune diseases affecting bone, thus effectively comprising the molecule that links the two systems. Here we review the function, gene regulation, and signal transduction of osteoimmune molecules, including RANKL, in the context of osteoclastogenesis as well as multiple other regulatory functions. Osteoimmunology has become indispensable for understanding the pathogenesis of a number of diseases such as rheumatoid arthritis (RA). We review the various osteoimmune pathologies, including the bone destruction in RA, in which pathogenic helper T cell subsets [such as IL-17-expressing helper T (Th17) cells] induce bone erosion through aberrant RANKL expression. We also focus on cellular interactions and the identification of the communication factors in the bone marrow, discussing the contribution of bone cells to the maintenance and regulation of hematopoietic stem and progenitors cells. Thus the time has come for a basic reappraisal of the framework for understanding both the immune and bone systems. The concept of a unified osteoimmune system will be absolutely indispensable for basic and translational approaches to diseases related to bone and/or the immune system. Copyright © 2017 the American Physiological Society.

Load sensing system

DOEpatents

Sohns, Carl W.; Nodine, Robert N.; Wallace, Steven Allen

1999-01-01

A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

Regenerative fuel cell systems for space station

NASA Technical Reports Server (NTRS)

Hoberecht, M. A.; Sheibley, D. W.

1985-01-01

Regenerative fuel cell (RFC) systems are the leading energy storage candidates for Space Station. Key design features are the advanced state of technology readiness and high degree of system level design flexibility. Technology readiness was demonstrated through testing at the single cell, cell stack, mechanical ancillary component, subsystem, and breadboard levels. Design flexibility characteristics include independent sizing of power and energy storage portions of the system, integration of common reactants with other space station systems, and a wide range of various maintenance approaches. The design features led to selection of a RFC system as the sole electrochemical energy storage technology option for the space station advanced development program.

Roles of miRNAs in microcystin-LR-induced Sertoli cell toxicity

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

Zhou, Yuan; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu 210093; Wang, Hui

2015-08-15

Microcystin (MC)-LR, a cyclic heptapeptide, is a potent reproductive system toxin. To understand the molecular mechanisms of MC-induced reproductive system cytotoxicity, we evaluated global changes of miRNA and mRNA expression in mouse Sertoli cells following MC-LR treatment. Our results revealed that the exposure to MC-LR resulted in an altered miRNA expression profile that might be responsible for the modulation of mRNA expression. Bio-functional analysis indicated that the altered genes were involved in specific cellular processes, including cell death and proliferation. Target gene analysis suggested that junction injury in Sertoli cells exposed to MC-LR might be mediated by miRNAs through themore » regulation of the Sertoli cell-Sertoli cell pathway. Collectively, these findings may enhance our understanding on the modes of action of MC-LR on mouse Sertoli cells as well as the molecular mechanisms underlying the toxicity of MC-LR on the male reproductive system. - Highlights: • miRNAs were altered in Sertoli cells exposed to MC-LR. • Alerted genes were involved in different cell functions including the cell morphology. • MC-LR adversely affected Sertoli cell junction formation through the regulating miRNAs.« less

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

NASA Technical Reports Server (NTRS)

Scheidegger, Brianne; Burke, Kenneth; Jakupca, Ian

2012-01-01

This presentation describes the results of the demonstration of a non-flow-through PEM fuel cell as part of a power system on the SCARAB rover at the NASA Glenn Research Center. 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 SCARAB rover s hotel loads. The power system, including the non-flow-through fuel cell technology, successfully demonstrated its goal as a range extender by powering hotel loads on the SCARAB rover, making this demonstration the first to use the non-flow-through fuel cell technology on a mobile platform.

Cellular and Molecular Mechanisms of Sexual Differentiation in the Mammalian Nervous System

PubMed Central

Forger, Nancy G.; Strahan, J. Alex; Castillo-Ruiz, Alexandra

2016-01-01

Neuroscientists are likely to discover new sex differences in the coming years, spurred by the National Institutes of Health initiative to include both sexes in preclinical studies. This review summarizes the current state of knowledge of the cellular and molecular mechanisms underlying sex differences in the mammalian nervous system, based primarily on work in rodents. Cellular mechanisms examined include neurogenesis, migration, the differentiation of neurochemical and morphological cell phenotype, and cell death. At the molecular level we discuss evolving roles for epigenetics, sex chromosome complement, the immune system, and newly identified cell signaling pathways. We review recent findings on the role of the environment, as well as genome-wide studies with some surprising results, causing us to rethink often-used models of sexual differentiation. We end by pointing to future directions, including an increased awareness of the important contributions of tissues outside of the nervous system to sexual differentiation of the brain. PMID:26790970

Glycans as Regulatory Elements of the Insulin/IGF System: Impact in Cancer Progression

PubMed Central

Andrade-da-Costa, Jéssica; Silva, Mariana Costa

2017-01-01

The insulin/insulin-like growth factor (IGF) system in mammals comprises a dynamic network of proteins that modulate several biological processes such as development, cell growth, metabolism, and aging. Dysregulation of the insulin/IGF system has major implications for several pathological conditions such as diabetes and cancer. Metabolic changes also culminate in aberrant glycosylation, which has been highlighted as a hallmark of cancer. Changes in glycosylation regulate every pathophysiological step of cancer progression including tumour cell-cell dissociation, cell migration, cell signaling and metastasis. This review discusses how the insulin/IGF system integrates with glycosylation alterations and impacts on cell behaviour, metabolism and drug resistance in cancer. PMID:28880250

The role of radiation hard solar cells in minimizing the costs of global satellite communications systems

NASA Technical Reports Server (NTRS)

Summers, Geoffrey P.; Walters, Robert J.; Messenger, Scott R.; Burke, Edward A.

1995-01-01

An analysis embodied in a PC computer program is presented which quantitatively demonstrates how the availability of radiation hard solar cells can minimize the cost of a global satellite communication system. The chief distinction between the currently proposed systems, such as Iridium Odyssey and Ellipsat, is the number of satellites employed and their operating altitudes. Analysis of the major costs associated with implementing these systems shows that operation within the earth's radiation belts can reduce the total system cost by as much as a factor of two, so long as radiation hard components including solar cells, can be used. A detailed evaluation of several types of planar solar cells is given, including commercially available Si and GaAs/Ge cells, and InP/Si cells which are under development. The computer program calculates the end of life (EOL) power density of solar arrays taking into account the cell geometry, coverglass thickness, support frame, electrical interconnects, etc. The EOL power density can be determined for any altitude from low earth orbit (LEO) to geosynchronous (GEO) and for equatorial to polar planes of inclination. The mission duration can be varied over the entire range planned for the proposed satellite systems. An algorithm is included in the program for determining the degradation of cell efficiency for different cell technologies due to proton and electron irradiation. The program can be used to determine the optimum configuration for any cell technology for a particular orbit and for a specified mission life. Several examples of applying the program are presented, in which it is shown that the EOL power density of different technologies can vary by an order of magnitude for certain missions. Therefore, although a relatively radiation soft technology can be made to provide the required EOL power by simply increasing the size of the array, the impact on the total system budget could be unacceptable, due to increased launch and hardware costs. In aggregate these factors can account for more than a 10% increase in the total system cost. Since the estimated total costs of proposed global coverage systems range from $1 Billion to $9 Billion, the availability of radiation hard solar cells could make a decisive difference in the selection of a particular constellation architecture.

Advances in reprogramming somatic cells to induced pluripotent stem cells.

PubMed

Patel, Minal; Yang, Shuying

2010-09-01

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

Hybrid Power Management Program Evaluated Fuel Cell/Ultracapacitor Combinations and Developed Other New Applications

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.

2004-01-01

In fiscal year 2003, the continuation of the Hybrid Power Management (HPM) Program through NASA Glenn Research Center's Commercial Technology Office resulted in several new successful applications of this pioneering technology. HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors, fuel cells, and photovoltaics. HPM has extremely wide potential, with applications from nanowatts to megawatts--including power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy. Fuel cells provide excellent efficiency and energy density, but do not have good power density. In contrast, ultracapacitors have excellent power density and virtually unlimited cycle life. To improve the power density of the fuel cell, the combination of fuel cells and ultracapacitors was evaluated.

Assessment of the environmental aspects of the DOE phosphoric acid fuel cell program

NASA Technical Reports Server (NTRS)

Lundblad, H. L.; Cavagrotti, R. R.

1983-01-01

The likely facets of a nationwide phosphoric acid fuel cell (PAFC) power plant commercial system are described. The beneficial and adverse environmental impacts produced by the system are assessed. Eleven specific system activities are characterized and evaluated. Also included is a review of fuel cell technology and a description of DOE's National Fuel Cell Program. Based on current and reasonably foreseeable PAFC characteristics, no environmental or energy impact factor was identified that would significantly inhibit the commercialization of PAFC power plant technology.

Long life Regenerative Fuel Cell technology development plan

NASA Technical Reports Server (NTRS)

Littman, Franklin D.; Cataldo, Robert L.; Mcelroy, James F.; Stedman, Jay K.

1992-01-01

This paper summarizes a technology roadmap for completing advanced development of a Proton Exchange Membrane (PEM) Regenerative Fuel Cell (RFC) to meet long life (20,000 hrs at 50 percent duty cycle) mobile or portable power system applications on the surface of the moon and Mars. Development of two different sized RFC power system modules is included in this plan (3 and 7.5 kWe). A conservative approach was taken which includes the development of a Ground Engineering System, Qualification Unit, and Flight Unit. This paper includes a concept description, technology assessment, development issues, development tasks, and development schedule.

Immunopathology of inflammatory bowel disease

PubMed Central

Wallace, Kori L; Zheng, Li-Bo; Kanazawa, Yoshitake; Shih, David Q

2014-01-01

Inflammatory bowel disease (IBD) results from a complex series of interactions between susceptibility genes, the environment, and the immune system. The host microbiome, as well as viruses and fungi, play important roles in the development of IBD either by causing inflammation directly or indirectly through an altered immune system. New technologies have allowed researchers to be able to quantify the various components of the microbiome, which will allow for future developments in the etiology of IBD. Various components of the mucosal immune system are implicated in the pathogenesis of IBD and include intestinal epithelial cells, innate lymphoid cells, cells of the innate (macrophages/monocytes, neutrophils, and dendritic cells) and adaptive (T-cells and B-cells) immune system, and their secreted mediators (cytokines and chemokines). Either a mucosal susceptibility or defect in sampling of gut luminal antigen, possibly through the process of autophagy, leads to activation of innate immune response that may be mediated by enhanced toll-like receptor activity. The antigen presenting cells then mediate the differentiation of naïve T-cells into effector T helper (Th) cells, including Th1, Th2, and Th17, which alter gut homeostasis and lead to IBD. In this review, the effects of these components in the immunopathogenesis of IBD will be discussed. PMID:24415853

Immunopathology of inflammatory bowel disease.

PubMed

Wallace, Kori L; Zheng, Li-Bo; Kanazawa, Yoshitake; Shih, David Q

2014-01-07

Inflammatory bowel disease (IBD) results from a complex series of interactions between susceptibility genes, the environment, and the immune system. The host microbiome, as well as viruses and fungi, play important roles in the development of IBD either by causing inflammation directly or indirectly through an altered immune system. New technologies have allowed researchers to be able to quantify the various components of the microbiome, which will allow for future developments in the etiology of IBD. Various components of the mucosal immune system are implicated in the pathogenesis of IBD and include intestinal epithelial cells, innate lymphoid cells, cells of the innate (macrophages/monocytes, neutrophils, and dendritic cells) and adaptive (T-cells and B-cells) immune system, and their secreted mediators (cytokines and chemokines). Either a mucosal susceptibility or defect in sampling of gut luminal antigen, possibly through the process of autophagy, leads to activation of innate immune response that may be mediated by enhanced toll-like receptor activity. The antigen presenting cells then mediate the differentiation of naïve T-cells into effector T helper (Th) cells, including Th1, Th2, and Th17, which alter gut homeostasis and lead to IBD. In this review, the effects of these components in the immunopathogenesis of IBD will be discussed.

Effects of microgravity on the immune system

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald; Taylor, Gerald R.

1991-01-01

Changes in resistance to bacterial and viral infections in Apollo crew members has stimulated interest in the study of immunity and space flight. Results of studies from several laboratories in both humans and rodents have indicated alterations after space flight that include the following immunological parameters: thymus size, lymphocyte blastogenesis, interferon and interleukin production, natural killer cell activity, cytotoxic T-cell activity, leukocyte subset population distribution, response of bone marrow cells to colony stimulating factors, and delayed hypersensitivity skin test reactivity. The interactions of the immune system with other physiological systems, including muscle, bone, and the nervous system, may play a major role in the development of these immunological parameters during and after flight. There may also be direct effects of space flight on immune responses.

Performance and Safety Characteristics of Lithium-molybdenum Disulfide Cells

NASA Technical Reports Server (NTRS)

Stiles, J. A.

1984-01-01

The lithium-molybdenum disulfide system offers attractive characteristics including high rate capability, successful operation up to 75 C, a very low self-discharge rate, a good cycle life and safety characteristics which compare favorably to those of other lithium cells. Moreover, the materials and manufacturing costs for the system is effectively controlled, so the cells should ultimately be competitive with currently marketed rechargeable cells.

Modularized battery management for large lithium ion cells

NASA Astrophysics Data System (ADS)

Stuart, Thomas A.; Zhu, Wei

A modular electronic battery management system (BMS) is described along with important features for protecting and optimizing the performance of large lithium ion (LiIon) battery packs. Of particular interest is the use of a much improved cell equalization system that can increase or decrease individual cell voltages. Experimental results are included for a pack of six series connected 60 Ah (amp-hour) LiIon cells.

Fuel Cell Propulsion Systems for an All-electric Personal Air Vehicle

NASA Technical Reports Server (NTRS)

Kohout, Lisa L.; Schmitz, Paul C.

2003-01-01

There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

Fuel Cell Propulsion Systems for an All-Electric Personal Air Vehicle

NASA Technical Reports Server (NTRS)

Kohout, Lisa L.

2003-01-01

There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

Quorum sensing and microbial drug resistance.

PubMed

Chen, Yu-fan; Liu, Shi-yin; Liang, Zhi-bin; Lv, Ming-fa; Zhou, Jia-nuan; Zhang, Lian-hui

2016-10-20

Microbial drug resistance has become a serious problem of global concern, and the evolution and regulatory mechanisms of microbial drug resistance has become a hotspot of research in recent years. Recent studies showed that certain microbial resistance mechanisms are regulated by quorum sensing system. Quorum sensing is a ubiquitous cell-cell communication system in the microbial world, which associates with cell density. High-density microbial cells produce sufficient amount of small signal molecules, activating a range of downstream cellular processes including virulence and drug resistance mechanisms, which increases bacterial drug tolerance and causes infections on host organisms. In this review, the general mechanisms of microbial drug resistance and quorum-sensing systems are summarized with a focus on the association of quorum sensing and chemical signaling systems with microbial drug resistance mechanisms, including biofilm formation and drug efflux pump. The potential use of quorum quenching as a new strategy to control microbial resistance is also discussed.

High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device

DOEpatents

Atac, M.; McKay, T.A.

1998-04-21

An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD. 13 figs.

High resolution biomedical imaging system with direct detection of x-rays via a charge coupled device

DOEpatents

Atac, Muzaffer; McKay, Timothy A.

1998-01-01

An imaging system is provided for direct detection of x-rays from an irradiated biological tissue. The imaging system includes an energy source for emitting x-rays toward the biological tissue and a charge coupled device (CCD) located immediately adjacent the biological tissue and arranged transverse to the direction of irradiation along which the x-rays travel. The CCD directly receives and detects the x-rays after passing through the biological tissue. The CCD is divided into a matrix of cells, each of which individually stores a count of x-rays directly detected by the cell. The imaging system further includes a pattern generator electrically coupled to the CCD for reading a count from each cell. A display device is provided for displaying an image representative of the count read by the pattern generator from the cells of the CCD.

Bioreactor technology for production of valuable algal products

NASA Astrophysics Data System (ADS)

Liu, Guo-Cai; Cao, Ying

1998-03-01

Bioreactor technology has long been employed for the production of various (mostly cheap) food and pharmaceutical products. More recently, research has been mainly focused on the development of novel bioreactor technology for the production of high—value products. This paper reports the employment of novel bioreactor technology for the production of high-value biomass and metabolites by microalgae. These high-value products include microalgal biomass as health foods, pigments including phycocyanin and carotenoids, and polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. The processes involved include heterotrophic and mixotrophic cultures using organic substrates as the carbon source. We have demonstrated that these bioreactor cultivation systems are particularly suitable for the production of high-value products from various microalgae. These cultivation systems can be further modified to improve cell densities and productivities by using high cell density techniques such as fed-batch and membrane cell recycle systems. For most of the microalgae investigated, the maximum cell concentrations obtained using these bioreactor systems in our laboratories are much higher than any so far reported in the literature.

Cardiac tissue engineering using perfusion bioreactor systems

PubMed Central

Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

2009-01-01

This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

New decision support tool for acute lymphoblastic leukemia classification

NASA Astrophysics Data System (ADS)

Madhukar, Monica; Agaian, Sos; Chronopoulos, Anthony T.

2012-03-01

In this paper, we build up a new decision support tool to improve treatment intensity choice in childhood ALL. The developed system includes different methods to accurately measure furthermore cell properties in microscope blood film images. The blood images are exposed to series of pre-processing steps which include color correlation, and contrast enhancement. By performing K-means clustering on the resultant images, the nuclei of the cells under consideration are obtained. Shape features and texture features are then extracted for classification. The system is further tested on the classification of spectra measured from the cell nuclei in blood samples in order to distinguish normal cells from those affected by Acute Lymphoblastic Leukemia. The results show that the proposed system robustly segments and classifies acute lymphoblastic leukemia based on complete microscopic blood images.

Impact resistant battery enclosure systems

DOEpatents

Tsutsui, Waterloo; Feng, Yuezhong; Chen, Weinong Wayne; Siegmund, Thomas Heinrich

2017-10-31

Battery enclosure arrangements for a vehicular battery system. The arrangements, capable of impact resistance include plurality of battery cells and a plurality of kinetic energy absorbing elements. The arrangements further include a frame configured to encase the plurality of the kinetic energy absorbing elements and the battery cells. In some arrangements the frame and/or the kinetic energy absorbing elements can be made of topologically interlocked materials.

Purpose and regulation of stem cells: a systems-biology view from the Caenorhabditis elegans germ line.

PubMed

Cinquin, Olivier

2009-01-01

Stem cells are expected to play a key role in the development and maintenance of organisms, and hold great therapeutic promises. However, a number of questions must be answered to achieve an understanding of stem cells and put them to use. Here I review some of these questions, and how they relate to the model system provided by the Caenorhabditis elegans germ line, which is exceptional in its thorough genetic characterization and experimental accessibility under in vivo conditions. A fundamental question is how to define a stem cell; different definitions can be adopted that capture different features of interest. In the C. elegans germ line, stem cells can be defined by cell lineage or by cell commitment ('commitment' must itself be carefully defined). These definitions are associated with two other important questions about stem cells: their functions (which must be addressed following a systems approach, based on an evolutionary perspective) and their regulation. I review possible functions and their evolutionary groundings, including genome maintenance and powerful regulation of cell proliferation and differentiation, and possible regulatory mechanisms, including asymmetrical division and control of transit amplification by a developmental timer. I draw parallels between Drosophila and C. elegans germline stem cells; such parallels raise intriguing questions about Drosophila stem cells. I conclude by showing that the C. elegans germ line bears similarities with a number of other stem cell systems, which underscores its relevance to the understanding of stem cells.

An "age"-structured model of hematopoietic stem cell organization with application to chronic myeloid leukemia.

PubMed

Roeder, Ingo; Herberg, Maria; Horn, Matthias

2009-04-01

Previously, we have modeled hematopoietic stem cell organization by a stochastic, single cell-based approach. Applications to different experimental systems demonstrated that this model consistently explains a broad variety of in vivo and in vitro data. A major advantage of the agent-based model (ABM) is the representation of heterogeneity within the hematopoietic stem cell population. However, this advantage comes at the price of time-consuming simulations if the systems become large. One example in this respect is the modeling of disease and treatment dynamics in patients with chronic myeloid leukemia (CML), where the realistic number of individual cells to be considered exceeds 10(6). To overcome this deficiency, without losing the representation of the inherent heterogeneity of the stem cell population, we here propose to approximate the ABM by a system of partial differential equations (PDEs). The major benefit of such an approach is its independence from the size of the system. Although this mean field approach includes a number of simplifying assumptions compared to the ABM, it retains the key structure of the model including the "age"-structure of stem cells. We show that the PDE model qualitatively and quantitatively reproduces the results of the agent-based approach.

An Overview and History of Glyco-Engineering in Insect Expression Systems.

PubMed

Geisler, Christoph; Mabashi-Asazuma, Hideaki; Jarvis, Donald L

2015-01-01

Insect systems, including the baculovirus-insect cell and Drosophila S2 cell systems are widely used as recombinant protein production platforms. Historically, however, no insect-based system has been able to produce glycoproteins with human-type glycans, which often influence the clinical efficacy of therapeutic glycoproteins and the overall structures and functions of other recombinant glycoprotein products. In addition, some insect cell systems produce N-glycans with immunogenic epitopes. Over the past 20 years, these problems have been addressed by efforts to glyco-engineer insect-based expression systems. These efforts have focused on introducing the capacity to produce complex-type, terminally sialylated N-glycans and eliminating the capacity to produce immunogenic N-glycans. Various glyco-engineering approaches have included genetically engineering insect cells, baculoviral vectors, and/or insects with heterologous genes encoding the enzymes required to produce various glycosyltransferases, sugars, nucleotide sugars, and nucleotide sugar transporters, as well as an enzyme that can deplete GDP-fucose. In this chapter, we present an overview and history of glyco-engineering in insect expression systems as a prelude to subsequent chapters, which will highlight various methods used for this purpose.

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

None available

For the purpose of this STI product and unless otherwise stated, hybrid fuel cell systems are power generation systems in which a high temperature fuel cell is combined with another power generating technology. The resulting system exhibits a synergism in which the combination performs with an efficiency far greater than can be provided by either system alone. Hybrid fuel cell designs under development include fuel cell with gas turbine, fuel cell with reciprocating (piston) engine, and designs that combine different fuel cell technologies. Hybrid systems have been extensively analyzed and studied over the past five years by the Department ofmore » Energy (DOE), industry, and others. These efforts have revealed that this combination is capable of providing remarkably high efficiencies. This attribute, combined with an inherent low level of pollutant emission, suggests that hybrid systems are likely to serve as the next generation of advanced power generation systems.« less

Latest status of the clinical and industrial applications of cell sheet engineering and regenerative medicine.

PubMed

Egami, Mime; Haraguchi, Yuji; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo

2014-01-01

Cell sheet engineering, which allows tissue engineering to be realized without the use of biodegradable scaffolds as an original approach, using a temperature-responsive intelligent surface, has been applied in regenerative medicine for various tissues, and a number of clinical studies have been already performed for life-threatening diseases. By using the results and findings obtained from the initial clinical studies, additional investigative clinical studies in several tissues with cell sheet engineering are currently in preparation stage. For treating many patients effectively by cell sheet engineering, an automated system integrating cell culture, cell-sheet fabrication, and layering is essential, and the system should include an advanced three-dimensional suspension cell culture system and an in vitro bioreactor system to scale up the production of cultured cells and fabricate thicker vascularized tissues. In this paper, cell sheet engineering, its clinical application, and further the authors' challenge to develop innovative cell culture systems under newly legislated regulatory platform in Japan are summarized and discussed.

Mechanisms of lung aging.

PubMed

Brandenberger, Christina; Mühlfeld, Christian

2017-03-01

Lung aging is associated with structural remodeling, a decline of respiratory function and a higher susceptibility to acute and chronic lung diseases. Individual factors that modulate pulmonary aging include basic genetic configuration, environmental exposure, life-style and biography of systemic diseases. However, the actual aging of the lung takes place in pulmonary resident cells and is closely linked to aging of the immune system (immunosenescence). Therefore, this article reviews the current knowledge about the impact of aging on pulmonary cells and the immune system, without analyzing those factors that may accelerate the aging process in depth. Hallmarks of aging include alterations at molecular, cellular and cell-cell interaction levels. Because of the great variety of cell types in the lung, the consequences of aging display a broad spectrum of phenotypes. For example, aging is associated with more collagen and less elastin production by fibroblasts, thus increasing pulmonary stiffness and lowering compliance. Decreased sympathetic airway innervation may increase the constriction status of airway smooth muscle cells. Aging of resident and systemic immune cells leads to a pro-inflammatory milieu and reduced capacity of fighting infectious diseases. The current review provides an overview of cellular changes occurring with advancing age in general and in several cell types of the lung as well as of the immune system. Thereby, this survey not only aims at providing a better understanding of the mechanisms of pulmonary aging but also to identify gaps in knowledge that warrant further investigations.

78 FR 50340 - Travelers' Information Stations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

... information systems, and satellite radio. While motorists should not access weather information from cell... weather and traffic information beyond traditional AM and FM broadcast sources, including cell phone, mobile internet, automobile based information systems, and satellite radio. Therefore, due to...

Full system engineering design and operation of an oxygen plant

NASA Technical Reports Server (NTRS)

Colvin, James; Schallhorn, Paul; Ramonhalli, Kumar

1992-01-01

The production of oxygen from the indigenous resources on Mars is described. After discussing briefly the project's background and the experimental system design, specific experimental results of the electrolytic cell are presented. At the heart of the oxygen production system is a tubular solid zirconia electrolyte cell that will electrochemically separate oxygen from a high-temperature stream of Coleman grade carbon dioxide. Experimental results are discussed and certain system efficiencies are defined. The parameters varied include (1) the cell operating temperature; (2) the carbon dioxide flow rate; and (3) the voltage applied across the cell. The results confirm our theoretical expectations.

Cancer stem cells of the digestive system.

PubMed

Colvin, Hugh S; Nishida, Naohiro; Koseki, Jun; Konno, Masamitsu; Kawamoto, Koichi; Tsunekuni, Kenta; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

2014-12-01

Stem cells of the digestive system are ideal in many ways for research, given they are abundant, highly proliferative and have a uniform structural arrangement. This in turn has enormously aided the research of cancer stem cells of the digestive system, which is now shaping our understanding of cancer stem cells. In this review, the recent advances in the understanding of cancer stem cells of the digestive system have been summarized, including aspects such as their identification, origin, cell-cycle dormancy, relationship with epithelial-mesenchymal transition, cellular metabolism and the underlying molecular mechanisms. Newly acquired knowledge concerning cancer stem cells have led to the development of novel cancer therapeutics with provisional yet encouraging results. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Primary Cell Culture of Live Neurosurgically Resected Aged Adult Human Brain Cells and Single Cell Transcriptomics.

PubMed

Spaethling, Jennifer M; Na, Young-Ji; Lee, Jaehee; Ulyanova, Alexandra V; Baltuch, Gordon H; Bell, Thomas J; Brem, Steven; Chen, H Isaac; Dueck, Hannah; Fisher, Stephen A; Garcia, Marcela P; Khaladkar, Mugdha; Kung, David K; Lucas, Timothy H; O'Rourke, Donald M; Stefanik, Derek; Wang, Jinhui; Wolf, John A; Bartfai, Tamas; Grady, M Sean; Sul, Jai-Yoon; Kim, Junhyong; Eberwine, James H

2017-01-17

Investigation of human CNS disease and drug effects has been hampered by the lack of a system that enables single-cell analysis of live adult patient brain cells. We developed a culturing system, based on a papain-aided procedure, for resected adult human brain tissue removed during neurosurgery. We performed single-cell transcriptomics on over 300 cells, permitting identification of oligodendrocytes, microglia, neurons, endothelial cells, and astrocytes after 3 weeks in culture. Using deep sequencing, we detected over 12,000 expressed genes, including hundreds of cell-type-enriched mRNAs, lncRNAs and pri-miRNAs. We describe cell-type- and patient-specific transcriptional hierarchies. Single-cell transcriptomics on cultured live adult patient derived cells is a prime example of the promise of personalized precision medicine. Because these cells derive from subjects ranging in age into their sixties, this system permits human aging studies previously possible only in rodent systems. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Automated Cell Enrichment of Cytomegalovirus-specific T cells for Clinical Applications using the Cytokine-capture System.

PubMed

Kumaresan, Pappanaicken; Figliola, Mathew; Moyes, Judy S; Huls, M Helen; Tewari, Priti; Shpall, Elizabeth J; Champlin, Richard; Cooper, Laurence J N

2015-10-05

The adoptive transfer of pathogen-specific T cells can be used to prevent and treat opportunistic infections such as cytomegalovirus (CMV) infection occurring after allogeneic hematopoietic stem-cell transplantation. Viral-specific T cells from allogeneic donors, including third party donors, can be propagated ex vivo in compliance with current good manufacturing practice (cGMP), employing repeated rounds of antigen-driven stimulation to selectively propagate desired T cells. The identification and isolation of antigen-specific T cells can also be undertaken based upon the cytokine capture system of T cells that have been activated to secrete gamma-interferon (IFN-γ). However, widespread human application of the cytokine capture system (CCS) to help restore immunity has been limited as the production process is time-consuming and requires a skilled operator. The development of a second-generation cell enrichment device such as CliniMACS Prodigy now enables investigators to generate viral-specific T cells using an automated, less labor-intensive system. This device separates magnetically labeled cells from unlabeled cells using magnetic activated cell sorting technology to generate clinical-grade products, is engineered as a closed system and can be accessed and operated on the benchtop. We demonstrate the operation of this new automated cell enrichment device to manufacture CMV pp65-specific T cells obtained from a steady-state apheresis product obtained from a CMV seropositive donor. These isolated T cells can then be directly infused into a patient under institutional and federal regulatory supervision. All the bio-processing steps including removal of red blood cells, stimulation of T cells, separation of antigen-specific T cells, purification, and washing are fully automated. Devices such as this raise the possibility that T cells for human application can be manufactured outside of dedicated good manufacturing practice (GMP) facilities and instead be produced in blood banking facilities where staff can supervise automated protocols to produce multiple products.

An Overview of Power Electronics Applications in Fuel Cell Systems: DC and AC Converters

PubMed Central

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

An overview of power electronics applications in fuel cell systems: DC and AC converters.

PubMed

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.

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

NASA Technical Reports Server (NTRS)

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.

A unified pathogenesis for kidney diseases, including genetic diseases and cancers, by the protein-homeostasis-system hypothesis.

PubMed

Lee, Kyung-Yil

2017-06-01

Every cell of an organism is separated and protected by a cell membrane. It is proposed that harmony between intercellular communication and the health of an organism is controlled by a system, designated the protein-homeostasis-system (PHS). Kidneys consist of a variety of types of renal cells, each with its own characteristic cell-receptor interactions and producing characteristic proteins. A functional union of these renal cells can be determined by various renal function tests, and harmonious intercellular communication is essential for the healthy state of the host. Injury to a kind of renal cells can impair renal function and induce an imbalance in total body health. Every acute or chronic renal disease has unknown etiologic substances that are responsible for renal cell injury at the molecular level. The immune/repair system of the host should control the etiologic substances acting against renal cells; if this system fails, the disease progresses to end stage renal disease. Each renal disease has its characteristic pathologic lesions where immune cells and immune proteins, such as immunoglobulins and complements, are infiltrated. These immune cells and immune proteins may control the etiologic substances involved in renal pathologic lesions. Also, genetic renal diseases and cancers may originate from a protein deficiency or malfunctioning protein under the PHS. A unified pathogenesis for renal diseases, including acute glomerulonephritis, idiopathic nephrotic syndrome, immunoglobulin A nephropathy, genetic renal diseases such as Alport syndrome, and malignancies such as Wilms tumor and renal cell carcinoma, is proposed using the PHS hypothesis.

The JPL Direct Methanol Liquid-feed PEM Fuel Cell

NASA Technical Reports Server (NTRS)

Halpert, G.; Surampudi, S.

1994-01-01

Recently, there has been a breakthrough in fuel cell technology in the Energy Storage Systems Group at the Jet Propulsion Laboratory with the develpment of a direct methanol, liquid-feed, solid polymer electrolyte membrane (PEM) fuel cell... The methanol liquid-feed, solid polymer electrolyte (PEM) design has numerous system level advantages over the gas-feed design. These include:...

The architecture and conservation pattern of whole-cell control circuitry.

PubMed

McAdams, Harley H; Shapiro, Lucy

2011-05-27

The control circuitry that directs and paces Caulobacter cell cycle progression involves the entire cell operating as an integrated system. This control circuitry monitors the environment and the internal state of the cell, including the cell topology, as it orchestrates orderly activation of cell cycle subsystems and Caulobacter's asymmetric cell division. The proteins of the Caulobacter cell cycle control system and its internal organization are co-conserved across many alphaproteobacteria species, but there are great differences in the regulatory apparatus' functionality and peripheral connectivity to other cellular subsystems from species to species. This pattern is similar to that observed for the "kernels" of the regulatory networks that regulate development of metazoan body plans. The Caulobacter cell cycle control system has been exquisitely optimized as a total system for robust operation in the face of internal stochastic noise and environmental uncertainty. When sufficient details accumulate, as for Caulobacter cell cycle regulation, the system design has been found to be eminently rational and indeed consistent with good design practices for human-designed asynchronous control systems. Copyright © 2011 Elsevier Ltd. All rights reserved.

Modelling Spread of Oncolytic Viruses in Heterogeneous Cell Populations

NASA Astrophysics Data System (ADS)

Ellis, Michael; Dobrovolny, Hana

2014-03-01

One of the most promising areas in current cancer research and treatment is the use of viruses to attack cancer cells. A number of oncolytic viruses have been identified to date that possess the ability to destroy or neutralize cancer cells while inflicting minimal damage upon healthy cells. Formulation of predictive models that correctly describe the evolution of infected tumor systems is critical to the successful application of oncolytic virus therapy. A number of different models have been proposed for analysis of the oncolytic virus-infected tumor system, with approaches ranging from traditional coupled differential equations such as the Lotka-Volterra predator-prey models, to contemporary modeling frameworks based on neural networks and cellular automata. Existing models are focused on tumor cells and the effects of virus infection, and offer the potential for improvement by including effects upon normal cells. We have recently extended the traditional framework to a 2-cell model addressing the full cellular system including tumor cells, normal cells, and the impacts of viral infection upon both populations. Analysis of the new framework reveals complex interaction between the populations and potential inability to simultaneously eliminate the virus and tumor populations.

A tidal wave of signals: calcium and ROS at the forefront of rapid systemic signaling.

PubMed

Gilroy, Simon; Suzuki, Nobuhiro; Miller, Gad; Choi, Won-Gyu; Toyota, Masatsugu; Devireddy, Amith R; Mittler, Ron

2014-10-01

Systemic signaling pathways enable multicellular organisms to prepare all of their tissues and cells to an upcoming challenge that may initially only be sensed by a few local cells. They are activated in plants in response to different stimuli including mechanical injury, pathogen infection, and abiotic stresses. Key to the mobilization of systemic signals in higher plants are cell-to-cell communication events that have thus far been mostly unstudied. The recent identification of systemically propagating calcium (Ca(2+)) and reactive oxygen species (ROS) waves in plants has unraveled a new and exciting cell-to-cell communication pathway that, together with electric signals, could provide a working model demonstrating how plant cells transmit long-distance signals via cell-to-cell communication mechanisms. Here, we summarize recent findings on the ROS and Ca(2+) waves and outline a possible model for their integration. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Cancer immunotherapy. Importance of overcoming immune suppression].

PubMed

Malvicini, Mariana; Puchulo, Guillermo; Matar, Pablo; Mazzolini, Guillermo

2010-01-01

Increasing evidence indicates that the immune system is involved in the control of tumor progression. Effective antitumor immune response depends on the interaction between several components of the immune system, including antigen-presenting cells and different T cell subsets. However, tumor cells develop a number of mechanisms to escape recognition and elimination by the immune system. In this review we discuss these mechanisms and address possible therapeutic approaches to overcome the immune suppression generated by tumors.

GMP-Compliant Expansion of Clinical-Grade Human Mesenchymal Stromal/Stem Cells Using a Closed Hollow Fiber Bioreactor.

PubMed

Barckhausen, Christina; Rice, Brent; Baila, Stefano; Sensebé, Luc; Schrezenmeier, Hubert; Nold, Philipp; Hackstein, Holger; Rojewski, Markus Thomas

2016-01-01

This chapter describes a method for GMP-compliant expansion of human mesenchymal stromal/stem cells (hMSC) from bone marrow aspirates, using the Quantum(®) Cell Expansion System from Terumo BCT. The Quantum system is a functionally closed, automated hollow fiber bioreactor system designed to reproducibly grow cells in either GMP or research laboratory environments. The chapter includes protocols for preparation of media, setup of the Quantum system, coating of the hollow fiber bioreactor, as well as loading, feeding, and harvesting of cells. We suggest a panel of quality controls for the starting material, the interim product, as well as the final product.

Round Trip Energy Efficiency of NASA Glenn Regenerative Fuel Cell System

NASA Technical Reports Server (NTRS)

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.

Electrolyte Suitable for Use in a Lithium Ion Cell or Battery

NASA Technical Reports Server (NTRS)

McDonald, Robert C. (Inventor)

2014-01-01

Electrolyte suitable for use in a lithium ion cell or battery. According to one embodiment, the electrolyte includes a fluorinated lithium ion salt and a solvent system that solvates lithium ions and that yields a high dielectric constant, a low viscosity and a high flashpoint. In one embodiment, the solvent system includes a mixture of an aprotic lithium ion solvating solvent and an aprotic fluorinated solvent.

Operation of a Cartesian Robotic System in a Compact Microscope with Intelligent Controls

NASA Technical Reports Server (NTRS)

McDowell, Mark (Inventor)

2006-01-01

A Microscope Imaging System (CMIS) with intelligent controls is disclosed that provides techniques for scanning, identifying, detecting and tracking microscopic changes in selected characteristics or features of various surfaces including, but not limited to, cells, spheres, and manufactured products subject to difficult-to-see imperfections. The practice of the present invention provides applications that include colloidal hard spheres experiments, biological cell detection for patch clamping, cell movement and tracking, as well as defect identification in products, such as semiconductor devices, where surface damage can be significant, but difficult to detect. The CMIS system is a machine vision system, which combines intelligent image processing with remote control capabilities and provides the ability to autofocus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously.

Four-point bending protocols to study the effects of dynamic strain in osteoblastic cells in vitro.

PubMed

Galea, Gabriel L; Price, Joanna S

2015-01-01

Strain engendered within bone tissue by mechanical loading of the skeleton is a major influence on the processes of bone modeling and remodeling and so a critical determinant of bone mass and architecture. The cells best placed to respond to strain in bone tissue are the resident osteocytes and osteoblasts. To address the mechanisms of strain-related responses in osteoblast-like cells, our group uses both in vivo and in vitro approaches, including a system of four-point bending of the substrate on which cells are cultured. A range of cell lines can be studied using this system but we routinely compare their responses to those in primary cultures of osteoblast-like cells derived from explants of mouse long bones. These cells show a range of well-characterized responses to physiological levels of strain, including increased proliferation, which in vivo is a feature of the osteogenic response.

Regulatory immune cells in regulation of intestinal inflammatory response to microbiota

PubMed Central

Cong, Y; Liu, Z

2015-01-01

The intestinal lumen harbors nearly 100 trillion commensal bacteria that exert crucial function for health. An elaborate balance between immune responses and tolerance to intestinal microbiota is required to maintain intestinal homeostasis. This process depends on diverse regulatory mechanisms, including both innate and adaptive immunity. Dysregulation of the homeostasis between intestinal immune systems and microbiota has been shown to be associated with the development of inflammatory bowel diseases (IBD) in genetically susceptible populations. In this review, we discuss the recent progress reported in studies of distinct types of regulatory immune cells in the gut, including intestinal intraepithelial lymphocytes, Foxp3+ regulatory T cells, regulatory B cells, alternatively activated macrophages, dendritic cells, and innate lymphoid cells, and how dysfunction of this immune regulatory system contributes to intestinal diseases such as IBD. Moreover, we discuss the manipulation of these regulatory immune cells as a potential therapeutic method for management of intestinal inflammatory disorders. PMID:26080708

Regulatory immune cells in regulation of intestinal inflammatory response to microbiota.

PubMed

Sun, M; He, C; Cong, Y; Liu, Z

2015-09-01

The intestinal lumen harbors nearly 100 trillion commensal bacteria that exert crucial function for health. An elaborate balance between immune responses and tolerance to intestinal microbiota is required to maintain intestinal homeostasis. This process depends on diverse regulatory mechanisms, including both innate and adaptive immunity. Dysregulation of the homeostasis between intestinal immune systems and microbiota has been shown to be associated with the development of inflammatory bowel diseases (IBD) in genetically susceptible populations. In this review, we discuss the recent progress reported in studies of distinct types of regulatory immune cells in the gut, including intestinal intraepithelial lymphocytes, Foxp3(+) regulatory T cells, regulatory B cells, alternatively activated macrophages, dendritic cells, and innate lymphoid cells, and how dysfunction of this immune regulatory system contributes to intestinal diseases such as IBD. Moreover, we discuss the manipulation of these regulatory immune cells as a potential therapeutic method for management of intestinal inflammatory disorders.

Use of an adaptable cell culture kit for performing lymphocyte and monocyte cell cultures in microgravity

NASA Technical Reports Server (NTRS)

Hatton, J. P.; Lewis, M. L.; Roquefeuil, S. B.; Chaput, D.; Cazenave, J. P.; Schmitt, D. A.

1998-01-01

The results of experiments performed in recent years on board facilities such as the Space Shuttle/Spacelab have demonstrated that many cell systems, ranging from simple bacteria to mammalian cells, are sensitive to the microgravity environment, suggesting gravity affects fundamental cellular processes. However, performing well-controlled experiments aboard spacecraft offers unique challenges to the cell biologist. Although systems such as the European 'Biorack' provide generic experiment facilities including an incubator, on-board 1-g reference centrifuge, and contained area for manipulations, the experimenter must still establish a system for performing cell culture experiments that is compatible with the constraints of spaceflight. Two different cell culture kits developed by the French Space Agency, CNES, were recently used to perform a series of experiments during four flights of the 'Biorack' facility aboard the Space Shuttle. The first unit, Generic Cell Activation Kit 1 (GCAK-1), contains six separate culture units per cassette, each consisting of a culture chamber, activator chamber, filtration system (permitting separation of cells from supernatant in-flight), injection port, and supernatant collection chamber. The second unit (GCAK-2) also contains six separate culture units, including a culture, activator, and fixation chambers. Both hardware units permit relatively complex cell culture manipulations without extensive use of spacecraft resources (crew time, volume, mass, power), or the need for excessive safety measures. Possible operations include stimulation of cultures with activators, separation of cells from supernatant, fixation/lysis, manipulation of radiolabelled reagents, and medium exchange. Investigations performed aboard the Space Shuttle in six different experiments used Jurkat, purified T-cells or U937 cells, the results of which are reported separately. We report here the behaviour of Jurkat and U937 cells in the GCAK hardware in ground-based investigations simulating the conditions expected in the flight experiment. Several parameters including cell concentration, time between cell loading and activation, and storage temperature on cell survival were examined to characterise cell response and optimise the experiments to be flown aboard the Space Shuttle. Results indicate that the objectives of the experiments could be met with delays up to 5 days between cell loading into the hardware and initial in flight experiment activation, without the need for medium exchange. Experiment hardware of this kind, which is adaptable to a wide range of cell types and can be easily interfaced to different spacecraft facilities, offers the possibility for a wide range of experimenters successfully and easily to utilise future flight opportunities.

Alkaline water electrolysis technology for Space Station regenerative fuel cell energy storage

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Hoberecht, M. A.; Le, M.

1986-01-01

The regenerative fuel cell system (RFCS), designed for application to the Space Station energy storage system, is based on state-of-the-art alkaline electrolyte technology and incorporates a dedicated fuel cell system (FCS) and water electrolysis subsystem (WES). In the present study, emphasis is placed on the WES portion of the RFCS. To ensure RFCS availability for the Space Station, the RFCS Space Station Prototype design was undertaken which included a 46-cell 0.93 cu m static feed water electrolysis module and three integrated mechanical components.

Nanomedicine strategies for sustained, controlled, and targeted treatment of cancer stem cells of the digestive system.

PubMed

Xie, Fang-Yuan; Xu, Wei-Heng; Yin, Chuan; Zhang, Guo-Qing; Zhong, Yan-Qiang; Gao, Jie

2016-10-15

Cancer stem cells (CSCs) constitute a small proportion of the cancer cells that have self-renewal capacity and tumor-initiating ability. They have been identified in a variety of tumors, including tumors of the digestive system. CSCs exhibit some unique characteristics, which are responsible for cancer metastasis and recurrence. Consequently, the development of effective therapeutic strategies against CSCs plays a key role in increasing the efficacy of cancer therapy. Several potential approaches to target CSCs of the digestive system have been explored, including targeting CSC surface markers and signaling pathways, inducing the differentiation of CSCs, altering the tumor microenvironment or niche, and inhibiting ATP-driven efflux transporters. However, conventional therapies may not successfully eradicate CSCs owing to various problems, including poor solubility, stability, rapid clearance, poor cellular uptake, and unacceptable cytotoxicity. Nanomedicine strategies, which include drug, gene, targeted, and combinational delivery, could solve these problems and significantly improve the therapeutic index. This review briefly summarizes the ongoing development of strategies and nanomedicine-based therapies against CSCs of the digestive system.

Nanomedicine strategies for sustained, controlled, and targeted treatment of cancer stem cells of the digestive system

PubMed Central

Xie, Fang-Yuan; Xu, Wei-Heng; Yin, Chuan; Zhang, Guo-Qing; Zhong, Yan-Qiang; Gao, Jie

2016-01-01

Cancer stem cells (CSCs) constitute a small proportion of the cancer cells that have self-renewal capacity and tumor-initiating ability. They have been identified in a variety of tumors, including tumors of the digestive system. CSCs exhibit some unique characteristics, which are responsible for cancer metastasis and recurrence. Consequently, the development of effective therapeutic strategies against CSCs plays a key role in increasing the efficacy of cancer therapy. Several potential approaches to target CSCs of the digestive system have been explored, including targeting CSC surface markers and signaling pathways, inducing the differentiation of CSCs, altering the tumor microenvironment or niche, and inhibiting ATP-driven efflux transporters. However, conventional therapies may not successfully eradicate CSCs owing to various problems, including poor solubility, stability, rapid clearance, poor cellular uptake, and unacceptable cytotoxicity. Nanomedicine strategies, which include drug, gene, targeted, and combinational delivery, could solve these problems and significantly improve the therapeutic index. This review briefly summarizes the ongoing development of strategies and nanomedicine-based therapies against CSCs of the digestive system. PMID:27795813

Photovoltaic Test and Demonstration Project. [for solar cell power systems

NASA Technical Reports Server (NTRS)

Forestieri, A. F.; Brandhorst, H. W., Jr.; Deyo, J. N.

1976-01-01

The Photovoltaic Test and Demonstration Project was initiated by NASA in June, 1975, to develop economically feasible photovoltaic power systems suitable for a variety of terrestrial applications. Objectives include the determination of operating characteristic and lifetimes of a variety of solar cell systems and components and development of methodology and techniques for accurate measurements of solar cell and array performance and diagnostic measurements for solar power systems. Initial work will be concerned with residential applications, with testing of the first prototype system scheduled for June, 1976. An outdoor 10 kW array for testing solar power systems is under construction.

Study of component technologies for fuel cell on-site integrated energy system. Volume 2: Appendices

NASA Technical Reports Server (NTRS)

Lee, W. D.; Mathias, S.

1980-01-01

This data base catalogue was compiled in order to facilitate the analysis of various on site integrated energy system with fuel cell power plants. The catalogue is divided into two sections. The first characterizes individual components in terms of their performance profiles as a function of design parameters. The second characterizes total heating and cooling systems in terms of energy output as a function of input and control variables. The integrated fuel cell systems diagrams and the computer analysis of systems are included as well as the cash flows series for baseline systems.

Host-regulated Hepatitis B Virus Capsid Assembly in a Mammalian Cell-free System.

PubMed

Liu, Kuancheng; Hu, Jianming

2018-04-20

The hepatitis B virus (HBV) is an important global human pathogen and represents a major cause of hepatitis, liver cirrhosis and liver cancer. The HBV capsid is composed of multiple copies of a single viral protein, the capsid or core protein (HBc), plays multiple roles in the viral life cycle, and has emerged recently as a major target for developing antiviral therapies against HBV infection. Although several systems have been developed to study HBV capsid assembly, including heterologous overexpression systems like bacteria and insect cells, in vitro assembly using purified protein, and mammalian cell culture systems, the requirement for non-physiological concentrations of HBc and salts and the difficulty in manipulating host regulators of assembly presents major limitations for detailed studies on capsid assembly under physiologically relevant conditions. We have recently developed a mammalian cell-free system based on the rabbit reticulocyte lysate (RRL), in which HBc is expressed at physiological concentrations and assembles into capsids under near-physiological conditions. This system has already revealed HBc assembly requirements that are not anticipated based on previous assembly systems. Furthermore, capsid assembly in this system is regulated by endogenous host factors that can be readily manipulated. Here we present a detailed protocol for this cell-free capsid assembly system, including an illustration on how to manipulate host factors that regulate assembly.

Dermatology Terms

MedlinePlus

... shows as swelling, pain, tenderness, redness and/or heat. Immune system cells are seen in the specimen being examined. These inflammatory cells include 1) neutrophils, which are the white blood cells that make up pus and are seen ...

Miniature Bioreactor System for Long-Term Cell Culture

NASA Technical Reports Server (NTRS)

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.

The Caenorhabditis elegans Q neuroblasts: A powerful system to study cell migration at single-cell resolution in vivo.

PubMed

Rella, Lorenzo; Fernandes Póvoa, Euclides E; Korswagen, Hendrik C

2016-04-01

During development, cell migration plays a central role in the formation of tissues and organs. Understanding the molecular mechanisms that drive and control these migrations is a key challenge in developmental biology that will provide important insights into disease processes, including cancer cell metastasis. In this article, we discuss the Caenorhabditis elegans Q neuroblasts and their descendants as a tool to study cell migration at single-cell resolution in vivo. The highly stereotypical migration of these cells provides a powerful system to study the dynamic cytoskeletal processes that drive migration as well as the evolutionarily conserved signaling pathways (including different Wnt signaling cascades) that guide the cells along their specific trajectories. Here, we provide an overview of what is currently known about Q neuroblast migration and highlight the live-cell imaging, genome editing, and quantitative gene expression techniques that have been developed to study this process. © 2016 Wiley Periodicals, Inc.

Cell-Based Biohybrid Drug Delivery Systems: The Best of the Synthetic and Natural Worlds.

PubMed

Banskota, Samagya; Yousefpour, Parisa; Chilkoti, Ashutosh

2017-01-01

The goal of drug delivery is to deliver therapeutics to the site of disease while reducing unwanted side effects. In recent years, a diverse variety of synthetic nano and microparticles have been developed as drug delivery systems. The success of these systems for drug delivery lies in their ability to overcome biological barriers such as the blood-brain barrier, to evade immune clearance and avoid nonspecific biodistribution. This Review provides an overview of recent advances in the design of biohybrid drug delivery systems, which combine cells with synthetic systems to overcome some of these biological hurdles. Examples include eukaryotic cells, such as stem cells, red blood cells, immune cells, platelets, and cancer cells that are used to carry drug-loaded synthetic particles. Synthetic particles can also be cloaked with naturally derived cell membranes and thereby evade immune clearance, exhibit prolonged systemic circulation, and target specific tissues by capitalizing on the interaction/homing tendency of certain cells and their membrane components to particular tissues. Different designs of cell-based biohybrid systems and their applications, as well as their promise and limitations, are discussed herein. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Automated Microfluidic Filtration and Immunocytochemistry Detection System for Capture and Enumeration of Circulating Tumor Cells and Other Rare Cell Populations in Blood.

PubMed

Pugia, Michael; Magbanua, Mark Jesus M; Park, John W

2017-01-01

Isolation by size using a filter membrane offers an antigen-independent method for capturing rare cells present in blood of cancer patients. Multiple cell types, including circulating tumor cells (CTCs), captured on the filter membrane can be simultaneously identified via immunocytochemistry (ICC) analysis of specific cellular biomarkers. Here, we describe an automated microfluidic filtration method combined with a liquid handling system for sequential ICC assays to detect and enumerate non-hematologic rare cells in blood.

Nanopipette Apparatus for Manipulating Cells

NASA Technical Reports Server (NTRS)

Vilozny, Boaz (Inventor); Seger, R. Adam (Inventor); Actis, Paolo (Inventor); Pourmand, Nader (Inventor)

2017-01-01

Disclosed herein are methods and systems for controlled ejection of desired material onto surfaces including in single cells using nanopipettes, as well as ejection onto and into cells. Some embodiments are directed to a method and system comprising nanopipettes combined with an xyz controller for depositing a user defined pattern on an arbitrary substrate for the purpose of controlled cell adhesion and growth. Alternate embodiments are directed to a method and system comprising nanopipettes combined with an xyz controller and electronic control of a voltage differential in a bore of the nanopipette electroosmotically injecting material into a cell in a high-throughput manner and with minimal damage to the cell. Yet other embodiments are directed to method and system comprising functionalized nanopipettes combined with scanning ion conductance microscopy for studying molecular interactions and detection of biomolecules inside a single living cell.

Water injected fuel cell system compressor

DOEpatents

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.

IEEE Photovoltaic Specialists Conference, 20th, Las Vegas, NV, Sept. 26-30, 1988, Conference Record. Volumes 1 & 2

NASA Astrophysics Data System (ADS)

Various papers on photovoltaics are presented. The general topics considered include: amorphous materials and cells; amorphous silicon-based solar cells and modules; amorphous silicon-based materials and processes; amorphous materials characterization; amorphous silicon; high-efficiency single crystal solar cells; multijunction and heterojunction cells; high-efficiency III-V cells; modeling and characterization of high-efficiency cells; LIPS flight experience; space mission requirements and technology; advanced space solar cell technology; space environmental effects and modeling; space solar cell and array technology; terrestrial systems and array technology; terrestrial utility and stand-alone applications and testing; terrestrial concentrator and storage technology; terrestrial stand-alone systems applications; terrestrial systems test and evaluation; terrestrial flatplate and concentrator technology; use of polycrystalline materials; polycrystalline II-VI compound solar cells; analysis of and fabrication procedures for compound solar cells.

Analyzing the texture changes in the quantitative phase maps of adipocytes

NASA Astrophysics Data System (ADS)

Roitshtain, Darina; Sharabani-Yosef, Orna; Gefen, Amit; Shaked, Natan T.

2016-03-01

We present a new analysis tool for studying texture changes in the quantitative phase maps of live cells acquired by wide-field interferometry. The sensitivity of wide-field interferometry systems to small changes in refractive index enables visualizing cells and inner cell organelles without the using fluorescent dyes or other cell-invasive approaches, which may affect the measurement and require external labeling. Our label-free texture-analysis tool is based directly on the optical path delay profile of the sample and does not necessitate decoupling refractive index and thickness in the cell quantitative phase profile; thus, relevant parameters can be calculated using a single-frame acquisition. Our experimental system includes low-coherence wide-field interferometer, combined with simultaneous florescence microscopy system for validation. We used this system and analysis tool for studying lipid droplets formation in adipocytes. The latter demonstration is relevant for various cellular functions such as lipid metabolism, protein storage and degradation to viral replication. These processes are functionally linked to several physiological and pathological conditions, including obesity and metabolic diseases. Quantification of these biological phenomena based on the texture changes in the cell phase map has a potential as a new cellular diagnosis tool.

Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems

NASA Astrophysics Data System (ADS)

Ally, Jamie; Pryor, Trevor

The Sustainable Transport Energy Programme (STEP) is an initiative of the Government of Western Australia, to explore hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure in Perth. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell power sources operating in regular service alongside the existing natural gas and diesel bus fleets. The life-cycle assessment (LCA) of the fuel cell bus trial in Perth determines the overall environmental footprint and energy demand by studying all phases of the complete transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. The LCAs of the existing diesel and natural gas transportation systems are developed in parallel. The findings show that the trial is competitive with the diesel and natural gas bus systems in terms of global warming potential and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses. Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles and shows that a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation and primary energy demand impact categories.

Fuzzy energy management for hybrid fuel cell/battery systems for more electric aircraft

NASA Astrophysics Data System (ADS)

Corcau, Jenica-Ileana; Dinca, Liviu; Grigorie, Teodor Lucian; Tudosie, Alexandru-Nicolae

2017-06-01

In this paper is presented the simulation and analysis of a Fuzzy Energy Management for Hybrid Fuel cell/Battery Systems used for More Electric Aircraft. The fuel cell hybrid system contains of fuel cell, lithium-ion batteries along with associated dc to dc boost converters. In this configuration the battery has a dc to dc converter, because it is an active in the system. The energy management scheme includes the rule based fuzzy logic strategy. This scheme has a faster response to load change and is more robust to measurement imprecisions. Simulation will be provided using Matlab/Simulink based models. Simulation results are given to show the overall system performance.

The Future of Cell Biology: Emerging Model Organisms.

PubMed

Goldstein, Bob; King, Nicole

2016-11-01

Most current research in cell biology uses just a handful of model systems including yeast, Arabidopsis, Drosophila, Caenorhabditis elegans, zebrafish, mouse, and cultured mammalian cells. And for good reason - for many biological questions, the best system for the question is likely to be found among these models. However, in some cases, and particularly as the questions that engage scientists broaden, the best system for a question may be a little-studied organism. Modern research tools are facilitating a renaissance for unusual and interesting organisms as emerging model systems. As a result, we predict that an ever-expanding breadth of model systems may be a hallmark of future cell biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nanomedicines based drug delivery systems for anti-cancer targeting and treatment.

PubMed

Jain, Vikas; Jain, Shikha; Mahajan, S C

2015-01-01

Cancer is defined as an uncontrolled growth of abnormal cells. Current treatment strategies for cancer include combination of radiation, chemotherapy and surgery. The long-term use of conventional drug delivery systems for cancer chemotherapy leads to fatal damage of normal proliferate cells and this is particularly used for the management of solid tumors, where utmost tumor cells are not invaded quickly. A targeted drug delivery system (TDDS) is a system, which releases the drug at a preselected biosite in a controlled manner. Nanotechnology based delivery systems are making a significant impact on cancer treatment and the polymers play key role in the development of nanopraticlulate carriers for cancer therapy. Some important technological advantages of nanotherapeutic drug delivery systems (NDDS) include prolonged half-life, improved bio-distribution, increased circulation time of the drug, controlled and sustained release of the drug, versatility of route of administration, increased intercellular concentration of drug and many more. This review covers the current research on polymer based anticancer agents, the rationale for development of these polymer therapeutical systems and discusses the benefits and challenges of cancer nanomedicines including polymer-drug conjugates, micelles, dendrimers, immunoconjugates, liposomes, nanoparticles.

Integration of systems biology with organs-on-chips to humanize therapeutic development

NASA Astrophysics Data System (ADS)

Edington, Collin D.; Cirit, Murat; Chen, Wen Li Kelly; Clark, Amanda M.; Wells, Alan; Trumper, David L.; Griffith, Linda G.

2017-02-01

"Mice are not little people" - a refrain becoming louder as the gaps between animal models and human disease become more apparent. At the same time, three emerging approaches are headed toward integration: powerful systems biology analysis of cell-cell and intracellular signaling networks in patient-derived samples; 3D tissue engineered models of human organ systems, often made from stem cells; and micro-fluidic and meso-fluidic devices that enable living systems to be sustained, perturbed and analyzed for weeks in culture. Integration of these rapidly moving fields has the potential to revolutionize development of therapeutics for complex, chronic diseases, including those that have weak genetic bases and substantial contributions from gene-environment interactions. Technical challenges in modeling complex diseases with "organs on chips" approaches include the need for relatively large tissue masses and organ-organ cross talk to capture systemic effects, such that current microfluidic formats often fail to capture the required scale and complexity for interconnected systems. These constraints drive development of new strategies for designing in vitro models, including perfusing organ models, as well as "mesofluidic" pumping and circulation in platforms connecting several organ systems, to achieve the appropriate physiological relevance.

Energy storage cell impedance measuring apparatus, methods and related systems

DOEpatents

Morrison, John L.; Morrison, William H.; Christophersen, Jon P.

2017-12-26

Energy storage cell impedance testing devices, circuits, and related methods are disclosed. An energy storage cell impedance measuring device includes a sum of sinusoids (SOS) current excitation circuit including differential current sources configured to isolate a ground terminal of the differential current sources from a positive terminal and a negative terminal of an energy storage cell. A method includes applying an SOS signal comprising a sum of sinusoidal current signals to the energy storage cell with the SOS current excitation circuit, each of the sinusoidal current signals oscillating at a different one of a plurality of different frequencies. The method also includes measuring an electrical signal at a positive terminal and a negative terminal of the energy storage cell, and computing an impedance of the energy storage cell at each of the plurality of different frequencies using the measured electrical signal.

A role for the ESCRT system in cell division in archaea.

PubMed

Samson, Rachel Y; Obita, Takayuki; Freund, Stefan M; Williams, Roger L; Bell, Stephen D

2008-12-12

Archaea are prokaryotic organisms that lack endomembrane structures. However, a number of hyperthermophilic members of the Kingdom Crenarchaea, including members of the Sulfolobus genus, encode homologs of the eukaryotic endosomal sorting system components Vps4 and ESCRT-III (endosomal sorting complex required for transport-III). We found that Sulfolobus ESCRT-III and Vps4 homologs underwent regulation of their expression during the cell cycle. The proteins interacted and we established the structural basis of this interaction. Furthermore, these proteins specifically localized to the mid-cell during cell division. Overexpression of a catalytically inactive mutant Vps4 in Sulfolobus resulted in the accumulation of enlarged cells, indicative of failed cell division. Thus, the archaeal ESCRT system plays a key role in cell division.

Massachusetts Fuel Cell Bus Project: Demonstrating a Total Transit Solution for Fuel Cell Electric Buses in Boston

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

The Federal Transit Administration's National Fuel Cell Bus Program focuses on developing commercially viable fuel cell bus technologies. Nuvera is leading the Massachusetts Fuel Cell Bus project to demonstrate a complete transit solution for fuel cell electric buses that includes one bus and an on-site hydrogen generation station for the Massachusetts Bay Transportation Authority (MBTA). A team consisting of ElDorado National, BAE Systems, and Ballard Power Systems built the fuel cell electric bus, and Nuvera is providing its PowerTap on-site hydrogen generator to provide fuel for the bus.

Flexible fuel cell gas manifold system

DOEpatents

Cramer, Michael; Shah, Jagdish; Hayes, Richard P.; Kelley, Dana A.

2005-05-03

A fuel cell stack manifold system in which a flexible manifold body includes a pan having a central area, sidewall extending outward from the periphery of the central area, and at least one compound fold comprising a central area fold connecting adjacent portions of the central area and extending between opposite sides of the central area, and a sidewall fold connecting adjacent portions of the sidewall. The manifold system further includes a rail assembly for attachment to the manifold body and adapted to receive pins by which dielectric insulators are joined to the manifold assembly.

The S(c)ensory Immune System Theory.

PubMed

Veiga-Fernandes, Henrique; Freitas, António A

2017-10-01

Viewpoints on the immune system have evolved across different paradigms, including the clonal selection theory, the idiotypic network, and the danger and tolerance models. Herein, we propose that in multicellular organisms, where panoplies of cells from different germ layers interact and immune cells are constantly generated, the behavior of the immune system is defined by the rules governing cell survival, systems physiology and organismic homeostasis. Initially, these rules were imprinted at the single cell-protist level, but supervened modifications in the transition to multicellular organisms. This context determined the emergence of the 'sensory immune system', which operates in a s(c)ensor mode to ensure systems physiology, organismic homeostasis, and perpetuation of its replicating molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fuel cell system combustor

DOEpatents

Pettit, William Henry

2001-01-01

A fuel cell system including a fuel reformer heated by a catalytic combustor fired by anode and cathode effluents. The combustor includes a turbulator section at its input end for intimately mixing the anode and cathode effluents before they contact the combustors primary catalyst bed. The turbulator comprises at least one porous bed of mixing media that provides a tortuous path therethrough for creating turbulent flow and intimate mixing of the anode and cathode effluents therein.

Regenerative fuel cell energy storage system for a low earth orbit space station

NASA Technical Reports Server (NTRS)

Martin, R. E.; Garow, J.; Michaels, K. B.

1988-01-01

A study was conducted to define characteristics of a Regenerative Fuel Cell System (RFCS) for low earth orbit Space Station missions. The RFCS's were defined and characterized based on both an alkaline electrolyte fuel cell integrated with an alkaline electrolyte water electrolyzer and an alkaline electrolyte fuel cell integrated with an acid solid polymer electrolyte (SPE) water electrolyzer. The study defined the operating characteristics of the systems including system weight, volume, and efficiency. A maintenance philosophy was defined and the implications of system reliability requirements and modularization were determined. Finally, an Engineering Model System was defined and a program to develop and demonstrate the EMS and pacing technology items that should be developed in parallel with the EMS were identified. The specific weight of an optimized RFCS operating at 140 F was defined as a function of system efficiency for a range of module sizes. An EMS operating at a nominal temperature of 180 F and capable of delivery of 10 kW at an overall efficiency of 55.4 percent is described. A program to develop the EMS is described including a technology development effort for pacing technology items.

Optimizing Battery Usage and Management for Long Life

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

Smith, Kandler; Shi, Ying; Wood, Eric

2016-06-16

This presentation discusses the impact of system design factors on battery aging and end of life. Topics include sizing of the SOC operating window, cell balancing and thermal management systems and their value in reducing pack degradation rates and cell imbalance growth over lifetime.

Device Performance Capabilities | Photovoltaic Research | NREL

Science.gov Websites

multijunction cells and modules. We use I-V measurement systems to assess the main performance parameters for PV cells and modules. I-V measurement systems determine the output performance of devices, including: open the device (η). Some I-V systems may also be used to perform dark I-V measurements to determine diode

Expression profiles of inka2 in the murine nervous system.

PubMed

Iwasaki, Yumi; Yumoto, Takahito; Sakakibara, Shin-Ichi

2015-01-01

Dynamic rearrangement of the actin cytoskeleton impacts many cellular characteristics in both the developing and adult central nervous systems (CNS), including the migration and adhesion of highly motile neural progenitor cells, axon guidance of immature neurons, and reconstruction of synaptic structures in the adult brain. Inka1, a known regulator of actin cytoskeleton reconstruction, is predominantly expressed by the neural crest cell lineage and regulates the migration and differentiation of these cells. In the present study, we identified a novel gene, designated as inka2, which is related to inka1. Inka2/fam212b is an evolutionarily conserved gene found in different vertebrate species and constitutes a novel gene family together with inka1. Northern blot analysis showed that inka2 mRNA was highly enriched in the nervous system. The spatiotemporal propagation cell profiles of those cells that expressed inka2 transcripts were compatible with those of Olig2-positive oligodendrocyte progenitor cells, which originate in the ventral ventricular zone during embryogenesis. Intense expression of inka2 was also noted in the proliferative neuronal progenitors in the developing cerebellum. On the other hand, immature newborn neurons in the embryonic brain showed no expression of inka2, except for the cells residing in the marginal zone of the embryonic telencephalon, which is known to contain transient cells including the non-subplate pioneer neurons and Cajal-Retzius cells. As brain development proceeds during the postnatal stage, inka2 expression emerged in some populations of immature neurons, including the neocortical pyramidal neurons, hippocampal pyramidal neurons, and granule cells migrating in the cerebellar cortex. In the adult brain, the expression of inka2 was interestingly confined in terminally differentiated neurons in the restricted forebrain regions. Taken together, as a novel regulator of actin cytoskeletons in the CNS, inka2 may be involved in multiple actin-driven processes, including cell migration and establishment of neuronal polarity. Copyright © 2015 Elsevier B.V. All rights reserved.

Progress in corneal wound healing

PubMed Central

Ljubimov, Alexander V.; Saghizadeh, Mehrnoosh

2015-01-01

Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal epithelium, and nanocarriers for corneal drug delivery are discussed. Attention is also paid to problems in wound healing understanding and treatment, such as lack of specific epithelial stem cell markers, reliable identification of stem cells, efficient prevention of haze and stromal scar formation, lack of data on wound regulating microRNAs in keratocytes and endothelial cells, as well as virtual lack of targeted systems for drug and gene delivery to select corneal cells. PMID:26197361

Progress in corneal wound healing.

PubMed

Ljubimov, Alexander V; Saghizadeh, Mehrnoosh

2015-11-01

Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β (TGF-β) system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal epithelium, and nanocarriers for corneal drug delivery are discussed. Attention is also paid to problems in wound healing understanding and treatment, such as lack of specific epithelial stem cell markers, reliable identification of stem cells, efficient prevention of haze and stromal scar formation, lack of data on wound regulating microRNAs in keratocytes and endothelial cells, as well as virtual lack of targeted systems for drug and gene delivery to select corneal cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fuel cell system blower configuration

DOEpatents

Patel, Kirtikumar H.; Saito, Kazuo

2017-11-28

An exemplary fuel cell system includes a cell stack assembly having a plurality of cathode components and a plurality of anode components. A first reactant blower has an outlet situated to provide a first reactant to the cathode components. A second reactant blower has an outlet situated to provide a second reactant to the anode components. The second reactant blower includes a fan portion that moves the second reactant through the outlet. The second reactant blower also includes a motor portion that drives the fan portion and a bearing portion associated with the fan portion and the motor portion. The motor portion has a motor coolant inlet coupled with the outlet of the first reactant blower to receive some of the first reactant for cooling the motor portion.

Current reprogramming systems in regenerative medicine: from somatic cells to induced pluripotent stem cells.

PubMed

Hu, Chenxia; Li, Lanjuan

2016-01-01

Induced pluripotent stem cells (iPSCs) paved the way for research fields including cell therapy, drug screening, disease modeling and the mechanism of embryonic development. Although iPSC technology has been improved by various delivery systems, direct transduction and small molecule regulation, low reprogramming efficiency and genomic modification steps still inhibit its clinical use. Improvements in current vectors and the exploration of novel vectors are required to balance efficiency and genomic modification for reprogramming. Herein, we set out a comprehensive analysis of current reprogramming systems for the generation of iPSCs from somatic cells. By clarifying advantages and disadvantages of the current reprogramming systems, we are striding toward an effective route to generate clinical grade iPSCs.

Rap G protein signal in normal and disordered lymphohematopoiesis

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

Minato, Nagahiro, E-mail: minato@imm.med.kyoto-u.ac.jp

2013-09-10

Rap proteins (Rap1, Rap2a, b, c) are small molecular weight GTPases of the Ras family. Rap G proteins mediate diverse cellular events such as cell adhesion, proliferation, and gene activation through various signaling pathways. Activation of Rap signal is regulated tightly by several specific regulatory proteins including guanine nucleotide exchange factors and GTPase-activating proteins. Beyond cell biological studies, increasing attempts have been made in the past decade to define the roles of Rap signal in specific functions of normal tissue systems as well as in cancer. In the immune and hematopoietic systems, Rap signal plays crucial roles in the developmentmore » and function of essentially all lineages of lymphocytes and hematopoietic cells, and importantly, deregulated Rap signal may lead to unique pathological conditions depending on the affected cell types, including various types of leukemia and autoimmunity. The phenotypical studies have unveiled novel, even unexpected functional aspects of Rap signal in cells from a variety of tissues, providing potentially important clues for controlling human diseases, including malignancy.« less

Recent progress in Si thin film technology for solar cells

NASA Astrophysics Data System (ADS)

Kuwano, Yukinori; Nakano, Shoichi; Tsuda, Shinya

1991-11-01

Progress in Si thin film technology 'specifically amorphous Si (a-Si) and polycrystalline Si (poly-Si) thin film' for solar cells is summarized here from fabrication method, material, and structural viewpoints. In addition to a-Si, primary results on poly-Si thin film research are discussed. Various applications for a-Si solar cells are mentioned, and consumer applications and a-Si solar cell photovoltaic systems are introduced. New product developments include see-through solar cells, solar cell roofing tiles, and ultra-light flexible solar cells. As for new systems, air conditioning equipment powered by solar cells is described. Looking to the future, the proposed GENESIS project is discussed.

Starting characteristics of direct current motors powered by solar cells

NASA Technical Reports Server (NTRS)

Singer, S.; Appelbaum, J.

1989-01-01

Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

Automated cell counts on CSF samples: A multicenter performance evaluation of the GloCyte system.

PubMed

Hod, E A; Brugnara, C; Pilichowska, M; Sandhaus, L M; Luu, H S; Forest, S K; Netterwald, J C; Reynafarje, G M; Kratz, A

2018-02-01

Automated cell counters have replaced manual enumeration of cells in blood and most body fluids. However, due to the unreliability of automated methods at very low cell counts, most laboratories continue to perform labor-intensive manual counts on many or all cerebrospinal fluid (CSF) samples. This multicenter clinical trial investigated if the GloCyte System (Advanced Instruments, Norwood, MA), a recently FDA-approved automated cell counter, which concentrates and enumerates red blood cells (RBCs) and total nucleated cells (TNCs), is sufficiently accurate and precise at very low cell counts to replace all manual CSF counts. The GloCyte System concentrates CSF and stains RBCs with fluorochrome-labeled antibodies and TNCs with nucleic acid dyes. RBCs and TNCs are then counted by digital image analysis. Residual adult and pediatric CSF samples obtained for clinical analysis at five different medical centers were used for the study. Cell counts were performed by the manual hemocytometer method and with the GloCyte System following the same protocol at all sites. The limits of the blank, detection, and quantitation, as well as precision and accuracy of the GloCyte, were determined. The GloCyte detected as few as 1 TNC/μL and 1 RBC/μL, and reliably counted as low as 3 TNCs/μL and 2 RBCs/μL. The total coefficient of variation was less than 20%. Comparison with cell counts obtained with a hemocytometer showed good correlation (>97%) between the GloCyte and the hemocytometer, including at very low cell counts. The GloCyte instrument is a precise, accurate, and stable system to obtain red cell and nucleated cell counts in CSF samples. It allows for the automated enumeration of even very low cell numbers, which is crucial for CSF analysis. These results suggest that GloCyte is an acceptable alternative to the manual method for all CSF samples, including those with normal cell counts. © 2017 John Wiley & Sons Ltd.

Vapor cycle cooling system

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

Midolo, L.

1980-07-08

A description is given of a rotary vane cooling system including a two phase coolant, comprising: a vaporizable liquid working medium within said cooling system; an evaporator having an inlet and an outlet; a condenser having an inlet and an outlet; a two stage rotary vane compressor, including means for connecting the outlet of a first compressor stage to the inlet of a second compressor stage; said two stage rotary vane compressor being connected between the outlet of said evaporator and the inlet at said condenser; an expansion device connected between the outlet of said condenser and the inlet ofmore » said evaporator; said two stage compressor including a housing having a chamber therein, a rotor on a rotatable shaft; said rotor being positioned within said chamber; said rotor having a plurality of slidable vanes which form a plurality of cells, within said chamber, which change in volume as the rotor rotates; said plurality of cells including a pluraity of cells on one side of said rotor which corresponds to said first compressor stage and a plurality of cells on the other side of said rotor which corresponds to said second compressor stage; said cells corresponding to said first compressor stage having a greater maximum volume than the cells corresponding to said second compressor stage; and means for supplying at least a portion of the vapor resulting from the expansion in said expansion device to the inlet of the second compressor stage for providing cooling in the inlet of said second compressor stage.« less

Preparation of Murine Submandibular Salivary Gland for Upright Intravital Microscopy.

PubMed

Ficht, Xenia; Thelen, Flavian; Stolp, Bettina; Stein, Jens V

2018-05-07

The submandibular salivary gland (SMG) is one of the three major salivary glands, and is of interest for many different fields of biological research, including cell biology, oncology, dentistry, and immunology. The SMG is an exocrine gland comprised of secretory epithelial cells, myofibroblasts, endothelial cells, nerves, and extracellular matrix. Dynamic cellular processes in the rat and mouse SMG have previously been imaged, mostly using inverted multi-photon microscope systems. Here, we describe a straightforward protocol for the surgical preparation and stabilization of the murine SMG in anesthetized mice for in vivo imaging with upright multi-photon microscope systems. We present representative intravital image sets of endogenous and adoptively transferred fluorescent cells, including the labeling of blood vessels or salivary ducts and second harmonic generation to visualize fibrillar collagen. In sum, our protocol allows for surgical preparation of mouse salivary glands in upright microscopy systems, which are commonly used for intravital imaging in the field of immunology.

Immunological changes with kinase inhibitor therapy for chronic lymphocytic leukemia.

PubMed

Pleyer, Christopher; Wiestner, Adrian; Sun, Clare

2018-05-15

Ibrutinib and idelalisib are kinase inhibitors that have revolutionized the treatment of chronic lymphocytic leukemia (CLL). Capable of inducing durable remissions, these agents also modulate the immune system. Both ibrutinib and idelalisib abrogate the tumor-supporting microenvironment by disrupting cell-cell interactions, modulating the T-cell compartment, and altering the cytokine milieu. Ibrutinib also partially restores T-cell and myeloid defects associated with CLL. In contrast, immune-related adverse effects, including pneumonitis, colitis, hepatotoxicity, and infections are of particular concern with idelalisib. While opportunistic infections and viral reactivations occur with both ibrutinib and idelalisib, these complications are less common and less severe with ibrutinib, especially when used as monotherapy without additional immunosuppressive agents. This review discusses the impact of ibrutinib and idelalisib on the immune system, including infectious and auto-immune complications as well as their specific effects on the B-cell, T-cell, and myeloid compartment.

Suitability and perspectives on using recombinant insect cells for the production of virus-like particles.

PubMed

Yamaji, Hideki

2014-03-01

Virus-like particles (VLPs) can be produced in recombinant protein production systems by expressing viral surface proteins that spontaneously assemble into particulate structures similar to authentic viral or subviral particles. VLPs serve as excellent platforms for the development of safe and effective vaccines and diagnostic antigens. Among various recombinant protein production systems, the baculovirus-insect cell system has been used extensively for the production of a wide variety of VLPs. This system is already employed for the manufacture of a licensed human papillomavirus-like particle vaccine. However, the baculovirus-insect cell system has several inherent limitations including contamination of VLPs with progeny baculovirus particles. Stably transformed insect cells have emerged as attractive alternatives to the baculovirus-insect cell system. Different types of VLPs, with or without an envelope and composed of either single or multiple structural proteins, have been produced in stably transformed insect cells. VLPs produced by stably transformed insect cells have successfully elicited immune responses in vivo. In some cases, the yield of VLPs attained with recombinant insect cells was comparable to, or higher than, that obtained by baculovirus-infected insect cells. Recombinant insect cells offer a promising approach to the development and production of VLPs.

Ionophore-A23187-induced cellular cytotoxicity: a cell fragment mediated process.

PubMed Central

Nash, G S; Niedt, G W; MacDermott, R P

1980-01-01

Calcium ionophore A23187 was found to induce human white blood cells to kill human red blood cells. Optimal conditions for ionophore-induced cellular cytotoxicity (IICC) included an 18 h time period, an incubation temperature of 25 degrees, a 25:1 or 50:1 killer:target cell ratio,and a final ionophore concentration of 2 . 5 microgram/ml. WBC or granulocytes which were either frozen and thawed three times or sonicated were capable of mediating IICC. As intact cells, granulocytes (67 . 2% cytotoxicity), monocytes (34 . 8%), B cells (22 . 0%) and Null cells (19 . 3%) were effector cells but T cells (7 . 4%) were not. After fragmenting these cells, all cell types including T cells were able to mediate IICC. When cell lines (K562, Chang, and NCTC) were used as effectors, none would mediate IICC when intact. After freezing and thawing, Chang and NCTC would not mediate IICC, whereas K562 cells did. These studies may be indicative of a calcium-dependent, membrane-localized mechanism in cellular cytotoxic processes, and may provide a useful indicator system for isolation of the enzyme systems involved in cellular cytotoxicity. PMID:6773881

Photoacoustic-fluorescence in vitro flow cytometry for quantification of absorption, scattering and fluorescence properties of the cells

NASA Astrophysics Data System (ADS)

Nedosekin, D. A.; Sarimollaoglu, M.; Foster, S.; Galanzha, E. I.; Zharov, V. P.

2013-03-01

Fluorescence flow cytometry is a well-established analytical tool that provides quantification of multiple biological parameters of cells at molecular levels, including their functional states, morphology, composition, proliferation, and protein expression. However, only the fluorescence and scattering parameters of the cells or labels are available for detection. Cell pigmentation, presence of non-fluorescent dyes or nanoparticles cannot be reliably quantified. Herewith, we present a novel photoacoustic (PA) flow cytometry design for simple integration of absorbance measurements into schematics of conventional in vitro flow cytometers. The integrated system allow simultaneous measurements of light absorbance, scattering and of multicolor fluorescence from single cells in the flow at rates up to 2 m/s. We compared various combinations of excitation laser sources for multicolor detection, including simultaneous excitation of PA and fluorescence using a single 500 kHz pulsed nanosecond laser. Multichannel detection scheme allows simultaneous detection of up to 8 labels, including 4 fluorescent tags and 4 PA colors. In vitro PA-fluorescence flow cytometer was used for studies of nanoparticles uptake and for the analysis of cell line pigmentation, including genetically encoded melanin expression in breast cancer cell line. We demonstrate that this system can be used for direct nanotoxicity studies with simultaneous quantification of nanoparticles content and assessment of cell viability using a conventional fluorescent apoptosis assays.

Phalange Tactile Load Cell

NASA Technical Reports Server (NTRS)

Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

2010-01-01

A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

Fight or Flight - Regulation of Emergency Hematopoiesis by Pyroptosis and Necroptosis

PubMed Central

Croker, Ben A.; Silke, John; Gerlic, Motti

2015-01-01

Purpose of review A feature of the innate immune response that is conserved across kingdoms is the induction of cell death. In this review, we discuss the direct and indirect effects of increased inflammatory cell death, including pyroptosis, a caspase-1-dependent cell death, and necroptosis, a RIPK3/MLKL-dependent, caspase-independent cell death, on emergency hematopoiesis. Recent findings Activation of non-apoptotic cell death pathways during infection can trigger release of cytokines and/or damage-associated molecular patterns (DAMPs) such as IL-1α, IL-1β, IL-18, IL-33, HMGB1 and mtDNA to promote emergency hematopoiesis. During systemic infection, pyroptosis and necroptosis can directly kill hematopoietic stem and progenitor cells, which results in impaired hematopoiesis, cytopenia and immunosuppression. Although originally described as discrete entities, there now appears to be more intimate connections between the non-apoptotic and death receptor signaling pathways. Summary The choice to undergo pyroptotic and necroptotic cell death constitutes a rapid response system serving to eliminate infected cells, including hematopoietic stem and progenitor cells. This system has the potential to be detrimental to emergency hematopoiesis during severe infection. We discuss the potential of pharmacological intervention for the pyroptosis and necroptosis pathways that may be beneficial during periods of infection and emergency hematopoiesis. PMID:26049749

SPE (tm) regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications

NASA Technical Reports Server (NTRS)

Mcelroy, J. F.

1990-01-01

Viewgraphs on SPE regenerative hydrogen/oxygen fuel cells for extraterrestrial surface and microgravity applications are presented. Topics covered include: hydrogen-oxygen regenerative fuel cell energy storage system; electrochemical cell reactions; SPE cell voltage stability; passive water removal SPE fuel cell; fuel cell performance; SPE water electrolyzers; hydrophobic oxygen phase separator; hydrophilic/electrochemical hydrogen phase separator; and unitized regenerative fuel cell.

Microfabricated systems and assays for studying the cytoskeletal organization, micromechanics, and motility patterns of cancerous cells

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

Huda, Sabil; Pilans, Didzis; Makurath, Monika

Cell motions are driven by coordinated actions of the intracellular cytoskeleton – actin, microtubules (MTs) and substrate/focal adhesions (FAs). This coordination is altered in metastatic cancer cells resulting in deregulated and increased cellular motility. Microfabrication tools, including photolithography, micromolding, microcontact printing, wet stamping and microfluidic devices have emerged as a powerful set of experimental tools with which to probe and define the differences in cytoskeleton organization/dynamics and cell motility patterns in non-metastatic and metastatic cancer cells. In this paper, we discuss four categories of microfabricated systems: (i) micropatterned substrates for studying of cell motility sub-processes (for example, MT targeting ofmore » FAs or cell polarization); (ii) systems for studying cell mechanical properties, (iii) systems for probing overall cell motility patterns within challenging geometric confines relevant to metastasis (for example, linear and ratchet geometries), and (iv) microfluidic devices that incorporate co-cultures of multiple cell types and chemical gradients to mimic in vivo intravasation/extravasation steps of metastasis. Finally, together, these systems allow for creating controlled microenvironments that not only mimic complex soft tissues, but are also compatible with live cell high-resolution imaging and quantitative analysis of single cell behavior.« less

Microfabricated systems and assays for studying the cytoskeletal organization, micromechanics, and motility patterns of cancerous cells

DOE PAGES

Huda, Sabil; Pilans, Didzis; Makurath, Monika; ...

2014-08-28

Cell motions are driven by coordinated actions of the intracellular cytoskeleton – actin, microtubules (MTs) and substrate/focal adhesions (FAs). This coordination is altered in metastatic cancer cells resulting in deregulated and increased cellular motility. Microfabrication tools, including photolithography, micromolding, microcontact printing, wet stamping and microfluidic devices have emerged as a powerful set of experimental tools with which to probe and define the differences in cytoskeleton organization/dynamics and cell motility patterns in non-metastatic and metastatic cancer cells. In this paper, we discuss four categories of microfabricated systems: (i) micropatterned substrates for studying of cell motility sub-processes (for example, MT targeting ofmore » FAs or cell polarization); (ii) systems for studying cell mechanical properties, (iii) systems for probing overall cell motility patterns within challenging geometric confines relevant to metastasis (for example, linear and ratchet geometries), and (iv) microfluidic devices that incorporate co-cultures of multiple cell types and chemical gradients to mimic in vivo intravasation/extravasation steps of metastasis. Finally, together, these systems allow for creating controlled microenvironments that not only mimic complex soft tissues, but are also compatible with live cell high-resolution imaging and quantitative analysis of single cell behavior.« less

Load sensing system

DOEpatents

Sohns, C.W.; Nodine, R.N.; Wallace, S.A.

1999-05-04

A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast inventories of stored nuclear material can be continuously monitored and inventoried of minimal cost. 4 figs.

A Theoretical Solid Oxide Fuel Cell Model for System Controls and Stability Design

NASA Technical Reports Server (NTRS)

Kopasakis, George; Brinson, Thomas; Credle, Sydni; Xu, Ming

2006-01-01

As the aviation industry moves towards higher efficiency electrical power generation, all electric aircraft, or zero emissions and more quiet aircraft, fuel cells are sought as the technology that can deliver on these high expectations. The Hybrid Solid Oxide Fuel Cell system combines the fuel cell with a microturbine to obtain up to 70 percent cycle efficiency, and then distributes the electrical power to the loads via a power distribution system. The challenge is to understand the dynamics of this complex multi-discipline system, and design distributed controls that take the system through its operating conditions in a stable and safe manner while maintaining the system performance. This particular system is a power generation and distribution system and the fuel cell and microturbine model fidelity should be compatible with the dynamics of the power distribution system in order to allow proper stability and distributed controls design. A novel modeling approach is proposed for the fuel cell that will allow the fuel cell and the power system to be integrated and designed for stability, distributed controls, and other interface specifications. This investigation shows that for the fuel cell, the voltage characteristic should be modeled, but in addition, conservation equation dynamics, ion diffusion, charge transfer kinetics, and the electron flow inherent impedance should also be included.

Applications of CRISPR/Cas System to Bacterial Metabolic Engineering.

PubMed

Cho, Suhyung; Shin, Jongoh; Cho, Byung-Kwan

2018-04-05

The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas) adaptive immune system has been extensively used for gene editing, including gene deletion, insertion, and replacement in bacterial and eukaryotic cells owing to its simple, rapid, and efficient activities in unprecedented resolution. Furthermore, the CRISPR interference (CRISPRi) system including deactivated Cas9 (dCas9) with inactivated endonuclease activity has been further investigated for regulation of the target gene transiently or constitutively, avoiding cell death by disruption of genome. This review discusses the applications of CRISPR/Cas for genome editing in various bacterial systems and their applications. In particular, CRISPR technology has been used for the production of metabolites of high industrial significance, including biochemical, biofuel, and pharmaceutical products/precursors in bacteria. Here, we focus on methods to increase the productivity and yield/titer scan by controlling metabolic flux through individual or combinatorial use of CRISPR/Cas and CRISPRi systems with introduction of synthetic pathway in industrially common bacteria including Escherichia coli . Further, we discuss additional useful applications of the CRISPR/Cas system, including its use in functional genomics.

Influence of physical activity on the immune system in breast cancer patients during chemotherapy.

PubMed

Schmidt, Thorsten; Jonat, Walter; Wesch, Daniela; Oberg, Hans-Heinrich; Adam-Klages, Sabine; Keller, Lisa; Röcken, Christoph; Mundhenke, Christoph

2018-03-01

Physical activity can impact the immune system in different ways, e.g. by alteration of the humoral and cellular immune response. Physical activity at medium intensity enhances numbers of cytotoxic T cells, NK cells and macrophages in healthy people. The aim of this study was to compare the effects of endurance and resistance training on the immune system in breast cancer patients during adjuvant chemotherapy. In a prospective, controlled and randomized intervention exploratory trial, 12-week supervised endurance or resistance training were compared with usual care twice a week. Endpoints were the absolute numbers of the immune cells such as CD3 + T lymphocytes including CD4 + - and CD8 + , αβ T cells, γδT cells, CD3 - /CD16 + /56 + NK cells and CD19 + B cells, before and after 12 weeks of treatment. Cell numbers were analyzed using fluorescence-activated cell sorting. Despite different physical interventions in all groups immune cell count decreased in CD3 T cells including TCR αβ and CD4 T cells, NK cells and CD19 B cells 12 weeks after initiation of chemotherapy and start of the physical intervention program, while the reduction of γδ T cells and CD8 T cells is less prominent in the RT and UC group. Chemotherapy led to a decrease in nearly all measured immune cells. In this study, physical intervention with endurance or resistance training did not suppress cellular immunity any further. Larger multicenter trials are needed to evaluate the exact impact of sports intervention on immune cell subpopulations.

Optimizing Battery Usage and Management for Long Life

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

Smith, Kandler; Shi, Ying; Wood, Eric

2016-06-16

This presentation discusses the impact of system design factors on battery aging and end of life. Topics include sizing of the state-of-charge operating window, cell balancing, and thermal management systems and their value in reducing pack degradation rates and cell imbalance growth over lifetime.

System and method for charging electrochemical cells in series

DOEpatents

DeLuca, William H.; Hornstra, Jr, Fred; Gelb, George H.; Berman, Baruch; Moede, Larry W.

1980-01-01

A battery charging system capable of equalizing the charge of each individual cell at a selected full charge voltage includes means for regulating charger current to first increase current at a constant rate until a bulk charging level is achieved or until any cell reaches a safe reference voltage. A system controller then begins to decrease the charging rate as long as any cell exceeds the reference voltage until an equalization current level is reached. At this point, the system controller activates a plurality of shunt modules to permit shunting of current around any cell having a voltage exceeding the reference voltage. Leads extending between the battery of cells and shunt modules are time shared to permit alternate shunting of current and voltage monitoring without the voltage drop caused by the shunt current. After each cell has at one time exceeded the reference voltage, the charging current is terminated.

Fuel cell system

DOEpatents

Early, Jack; Kaufman, Arthur; Stawsky, Alfred

1982-01-01

A fuel cell system is comprised of a fuel cell module including sub-stacks of series-connected fuel cells, the sub-stacks being held together in a stacked arrangement with cold plates of a cooling means located between the sub-stacks to function as electrical terminals. The anode and cathode terminals of the sub-stacks are connected in parallel by means of the coolant manifolds which electrically connect selected cold plates. The system may comprise a plurality of the fuel cell modules connected in series. The sub-stacks are designed to provide a voltage output equivalent to the desired voltage demand of a low voltage, high current DC load such as an electrolytic cell to be driven by the fuel cell system. This arrangement in conjunction with switching means can be used to drive a DC electrical load with a total voltage output selected to match that of the load being driven. This arrangement eliminates the need for expensive voltage regulation equipment.

Solar cell array design handbook - The principles and technology of photovoltaic energy conversion

NASA Technical Reports Server (NTRS)

Rauschenbach, H. S.

1980-01-01

Photovoltaic solar cell array design and technology for ground-based and space applications are discussed from the user's point of view. Solar array systems are described, with attention given to array concepts, historical development, applications and performance, and the analysis of array characteristics, circuits, components, performance and reliability is examined. Aspects of solar cell array design considered include the design process, photovoltaic system and detailed array design, and the design of array thermal, radiation shielding and electromagnetic components. Attention is then given to the characteristics and design of the separate components of solar arrays, including the solar cells, optical elements and mechanical elements, and the fabrication, testing, environmental conditions and effects and material properties of arrays and their components are discussed.

Disordered anodes for Ni-metal rechargeable battery

DOEpatents

Young, Kwo-hsiung; Wang, Lixin; Mays, William C.

2016-11-22

An electrochemical cell is provided that includes a structurally and compositionally disordered electrochemically active alloy material as an anode active material with unexpected capacity against a nickel hydroxide based cathode active material. The disordered metal hydroxide alloy includes three or more transition metal elements and is formed in such a way so as to produce the necessary disorder in the overall system. When an anode active material includes nickel as a predominant, the resulting cells represent the first demonstration of a functional Ni/Ni cell.

Fuel cell elements with improved water handling capacity

NASA Technical Reports Server (NTRS)

Kindler, Andrew (Inventor); Lee, Albany (Inventor)

2001-01-01

New fuel cell components for use in liquid feed fuel cell systems are provided. The components include biplates and endplates, having a hydrophilic surface and allow high efficiency operation. Conductive elements and a wicking device also form a part of the fuel cell components of the invention.

Raman spectroscopy for discrimination of neural progenitor cells and their lineages (Conference Presentation)

NASA Astrophysics Data System (ADS)

Chen, Keren; Ong, William; Chew, Sing Yian; Liu, Quan

2017-02-01

Neurological diseases are one of the leading causes of adult disability and they are estimated to cause more deaths than cancer in the elderly population by 2040. Stem cell therapy has shown great potential in treating neurological diseases. However, before cell therapy can be widely adopted in the long term, a number of challenges need to be addressed, including the fundamental research about cellular development of neural progenitor cells. To facilitate the fundamental research of neural progenitor cells, many methods have been developed to identify neural progenitor cells. Although great progress has been made, there is still lack of an effective method to achieve fast, label-free and noninvasive differentiation of neural progenitor cells and their lineages. As a fast, label-free and noninvasive technique, spontaneous Raman spectroscopy has been conducted to characterize many types of stem cells including neural stem cells. However, to our best knowledge, it has not been studied for the discrimination of neural progenitor cells from specific lineages. Here we report the differentiation of neural progenitor cell from their lineages including astrocytes, oligodendrocytes and neurons using spontaneous Raman spectroscopy. Moreover, we also evaluate the influence of system parameters during spectral acquisition on the quality of measured Raman spectra and the accuracy of classification using the spectra, which yield a set of optimal system parameters facilitating future studies.

Fuel cell system including a unit for electrical isolation of a fuel cell stack from a manifold assembly and method therefor

DOEpatents

Kelley; Dana A. , Farooque; Mohammad , Davis; Keith

2007-10-02

A fuel cell system with improved electrical isolation having a fuel cell stack with a positive potential end and a negative potential, a manifold for use in coupling gases to and from a face of the fuel cell stack, an electrical isolating assembly for electrically isolating the manifold from the stack, and a unit for adjusting an electrical potential of the manifold such as to impede the flow of electrolyte from the stack across the isolating assembly.

40 CFR 86.155-98 - Records required; refueling test.

Code of Federal Regulations, 2012 CFR

2012-07-01

...-integrated systems, fuel system (including fuel tank(s) capacity and location), basic engine description... odometer reading. (g) All pertinent instrument information including nozzle and fuel delivery system description. As an alternative, a reference to a vehicle test cell number may be used, with advance approval...

40 CFR 86.155-98 - Records required; refueling test.

Code of Federal Regulations, 2014 CFR

2014-07-01

...-integrated systems, fuel system (including fuel tank(s) capacity and location), basic engine description... odometer reading. (g) All pertinent instrument information including nozzle and fuel delivery system description. As an alternative, a reference to a vehicle test cell number may be used, with advance approval...

40 CFR 86.155-98 - Records required; refueling test.

Code of Federal Regulations, 2013 CFR

2013-07-01

...-integrated systems, fuel system (including fuel tank(s) capacity and location), basic engine description... odometer reading. (g) All pertinent instrument information including nozzle and fuel delivery system description. As an alternative, a reference to a vehicle test cell number may be used, with advance approval...

40 CFR 86.155-98 - Records required; refueling test.

Code of Federal Regulations, 2010 CFR

2010-07-01

...-integrated systems, fuel system (including fuel tank(s) capacity and location), basic engine description... odometer reading. (g) All pertinent instrument information including nozzle and fuel delivery system description. As an alternative, a reference to a vehicle test cell number may be used, with advance approval...

40 CFR 86.155-98 - Records required; refueling test.

Code of Federal Regulations, 2011 CFR

2011-07-01

...-integrated systems, fuel system (including fuel tank(s) capacity and location), basic engine description... odometer reading. (g) All pertinent instrument information including nozzle and fuel delivery system description. As an alternative, a reference to a vehicle test cell number may be used, with advance approval...

ImmunoScenarios: A Game for the Immune System.

ERIC Educational Resources Information Center

Taylor, Mark F.; Jackson, Sally W.

1996-01-01

Describes a board game, ImmunoScenarios, which was developed to reinforce the ideas about the immune system discussed in lecture classes. Emphasizes important characteristics of the body's specific defense system including specificity, cooperation among various cells, and memory. Includes directions for playing, student handouts, and scenarios.…

Tissue engineering bioreactor systems for applying physical and electrical stimulations to cells.

PubMed

Jin, GyuHyun; Yang, Gi-Hoon; Kim, GeunHyung

2015-05-01

Bioreactor systems in tissue engineering applications provide various types of stimulation to mimic the tissues in vitro and in vivo. Various bioreactors have been designed to induce high cellular activities, including initial cell attachment, cell growth, and differentiation. Although cell-stimulation processes exert mostly positive effects on cellular responses, in some cases such stimulation can also have a negative effect on cultured cells. In this review, we discuss various types of bioreactor and the positive and negative effects of stimulation (physical, chemical, and electrical) on various cultured cell types. © 2014 Wiley Periodicals, Inc.

GEM System: automatic prototyping of cell-wide metabolic pathway models from genomes.

PubMed

Arakawa, Kazuharu; Yamada, Yohei; Shinoda, Kosaku; Nakayama, Yoichi; Tomita, Masaru

2006-03-23

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. 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. 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.

Development of Genome Engineering Tools from Plant-Specific PPR Proteins Using Animal Cultured Cells.

PubMed

Kobayashi, Takehito; Yagi, Yusuke; Nakamura, Takahiro

2016-01-01

The pentatricopeptide repeat (PPR) motif is a sequence-specific RNA/DNA-binding module. Elucidation of the RNA/DNA recognition mechanism has enabled engineering of PPR motifs as new RNA/DNA manipulation tools in living cells, including for genome editing. However, the biochemical characteristics of PPR proteins remain unknown, mostly due to the instability and/or unfolding propensities of PPR proteins in heterologous expression systems such as bacteria and yeast. To overcome this issue, we constructed reporter systems using animal cultured cells. The cell-based system has highly attractive features for PPR engineering: robust eukaryotic gene expression; availability of various vectors, reagents, and antibodies; highly efficient DNA delivery ratio (>80 %); and rapid, high-throughput data production. In this chapter, we introduce an example of such reporter systems: a PPR-based sequence-specific translational activation system. The cell-based reporter system can be applied to characterize plant genes of interested and to PPR engineering.

Friend or foe: the dichotomous impact of T cells on neuro-de/re-generation during aging.

PubMed

Coder, Brandon; Wang, Weikan; Wang, Liefeng; Wu, Zhongdao; Zhuge, Qichuan; Su, Dong-Ming

2017-01-24

The interaction between T cells and the central nervous system (CNS) in homeostasis and injury has been recognized being both pathogenic (CD4+ T-helper 1 - Th1, Th17 and γδT) and ameliorative (Th2 and regulatory T cells - Tregs). However, in-depth studies aimed to elucidate the precise in the aged microenvironment and the dichotomous role of Tregs have just begun and many aspects remain unclear. This is due, not only to a mutual dependency and reciprocal causation of alterations and diseases between the nervous and T cell immune systems, but also to an inconsistent aging of the two systems, which dynamically changes with CNS injury/recovery and/or aging process. Cellular immune system aging, particularly immunosenescence and T cell aging initiated by thymic involution - sources of chronic inflammation in the elderly (termed inflammaging), potentially induces an acceleration of brain aging and memory loss. In turn, aging of the brain via neuro-endocrine-immune network drives total body systemic aging, including that of the immune system. Therefore, immunotherapeutics including vaccination and "protective autoimmunity" provide promising means to rejuvenate neuro-inflammatory disorders and repair CNS acute injury and chronic neuro-degeneration. We review the current understanding and recent discoveries linking the aging immune system with CNS injury and neuro-degeneration. Additionally, we discuss potential recovery and rejuvenation strategies, focusing on targeting the aging T cell immune system in an effort to alleviate acute brain injury and chronic neuro-degeneration during aging, via the "thymus-inflammaging-neurodegeneration axis".

Friend or foe: the dichotomous impact of T cells on neuro-de/re-generation during aging

PubMed Central

Wang, Liefeng; Wu, Zhongdao; Zhuge, Qichuan; Su, Dong-Ming

2017-01-01

The interaction between T cells and the central nervous system (CNS) in homeostasis and injury has been recognized being both pathogenic (CD4+ T-helper 1 - Th1, Th17 and γδT) and ameliorative (Th2 and regulatory T cells - Tregs). However, in-depth studies aimed to elucidate the precise in the aged microenvironment and the dichotomous role of Tregs have just begun and many aspects remain unclear. This is due, not only to a mutual dependency and reciprocal causation of alterations and diseases between the nervous and T cell immune systems, but also to an inconsistent aging of the two systems, which dynamically changes with CNS injury/recovery and/or aging process. Cellular immune system aging, particularly immunosenescence and T cell aging initiated by thymic involution - sources of chronic inflammation in the elderly (termed inflammaging), potentially induces an acceleration of brain aging and memory loss. In turn, aging of the brain via neuro-endocrine-immune network drives total body systemic aging, including that of the immune system. Therefore, immunotherapeutics including vaccination and “protective autoimmunity” provide promising means to rejuvenate neuro-inflammatory disorders and repair CNS acute injury and chronic neuro-degeneration. We review the current understanding and recent discoveries linking the aging immune system with CNS injury and neuro-degeneration. Additionally, we discuss potential recovery and rejuvenation strategies, focusing on targeting the aging T cell immune system in an effort to alleviate acute brain injury and chronic neuro-degeneration during aging, via the “thymus-inflammaging-neurodegeneration axis”. PMID:27738345

Mechanical dynamics in live cells and fluorescence-based force/tension sensors

PubMed Central

Yang, Chao; Zhang, Xiaohan; Guo, Yichen; Meng, Fanjie; Sachs, Frederick; Guo, Jun

2016-01-01

Three signaling systems play the fundamental roles in modulating cell activities: chemical, electrical, and mechanical. While the former two are well studied, the mechanical signaling system is still elusive because of the lack of methods to measure structural forces in real time at cellular and subcellular levels. Indeed, almost all biological processes are responsive to modulation by mechanical forces that trigger dispersive downstream electrical and biochemical pathways. Communication among the three systems is essential to make cells and tissues receptive to environmental changes. Cells have evolved many sophisticated mechanisms for the generation, perception and transduction of mechanical forces, including motor proteins and mechanosensors. In this review, we introduce some background information about mechanical dynamics in live cells, including the ubiquitous mechanical activity, various types of mechanical stimuli exerted on cells and the different mechanosensors. We also summarize recent results obtained using genetically encoded FRET (fluorescence resonance energy transfer)-based force/tension sensors; a new technique used to measure mechanical forces in structural proteins. The sensors have been incorporated into many specific structural proteins and have measured the force gradients in real time within live cells, tissues, and animals. PMID:25958335

An improved out-cell to in-cell rapid transfer system at the HFEF-south

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

Bacca, J.P.; Sherman, E.K.

1990-01-01

The Argonne National Laboratory (ANL) Hot Fuel Examination Facility-South (HFEF-S), located at the ANL-West site of the Idaho National Engineering Laboratory, is currently undergoing extensive refurbishment and modifications in preparation for its use, beginning in 1991, in demonstrating remote recycling of fast reactor, metal-alloy fuel as part of the US Department of Energy liquid-metal reactor, Integral Fast Reactor (IFR) program. Included in these improvements to HFEF-S is a new, small-item, rapid transfer system (RTS). When installed, this system will enable the rapid transfer of small items from the hot-cell exterior into the argon cell (argon-gas atmosphere) of the facility withoutmore » necessitating the use of time-consuming and laborious procedures. The new RTS will also provide another important function associated with HFEF-S hot-cell operation in the IFR Fuel Recycle Program; namely, the rapid insertion of clean, radioactive contamination-measuring smear paper specimens into the hot cells for area surveys, and the expedited removal of these contaminated (including alpha as well as beta/gamma contamination) smears from the argon cell for transfer to an adjacent health physics field laboratory in the facility for nuclear contamination/radiation counting.« less

Stem cells with potential to generate insulin producing cells in man.

PubMed

Zulewski, Henryk

2006-10-14

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Stem cells with potential to generate insulin-producing cells in man.

PubMed

Zulewski, Henryk

2007-03-02

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Miming the cancer-immune system competition by kinetic Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Bianca, Carlo; Lemarchand, Annie

2016-10-01

In order to mimic the interactions between cancer and the immune system at cell scale, we propose a minimal model of cell interactions that is similar to a chemical mechanism including autocatalytic steps. The cells are supposed to bear a quantity called activity that may increase during the interactions. The fluctuations of cell activity are controlled by a so-called thermostat. We develop a kinetic Monte Carlo algorithm to simulate the cell interactions and thermalization of cell activity. The model is able to reproduce the well-known behavior of tumors treated by immunotherapy: the first apparent elimination of the tumor by the immune system is followed by a long equilibrium period and the final escape of cancer from immunosurveillance.

The 1982 Goddard Space Flight Center Battery Workshop

NASA Technical Reports Server (NTRS)

Halpert, G. (Editor)

1983-01-01

Various topics concerned with advanced battery technology are addressed including lithium cell and battery safety developments, mathematical modelling, charge control of aerospace power systems, and the application of nickel hydrogen cells/batteries vis-a-vis nickel cadmium cells/batteries.

Doxorubicin

MedlinePlus

... non-Hodgkin's lymphoma (cancer that begins in the cells of the immune system); and certain types of leukemia (cancer of the white blood cells), including acute lymphoblastic leukemia (ALL) and acute myeloid ...

An Analysis for Capital Expenditure Decisions at a Naval Regional Medical Center.

DTIC Science & Technology

1981-12-01

Service Equipment Review Committee 1. Portable defibrilator Computed tomographic scanner and cardioscope 2. ECG cart Automated blood cell counter 3. Gas...system sterilizer Gas system sterilizer 4. Automated blood cell Portable defibrilator and counter cardioscope 5. Computed tomographic ECG cart scanner...dictating and automated typing) systems. e. Filing equipment f. Automatic data processing equipment including data communications equipment. g

Advanced systemic mastocytosis: from molecular and genetic progress to clinical practice.

PubMed

Ustun, Celalettin; Arock, Michel; Kluin-Nelemans, Hanneke C; Reiter, Andreas; Sperr, Wolfgang R; George, Tracy; Horny, Hans-Peter; Hartmann, Karin; Sotlar, Karl; Damaj, Gandhi; Hermine, Olivier; Verstovsek, Srdan; Metcalfe, Dean D; Gotlib, Jason; Akin, Cem; Valent, Peter

2016-10-01

Systemic mastocytosis is a heterogeneous disease characterized by the accumulation of neoplastic mast cells in the bone marrow and other organ organs/tissues. Mutations in KIT, most frequently KIT D816V, are detected in over 80% of all systemic mastocytosis patients. While most systemic mastocytosis patients suffer from an indolent disease variant, some present with more aggressive variants, collectively called "advanced systemic mastocytosis", which include aggressive systemic mastocytosis, systemic mastocytosis with an associated hematologic, clonal non mast cell-lineage disease, and mast cell leukemia. Whereas patients with indolent systemic mastocytosis have a near normal life expectancy, patients with advanced systemic mastocytosis have a reduced life expectancy. Although cladribine and interferon-alpha are of benefit in a group of patients with advanced systemic mastocytosis, no curative therapy is available for these patients except possible allogeneic hematopoietic stem cell transplantation. Recent studies have also revealed additional somatic defects (apart from mutations in KIT) in a majority of patients with advanced systemic mastocytosis. These include TET2, SRSF2, ASXL1, RUNX1, JAK2, and/or RAS mutations, which may adversely impact prognosis and survival in particular systemic mastocytosis with an associated hematological neoplasm. In addition, several additional signaling molecules involved in the abnormal proliferation of mast cells in systemic mastocytosis have been identified. These advances have led to a better understanding of the biology of advanced systemic mastocytosis and to the development of new targeted treatment concepts. Herein, we review the biology and pathogenesis of advanced systemic mastocytosis, with a special focus on novel molecular findings as well as current and evolving therapeutic options. Copyright© Ferrata Storti Foundation.

Statistical Characterization of 18650-Format Lithium-Ion Cell Thermal Runaway Energy Distributions

NASA Technical Reports Server (NTRS)

Walker, William Q.; Rickman, Steven; Darst, John; Finegan, Donal; Bayles, Gary; Darcy, Eric

2017-01-01

Effective thermal management systems, designed to handle the impacts of thermal runaway (TR) and to prevent cell-to-cell propagation, are key to safe operation of lithium-ion (Li-ion) battery assemblies. Critical factors for optimizing these systems include the total energy released during a single cell TR event and the fraction of the total energy that is released through the cell casing vs. through the ejecta material. A unique calorimeter was utilized to examine the TR behavior of a statistically significant number of 18650-format Li-ion cells with varying manufacturers, chemistries, and capacities. The calorimeter was designed to contain the TR energy in a format conducive to discerning the fractions of energy released through the cell casing vs. through the ejecta material. Other benefits of this calorimeter included the ability to rapidly test of large quantities of cells and the intentional minimization of secondary combustion effects. High energy (270 Wh/kg) and moderate energy (200 Wh/kg) 18650 cells were tested. Some of the cells had an imbedded short circuit (ISC) device installed to aid in the examination of TR mechanisms under more realistic conditions. Other variations included cells with bottom vent (BV) features and cells with thin casings (0.22 1/4m). After combining the data gathered with the calorimeter, a statistical approach was used to examine the probability of certain TR behavior, and the associated energy distributions, as a function of capacity, venting features, cell casing thickness and temperature.

Array Automated Assembly Task Low Cost Silicon Solar Array Project, Phase 2

NASA Technical Reports Server (NTRS)

Rhee, S. S.; Jones, G. T.; Allison, K. L.

1978-01-01

Progress in the development of solar cells and module process steps for low-cost solar arrays is reported. Specific topics covered include: (1) a system to automatically measure solar cell electrical performance parameters; (2) automation of wafer surface preparation, printing, and plating; (3) laser inspection of mechanical defects of solar cells; and (4) a silicon antireflection coating system. Two solar cell process steps, laser trimming and holing automation and spray-on dopant junction formation, are described.

The Yin and Yang of YY1 in the nervous system

PubMed Central

He, Ye; Casaccia-Bonnefil, Patrizia

2008-01-01

The transcription factor Yin Yang 1 (YY1) is a multifunctional protein that can activate or repress gene expression depending on the cellular context. YY1 is ubiquitously expressed and highly conserved between species. However its role varies in diverse cell types and includes proliferation, differentiation and apoptosis. This review will focus on the function of YY1 in the nervous system including its role in neural development, neuronal function, developmental myelination and neurological disease. The multiple functions of YY1 in distinct cell types are reviewed and the possible mechanisms underlying the cell specificity for these functions are discussed. PMID:18485096

Modeling Ebola Virus Genome Replication and Transcription with Minigenome Systems.

PubMed

Cressey, Tessa; Brauburger, Kristina; Mühlberger, Elke

2017-01-01

In this chapter, we describe the minigenome system for Ebola virus (EBOV), which reconstitutes EBOV polymerase activity in cells and can be used to model viral genome replication and transcription. This protocol comprises all steps including cell culture, plasmid preparation, transfection, and luciferase reporter assay readout.

High-rate lithium thionyl chloride cells

NASA Technical Reports Server (NTRS)

Goebel, F.

1982-01-01

A high-rate C cell with disc electrodes was developed to demonstrate current rates which are comparable to other primary systems. The tests performed established the limits of abuse beyond which the cell becomes hazardous. Tests include: impact, shock, and vibration tests; temperature cycling; and salt water immersion of fresh cells.

Brain mast cells link the immune system to anxiety-like behavior

PubMed Central

Nautiyal, Katherine M.; Ribeiro, Ana C.; Pfaff, Donald W.; Silver, Rae

2008-01-01

Mast cells are resident in the brain and contain numerous mediators, including neurotransmitters, cytokines, and chemokines, that are released in response to a variety of natural and pharmacological triggers. The number of mast cells in the brain fluctuates with stress and various behavioral and endocrine states. These properties suggest that mast cells are poised to influence neural systems underlying behavior. Using genetic and pharmacological loss-of-function models we performed a behavioral screen for arousal responses including emotionality, locomotor, and sensory components. We found that mast cell deficient KitW−sh/W−sh (sash−/−) mice had a greater anxiety-like phenotype than WT and heterozygote littermate control animals in the open field arena and elevated plus maze. Second, we show that blockade of brain, but not peripheral, mast cell activation increased anxiety-like behavior. Taken together, the data implicate brain mast cells in the modulation of anxiety-like behavior and provide evidence for the behavioral importance of neuroimmune links. PMID:19004805

Brain mast cells link the immune system to anxiety-like behavior.

PubMed

Nautiyal, Katherine M; Ribeiro, Ana C; Pfaff, Donald W; Silver, Rae

2008-11-18

Mast cells are resident in the brain and contain numerous mediators, including neurotransmitters, cytokines, and chemokines, that are released in response to a variety of natural and pharmacological triggers. The number of mast cells in the brain fluctuates with stress and various behavioral and endocrine states. These properties suggest that mast cells are poised to influence neural systems underlying behavior. Using genetic and pharmacological loss-of-function models we performed a behavioral screen for arousal responses including emotionality, locomotor, and sensory components. We found that mast cell deficient Kit(W-sh/W-sh) (sash(-/-)) mice had a greater anxiety-like phenotype than WT and heterozygote littermate control animals in the open field arena and elevated plus maze. Second, we show that blockade of brain, but not peripheral, mast cell activation increased anxiety-like behavior. Taken together, the data implicate brain mast cells in the modulation of anxiety-like behavior and provide evidence for the behavioral importance of neuroimmune links.

An integrated view of suppressor T cell subsets in immunoregulation

PubMed Central

Jiang, Hong; Chess, Leonard

2004-01-01

The immune system evolved to protect organisms from a virtually infinite variety of disease-causing agents but to avoid harmful responses to self. Because immune protective mechanisms include the elaboration of potent inflammatory molecules, antibodies, and killer cell activation — which together can not only destroy invading microorganisms, pathogenic autoreactive cells, and tumors, but also mortally injure normal cells — the immune system is inherently a “double-edged sword” and must be tightly regulated. Immune response regulation includes homeostatic mechanisms intrinsic to the activation and differentiation of antigen-triggered immunocompetent cells and extrinsic mechanisms mediated by suppressor cells. This review series will focus on recent advances indicating that distinct subsets of regulatory CD4+ and CD8+ T cells as well as NK T cells control the outgrowth of potentially pathogenic antigen-reactive T cells and will highlight the evidence that these suppressor T cells may play potentially important clinical roles in preventing and treating immune-mediated disease. Here we provide a historical overview of suppressor cells and the experimental basis for the existence of functionally and phenotypically distinct suppressor subsets. Finally, we will speculate on how the distinct suppressor cell subsets may function in concert to regulate immune responses. PMID:15520848

Synthetic Biology and Microbial Fuel Cells: Towards Self-Sustaining Life Support Systems

NASA Technical Reports Server (NTRS)

Hogan, John Andrew

2014-01-01

NASA ARC and the J. Craig Venter Institute (JCVI) collaborated to investigate the development of advanced microbial fuels cells (MFCs) for biological wastewater treatment and electricity production (electrogenesis). Synthetic biology techniques and integrated hardware advances were investigated to increase system efficiency and robustness, with the intent of increasing power self-sufficiency and potential product formation from carbon dioxide. MFCs possess numerous advantages for space missions, including rapid processing, reduced biomass and effective removal of organics, nitrogen and phosphorus. Project efforts include developing space-based MFC concepts, integration analyses, increasing energy efficiency, and investigating novel bioelectrochemical system applications

A single-cell and feeder-free culture system for monkey embryonic stem cells.

PubMed

Ono, Takashi; Suzuki, Yutaka; Kato, Yosuke; Fujita, Risako; Araki, Toshihiro; Yamashita, Tomoko; Kato, Hidemasa; Torii, Ryuzo; Sato, Naoya

2014-01-01

Primate pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), hold great potential for research and application in regenerative medicine and drug discovery. To maximize primate PSC potential, a practical system is required for generating desired functional cells and reproducible differentiation techniques. Much progress regarding their culture systems has been reported to date; however, better methods would still be required for their practical use, particularly in industrial and clinical fields. Here we report a new single-cell and feeder-free culture system for primate PSCs, the key feature of which is an originally formulated serum-free medium containing FGF and activin. In this culture system, cynomolgus monkey ESCs can be passaged many times by single-cell dissociation with traditional trypsin treatment and can be propagated with a high proliferation rate as a monolayer without any feeder cells; further, typical PSC properties and genomic stability can be retained. In addition, it has been demonstrated that monkey ESCs maintained in the culture system can be used for various experiments such as in vitro differentiation and gene manipulation. Thus, compared with the conventional culture system, monkey ESCs grown in the aforementioned culture system can serve as a cell source with the following practical advantages: simple, stable, and easy cell maintenance; gene manipulation; cryopreservation; and desired differentiation. We propose that this culture system can serve as a reliable platform to prepare primate PSCs useful for future research and application.

A fully defined and scalable 3D culture system for human pluripotent stem cell expansion and differentiation

NASA Astrophysics Data System (ADS)

Lei, Yuguo; Schaffer, David V.

2013-12-01

Human pluripotent stem cells (hPSCs), including human embryonic stem cells and induced pluripotent stem cells, are promising for numerous biomedical applications, such as cell replacement therapies, tissue and whole-organ engineering, and high-throughput pharmacology and toxicology screening. Each of these applications requires large numbers of cells of high quality; however, the scalable expansion and differentiation of hPSCs, especially for clinical utilization, remains a challenge. We report a simple, defined, efficient, scalable, and good manufacturing practice-compatible 3D culture system for hPSC expansion and differentiation. It employs a thermoresponsive hydrogel that combines easy manipulation and completely defined conditions, free of any human- or animal-derived factors, and entailing only recombinant protein factors. Under an optimized protocol, the 3D system enables long-term, serial expansion of multiple hPSCs lines with a high expansion rate (∼20-fold per 5-d passage, for a 1072-fold expansion over 280 d), yield (∼2.0 × 107 cells per mL of hydrogel), and purity (∼95% Oct4+), even with single-cell inoculation, all of which offer considerable advantages relative to current approaches. Moreover, the system enabled 3D directed differentiation of hPSCs into multiple lineages, including dopaminergic neuron progenitors with a yield of ∼8 × 107 dopaminergic progenitors per mL of hydrogel and ∼80-fold expansion by the end of a 15-d derivation. This versatile system may be useful at numerous scales, from basic biological investigation to clinical development.

Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium.

PubMed

Kellogg, Stephanie L; Little, Jaime L; Hoff, Jessica S; Kristich, Christopher J

2017-05-01

Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis , exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. Copyright © 2017 American Society for Microbiology.

Requirement of the CroRS Two-Component System for Resistance to Cell Wall-Targeting Antimicrobials in Enterococcus faecium

PubMed Central

Kellogg, Stephanie L.; Little, Jaime L.; Hoff, Jessica S.

2017-01-01

ABSTRACT Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis. Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis. Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis, exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium. Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. PMID:28223383

The intestinal microbiome and skeletal fitness: connecting bugs and bones

PubMed Central

Charles, Julia F.; Ermann, Joerg; Aliprantis, Antonios O.

2015-01-01

Recent advances have dramatically increased our understanding of how organ systems interact. This has been especially true for immunology and bone biology, where the term “osteoimmunology” was coined to capture this relationship. The importance of the microbiome to the immune system has also emerged as a driver of health and disease. It makes sense therefore to ask the question: how does the intestinal microbiome influence bone biology and does dysbiosis promote bone disease? Surprisingly, few studies have analyzed this connection. A broader interpretation of this question reveals many mechanisms whereby the microbiome may affect bone cells. These include effects of the microbiome on immune cells, including myeloid progenitors and Th17 cells, as well as steroid hormones, fatty acids, serotonin and vitamin D. As mechanistic interactions of the microbiome and skeletal system are revealed within and without the immune system, novel strategies to optimize skeletal fitness may emerge. PMID:25840106

The Histochemistry and Cell Biology omnium-gatherum: the year 2015 in review.

PubMed

Taatjes, Douglas J; Roth, Jürgen

2016-03-01

We provide here our annual review/synopsis of all of the articles published in Histochemistry and Cell Biology (HCB) for the preceding year. In 2015, HCB published 102 articles, representing a wide variety of topics and methodologies. For ease of access to these differing topics, we have created categories, as determined by the types of articles presented to provide a quick index representing the general areas covered. This year, these categories include: (1) advances in methodologies; (2) molecules in health and disease; (3) organelles, subcellular structures, and compartments; (4) the nucleus; (5) stem cells and tissue engineering; (6) cell cultures: properties and capabilities; (7) connective tissues and extracellular matrix; (8) developmental biology; (9) nervous system; (10) musculoskeletal system; (11) respiratory and cardiovascular system; (12) liver and gastrointestinal tract; and (13) male and female reproductive systems. Of note, the categories proceed from methods development, to molecules, intracellular compartments, stem cells and cell culture, extracellular matrix, developmental biology, and finishing with various organ systems, hopefully presenting a logical journey from methods to organismal molecules, cells, and whole tissue systems.

Bluetooth wireless monitoring, diagnosis and calibration interface for control system of fuel cell bus in Olympic demonstration

NASA Astrophysics Data System (ADS)

Hua, Jianfeng; Lin, Xinfan; Xu, Liangfei; Li, Jianqiu; Ouyang, Minggao

With the worldwide deterioration of the natural environment and the fossil fuel crisis, the possible commercialization of fuel cell vehicles has become a hot topic. In July 2008, Beijing started a clean public transportation plan for the 29th Olympic games. Three fuel cell city buses and 497 other low-emission vehicles are now serving the Olympic core area and Beijing urban areas. The fuel cell buses will operate along a fixed bus line for 1 year as a public demonstration of green energy vehicles. Due to the specialized nature of fuel cell engines and electrified power-train systems, measurement, monitoring and calibration devices are indispensable. Based on the latest Bluetooth wireless technology, a novel Bluetooth universal data interface was developed for the control system of the fuel cell city bus. On this platform, a series of wireless portable control auxiliary systems have been implemented, including wireless calibration, a monitoring system and an in-system programming platform, all of which are ensuring normal operation of the fuel cell buses used in the demonstration.

Regenerative Fuel Cells for Space Power and Energy Conversion (NaBH4/H2O2 Fuel Cell Development)

NASA Technical Reports Server (NTRS)

Valdez, Thomas I.; Miley, George H.; Luo, Nie; Burton, Rodney; Mather, Joseph; Hawkins, Glenn; Byrd, Ethan; Gu, Lifeng; Shrestha, Prajakti Joshi

2006-01-01

A viewgraph presentation describing hydrogen peroxide and sodium borohydride development is shown. The topics include: 1) Motivation; 2) The Sodium Borohydride Fuel Cell; 3) Fuel Cell Comparisons; 4) MEA Optimization; 5) 500-Watt Stack Testing; 6) System Modeling: Fuel Cell Power Source for Lunar Rovers; and 7) Conclusions

UML as a cell and biochemistry modeling language.

PubMed

Webb, Ken; White, Tony

2005-06-01

The systems biology community is building increasingly complex models and simulations of cells and other biological entities, and are beginning to look at alternatives to traditional representations such as those provided by ordinary differential equations (ODE). The lessons learned over the years by the software development community in designing and building increasingly complex telecommunication and other commercial real-time reactive systems, can be advantageously applied to the problems of modeling in the biology domain. Making use of the object-oriented (OO) paradigm, the unified modeling language (UML) and Real-Time Object-Oriented Modeling (ROOM) visual formalisms, and the Rational Rose RealTime (RRT) visual modeling tool, we describe a multi-step process we have used to construct top-down models of cells and cell aggregates. The simple example model described in this paper includes membranes with lipid bilayers, multiple compartments including a variable number of mitochondria, substrate molecules, enzymes with reaction rules, and metabolic pathways. We demonstrate the relevance of abstraction, reuse, objects, classes, component and inheritance hierarchies, multiplicity, visual modeling, and other current software development best practices. We show how it is possible to start with a direct diagrammatic representation of a biological structure such as a cell, using terminology familiar to biologists, and by following a process of gradually adding more and more detail, arrive at a system with structure and behavior of arbitrary complexity that can run and be observed on a computer. We discuss our CellAK (Cell Assembly Kit) approach in terms of features found in SBML, CellML, E-CELL, Gepasi, Jarnac, StochSim, Virtual Cell, and membrane computing systems.

Hybrid Solid Oxide Fuel Cell/Gas Turbine System Design for High Altitude Long Endurance Aerospace Missions

NASA Technical Reports Server (NTRS)

Himansu, Ananda; Freeh, Joshua E.; Steffen, Christopher J., Jr.; Tornabene, Robert T.; Wang, Xiao-Yen J.

2006-01-01

A system level analysis, inclusive of mass, is carried out for a cryogenic hydrogen fueled hybrid solid oxide fuel cell and bottoming gas turbine (SOFC/GT) power system. The system is designed to provide primary or secondary electrical power for an unmanned aerial vehicle (UAV) over a high altitude, long endurance mission. The net power level and altitude are parametrically varied to examine their effect on total system mass. Some of the more important technology parameters, including turbomachinery efficiencies and the SOFC area specific resistance, are also studied for their effect on total system mass. Finally, two different solid oxide cell designs are compared to show the importance of the individual solid oxide cell design on the overall system. We show that for long mission durations of 10 days or more, the fuel mass savings resulting from the high efficiency of a SOFC/GT system more than offset the larger powerplant mass resulting from the low specific power of the SOFC/GT system. These missions therefore favor high efficiency, low power density systems, characteristics typical of fuel cell systems in general.

NASA PEMFC Development Background and History

NASA Technical Reports Server (NTRS)

Hoberecht, Mark

2011-01-01

NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. Four vendors have designed and fabricated non-flow-through fuel cell stacks under NASA funding. One of these vendors is considered the "baseline" vendor, and the remaining three vendors are competing for the "alternate" role. Each has undergone testing of their stack hardware integrated with a NASA balance-of-plant. Future Exploration applications for this hardware include primary fuel cells for a Lunar Lander and regenerative fuel cells for Surface Systems.

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

PubMed Central

Akopian, Veronika; 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.; McKay, Ronald D. G.; Miyazaki, Takamichi; Nakatsuji, Norio; Oh, Steve K. W.; Pera, Martin F.; Rossant, Janet; Stacey, Glyn N.; Suemori, Hirofumi

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 propagation in the presence of Knockout Serum Replacer, FGF-2, and mouse embryonic fibroblast feeder cell layers serving as a positive control. The cultures were assessed for up to ten passages for attachment, death, and differentiated morphology by phase contrast microscopy, for growth by serial cell counts, and for maintenance of stem cell surface marker expression by flow cytometry. Of the eight culture systems, only the control and those based on two commercial media, mTeSR1 and STEMPRO, supported maintenance of most cell lines for ten passages. Cultures grown in the remaining media failed before this point due to lack of attachment, cell death, or overt cell differentiation. Possible explanations for relative success of the commercial formulations in this study, and the lack of success with other formulations from academic groups compared to previously published results, include: the complex combination of growth factors present in the commercial preparations; improved development, manufacture, and quality control in the commercial products; differences in epigenetic adaptation to culture in vitro between different ES cell lines grown in different laboratories. PMID:20186512

A model-based approach for automated in vitro cell tracking and chemotaxis analyses.

PubMed

Debeir, Olivier; Camby, Isabelle; Kiss, Robert; Van Ham, Philippe; Decaestecker, Christine

2004-07-01

Chemotaxis may be studied in two main ways: 1) counting cells passing through an insert (e.g., using Boyden chambers), and 2) directly observing cell cultures (e.g., using Dunn chambers), both in response to stationary concentration gradients. This article promotes the use of Dunn chambers and in vitro cell-tracking, achieved by video microscopy coupled with automatic image analysis software, in order to extract quantitative and qualitative measurements characterizing the response of cells to a diffusible chemical agent. Previously, we set up a videomicroscopy system coupled with image analysis software that was able to compute cell trajectories from in vitro cell cultures. In the present study, we are introducing a new software increasing the application field of this system to chemotaxis studies. This software is based on an adapted version of the active contour methodology, enabling each cell to be efficiently tracked for hours and resulting in detailed descriptions of individual cell trajectories. The major advantages of this method come from an improved robustness with respect to variability in cell morphologies between different cell lines and dynamical changes in cell shape during cell migration. Moreover, the software includes a very small number of parameters which do not require overly sensitive tuning. Finally, the running time of the software is very short, allowing improved possibilities in acquisition frequency and, consequently, improved descriptions of complex cell trajectories, i.e. trajectories including cell division and cell crossing. We validated this software on several artificial and real cell culture experiments in Dunn chambers also including comparisons with manual (human-controlled) analyses. We developed new software and data analysis tools for automated cell tracking which enable cell chemotaxis to be efficiently analyzed. Copyright 2004 Wiley-Liss, Inc.

A Theoretical Solid Oxide Fuel Cell Model for Systems Controls and Stability Design

NASA Technical Reports Server (NTRS)

Kopasakis, George; Brinson, Thomas; Credle, Sydni

2008-01-01

As the aviation industry moves toward higher efficiency electrical power generation, all electric aircraft, or zero emissions and more quiet aircraft, fuel cells are sought as the technology that can deliver on these high expectations. The hybrid solid oxide fuel cell system combines the fuel cell with a micro-turbine to obtain up to 70% cycle efficiency, and then distributes the electrical power to the loads via a power distribution system. The challenge is to understand the dynamics of this complex multidiscipline system and the design distributed controls that take the system through its operating conditions in a stable and safe manner while maintaining the system performance. This particular system is a power generation and a distribution system, and the fuel cell and micro-turbine model fidelity should be compatible with the dynamics of the power distribution system in order to allow proper stability and distributed controls design. The novelty in this paper is that, first, the case is made why a high fidelity fuel cell mode is needed for systems control and stability designs. Second, a novel modeling approach is proposed for the fuel cell that will allow the fuel cell and the power system to be integrated and designed for stability, distributed controls, and other interface specifications. This investigation shows that for the fuel cell, the voltage characteristic should be modeled but in addition, conservation equation dynamics, ion diffusion, charge transfer kinetics, and the electron flow inherent impedance should also be included.

Development and biological applications of optical tweezers and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Xie, Chang'an

Optical tweezers is a three-dimensional manipulation tool that employs a gradient force that originates from the single highly focused laser beam. Raman spectroscopy is a molecular analytical tool that can give a highly unique "fingerprint" for each substance by measuring the unique vibrations of its molecules. The combination of these two optical techniques offers a new tool for the manipulation and identification of single biological cells and microscopic particles. In this thesis, we designed and implemented a Laser-Tweezers-Raman-Spectroscopy (LTRS) system, also called the Raman-tweezers, for the simultaneous capture and analysis of both biological particles and non-biological particles. We show that microparticles can be conveniently captured at the focus of a laser beam and the Raman spectra of trapped particles can be acquired with high quality. The LTRS system overcomes the intrinsic Brownian motion and cell motility of microparticles in solution and provides a promising tool for in situ identifying suspicious agents. In order to increase the signal to noise ratio, several schemes were employed in LTRS system to reduce the blank noise and the fluorescence signal coming from analytes and the surrounding background. These techniques include near-infrared excitation, optical levitation, confocal microscopy, and frequency-shifted Raman difference. The LTRS system has been applied for the study in cell biology at the single cell level. With the built Raman-tweezers system, we studied the dynamic physiological processes of single living cells, including cell cycle, the transcription and translation of recombinant protein in transgenic yeast cells and the T cell activation. We also studied cell damage and associated biochemical processes in optical traps, UV radiations, and evaluated heating by near-infrared Raman spectroscopy. These studies show that the Raman-tweezers system is feasible to provide rapid and reliable diagnosis of cellular disorders and can be used as a valuable tool to study cellular processes within single living cells or intracellular organelles and may aid research in molecular and cellular biology.

Hybrid power management system and method

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J. (Inventor)

2007-01-01

A system and method for hybrid power management. The system includes photovoltaic cells, ultracapacitors, and pulse generators. In one embodiment, the hybrid power management system is used to provide power for a highway safety flasher.

Hybrid Power Management System and Method

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J. (Inventor)

2008-01-01

A system and method for hybrid power management. The system includes photovoltaic cells, ultracapacitors, and pulse generators. In one embodiment, the hybrid power management system is used to provide power for a highway safety flasher.

Compressed gas fuel storage system

DOEpatents

Wozniak, John J.; Tiller, Dale B.; Wienhold, Paul D.; Hildebrand, Richard J.

2001-01-01

A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

Whole-cell biocomputing

NASA Technical Reports Server (NTRS)

Simpson, M. L.; Sayler, G. S.; Fleming, J. T.; Applegate, B.

2001-01-01

The ability to manipulate systems on the molecular scale naturally leads to speculation about the rational design of molecular-scale machines. Cells might be the ultimate molecular-scale machines and our ability to engineer them is relatively advanced when compared with our ability to control the synthesis and direct the assembly of man-made materials. Indeed, engineered whole cells deployed in biosensors can be considered one of the practical successes of molecular-scale devices. However, these devices explore only a small portion of cellular functionality. Individual cells or self-organized groups of cells perform extremely complex functions that include sensing, communication, navigation, cooperation and even fabrication of synthetic nanoscopic materials. In natural systems, these capabilities are controlled by complex genetic regulatory circuits, which are only partially understood and not readily accessible for use in engineered systems. Here, we focus on efforts to mimic the functionality of man-made information-processing systems within whole cells.

System and method for networking electrochemical devices

DOEpatents

Williams, Mark C.; Wimer, John G.; Archer, David H.

1995-01-01

An improved electrochemically active system and method including a plurality of electrochemical devices, such as fuel cells and fluid separation devices, in which the anode and cathode process-fluid flow chambers are connected in fluid-flow arrangements so that the operating parameters of each of said plurality of electrochemical devices which are dependent upon process-fluid parameters may be individually controlled to provide improved operating efficiency. The improvements in operation include improved power efficiency and improved fuel utilization in fuel cell power generating systems and reduced power consumption in fluid separation devices and the like through interstage process fluid parameter control for series networked electrochemical devices. The improved networking method includes recycling of various process flows to enhance the overall control scheme.

Application of Cell-Specific Isolation to the Study of Dopamine Signaling in Drosophila

PubMed Central

Iyer, Eswar Prasad R.; Iyer, Srividya Chandramouli; Cox, Daniel N.

2014-01-01

Dopamine neurotransmission accounts for a number of important brain functions across species including memory formation, the anticipation of reward, cognitive facilities, and drug addiction. Despite this functional significance, relatively little is known of the cellular pathways associated with drug-induced molecular adaptations within individual neurons. Due to its genetic tractability, simplicity, and economy of scale, Drosophila melanogaster has become an important tool in the study of neurological disease states, including drug addiction. To facilitate high-resolution functional analyses of dopamine signaling, it is highly advantageous to obtain genetic material, such as RNA or protein, from a homogeneous cell source. This process can be particularly challenging in most organisms including small model system organisms such as Drosophila melanogaster. Magnetic bead-based cell sorting has emerged as a powerful tool that can be used to isolate select populations of cells, from a whole organism or tissue such as the brain, for genomic as well as proteomic expression profiling. Coupled with the temporal and spatial specificity of the GAL4/UAS system, we demonstrate the application of magnetic bead-based cell sorting towards the isolation of dopaminergic neurons from the Drosophila adult nervous system. RNA derived from these neurons is of high quality and suitable for downstream applications such as microarray expression profiling or quantitative rtPCR. The versatility of this methodology stems from the fact that the cell-specific isolation method employed can be used under a variety of experimental conditions designed to survey molecular adaptations in dopamine signaling neurons including in response to drugs of abuse. PMID:23296786

WORKING PARK-FUEL CELL COMBINED HEAT AND POWER SYSTEM

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

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 energymore » markets.« less

U.S. Clean Energy Hydrogen and Fuel Cell Technologies: A Competitiveness Analysis

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

Fullenkamp, Patrick; Holody, Diane; James, Brian

The objectives of this project are a 1) Global Competitiveness Analysis of hydrogen and fuel cell systems and components manufactured including 700 bar compressed hydrogen storage system in the U.S., Europe, Asia, and other key areas to be identified to determine the global cost leaders, the best current manufacturing processes, the key factors determining competitiveness, and the potential means of cost reductions; and an 2) Analysis to assess the status of global hydrogen and fuel cell markets. The analysis of units, megawatts by country and by application will focus on polymer electrolyte membrane (PEM) fuel cell systems (automotive and stationary).

Stability of Materials in High Temperature Water Vapor: SOFC Applications

NASA Technical Reports Server (NTRS)

Opila, E. J.; Jacobson, N. S.

2010-01-01

Solid oxide fuel cell material systems require long term stability in environments containing high-temperature water vapor. Many materials in fuel cell systems react with high-temperature water vapor to form volatile hydroxides which can degrade cell performance. In this paper, experimental methods to characterize these volatility reactions including the transpiration technique, thermogravimetric analysis, and high pressure mass spectrometry are reviewed. Experimentally determined data for chromia, silica, and alumina volatility are presented. In addition, data from the literature for the stability of other materials important in fuel cell systems are reviewed. Finally, methods for predicting material recession due to volatilization reactions are described.

Advantages of thin silicon solar cells for use in space

NASA Technical Reports Server (NTRS)

Denman, O. S.

1978-01-01

A system definition study on the Solar Power Satellite System showed that a thin, 50 micrometers, silicon solar cell has significant advantages. The advantages include a significantly lower performance degradation in a radiation environment and high power-to-mass ratios. The advantages of such cells for an employment in space is further investigated. Basic questions concerning the operation of solar cells are considered along with aspects of radiation induced performance degradation. The question arose in this connection how thin a silicon solar cell had to be to achieve resistance to radiation degradation and still have good initial performance. It was found that single-crystal silicon solar cells could be as thin as 50 micrometers and still develop high conversion efficiencies. It is concluded that the use of 50 micrometer silicon solar cells in space-based photovoltaic power systems would be advantageous.

Propulsion Investigation for Zero and Near-Zero Emissions Aircraft

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.; Berton, Jeffrey J.; Brown, Gerald v.; Dolce, James L.; Dravid, Marayan V.; Eichenberg, Dennis J.; Freeh, Joshua E.; Gallo, Christopher A.; Jones, Scott M.; Kundu, Krishna P.;

The US Army Foreign Comparative Test fuel cell program

NASA Astrophysics Data System (ADS)

Bostic, Elizabeth; Sifer, Nicholas; Bolton, Christopher; Ritter, Uli; Dubois, Terry

The US Army RDECOM initiated a Foreign Comparative Test (FCT) Program to acquire lightweight, high-energy dense fuel cell systems from across the globe for evaluation as portable power sources in military applications. Five foreign companies, including NovArs, Smart Fuel Cell, Intelligent Energy, Ballard Power Systems, and Hydrogenics, Inc., were awarded competitive contracts under the RDECOM effort. This paper will report on the status of the program as well as the experimental results obtained from one of the units. The US Army has interests in evaluating and deploying a variety of fuel cell systems, where these systems show added value when compared to current power sources in use. For low-power applications, fuel cells utilizing high-energy dense fuels offer significant weight savings over current battery technologies. This helps reduce the load a solider must carry for longer missions. For high-power applications, the low operating signatures (acoustic and thermal) of fuel cell systems make them ideal power generators in stealth operations. Recent testing has been completed on the Smart Fuel Cell A25 system that was procured through the FCT program. The "A-25" is a direct methanol fuel cell hybrid and was evaluated as a potential candidate for soldier and sensor power applications.

Multiple Applications of Alamar Blue as an Indicator of Metabolic Function and Cellular Health in Cell Viability Bioassays

PubMed Central

Rampersad, Sephra N.

2012-01-01

Accurate prediction of the adverse effects of test compounds on living systems, detection of toxic thresholds, and expansion of experimental data sets to include multiple toxicity end-point analysis are required for any robust screening regime. Alamar Blue is an important redox indicator that is used to evaluate metabolic function and cellular health. The Alamar Blue bioassay has been utilized over the past 50 years to assess cell viability and cytotoxicity in a range of biological and environmental systems and in a number of cell types including bacteria, yeast, fungi, protozoa and cultured mammalian and piscine cells. It offers several advantages over other metabolic indicators and other cytotoxicity assays. However, as with any bioassay, suitability must be determined for each application and cell model. This review seeks to highlight many of the important considerations involved in assay use and design in addition to the potential pitfalls. PMID:23112716

Otic Langerhans' Cell Histiocytosis in an Adult: A Case Report and Review of the Literature

PubMed Central

Gungadeen, Anil; Kullar, Peter; Yates, Philip

2013-01-01

Objective. To present a case of otic Langerhans' cell histiocytosis in an adult. Also included the diagnosis and management of the condition and a review of the relevant literature. Case Report. We report a case of a 41-year-old man with a history of persistent unilateral ear discharge associated with an aural polyp. Radiological imaging showed bony lesions of the skull and a soft-tissue mass within the middle ear. Histological analysis of the polyp demonstrated Langerhans' cell histiocytosis. His otological symptoms were completely resolved with the systemic therapy. Conclusions. Otic Langerhans' cell histiocytosis can present in adults. Persistent ear symptoms along with evidence of soft-tissue masses within the ear and bony lesions of the skull or elsewhere should prompt the otolaryngologists to include Langerhans' cell histiocytosis in their differential diagnosis. Management should be with systemic therapy rather than local surgical treatment. PMID:23762704

Activation of cellular death programs associated with immunosenescence-like phenotype in TPPII knockout mice

PubMed Central

Huai, Jisen; Firat, Elke; Nil, Ahmed; Million, Daniele; Gaedicke, Simone; Kanzler, Benoit; Freudenberg, Marina; van Endert, Peter; Kohler, Gabriele; Pahl, Heike L.; Aichele, Peter; Eichmann, Klaus; Niedermann, Gabriele

2008-01-01

The giant cytosolic protease tripeptidyl peptidase II (TPPII) has been implicated in the regulation of proliferation and survival of malignant cells, particularly lymphoma cells. To address its functions in normal cellular and systemic physiology we have generated TPPII-deficient mice. TPPII deficiency activates cell type-specific death programs, including proliferative apoptosis in several T lineage subsets and premature cellular senescence in fibroblasts and CD8+ T cells. This coincides with up-regulation of p53 and dysregulation of NF-κB. Prominent degenerative alterations at the organismic level were a decreased lifespan and symptoms characteristic of immunohematopoietic senescence. These symptoms include accelerated thymic involution, lymphopenia, impaired proliferative T cell responses, extramedullary hematopoiesis, and inflammation. Thus, TPPII is important for maintaining normal cellular and systemic physiology, which may be relevant for potential therapeutic applications of TPPII inhibitors. PMID:18362329

Microfluidic strategies for understanding the mechanics of cells and cell-mimetic systems

PubMed Central

Dahl, Joanna B.; Lin, Jung-Ming G.; Muller, Susan J.; Kumar, Sanjay

2016-01-01

Microfluidic systems are attracting increasing interest for the high-throughput measurement of cellular biophysical properties and for the creation of engineered cellular microenvironments. Here we review recent applications of microfluidic technologies to the mechanics of living cells and synthetic cell-mimetic systems. We begin by discussing the use of microfluidic devices to dissect the mechanics of cellular mimics such as capsules and vesicles. We then explore applications to circulating cells, including erythrocytes and other normal blood cells, and rare populations with potential disease diagnostic value, such as circulating tumor cells. We conclude by discussing how microfluidic devices have been used to investigate the mechanics, chemotaxis, and invasive migration of adherent cells. In these ways, microfluidic technologies represent an increasingly important toolbox for investigating cellular mechanics and motility at high throughput and in a format that lends itself to clinical translation. PMID:26134738

Production of Japanese encephalitis virus-like particles in insect cells.

PubMed

Yamaji, Hideki; Konishi, Eiji

2013-01-01

Virus-like particles (VLPs) are composed of one or several recombinant viral surface proteins that spontaneously assemble into particulate structures without the incorporation of virus DNA or RNA. The baculovirus-insect cell system has been used extensively for the production of recombinant virus proteins including VLPs. While the baculovirus-insect cell system directs the transient expression of recombinant proteins in a batch culture, stably transformed insect cells allow constitutive production. In our recent study, a secretory form of Japanese encephalitis (JE) VLPs was successfully produced by Trichoplusia ni BTI-TN-5B1-4 (High Five) cells engineered to coexpress the JE virus (JEV) premembrane (prM) and envelope (E) proteins. A higher yield of E protein was attained with recombinant High Five cells than with the baculovirus-insect cell system. This study demonstrated that recombinant insect cells offer a promising approach to the high-level production of VLPs for use as vaccines and diagnostic antigens.

Expression profiling of peroxisome proliferator-activated receptor-delta (PPAR-delta) in mouse tissues using tissue microarray.

PubMed

Higashiyama, Hiroyuki; Billin, Andrew N; Okamoto, Yuji; Kinoshita, Mine; Asano, Satoshi

2007-05-01

Peroxisome proliferator-activated receptor-delta (PPAR-delta) is known as a transcription factor involved in the regulation of fatty acid oxidation and mitochondrial biogenesis in several tissues, such as skeletal muscle, liver and adipose tissues. In this study, to elucidate systemic physiological functions of PPAR-delta, we examined the tissue distribution and localization of PPAR-delta in adult mouse tissues using tissue microarray (TMA)-based immunohistochemistry. PPAR-delta positive signals were observed on variety of tissues/cells in multiple systems including cardiovascular, urinary, respiratory, digestive, endocrine, nervous, hematopoietic, immune, musculoskeletal, sensory and reproductive organ systems. In these organs, PPAR-delta immunoreactivity was generally localized on the nucleus, although cytoplasmic localization was observed on several cell types including neurons in the nervous system and cells of the islet of Langerhans. These expression profiling data implicate various physiological roles of PPAR-delta in multiple organ systems. TMA-based immunohistochemistry enables to profile comprehensive protein localization and distribution in a high-throughput manner.

Rebalancing electrolytes in redox flow battery systems

DOEpatents

Chang, On Kok; Pham, Ai Quoc

2014-12-23

Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe.sup.2+) which may be oxidized to ferric iron (Fe.sup.3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

Childhood Hematopoietic Cell Transplantation (PDQ®)—Health Professional Version

Cancer.gov

Hematopoietic cell transplantation involves the infusion of blood stem cells (peripheral/umbilical cord blood, bone marrow) into a patient to reconstitute the blood system. Get detailed information about autologous and allogeneic transplant, including cell selection, HLA matching, and preparative regimens, and the acute complications and late effects of treatment in this summary for clinicians.

Manual of phosphoric acid fuel cell power plant cost model and computer program

NASA Technical Reports Server (NTRS)

Lu, C. Y.; Alkasab, K. A.

1984-01-01

Cost analysis of phosphoric acid fuel cell power plant includes two parts: a method for estimation of system capital costs, and an economic analysis which determines the levelized annual cost of operating the system used in the capital cost estimation. A FORTRAN computer has been developed for this cost analysis.

The intracellular angiotensin system buffers deleterious effects of the extracellular paracrine system

PubMed Central

Villar-Cheda, Begoña; Costa-Besada, Maria A; Valenzuela, Rita; Perez-Costas, Emma; Melendez-Ferro, Miguel; Labandeira-Garcia, Jose L

2017-01-01

The ‘classical’ renin–angiotensin system (RAS) is a circulating system that controls blood pressure. Local/paracrine RAS, identified in a variety of tissues, including the brain, is involved in different functions and diseases, and RAS blockers are commonly used in clinical practice. A third type of RAS (intracellular/intracrine RAS) has been observed in some types of cells, including neurons. However, its role is still unknown. The present results indicate that in brain cells the intracellular RAS counteracts the intracellular superoxide/H2O2 and oxidative stress induced by the extracellular/paracrine angiotensin II acting on plasma membrane receptors. Activation of nuclear receptors by intracellular or internalized angiotensin triggers a number of mechanisms that protect the cell, such as an increase in the levels of protective angiotensin type 2 receptors, intracellular angiotensin, PGC-1α and IGF-1/SIRT1. Interestingly, this protective mechanism is altered in isolated nuclei from brains of aged animals. The present results indicate that at least in the brain, AT1 receptor blockers acting only on the extracellular or paracrine RAS may offer better protection of cells. PMID:28880266

Nuclear Reactors for Space Power, Understanding the Atom Series.

ERIC Educational Resources Information Center

Corliss, William R.

The historical development of rocketry and nuclear technology includes a specific description of Systems for Nuclear Auxiliary Power (SNAP) programs. Solar cells and fuel cells are considered as alternative power supplies for space use. Construction and operation of space power plants must include considerations of the transfer of heat energy to…

Redox flow cell energy storage systems

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1979-01-01

NASA-Redox systems are electrochemical storage devices that use two fully soluble Redox couples, anode and cathode fluids, as active electrode materials separated by a highly selective ion exchange membrane. The reactants are contained in large storage tanks and pumped through a stack of Redox flow cells where the electrochemical reactions (reduction and oxidation) take place at porous carbon felt electrodes. A string or stack of these power producing cells is connected in series in a bipolar manner. Redox energy storage systems promise to be inexpensive and possess many features that provide for flexible design, long life, high reliability and minimal operation and maintenance costs. These features include independent sizing of power and storage capacity requirements and inclusion within the cell stack of a cell that monitors the state of charge of the system as a whole, and a rebalance cell which permits continuous correction to be made for minor side reactions that would tend to result in the anode fluid and cathode fluids becoming electrochemically out of balance. These system features are described and discussed.

Hybrid fuel cell/diesel generation total energy system, part 2

NASA Astrophysics Data System (ADS)

Blazek, C. F.

1982-11-01

Meeting the Goldstone Deep Space Communications Complex (DGSCC) electrical and thermal requirements with the existing system was compared with using fuel cells. Fuel cell technology selection was based on a 1985 time frame for installation. The most cost-effective fuel feedstock for fuel cell application was identified. Fuels considered included diesel oil, natural gas, methanol and coal. These fuel feedstocks were considered not only on the cost and efficiency of the fuel conversion process, but also on complexity and integration of the fuel processor on system operation and thermal energy availability. After a review of fuel processor technology, catalytic steam reformer technology was selected based on the ease of integration and the economics of hydrogen production. The phosphoric acid fuel cell was selected for application at the GDSCC due to its commercial readiness for near term application. Fuel cell systems were analyzed for both natural gas and methanol feedstock. The subsequent economic analysis indicated that a natural gas fueled system was the most cost effective of the cases analyzed.

Hybrid fuel cell/diesel generation total energy system, part 2

NASA Technical Reports Server (NTRS)

Blazek, C. F.

1982-01-01

Meeting the Goldstone Deep Space Communications Complex (DGSCC) electrical and thermal requirements with the existing system was compared with using fuel cells. Fuel cell technology selection was based on a 1985 time frame for installation. The most cost-effective fuel feedstock for fuel cell application was identified. Fuels considered included diesel oil, natural gas, methanol and coal. These fuel feedstocks were considered not only on the cost and efficiency of the fuel conversion process, but also on complexity and integration of the fuel processor on system operation and thermal energy availability. After a review of fuel processor technology, catalytic steam reformer technology was selected based on the ease of integration and the economics of hydrogen production. The phosphoric acid fuel cell was selected for application at the GDSCC due to its commercial readiness for near term application. Fuel cell systems were analyzed for both natural gas and methanol feedstock. The subsequent economic analysis indicated that a natural gas fueled system was the most cost effective of the cases analyzed.

A cell-free translocation system using extracts of cultured insect cells to yield functional membrane proteins.

PubMed

Ezure, Toru; Nanatani, Kei; Sato, Yoko; Suzuki, Satomi; Aizawa, Keishi; Souma, Satoshi; Ito, Masaaki; Hohsaka, Takahiro; von Heijine, Gunnar; Utsumi, Toshihiko; Abe, Keietsu; Ando, Eiji; Uozumi, Nobuyuki

2014-01-01

Cell-free protein synthesis is a powerful method to explore the structure and function of membrane proteins and to analyze the targeting and translocation of proteins across the ER membrane. Developing a cell-free system based on cultured cells for the synthesis of membrane proteins could provide a highly reproducible alternative to the use of tissues from living animals. We isolated Sf21 microsomes from cultured insect cells by a simplified isolation procedure and evaluated the performance of the translocation system in combination with a cell-free translation system originating from the same source. The isolated microsomes contained the basic translocation machinery for polytopic membrane proteins including SRP-dependent targeting components, translocation channel (translocon)-dependent translocation, and the apparatus for signal peptide cleavage and N-linked glycosylation. A transporter protein synthesized with the cell-free system could be functionally reconstituted into a lipid bilayer. In addition, single and double labeling with non-natural amino acids could be achieved at both the lumen side and the cytosolic side in this system. Moreover, tail-anchored proteins, which are post-translationally integrated by the guided entry of tail-anchored proteins (GET) machinery, were inserted correctly into the microsomes. These results showed that the newly developed cell-free translocation system derived from cultured insect cells is a practical tool for the biogenesis of properly folded polytopic membrane proteins as well as tail-anchored proteins.

Bovine papillomavirus type 4 L1 gene transfection in a Drosophila S2 cell expression system: absence of L1 protein expression

PubMed Central

Góes, Luiz Gustavo Bentim; de Freitas, Antonio Carlos; Ferraz, Oilita Pereira; Rieger, Tania Tassinari; dos Santos, José Ferreira; Pereira, Alexandre; Beçak, Willy; Lindsey, Charles J.; de Cassia Stocco, Rita

2008-01-01

The development of a bovine papillomavirus (BPV) vaccine is an outstanding challenge. BPV protein L1 gene transfection in the Drosophila melanogaster S2 cell expression system failed to produce L1 protein notwithstanding correct L1 gene insertion. Severe genetic inbalance in the host cell line, including cytogenetic alterations, may account for the lack of protein expression. PMID:24031166

CRISPR/Cas9-Mediated Mutagenesis of Human Pluripotent Stem Cells in Defined Xeno-Free E8 Medium.

PubMed

Soh, Chew-Li; Huangfu, Danwei

2017-01-01

The recent advent of engineered nucleases including the CRISPR/Cas9 system has greatly facilitated genome manipulation in human pluripotent stem cells (hPSCs). In addition to facilitating hPSC-based disease studies, the application of genome engineering in hPSCs has also opened up new avenues for cell replacement therapy. To improve consistency and reproducibility of hPSC-based studies, and to meet the safety and regulatory requirements for clinical translation, it is necessary to use a defined, xeno-free cell culture system. This chapter describes protocols for CRISPR/Cas9 genome editing in an inducible Cas9 hPSC-based system, using cells cultured in chemically defined, xeno-free E8 Medium on a recombinant human vitronectin substrate. We detail procedures for the design and transfection of CRISPR guide RNAs, colony selection, and the expansion and validation of clonal mutant lines, all within this fully defined culture condition. These methods may be applied to a wide range of genome-engineering applications in hPSCs, including those that utilize different types of site-specific nucleases such as zinc finger nucleases (ZFNs) and TALENs, and form a closer step towards clinical utility of these cells.

Amorphous silicon solar cells

NASA Astrophysics Data System (ADS)

Takahashi, K.; Konagai, M.

The fabrication, performance, and applications of a-Si solar cells are discussed, summarizing the results of recent experimental investigations and trial installations. Topics examined include the fundamental principles and design strategies of solar power installations; the characteristics of monocrystalline-Si solar cells; techniques for reducing the cost of solar cells; independent, linked, and hybrid solar power systems; proposed satellite solar power systems; and the use of solar cells in consumer appliances. Consideration is given to the history of a-Si, a-Si fabrication techniques, quality criteria for a-Si films, solar cells based on a-Si, and techniques for increasing the efficiency and lowering the cost of a-Si solar cells. Graphs, diagrams, drawings, and black-and-white and color photographs are provided.

Jet fuel based high pressure solid oxide fuel cell system

NASA Technical Reports Server (NTRS)

Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

2013-01-01

A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

NASA Technical Reports Server (NTRS)

Srinivasan, Hari (Inventor); Hardin, Larry (Inventor); Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Dasgupta, Arindam (Inventor); Bayt, Robert (Inventor)

2015-01-01

A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

Living Cell Microarrays: An Overview of Concepts

PubMed Central

Jonczyk, Rebecca; Kurth, Tracy; Lavrentieva, Antonina; Walter, Johanna-Gabriela; Scheper, Thomas; Stahl, Frank

2016-01-01

Living cell microarrays are a highly efficient cellular screening system. Due to the low number of cells required per spot, cell microarrays enable the use of primary and stem cells and provide resolution close to the single-cell level. Apart from a variety of conventional static designs, microfluidic microarray systems have also been established. An alternative format is a microarray consisting of three-dimensional cell constructs ranging from cell spheroids to cells encapsulated in hydrogel. These systems provide an in vivo-like microenvironment and are preferably used for the investigation of cellular physiology, cytotoxicity, and drug screening. Thus, many different high-tech microarray platforms are currently available. Disadvantages of many systems include their high cost, the requirement of specialized equipment for their manufacture, and the poor comparability of results between different platforms. In this article, we provide an overview of static, microfluidic, and 3D cell microarrays. In addition, we describe a simple method for the printing of living cell microarrays on modified microscope glass slides using standard DNA microarray equipment available in most laboratories. Applications in research and diagnostics are discussed, e.g., the selective and sensitive detection of biomarkers. Finally, we highlight current limitations and the future prospects of living cell microarrays. PMID:27600077

Toxicity of silver nanoparticles in biological systems: Does the complexity of biological systems matter?

PubMed

Vazquez-Muñoz, Roberto; Borrego, Belen; Juárez-Moreno, Karla; García-García, Maritza; Mota Morales, Josué D; Bogdanchikova, Nina; Huerta-Saquero, Alejandro

2017-07-05

Currently, nanomaterials are more frequently in our daily life, specifically in biomedicine, electronics, food, textiles and catalysis just to name a few. Although nanomaterials provide many benefits, recently their toxicity profiles have begun to be explored. In this work, the toxic effects of silver nanoparticles (35nm-average diameter and Polyvinyl-Pyrrolidone-coated) on biological systems of different levels of complexity was assessed in a comprehensive and comparatively way, through a variety of viability and toxicological assays. The studied organisms included viruses, bacteria, microalgae, fungi, animal and human cells (including cancer cell lines). It was found that biological systems of different taxonomical groups are inhibited at concentrations of silver nanoparticles within the same order of magnitude. Thus, the toxicity of nanomaterials on biological/living systems, constrained by their complexity, e.g. taxonomic groups, resulted contrary to the expected. The fact that cells and virus are inhibited with a concentration of silver nanoparticles within the same order of magnitude could be explained considering that silver nanoparticles affects very primitive cellular mechanisms by interacting with fundamental structures for cells and virus alike. Copyright © 2017 Elsevier B.V. All rights reserved.

ID’ing Innate and Innate-like Lymphoid Cells

PubMed Central

Verykokakis, Mihalis; Zook, Erin C.; Kee, Barbara L.

2014-01-01

Summary The immune system can be divided into innate and adaptive components that differ in their rate and mode of cellular activation, with innate immune cells being the first responders to invading pathogens. Recent advances in the identification and characterization of innate lymphoid cells have revealed reiterative developmental programs that result in cells with effector fates that parallel those of adaptive lymphoid cells and are tailored to effectively eliminate a broad spectrum of pathogenic challenges. However, activation of these cells can also be associated with pathologies such as autoimmune disease. One major distinction between innate and adaptive immune system cells is the constitutive expression of ID proteins in the former and inducible expression in the latter. ID proteins function as antagonists of the E protein transcription factors that play critical roles in lymphoid specification as well as B and T-lymphocyte development. In this review, we examine the transcriptional mechanisms controlling the development of innate lymphocytes, including natural killer cells and the recently identified innate lymphoid cells (ILC1, ILC2, and ILC3), and innate-like lymphocytes, including natural killer T cells, with an emphasis on the known requirements for the ID proteins. PMID:25123285

ID'ing innate and innate-like lymphoid cells.

PubMed

Verykokakis, Mihalis; Zook, Erin C; Kee, Barbara L

2014-09-01

The immune system can be divided into innate and adaptive components that differ in their rate and mode of cellular activation, with innate immune cells being the first responders to invading pathogens. Recent advances in the identification and characterization of innate lymphoid cells have revealed reiterative developmental programs that result in cells with effector fates that parallel those of adaptive lymphoid cells and are tailored to effectively eliminate a broad spectrum of pathogenic challenges. However, activation of these cells can also be associated with pathologies such as autoimmune disease. One major distinction between innate and adaptive immune system cells is the constitutive expression of ID proteins in the former and inducible expression in the latter. ID proteins function as antagonists of the E protein transcription factors that play critical roles in lymphoid specification as well as B- and T-lymphocyte development. In this review, we examine the transcriptional mechanisms controlling the development of innate lymphocytes, including natural killer cells and the recently identified innate lymphoid cells (ILC1, ILC2, and ILC3), and innate-like lymphocytes, including natural killer T cells, with an emphasis on the known requirements for the ID proteins. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chemokine receptor binding and signal transduction in native cells of the central nervous system.

PubMed

Davis, Christopher N; Chen, Shuzhen; Boehme, Stefen A; Bacon, Kevin B; Harrison, Jeffrey K

2003-04-01

Chemokine receptors belong to the superfamily of seven-transmembrane-spanning, G-protein-coupled receptors, and their expression by central nervous system cells is clearly documented. As this gene family has become the target of novel therapeutic development, the analysis of these receptors requires radioligand binding techniques as well as methods that entail assessing receptor stimulation of signal transduction pathways. Herein, we describe specific protocols for measuring radiolabeled chemokine binding to their cognate receptors on cultured glial cells as well as to receptors expressed in heterologous cell systems. Multiple downstream signaling pathways, including intracellular calcium influx and receptor-dependent kinase activation, are associated with chemokine receptor stimulation. Protocols for measuring these signaling events in chemokine-receptor-expressing cells are also presented.

Neural Crossroads in the Hematopoietic Stem Cell Niche.

PubMed

Agarwala, Sobhika; Tamplin, Owen J

2018-05-29

The hematopoietic stem cell (HSC) niche supports steady-state hematopoiesis and responds to changing needs during stress and disease. The nervous system is an important regulator of the niche, and its influence is established early in development when stem cells are specified. Most research has focused on direct innervation of the niche, however recent findings show there are different modes of neural control, including globally by the central nervous system (CNS) and hormone release, locally by neural crest-derived mesenchymal stem cells, and intrinsically by hematopoietic cells that express neural receptors and neurotransmitters. Dysregulation between neural and hematopoietic systems can contribute to disease, however new therapeutic opportunities may be found among neuroregulator drugs repurposed to support hematopoiesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Review: the role of neural crest cells in the endocrine system.

PubMed

Adams, Meghan Sara; Bronner-Fraser, Marianne

2009-01-01

The neural crest is a pluripotent population of cells that arises at the junction of the neural tube and the dorsal ectoderm. These highly migratory cells form diverse derivatives including neurons and glia of the sensory, sympathetic, and enteric nervous systems, melanocytes, and the bones, cartilage, and connective tissues of the face. The neural crest has long been associated with the endocrine system, although not always correctly. According to current understanding, neural crest cells give rise to the chromaffin cells of the adrenal medulla, chief cells of the extra-adrenal paraganglia, and thyroid C cells. The endocrine tumors that correspond to these cell types are pheochromocytomas, extra-adrenal paragangliomas, and medullary thyroid carcinomas. Although controversies concerning embryological origin appear to have mostly been resolved, questions persist concerning the pathobiology of each tumor type and its basis in neural crest embryology. Here we present a brief history of the work on neural crest development, both in general and in application to the endocrine system. In particular, we present findings related to the plasticity and pluripotency of neural crest cells as well as a discussion of several different neural crest tumors in the endocrine system.

Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders.

PubMed

Park, Sanghui; Ko, Young H

2014-01-01

Primary infection with Epstein-Barr virus (EBV) is usually asymptomatic and, in a normal host, EBV remains latent in B cells after primary infection for the remainder of life. Uncommonly, EBV can infect T or natural killer (NK) cells in a person with a defect in innate immunity, and EBV infection can cause unique systemic lymphoproliferative diseases (LPD) of childhood. Primary infection in young children can be complicated by hemophagocytic lymphohistiocytosis or fulminant systemic T-cell LPD of childhood. Uncommonly, patients can develop chronic active EBV (CAEBV) disease-type T/NK LPD, which includes CAEBV infection of the systemic form, hydroa vacciniforme-like T-cell LPD, and mosquito-bite hypersensitivity. The clinical course of CAEBV disease-type T/NK LPD can be smoldering, persistent or progressive, depending on the balance between viral factors and host immunity. Aggressive NK-cell leukemia, hydroa vacciniforme-like T-cell lymphoma, or uncommonly extranodal NK/T-cell lymphoma can develop in children and young adults with CAEBV disease-type T/NK-cell LPD. Extranodal T/NK-cell lymphoma is a disease of adults, and its incidence begins to increase in the third decade and comprises the major subtype of T/NK LPD throughout life. Aggressive NK-cell leukemia and nodal T/NK-cell lymphoma of the elderly are fulminant diseases, and immune senescence may be an important pathogenetic factor. This review describes the current progress in identifying different types of EBV-associated T/NK-cell LPD and includes a brief presentation of data from Korea. © 2014 Japanese Dermatological Association.

Study of muscle cell dedifferentiation after skeletal muscle injury of mice with a Cre-Lox system.

PubMed

Mu, Xiaodong; Peng, Hairong; Pan, Haiying; Huard, Johnny; Li, Yong

2011-02-03

Dedifferentiation of muscle cells in the tissue of mammals has yet to be observed. One of the challenges facing the study of skeletal muscle cell dedifferentiation is the availability of a reliable model that can confidentially distinguish differentiated cell populations of myotubes and non-fused mononuclear cells, including stem cells that can coexist within the population of cells being studied. In the current study, we created a Cre/Lox-β-galactosidase system, which can specifically tag differentiated multinuclear myotubes and myotube-generated mononuclear cells based on the activation of the marker gene, β-galactosidase. By using this system in an adult mouse model, we found that β-galactosidase positive mononuclear cells were generated from β-galactosidase positive multinuclear myofibers upon muscle injury. We also demonstrated that these mononuclear cells can develop into a variety of different muscle cell lineages, i.e., myoblasts, satellite cells, and muscle derived stem cells. These novel findings demonstrated, for the first time, that cellular dedifferentiation of skeletal muscle cells actually occurs in mammalian skeletal muscle following traumatic injury in vivo.

Massively parallel nanowell-based single-cell gene expression profiling.

PubMed

Goldstein, Leonard D; Chen, Ying-Jiun Jasmine; Dunne, Jude; Mir, Alain; Hubschle, Hermann; Guillory, Joseph; Yuan, Wenlin; Zhang, Jingli; Stinson, Jeremy; Jaiswal, Bijay; Pahuja, Kanika Bajaj; Mann, Ishminder; Schaal, Thomas; Chan, Leo; Anandakrishnan, Sangeetha; Lin, Chun-Wah; Espinoza, Patricio; Husain, Syed; Shapiro, Harris; Swaminathan, Karthikeyan; Wei, Sherry; Srinivasan, Maithreyan; Seshagiri, Somasekar; Modrusan, Zora

2017-07-07

Technological advances have enabled transcriptome characterization of cell types at the single-cell level providing new biological insights. New methods that enable simple yet high-throughput single-cell expression profiling are highly desirable. Here we report a novel nanowell-based single-cell RNA sequencing system, ICELL8, which enables processing of thousands of cells per sample. The system employs a 5,184-nanowell-containing microchip to capture ~1,300 single cells and process them. Each nanowell contains preprinted oligonucleotides encoding poly-d(T), a unique well barcode, and a unique molecular identifier. The ICELL8 system uses imaging software to identify nanowells containing viable single cells and only wells with single cells are processed into sequencing libraries. Here, we report the performance and utility of ICELL8 using samples of increasing complexity from cultured cells to mouse solid tissue samples. Our assessment of the system to discriminate between mixed human and mouse cells showed that ICELL8 has a low cell multiplet rate (< 3%) and low cross-cell contamination. We characterized single-cell transcriptomes of more than a thousand cultured human and mouse cells as well as 468 mouse pancreatic islets cells. We were able to identify distinct cell types in pancreatic islets, including alpha, beta, delta and gamma cells. Overall, ICELL8 provides efficient and cost-effective single-cell expression profiling of thousands of cells, allowing researchers to decipher single-cell transcriptomes within complex biological samples.

Statistical Characterization of Commercial 18650-Format Lithium-Ion Cell Thermal Runaway Behavior Based on Calorimetric Testing Results

NASA Technical Reports Server (NTRS)

Walker, William; Darst, John; Finegan, Donal; Bayles, Gary; Johnson, Kenneth; Darcy, Eric; Rickman, Steven

2018-01-01

Effective thermal management systems, designed to handle the impacts of thermal runaway (TR) and to prevent cell-to-cell propagation, are key to safe operation of lithium-ion (Li-ion) battery assemblies. Critical factors for optimizing these systems include the total energy released during a single cell TR event and the fraction of the total energy that is released through the cell casing vs. through the ejecta material. A unique calorimeter was utilized to examine the TR behavior of a statistically significant number of 18650-format Li-ion cells with varying manufacturers, chemistries, and capacities. The calorimeter was designed to contain the TR energy in a format conducive to discerning the fractions of energy released through the cell casing vs. through the ejecta material. Other benefits of this calorimeter included the ability to rapidly test of large quantities of cells and the intentional minimization of secondary combustion effects. High energy (270 Wh kg-1) and moderate energy (200 Wh kg-1) 18650 cells were tested. Some of the cells had an imbedded short circuit (ISC) device installed to aid in the examination of TR mechanisms under more realistic conditions. Other variations included cells with bottom vent (BV) features and cells with thin casings (0.22 l(1/4)m). After combining the data gathered with the calorimeter, a statistical approach was used to examine the probability of certain TR behavior, and the associated energy distributions, as a function of capacity, venting features, cell casing thickness and temperature.?

Mechanical regulation of T-cell functions

PubMed Central

Chen, Wei; Zhu, Cheng

2013-01-01

Summary T cells are key players of the mammalian adaptive immune system. They experience different mechanical microenvironments during their life cycles, from the thymus, secondary lymph organs, and peripheral tissues that are free of externally applied force but display variable substrate rigidities, to the blood and lymphatic circulation systems where complicated hydrodynamic forces are present. Regardless of whether T cells are subject to external forces or generate their own internal forces, they response and adapt to different biomechanical cues to modulate their adhesion, migration, trafficking, and triggering of immune functions through mechanical regulation of various molecules that bear force. These include adhesive receptors, immunoreceptors, motor proteins, cytoskeletal proteins, and their associated molecules. Here we discuss the forces acting on various surface and cytoplasmic proteins of a T cell in different mechanical milieus. We review existing data on how force regulates protein conformational changes and interactions with counter molecules, including integrins, actin, and the T-cell receptor, and how each relates to T-cell functions. PMID:24117820

High voltage photovoltaic power converter

DOEpatents

Haigh, Ronald E.; Wojtczuk, Steve; Jacobson, Gerard F.; Hagans, Karla G.

2001-01-01

An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

Immunometabolism in systemic lupus erythematosus.

PubMed

Morel, Laurence

2017-05-01

Systemic lupus erythematosus (SLE) is an autoimmune disease mediated by pathogenic autoantibodies directed against nucleoprotein complexes. Beyond the activation of autoreactive B cells, this process involves dysregulation in many other types of immune cells, including CD4 + T cells, dendritic cells, macrophages and neutrophils. Metabolic substrate utilization and integration of cues from energy sensors are critical checkpoints of effector functions in the immune system, with common as well as cell-specific programmes. Patients with SLE and lupus-prone mice present with activated metabolism of CD4 + T cells, and the use of metabolic inhibitors to normalize these features is associated with therapeutic effects. Far less is known about the metabolic requirements of B cells and myeloid cells in SLE. This article reviews current knowledge of the alterations in metabolism of immune cells in patients with SLE and mouse models of lupus in the context of what is known about the metabolic regulation of these cells during normal immune responses. How these alterations might contribute to lupus pathogenesis and how they can be targeted therapeutically are also discussed.

Characterization of stem/progenitor cell cycle using murine circumvallate papilla taste bud organoid.

PubMed

Aihara, Eitaro; Mahe, Maxime M; Schumacher, Michael A; Matthis, Andrea L; Feng, Rui; Ren, Wenwen; Noah, Taeko K; Matsu-ura, Toru; Moore, Sean R; Hong, Christian I; Zavros, Yana; Herness, Scott; Shroyer, Noah F; Iwatsuki, Ken; Jiang, Peihua; Helmrath, Michael A; Montrose, Marshall H

2015-11-24

Leucine-rich repeat-containing G-protein coupled receptor 5-expressing (Lgr5(+)) cells have been identified as stem/progenitor cells in the circumvallate papillae, and single cultured Lgr5(+) cells give rise to taste cells. Here we use circumvallate papilla tissue to establish a three-dimensional culture system (taste bud organoids) that develops phenotypic characteristics similar to native tissue, including a multilayered epithelium containing stem/progenitor in the outer layers and taste cells in the inner layers. Furthermore, characterization of the cell cycle of the taste bud progenitor niche reveals striking dynamics of taste bud development and regeneration. Using this taste bud organoid culture system and FUCCI2 transgenic mice, we identify the stem/progenitor cells have at least 5 distinct cell cycle populations by tracking within 24-hour synchronized oscillations of proliferation. Additionally, we demonstrate that stem/progenitor cells have motility to form taste bud organoids. Taste bud organoids provides a system for elucidating mechanisms of taste signaling, disease modeling, and taste tissue regeneration.

Characterization of stem/progenitor cell cycle using murine circumvallate papilla taste bud organoid

PubMed Central

Aihara, Eitaro; Mahe, Maxime M.; Schumacher, Michael A.; Matthis, Andrea L.; Feng, Rui; Ren, Wenwen; Noah, Taeko K.; Matsu-ura, Toru; Moore, Sean R.; Hong, Christian I.; Zavros, Yana; Herness, Scott; Shroyer, Noah F.; Iwatsuki, Ken; Jiang, Peihua; Helmrath, Michael A.; Montrose, Marshall H.

2015-01-01

Leucine-rich repeat-containing G-protein coupled receptor 5-expressing (Lgr5+) cells have been identified as stem/progenitor cells in the circumvallate papillae, and single cultured Lgr5+ cells give rise to taste cells. Here we use circumvallate papilla tissue to establish a three-dimensional culture system (taste bud organoids) that develops phenotypic characteristics similar to native tissue, including a multilayered epithelium containing stem/progenitor in the outer layers and taste cells in the inner layers. Furthermore, characterization of the cell cycle of the taste bud progenitor niche reveals striking dynamics of taste bud development and regeneration. Using this taste bud organoid culture system and FUCCI2 transgenic mice, we identify the stem/progenitor cells have at least 5 distinct cell cycle populations by tracking within 24-hour synchronized oscillations of proliferation. Additionally, we demonstrate that stem/progenitor cells have motility to form taste bud organoids. Taste bud organoids provides a system for elucidating mechanisms of taste signaling, disease modeling, and taste tissue regeneration. PMID:26597788

Apparatus and methods for manipulation and optimization of biological systems

NASA Technical Reports Server (NTRS)

Sun, Ren (Inventor); Ho, Chih-Ming (Inventor); Wong, Pak Kin (Inventor); Yu, Fuqu (Inventor)

2012-01-01

The invention provides systems and methods for manipulating, e.g., optimizing and controlling, biological systems, e.g., for eliciting a more desired biological response of biological sample, such as a tissue, organ, and/or a cell. In one aspect, systems and methods of the invention operate by efficiently searching through a large parametric space of stimuli and system parameters to manipulate, control, and optimize the response of biological samples sustained in the system, e.g., a bioreactor. In alternative aspects, systems include a device for sustaining cells or tissue samples, one or more actuators for stimulating the samples via biochemical, electromagnetic, thermal, mechanical, and/or optical stimulation, one or more sensors for measuring a biological response signal of the samples resulting from the stimulation of the sample. In one aspect, the systems and methods of the invention use at least one optimization algorithm to modify the actuator's control inputs for stimulation, responsive to the sensor's output of response signals. The compositions and methods of the invention can be used, e.g., to for systems optimization of any biological manufacturing or experimental system, e.g., bioreactors for proteins, e.g., therapeutic proteins, polypeptides or peptides for vaccines, and the like, small molecules (e.g., antibiotics), polysaccharides, lipids, and the like. Another use of the apparatus and methods includes combination drug therapy, e.g. optimal drug cocktail, directed cell proliferations and differentiations, e.g. in tissue engineering, e.g. neural progenitor cells differentiation, and discovery of key parameters in complex biological systems.

Proton exchange membrane fuel cell systems engineering at Vickers Shipbuilding and Engineering Limited (VSEL)

NASA Astrophysics Data System (ADS)

Seymour, C. M.

1992-01-01

A project, jointly funded by VSEL and CJB Developments Limited, is aimed at the development of complete power generation systems based on PEM fuel cell technology. Potential markets for such systems are seen as being very broadly based, ranging from military land and marine systems through to commercial on-site power generation and transport. From the outset the project was applications driven, the intent being to identify market requirements, in terms of system specifications and to use these to produce development targets. The two companies have based their work on the Ballard PEM stack and have focused their efforts on the development of supporting systems. This benefits all three companies as it allows Ballard to obtain applications information on which to base future research and VSEL/CJBD are able to capitalise on the advanced development of the Ballard stack. Current work is focused on the production of a 20 kW, methanol fuelled, power generation system demonstrator, although work is also in hand to address a wider range of fuels including natural gas. The demonstrator, when complete, will be used to indicate the potential benefits of such systems and to act as a design aid for the applications phase of the project. Preliminary work on this next phase is already in hand, with studies to assess both systems and fuel cell stack design requirements for specific applications and to generate concept designs. Work to date has concentrated on the development of a methanol reformer, suitable for integration into a fuel cell system and on extensive testing and evaluation of the Ballard fuel cell stacks. This testing has covered a wide range of operating parameters, including different fuel and oxidant combinations. The effect of contaminants on the performance and life of the fuel cells is also under evaluation. PEM fuel cells still require a great deal of further development if they are to gain widespread commercial acceptance. A recent study conducted by VSEL in conjunction with the UK Department of Energy has addressed the fuel cell cost and performance requirements in order to both focus future research and to aid understanding of the time-scale to reach full commercialisation.

Expression of Recombinant Antibodies

PubMed Central

Frenzel, André; Hust, Michael; Schirrmann, Thomas

2013-01-01

Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines, and transgenic plants are promising to obtain antibodies with “human-like” post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications. PMID:23908655

Baculovirus-mediated expression of GPCRs in insect cells.

PubMed

Saarenpää, Tuulia; Jaakola, Veli-Pekka; Goldman, Adrian

2015-01-01

G-protein-coupled receptors (GPCRs) are a large family of seven transmembrane proteins that influence a considerable number of cellular events. For this reason, they are one of the most studied receptor types for their pharmacological and structural properties. Solving the structure of several GPCR receptor types has been possible using almost all expression systems, including Escherichia coli, yeast, mammalian, and insect cells. So far, however, most of the GPCR structures solved have been done using the baculovirus insect cell expression system. The reason for this is mainly due to cost-effectiveness, posttranslational modification efficiency, and overall effortless maintenance. The system has evolved so much that variables starting from vector type, purification tags, cell line, and growth conditions can be varied and optimized countless ways to suit the needs of new constructs. Here, we present the array of techniques that enable the rapid and efficient optimization of expression steps for maximal protein quality and quantity, including our emendations. © 2015 Elsevier Inc. All rights reserved.

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

PubMed

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

2014-02-01

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

Engagement of neural circuits underlying 2D spatial navigation in a rodent virtual reality system

PubMed Central

Aronov, Dmitriy; Tank, David W.

2015-01-01

SUMMARY Virtual reality (VR) enables precise control of an animal’s environment and otherwise impossible experimental manipulations. Neural activity in navigating rodents has been studied on virtual linear tracks. However, the spatial navigation system’s engagement in complete two-dimensional environments has not been shown. We describe a VR setup for rats, including control software and a large-scale electrophysiology system, which supports 2D navigation by allowing animals to rotate and walk in any direction. The entorhinal-hippocampal circuit, including place cells, grid cells, head direction cells and border cells, showed 2D activity patterns in VR similar to those in the real world. Hippocampal neurons exhibited various remapping responses to changes in the appearance or the shape of the virtual environment, including a novel form in which a VR-induced cue conflict caused remapping to lock to geometry rather than salient cues. These results suggest a general-purpose tool for novel types of experimental manipulations in navigating rats. PMID:25374363

Wick-and-pool electrodes for electrochemical cell

DOEpatents

Roche, Michael F.; Faist, Suzan M.; Eberhart, James G.; Ross, Laurids E.

1977-01-01

An electrode system includes a reservoir of liquid-metal reactant, and a wick extending from a submersed location within the reservoir into the molten electrolyte of an electrochemical cell structure. The wick is flooded with the liquid metal and thereby serves as one electrode within the cell. This electrode system has application in high-temperature batteries employing molten alkali metals or their alloys as active material within an electrode submersed within a molten salt electrolyte. It also can be used in electrochemical cells where the purification, separation or electrowinning of liquid metals is accomplished.

Wick-and-pool electrodes for electrochemical cell

DOEpatents

Roche, Michael F.; Faist, Suzan M.; Eberhart, James G.; Ross, Laurids E.

1980-01-01

An electrode system includes a reservoir of liquid-metal reactant, and a wick extending from a submersed location within the reservoir into the molten electrolyte of an electrochemical cell structure. The wick is flooded with the liquid metal and thereby serves as one electrode within the cell. This electrode system has application in high-temperature batteries employing molten alkali metals or their alloys as active material within an electrode submersed within a molten salt electrolyte. It also can be used in electrochemical cells where the purification, separation or electrowinning of liquid metals is accomplished.

Pressure-resisting cell for high-pressure, high-resolution nuclear magnetic resonance measurements at very high magnetic fields

NASA Astrophysics Data System (ADS)

Yamada, H.; Nishikawa, K.; Honda, M.; Shimura, T.; Akasaka, K.; Tabayashi, K.

2001-02-01

A pressure-resisting cell system has been developed for high-pressure high-resolution nuclear magnetic resonance (NMR) measurements up to a maximum pressure of 600 MPa. This cell system is capable of performing high-pressure experiments with any standard spectrometer, including modern high field NMR machines. A full description of the high-pressure NMR assembly mounted on a 750 MHz spectrometer is presented along with a detailed explanation of the procedure for preparing the pressure-resisting quartz and glass cells.

Particle platforms for cancer immunotherapy

PubMed Central

Serda, Rita Elena

2013-01-01

Elevated understanding and respect for the relevance of the immune system in cancer development and therapy has led to increased development of immunotherapeutic regimens that target existing cancer cells and provide long-term immune surveillance and protection from cancer recurrence. This review discusses using particles as immune adjuvants to create vaccines and to augment the anticancer effects of conventional chemotherapeutics. Several particle prototypes are presented, including liposomes, polymer nanoparticles, and porous silicon microparticles, the latter existing as either single- or multiparticle platforms. The benefits of using particles include immune-cell targeting, codelivery of antigens and immunomodulatory agents, and sustained release of the therapeutic payload. Nanotherapeutic-based activation of the immune system is dependent on both intrinsic particle characteristics and on the immunomodulatory cargo, which may include danger signals known as pathogen-associated molecular patterns and cytokines for effector-cell activation. PMID:23761969

Adult Neurogenesis and Neurodegenerative Diseases: A Systems Biology Perspective

PubMed Central

Horgusluoglu, Emrin; Nudelman, Kelly; Nho, Kwangsik; Saykin, Andrew J.

2016-01-01

New neurons are generated throughout adulthood in two regions of the brain, the olfactory bulb and dentate gyrus of the hippocampus, and are incorporated into the hippocampal network circuitry; disruption of this process has been postulated to contribute to neurodegenerative diseases including Alzheimer’s disease and Parkinson’s disease. Known modulators of adult neurogenesis include signal transduction pathways, the vascular and immune systems, metabolic factors, and epigenetic regulation. Multiple intrinsic and extrinsic factors such as neurotrophic factors, transcription factors, and cell cycle regulators control neural stem cell proliferation, maintenance in the adult neurogenic niche, and differentiation into mature neurons; these factors act in networks of signaling molecules that influence each other during construction and maintenance of neural circuits, and in turn contribute to learning and memory. The immune system and vascular system are necessary for neuronal formation and neural stem cell fate determination. Inflammatory cytokines regulate adult neurogenesis in response to immune system activation, whereas the vasculature regulates the neural stem cell niche. Vasculature, immune/support cell populations (microglia/astrocytes), adhesion molecules, growth factors, and the extracellular matrix also provide a homing environment for neural stem cells. Epigenetic changes during hippocampal neurogenesis also impact memory and learning. Some genetic variations in neurogenesis related genes may play important roles in the alteration of neural stem cells differentiation into new born neurons during adult neurogenesis, with important therapeutic implications. In this review, we discuss mechanisms of and interactions between these modulators of adult neurogenesis, as well as implications for neurodegenerative disease and current therapeutic research. PMID:26879907

Erythrocyte membrane based cationic polymer-mcDNA complexes as an efficient gene delivery system.

PubMed

Huang, Ping; Zhao, Jing; Wei, Chiju; Hou, Xiaohu; Chen, Pingzhang; Tan, Yan; He, Cheng-Yi; Wang, Zhiyong; Chen, Zhi-Ying

2016-12-20

Gene therapy has great promise for the treatment of obtained and inherited serious diseases. However, the lack of safe and efficient gene delivery systems remains a barrier for their clinical application. Here, we reported a potential gene delivery vehicle composed of the erythrocyte membrane and cationic polymers, for example the XtremeGENE from Roche and the ε-caprolactone modified polyethylenimine. In addition to high efficiency, this system showed negligible cytotoxicity compared to the two cationic polymers alone in various cell lines, including human embryonic kidney cells (293T), human liver cancer cells (Huh7 and HepG2), murine dendritic cells (DC2.4) and human umbilical cord mesenchymal stem cells (Hu-MSCs). Moreover, the results of confocal laser scanning microscopy and flow cytometry suggested that the cell uptake of this gene vector was improved and might be introduced by the fusion interaction between the erythrocyte membrane and targeted cells.Thus, all the results revealed that the erythrocyte membrane based gene delivery system might be able to serve as an excellent gene delivery system.

Effects of ionizing radiation on the immune system with special emphasis on the interaction of dendritic and T cells.

PubMed

Manda, Katrin; Glasow, Annegret; Paape, Daniel; Hildebrandt, Guido

2012-01-01

Dendritic cells (DCs), as professional antigen-presenting cells, are members of the innate immune system and function as key players during the induction phase of adaptive immune responses. Uptake, processing, and presentation of antigens direct the outcome toward either tolerance or immunity. The cells of the immune system are among the most highly radiosensitive cells in the body. For high doses of ionizing radiation (HD-IR) both immune-suppressive effects after whole body irradiation and possible immune activation during tumor therapy were observed. On the other hand, the effects of low doses of ionizing radiation (LD-IR) on the immune system are controversial and seem to show high variability among different individuals and species. There are reports revealing that protracted LD-IR can result in radioresistance. But immune-suppressive effects of chronic LD-IR are also reported, including the killing or sensitizing of certain cell types. This article shall review the current knowledge of radiation-induced effects on the immune system, paying special attention to the interaction of DCs and T cells.

Surfactant-based drug delivery systems for treating drug-resistant lung cancer.

PubMed

Kaur, Prabhjot; Garg, Tarun; Rath, Goutam; Murthy, R S R; Goyal, Amit K

2016-01-01

Among all cancers, lung cancer is the major cause of deaths. Lung cancer can be categorized into two classes for prognostic and treatment purposes: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Both categories of cancer are resistant to certain drugs. Various mechanisms behind drug resistance are over-expression of superficial membrane proteins [glycoprotein (P-gp)], lung resistance-associated proteins, aberration of the intracellular enzyme system, enhancement of the cell repair system and deregulation of cell apoptosis. Structure-performance relationships and chemical compatibility are consequently major fundamentals in surfactant-based formulations, with the intention that a great deal investigation is committed to this region. With the purpose to understand the potential of P-gp in transportation of anti-tumor drugs to cancer cells with much effectiveness and specificity, several surfactant-based delivery systems have been developed which may include microspheres, nanosized drug carriers (nanoparticles, nanoemulsions, stealth liposomes, nanogels, polymer-drug conjugates), novel powders, hydrogels and mixed micellar systems intended for systemic and/or localized delivery.

Sertoli cells as biochambers

NASA Technical Reports Server (NTRS)

Cameron, Don F. (Inventor); Hushen, Joelle J. (Inventor); Sanberg, Paul R. (Inventor); Saporta, Samuel (Inventor)

2004-01-01

According to the present invention, there is provided a biological chamber system having a biochamber defined by outer walls of Sertoli cells. Also provided is a transplantation facilitator including a biochamber. A method of making biochambers by co-culturing facilitator cells and therapeutic cells and then aggregating the facilitator celes is also provided. Also provided is a method of transplanting cells by incorporating transplant cells into a biochamber and transplanting the biochamber containing the transplant cells.

Rotating Aperture System

DOEpatents

Rusnak, Brian; Hall, James M.; Shen, Stewart; Wood, Richard L.

2005-01-18

A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

Recent advances in 2D and 3D in vitro systems using primary hepatocytes, alternative hepatocyte sources and non-parenchymal liver cells and their use in investigating mechanisms of hepatotoxicity, cell signaling and ADME.

PubMed

Godoy, Patricio; Hewitt, Nicola J; Albrecht, Ute; Andersen, Melvin E; Ansari, Nariman; Bhattacharya, Sudin; Bode, Johannes Georg; Bolleyn, Jennifer; Borner, Christoph; Böttger, Jan; Braeuning, Albert; Budinsky, Robert A; Burkhardt, Britta; Cameron, Neil R; Camussi, Giovanni; Cho, Chong-Su; Choi, Yun-Jaie; Craig Rowlands, J; Dahmen, Uta; Damm, Georg; Dirsch, Olaf; Donato, María Teresa; Dong, Jian; Dooley, Steven; Drasdo, Dirk; Eakins, Rowena; Ferreira, Karine Sá; Fonsato, Valentina; Fraczek, Joanna; Gebhardt, Rolf; Gibson, Andrew; Glanemann, Matthias; Goldring, Chris E P; Gómez-Lechón, María José; Groothuis, Geny M M; Gustavsson, Lena; Guyot, Christelle; Hallifax, David; Hammad, Seddik; Hayward, Adam; Häussinger, Dieter; Hellerbrand, Claus; Hewitt, Philip; Hoehme, Stefan; Holzhütter, Hermann-Georg; Houston, J Brian; Hrach, Jens; Ito, Kiyomi; Jaeschke, Hartmut; Keitel, Verena; Kelm, Jens M; Kevin Park, B; Kordes, Claus; Kullak-Ublick, Gerd A; LeCluyse, Edward L; Lu, Peng; Luebke-Wheeler, Jennifer; Lutz, Anna; Maltman, Daniel J; Matz-Soja, Madlen; McMullen, Patrick; Merfort, Irmgard; Messner, Simon; Meyer, Christoph; Mwinyi, Jessica; Naisbitt, Dean J; Nussler, Andreas K; Olinga, Peter; Pampaloni, Francesco; Pi, Jingbo; Pluta, Linda; Przyborski, Stefan A; Ramachandran, Anup; Rogiers, Vera; Rowe, Cliff; Schelcher, Celine; Schmich, Kathrin; Schwarz, Michael; Singh, Bijay; Stelzer, Ernst H K; Stieger, Bruno; Stöber, Regina; Sugiyama, Yuichi; Tetta, Ciro; Thasler, Wolfgang E; Vanhaecke, Tamara; Vinken, Mathieu; Weiss, Thomas S; Widera, Agata; Woods, Courtney G; Xu, Jinghai James; Yarborough, Kathy M; Hengstler, Jan G

2013-08-01

This review encompasses the most important advances in liver functions and hepatotoxicity and analyzes which mechanisms can be studied in vitro. In a complex architecture of nested, zonated lobules, the liver consists of approximately 80 % hepatocytes and 20 % non-parenchymal cells, the latter being involved in a secondary phase that may dramatically aggravate the initial damage. Hepatotoxicity, as well as hepatic metabolism, is controlled by a set of nuclear receptors (including PXR, CAR, HNF-4α, FXR, LXR, SHP, VDR and PPAR) and signaling pathways. When isolating liver cells, some pathways are activated, e.g., the RAS/MEK/ERK pathway, whereas others are silenced (e.g. HNF-4α), resulting in up- and downregulation of hundreds of genes. An understanding of these changes is crucial for a correct interpretation of in vitro data. The possibilities and limitations of the most useful liver in vitro systems are summarized, including three-dimensional culture techniques, co-cultures with non-parenchymal cells, hepatospheres, precision cut liver slices and the isolated perfused liver. Also discussed is how closely hepatoma, stem cell and iPS cell-derived hepatocyte-like-cells resemble real hepatocytes. Finally, a summary is given of the state of the art of liver in vitro and mathematical modeling systems that are currently used in the pharmaceutical industry with an emphasis on drug metabolism, prediction of clearance, drug interaction, transporter studies and hepatotoxicity. One key message is that despite our enthusiasm for in vitro systems, we must never lose sight of the in vivo situation. Although hepatocytes have been isolated for decades, the hunt for relevant alternative systems has only just begun.

Modern Topics in Energy and Power Technical Meeting

DTIC Science & Technology

2016-09-01

systems are abysmally low, primarily due to their poor electronic structure. The III-V-based solar cells show the highest solar PV efficiency and thus are...initiatives include creating jet fuel based on seawater, research on photovoltaics ( PVs ) of different types, lightweight fuel cell systems for unmanned air...technoeconomic analysis studies indicate that a 20% solar -to-hydrogen PEC conversion efficiency is necessary for a commercially viable system. Additional

The Role of Gap Junction Channels During Physiologic and Pathologic Conditions of the Human Central Nervous System

PubMed Central

Basilio, Daniel; Sáez, Juan C.; Orellana, Juan A.; Raine, Cedric S.; Bukauskas, Feliksas; Bennett, Michael V. L.; Berman, Joan W.

2013-01-01

Gap junctions (GJs) are expressed in most cell types of the nervous system, including neuronal stem cells, neurons, astrocytes, oligodendrocytes, cells of the blood brain barrier (endothelial cells and astrocytes) and under inflammatory conditions in microglia/macrophages. GJs connect cells by the docking of two hemichannels, one from each cell with each hemichannel being formed by 6 proteins named connexins (Cx). Unapposed hemichannels (uHC) also can be open on the surface of the cells allowing the release of different intracellular factors to the extracellular space. GJs provide a mechanism of cell-to-cell communication between adjacent cells that enables the direct exchange of intracellular messengers, such as calcium, nucleotides, IP3, and diverse metabolites, as well as electrical signals that ultimately coordinate tissue homeostasis, proliferation, differentiation, metabolism, cell survival and death. Despite their essential functions in physiological conditions, relatively little is known about the role of GJs and uHC in human diseases, especially within the nervous system. The focus of this review is to summarize recent findings related to the role of GJs and uHC in physiologic and pathologic conditions of the central nervous system. PMID:22438035

Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

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

Mahadevan, Kathyayani

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 stationarymore » 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).« less

Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

NASA Technical Reports Server (NTRS)

Appelbaum, Joseph; Singer, S.

1989-01-01

Direct current (dc) motors are used in terrestrial photovoltaic (PV) systems such as in water-pumping systems for irrigation and water supply. Direct current motors may also be used for space applications. Simple and low weight systems including dc motors may be of special interest in space where the motors are directly coupled to the solar cell array (with no storage). The system will operate only during times when sufficient insolation is available. An important performance characteristic of electric motors is the starting to rated torque ratio. Different types of dc motors have different starting torque ratios. These ratios are dictated by the size of solar cell array, and the developed motor torque may not be sufficient to overcome the load starting torque. By including a maximum power point tracker (MPPT) in the PV system, the starting to rated torque ratio will increase, the amount of which depends on the motor type. The starting torque ratio is calculated for the permanent magnet, series and shunt excited dc motors when powered by solar cell arrays for two cases: with and without MPPT's. Defining a motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 was obtained for the permanent magnet motor and a magnification of 7 for both the series and shunt motors. The effect of the variation of solar insolation on the motor starting torque was covered. All motor types are less sensitive to insolation variation in systems including MPPT's as compared to systems with MPPT's. The analysis of this paper will assist the PV system designed to determine whether or not to include an MPPT in the system for a specific motor type.

Improvement and scale-up of the NASA Redox storage system

NASA Technical Reports Server (NTRS)

Reid, M. A.; Thaller, L. H.

1980-01-01

A preprototype full-function 1.0 kW Redox system (2 kW peak) with 11 kW storage capacity has been built and integrated with the NASA/DOE photovoltaic test facility. The system includes four substacks of 39 cells each (1/3 sq ft active area) which are connected hydraulically in parallel and electrically in series. An open circuit voltage cell and a set of rebalance cells are used to continuously monitor the system state of charge and automatically maintain the anode and cathode reactants electrochemically in balance. Technological advances in membrane and electrodes and results of multicell stack tests are reviewed.

Integrated systems biology analysis of KSHV latent infection reveals viral induction and reliance on peroxisome mediated lipid metabolism

PubMed Central

Sychev, Zoi E.; Hu, Alex; Lagunoff, Michael

2017-01-01

Kaposi’s Sarcoma associated Herpesvirus (KSHV), an oncogenic, human gamma-herpesvirus, is the etiological agent of Kaposi’s Sarcoma the most common tumor of AIDS patients world-wide. KSHV is predominantly latent in the main KS tumor cell, the spindle cell, a cell of endothelial origin. KSHV modulates numerous host cell-signaling pathways to activate endothelial cells including major metabolic pathways involved in lipid metabolism. To identify the underlying cellular mechanisms of KSHV alteration of host signaling and endothelial cell activation, we identified changes in the host proteome, phosphoproteome and transcriptome landscape following KSHV infection of endothelial cells. A Steiner forest algorithm was used to integrate the global data sets and, together with transcriptome based predicted transcription factor activity, cellular networks altered by latent KSHV were predicted. Several interesting pathways were identified, including peroxisome biogenesis. To validate the predictions, we showed that KSHV latent infection increases the number of peroxisomes per cell. Additionally, proteins involved in peroxisomal lipid metabolism of very long chain fatty acids, including ABCD3 and ACOX1, are required for the survival of latently infected cells. In summary, novel cellular pathways altered during herpesvirus latency that could not be predicted by a single systems biology platform, were identified by integrated proteomics and transcriptomics data analysis and when correlated with our metabolomics data revealed that peroxisome lipid metabolism is essential for KSHV latent infection of endothelial cells. PMID:28257516

Neil Popovich | NREL

Science.gov Websites

(SEPIO). His areas of expertise include low temperature geothermal power production systems; mineral recovery from geothermal brines; fuel cell systems analysis/manufacturing/engineering; instrumentation

Electrolysis Propulsion for Spacecraft Applications

NASA Technical Reports Server (NTRS)

deGroot, Wim A.; Arrington, Lynn A.; McElroy, James F.; Mitlitsky, Fred; Weisberg, Andrew H.; Carter, Preston H., II; Myers, Blake; Reed, Brian D.

1997-01-01

Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined.

Energy Storage Project

NASA Technical Reports Server (NTRS)

Mercer, Carolyn R.; Jankovsky, Amy L.; Reid, Concha M.; Miller, Thomas B.; Hoberecht, Mark A.

2011-01-01

NASA's Exploration Technology Development Program funded the Energy Storage Project to develop battery and fuel cell technology to meet the expected energy storage needs of the Constellation Program for human exploration. Technology needs were determined by architecture studies and risk assessments conducted by the Constellation Program, focused on a mission for a long-duration lunar outpost. Critical energy storage needs were identified as batteries for EVA suits, surface mobility systems, and a lander ascent stage; fuel cells for the lander and mobility systems; and a regenerative fuel cell for surface power. To address these needs, the Energy Storage Project developed advanced lithium-ion battery technology, targeting cell-level safety and very high specific energy and energy density. Key accomplishments include the development of silicon composite anodes, lithiated-mixed-metal-oxide cathodes, low-flammability electrolytes, and cell-incorporated safety devices that promise to substantially improve battery performance while providing a high level of safety. The project also developed "non-flow-through" proton-exchange-membrane fuel cell stacks. The primary advantage of this technology set is the reduction of ancillary parts in the balance-of-plant--fewer pumps, separators and related components should result in fewer failure modes and hence a higher probability of achieving very reliable operation, and reduced parasitic power losses enable smaller reactant tanks and therefore systems with lower mass and volume. Key accomplishments include the fabrication and testing of several robust, small-scale nonflow-through fuel cell stacks that have demonstrated proof-of-concept. This report summarizes the project s goals, objectives, technical accomplishments, and risk assessments. A bibliography spanning the life of the project is also included.

Engineering Hydrogel Microenvironments to Recapitulate the Stem Cell Niche.

PubMed

Madl, Christopher M; Heilshorn, Sarah C

2018-06-04

Stem cells are a powerful resource for many applications including regenerative medicine, patient-specific disease modeling, and toxicology screening. However, eliciting the desired behavior from stem cells, such as expansion in a naïve state or differentiation into a particular mature lineage, remains challenging. Drawing inspiration from the native stem cell niche, hydrogel platforms have been developed to regulate stem cell fate by controlling microenvironmental parameters including matrix mechanics, degradability, cell-adhesive ligand presentation, local microstructure, and cell-cell interactions. We survey techniques for modulating hydrogel properties and review the effects of microenvironmental parameters on maintaining stemness and controlling differentiation for a variety of stem cell types. Looking forward, we envision future hydrogel designs spanning a spectrum of complexity, ranging from simple, fully defined materials for industrial expansion of stem cells to complex, biomimetic systems for organotypic cell culture models.

Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

NASA Astrophysics Data System (ADS)

Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

2017-02-01

The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

Steam reforming of fuel to hydrogen in fuel cells

DOEpatents

Fraioli, Anthony V.; Young, John E.

1984-01-01

A fuel cell capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

Skylab program CSM verification analysis report

NASA Technical Reports Server (NTRS)

Schaefer, J. L.; Vanderpol, G. A.

1970-01-01

The application of the SINDA computer program for the transient thermodynamic simulation of the Apollo fuel cell/radiator system for the limit condition of the proposed Skylab mission is described. Results are included for the thermal constraints imposed upon the Pratt and Whitney fuel cell power capability by the Block 2 EPS radiator system operating under the Skylab fixed attitude orbits.

Time lapse video recordings of highly purified human hematopoietic progenitor cells in culture.

PubMed

Denkers, I A; Dragowska, W; Jaggi, B; Palcic, B; Lansdorp, P M

1993-05-01

Major hurdles in studies of stem cell biology include the low frequency and heterogeneity of human hematopoietic precursor cells in bone marrow and the difficulty of directly studying the effect of various culture conditions and growth factors on such cells. We have adapted the cell analyzer imaging system for monitoring and recording the morphology of limited numbers of cells under various culture conditions. Hematopoietic progenitor cells with a CD34+ CD45RAlo CD71lo phenotype were purified from previously frozen organ donor bone marrow by fluorescence activated cell sorting. Cultures of such cells were analyzed with the imaging system composed of an inverted microscope contained in an incubator, a video camera, an optical memory disk recorder and a computer-controlled motorized microscope XYZ precision stage. Fully computer-controlled video images at defined XYZ positions were captured at selected time intervals and recorded at a predetermined sequence on an optical memory disk. In this study, the cell analyzer system was used to obtain descriptions and measurements of hematopoietic cell behavior, like cell motility, cell interactions, cell shape, cell division, cell cycle time and cell size changes under different culture conditions.

Engineering of Systematic Elimination of a Targeted Chromosome in Human Cells.

PubMed

Sato, Hiroshi; Kato, Hiroki; Yamaza, Haruyoshi; Masuda, Keiji; Nguyen, Huong Thi Nguyen; Pham, Thanh Thi Mai; Han, Xu; Hirofuji, Yuta; Nonaka, Kazuaki

2017-01-01

Embryonic trisomy leads to abortion or congenital genetic disorders in humans. The most common autosomal chromosome abnormalities are trisomy of chromosomes 13, 18, and 21. Although alteration of gene dosage is thought to contribute to disorders caused by extra copies of chromosomes, genes associated with specific disease phenotypes remain unclear. To generate a normal cell from a trisomic cell as a means of etiological analysis or candidate therapy for trisomy syndromes, we developed a system to eliminate a targeted chromosome from human cells. Chromosome 21 was targeted by integration of a DNA cassette in HeLa cells that harbored three copies of chromosome 21. The DNA cassette included two inverted loxP sites and a herpes simplex virus thymidine kinase (HSV-tk) gene. This system causes missegregation of chromosome 21 after expression of Cre recombinase and subsequently enables the selection of cells lacking the chromosome by culturing in a medium that includes ganciclovir (GCV). Cells harboring only two copies of chromosome 21 were efficiently induced by transfection of a Cre expression vector, indicating that this approach is useful for eliminating a targeted chromosome.

Power attenuation characteristics as switch-over criterion in personal satellite mobile communications

NASA Technical Reports Server (NTRS)

Castro, Jonathan P.

1993-01-01

A third generation mobile system intends to support communications in all environments (i.e., outdoors, indoors at home or office and when moving). This system will integrate services that are now available in architectures such as cellular, cordless, mobile data networks, paging, including satellite services to rural areas. One way through which service integration will be made possible is by supporting a hierarchical cellular structure based on umbrella cells, macro cells, micro and pico cells. In this type of structure, satellites are part of the giant umbrella cells allowing continuous global coverage, the other cells belong to cities, neighborhoods, and buildings respectively. This does not necessarily imply that network operation of terrestrial and satellite segments interconnect to enable roaming and spectrum sharing. However, the cell concept does imply hand-off between different cell types, which may involve change of frequency. Within this propsective, the present work uses power attenuation characteristics to determine a dynamic criterion that allows smooth transition from space to terrestrial networks. The analysis includes a hybrid channel that combines Rician, Raleigh and Log Normal fading characteristics.

High throughput laser processing

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

Harley, Gabriel; Pass, Thomas; Cousins, Peter John

A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

Cultivation of mammalian cells using a single-use pneumatic bioreactor system.

PubMed

Obom, Kristina M; Cummings, Patrick J; Ciafardoni, Janelle A; Hashimura, Yasunori; Giroux, Daniel

2014-10-10

Recent advances in mammalian, insect, and stem cell cultivation and scale-up have created tremendous opportunities for new therapeutics and personalized medicine innovations. However, translating these advances into therapeutic applications will require in vitro systems that allow for robust, flexible, and cost effective bioreactor systems. There are several bioreactor systems currently utilized in research and commercial settings; however, many of these systems are not optimal for establishing, expanding, and monitoring the growth of different cell types. The culture parameters most challenging to control in these systems include, minimizing hydrodynamic shear, preventing nutrient gradient formation, establishing uniform culture medium aeration, preventing microbial contamination, and monitoring and adjusting culture conditions in real-time. Using a pneumatic single-use bioreactor system, we demonstrate the assembly and operation of this novel bioreactor for mammalian cells grown on micro-carriers. This bioreactor system eliminates many of the challenges associated with currently available systems by minimizing hydrodynamic shear and nutrient gradient formation, and allowing for uniform culture medium aeration. Moreover, the bioreactor's software allows for remote real-time monitoring and adjusting of the bioreactor run parameters. This bioreactor system also has tremendous potential for scale-up of adherent and suspension mammalian cells for production of a variety therapeutic proteins, monoclonal antibodies, stem cells, biosimilars, and vaccines.

Biliary system

MedlinePlus

The biliary system creates, moves, stores, and releases bile into the duodenum . This helps the body digest food. It also assists ... from the liver to the duodenum. The biliary system includes: The gallbladder Bile ducts and certain cells ...

Mechanisms for Flow-Enhanced Cell Adhesion

PubMed Central

Zhu, Cheng; Yago, Tadayuki; Lou, Jizhong; Zarnitsyna, Veronika I.; McEver, Rodger P.

2009-01-01

Cell adhesion is mediated by specific receptor—ligand bonds. In several biological systems, increasing flow has been observed to enhance cell adhesion despite the increasing dislodging fluid shear forces. Flow-enhanced cell adhesion includes several aspects: flow augments the initial tethering of flowing cells to a stationary surface, slows the velocity and increases the regularity of rolling cells, and increases the number of rollingly adherent cells. Mechanisms for this intriguing phenomenon may include transport-dependent acceleration of bond formation and force-dependent deceleration of bond dissociation. The former includes three distinct transport modes: sliding of cell bottom on the surface, Brownian motion of the cell, and rotational diffusion of the interacting molecules. The latter involves a recently demonstrated counterintuitive behavior called catch bonds where force prolongs rather than shortens the lifetimes of receptor—ligand bonds. In this article, we summarize our recently published data that used dimensional analysis and mutational analysis to elucidate the above mechanisms for flow-enhanced leukocyte adhesion mediated by L-selectinligand interactions. PMID:18299992

A device for real-time live-cell microscopy during dynamic dual-modal mechanostimulation

NASA Astrophysics Data System (ADS)

Lorusso, D.; Nikolov, H. N.; Chmiel, T.; Beach, R. J.; Sims, S. M.; Dixon, S. J.; Holdsworth, D. W.

2017-03-01

Mechanotransduction - the process by which cells sense and respond to mechanical stimuli - is essential for several physiological processes including skeletal homeostasis. Mammalian cells are thought to be sensitive to different modes of mechanical stimuli, including vibration and fluid shear. To better understand the mechanisms underlying the early stages of mechanotransduction, we describe the development of devices for mechanostimulation (by vibration and fluid shear) of live cells that can be integrated with real-time optical microscopy. The integrated system can deliver up to 3 Pa of fluid shear simultaneous with high-frequency sinusoidal vibrations up to 1 g. Stimuli can be applied simultaneously or independently to cells during real-time microscopic imaging. A custom microfluidic chamber was prepared from polydimethylsiloxane on a glass-bottom cell culture dish. Fluid flow was applied with a syringe pump to induce shear stress. This device is compatible with a custom-designed motion control vibration system. A voice coil actuates the system that is suspended on linear air bushings. Accelerations produced by the system were monitored with an on-board accelerometer. Displacement was validated optically using particle tracking digital high-speed imaging (1200 frames per second). During operation at nominally 45 Hz and 0.3 g, displacements were observed to be within 3.56% of the expected value. MC3T3-E1 osteoblast like cells were seeded into the microfluidic device and loaded with the calcium sensitive fluorescent probe fura-2, then mounted onto the dual-modal mechanostimulation platform. Cells were then imaged and monitored for fluorescence emission. In summary, we have developed a system to deliver physiologically relevant vibrations and fluid shear to live cells during real-time imaging and photometry. Monitoring the behavior of live cells loaded with appropriate fluorescent probes will enable characterization of the signals activated during the initial stages of mechanotransduction.

Cell-free protein synthesis: the state of the art.

PubMed

Whittaker, James W

2013-02-01

Cell-free protein synthesis harnesses the synthetic power of biology, programming the ribosomal translational machinery of the cell to create macromolecular products. Like PCR, which uses cellular replication machinery to create a DNA amplifier, cell-free protein synthesis is emerging as a transformative technology with broad applications in protein engineering, biopharmaceutical development, and post-genomic research. By breaking free from the constraints of cell-based systems, it takes the next step towards synthetic biology. Recent advances in reconstituted cell-free protein synthesis (Protein synthesis Using Recombinant Elements expression systems) are creating new opportunities to tailor the reactions for specialized applications including in vitro protein evolution, printing protein microarrays, isotopic labeling, and incorporating nonnatural amino acids.

Fifth Congress of Industrial Cell Technology 2014.

PubMed

Rasch, Anja

2015-01-01

The highly specialized and informative Fifth Congress of Industrial Cell Technology took place in Luebeck, close to Hamburg, on 11-12 September 2014. It was organized by the Fraunhofer Institution for Marine Biotechnology (EMB), Luebeck and supported by the cluster agency Life Science Nord Management GmbH as well as the Luebeck Chamber of Industry and Commerce. The central aim of the congress was to promote the name-giving platform applications of industrial cell technologies, in other words, the development of complex cell culture systems, analyzing technologies, innovative instruments and materials, etc. This year's sessions were: smart cell culture, bioreactor systems and cell goods including 3D bioprinting. This article highlights selected presentations of the congress.

Banning standard cell engineering notebook

NASA Technical Reports Server (NTRS)

1976-01-01

A family of standardized thick-oxide P-MOS building blocks (standard cells) is described. The information is presented in a form useful for systems designs, logic design, and the preparation of inputs to both sets of Design Automation programs for array design and analysis. A data sheet is provided for each cell and gives the cell name, the cell number, its logic symbol, Boolean equation, truth table, circuit schematic circuit composite, input-output capacitances, and revision date. The circuit type file, also given for each cell, together with the logic drawing contained on the data sheet provides all the information required to prepare input data files for the Design Automation Systems. A detailed description of the electrical design procedure is included.

Sympathetic Nervous System Modulation of Inflammation and Remodeling in the Hypertensive Heart

PubMed Central

Levick, Scott P.; Murray, David B.; Janicki, Joseph S.; Brower, Gregory L.

2010-01-01

Chronic activation of the sympathetic nervous system (SNS) is a key component of cardiac hypertrophy and fibrosis. However, previous studies have provided evidence to also implicate inflammatory cells, including mast cells, in the development of cardiac fibrosis. The current study investigated the potential interaction of cardiac mast cells with the SNS. Eight week old male SHR were sympathectomized to establish the effect of the SNS on cardiac mast cell density, myocardial remodeling and cytokine production in the hypertensive heart. Age-matched WKY served as controls. Cardiac fibrosis and hypertension were significantly attenuated and left ventricular mass normalized while cardiac mast cell density was markedly increased in sympathectomized SHR. Sympathectomy normalized myocardial levels of IFN-γ, IL-6 and IL-10, but had no effect on IL-4. The effect of norepinephrine and substance P on isolated cardiac mast cell activation was investigated as potential mechanisms of interaction between the two. Only substance P elicited mast cell degranulation. Substance P was also shown to induce the production of angiotensin II by a mixed population of isolated cardiac inflammatory cells, including mast cells, lymphocytes and macrophages. These results demonstrate the ability of neuropeptides to regulate inflammatory cell function, providing a potential mechanism by which the SNS and afferent nerves may interact with inflammatory cells in the hypertensive heart. PMID:20048196

GATE Center for Automotive Fuel Cell Systems at Virginia Tech

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

Nelson, Douglas

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 whichmore » 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.« less

Human ES cells – haematopoiesis and transplantation strategies*

PubMed Central

Kaufman, DS; Thomson, JA

2002-01-01

Human embryonic stem (ES) cells provide a novel opportunity to study early developmental events in a human system. We have used human ES cell lines, including clonally derived lines, to evaluate haematopoiesis. Co-culture of the human ES cells with irradiated bone marrow stromal cell lines in the presence of fetal bovine serum (FBS), but without other exogenous cytokines, leads to differentiation of the human ES cells within a matter of days. A portion of these differentiated cells express CD34, the best-defined marker for early haematopoietic cells. Haematopoietic colony-forming cells (CFCs) are demonstrated by methylcellulose assay. Myeloid, erythroid, megakaryocyte and multipotential CFCs can all be derived under these conditions. Enrichment of CD34+ cells derived from the human ES cells markedly increases the yield of CFCs, as would be expected for cells derived from adult bone marrow or umbilical cord blood. Transcription factors are also expressed in a manner consistent with haematopoietic differentiation. This system now presents the potential to evaluate specific conditions needed to induce or support events in early human blood development. Human ES cells are also a novel source of cells for transplantation therapies. The immunogenicity of ES cell-derived cells is unknown. The unique properties of ES cells afford the opportunity to explore novel mechanisms to prevent immune-mediated rejection. Potential strategies to overcome rejection will be presented, including creation of haematopoietic chimerism as a means to successfully transplant cells and tissues derived from human ES cells. PMID:12033728

Energy storage considerations for a robotic Mars surface sampler

NASA Technical Reports Server (NTRS)

O'Donnell, P. M.; Cataldo, R. L.; Gonzalez-Sanabria, O. D.

1988-01-01

The characteristics of various energy storage systems (including Ni-Cd, Ni-H2, Ag-Zn, Li-XS, Na-S, PbSO4, and regenerative fuel cell systems) considered for a robotic Mars surface sampler are reviewed. It is concluded that the bipolar nickel-hydrogen battery and the sodium-sulfur battery are both viable candidates as storage systems for the rover's Radioisotope Thermoelectric Generator. For a photovoltaic storage system, the regenerative fuel cell and the bipolar nickel-hydrogen battery are the primary candidates.

Systems and methods for rebalancing redox flow battery electrolytes

DOEpatents

Pham, Ai Quoc; Chang, On Kok

2015-03-17

Various methods of rebalancing electrolytes in a redox flow battery system include various systems using a catalyzed hydrogen rebalance cell configured to minimize the risk of dissolved catalyst negatively affecting flow battery performance. Some systems described herein reduce the chance of catalyst contamination of RFB electrolytes by employing a mediator solution to eliminate direct contact between the catalyzed membrane and the RFB electrolyte. Other methods use a rebalance cell chemistry that maintains the catalyzed electrode at a potential low enough to prevent the catalyst from dissolving.

Charging system and method for multicell storage batteries

DOEpatents

Cox, Jay A.

1978-01-01

A battery-charging system includes a first charging circuit connected in series with a plurality of battery cells for controlled current charging. A second charging circuit applies a controlled voltage across each individual cell for equalization of the cells to the fully charged condition. This controlled voltage is determined at a level above the fully charged open-circuit voltage but at a sufficiently low level to prevent corrosion of cell components by electrochemical reaction. In this second circuit for cell equalization, a transformer primary receives closely regulated, square-wave voltage which is coupled to a plurality of equal secondary coil windings. Each secondary winding is connected in parallel to each cell of a series-connected pair of cells through half-wave rectifiers and a shared, intermediate conductor.

Fuzzy Petri nets to model vision system decisions within a flexible manufacturing system

NASA Astrophysics Data System (ADS)

Hanna, Moheb M.; Buck, A. A.; Smith, R.

1994-10-01

The paper presents a Petri net approach to modelling, monitoring and control of the behavior of an FMS cell. The FMS cell described comprises a pick and place robot, vision system, CNC-milling machine and 3 conveyors. The work illustrates how the block diagrams in a hierarchical structure can be used to describe events at different levels of abstraction. It focuses on Fuzzy Petri nets (Fuzzy logic with Petri nets) including an artificial neural network (Fuzzy Neural Petri nets) to model and control vision system decisions and robot sequences within an FMS cell. This methodology can be used as a graphical modelling tool to monitor and control the imprecise, vague and uncertain situations, and determine the quality of the output product of an FMS cell.

Quantitative assessment of neurite outgrowth in human embryonic stem cell derived hN2 cells using automated high-content image analysis

EPA Science Inventory

Throughout development neurons undergo a number of morphological changes including neurite outgrowth from the cell body. Exposure to neurotoxic chemicals that interfere with this process may result in permanent deficits in nervous system function. Traditionally, rodent primary ne...

Modeling human development in 3D culture.

PubMed

Ader, Marius; Tanaka, Elly M

2014-12-01

Recently human embryonic stem cell research has taken on a new dimension - the third dimension. Capitalizing on increasing knowledge on directing pluripotent cells along different lineages, combined with ECM supported three-dimensional culture conditions, it has become possible to generate highly organized tissues of the central nervous system, gut, liver and kidney. Each system has been used to study different aspects of organogenesis and function including physical forces underlying optic cup morphogenesis, the function of disease related genes in progenitor cell control, as well as interaction of the generated tissues with host tissue upon transplantation. Pluripotent stem cell derived organoids represent powerful systems for the study of how cells self-organize to generate tissues with a given shape, pattern and form. Copyright © 2014 Elsevier Ltd. All rights reserved.

Thermofluid Modeling of Fuel Cells

NASA Astrophysics Data System (ADS)

Young, John B.

2007-01-01

Fuel cells offer the prospect of silent electrical power generation at high efficiency with near-zero pollutant emission. Many materials and fabrication problems have now been solved and attention has shifted toward system modeling, including the fluid flows that supply the cells with hydrogen and oxygen. This review describes the current thermofluid modeling capabilities for proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs), the most promising candidates for commercial exploitation. Topics covered include basic operating principles and stack design, convective-diffusive flow in porous solids, special modeling issues for PEMFCs and SOFCs, and the use of computational fluid dynamics (CFD) methods.

In-situ short circuit protection system and method for high-energy electrochemical cells

DOEpatents

Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

2000-01-01

An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

In-situ short-circuit protection system and method for high-energy electrochemical cells

DOEpatents

Gauthier, Michel; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Rouillard, Jean; Rouillard, Roger; Shiota, Toshimi; Trice, Jennifer L.

2003-04-15

An in-situ thermal management system for an energy storage device. The energy storage device includes a plurality of energy storage cells each being coupled in parallel to common positive and negative connections. Each of the energy storage cells, in accordance with the cell's technology, dimensions, and thermal/electrical properties, is configured to have a ratio of energy content-to-contact surface area such that thermal energy produced by a short-circuit in a particular cell is conducted to a cell adjacent the particular cell so as to prevent the temperature of the particular cell from exceeding a breakdown temperature. In one embodiment, a fuse is coupled in series with each of a number of energy storage cells. The fuses are activated by a current spike capacitively produced by a cell upon occurrence of a short-circuit in the cell, thereby electrically isolating the short-circuited cell from the common positive and negative connections.

Composite polymer systems with control of local substrate elasticity and their effect on cytoskeletal and morphological characteristics of adherent cells.

PubMed

Chou, Szu-Yuan; Cheng, Chao-Min; LeDuc, Philip R

2009-06-01

At the interface between extracellular substrates and biological materials, substrate elasticity strongly influences cell morphology and function. The associated biological ramifications comprise a diversity of critical responses including apoptosis, differentiation, and motility, which can affect medical devices such as stents. The interactions of the extracellular environment with the substrate are also affected by local properties wherein cells sense and respond to different physical inputs. To investigate the effects of having localized elasticity control of substrate microenvironments on cell response, we have developed a method to control material interface interactions with cells by dictating local substrate elasticity. This system is created by generating a composite material system with alternating, linear regions of polymers that have distinct stiffness characteristics. This approach was used to examine cytoskeletal and morphological changes in NIH 3T3 fibroblasts with emphasis on both local and global properties, noting that cells sense and respond to distinct material elasticities. Isolated cells sense and respond to these local differences in substrate elasticity by extending processes along the interface. Also, cells grown on softer elastic regions at higher densities (in contact with each other) have a higher projected area than isolated cells. Furthermore, when using chemical agents such as cytochalasin-D to disrupt the actin cytoskeleton, there is a significant increase in projected area for cells cultured on softer elastic regions This method has the potential to promote understanding of biomaterial-affected responses in a diversity of areas including morphogenesis, mechanotransduction, stents, and stem cell differentiation.

Circuit Design Features of a Stable Two-Cell System.

PubMed

Zhou, Xu; Franklin, Ruth A; Adler, Miri; Jacox, Jeremy B; Bailis, Will; Shyer, Justin A; Flavell, Richard A; Mayo, Avi; Alon, Uri; Medzhitov, Ruslan

2018-02-08

Cell communication within tissues is mediated by multiple paracrine signals including growth factors, which control cell survival and proliferation. Cells and the growth factors they produce and receive constitute a circuit with specific properties that ensure homeostasis. Here, we used computational and experimental approaches to characterize the features of cell circuits based on growth factor exchange between macrophages and fibroblasts, two cell types found in most mammalian tissues. We found that the macrophage-fibroblast cell circuit is stable and robust to perturbations. Analytical screening of all possible two-cell circuit topologies revealed the circuit features sufficient for stability, including environmental constraint and negative-feedback regulation. Moreover, we found that cell-cell contact is essential for the stability of the macrophage-fibroblast circuit. These findings illustrate principles of cell circuit design and provide a quantitative perspective on cell interactions. Copyright © 2018 Elsevier Inc. All rights reserved.

Development of a functional thyroid model based on an organoid culture system.

PubMed

Saito, Yoshiyuki; Onishi, Nobuyuki; Takami, Hiroshi; Seishima, Ryo; Inoue, Hiroyoshi; Hirata, Yuki; Kameyama, Kaori; Tsuchihashi, Kenji; Sugihara, Eiji; Uchino, Shinya; Ito, Koichi; Kawakubo, Hirofumi; Takeuchi, Hiroya; Kitagawa, Yuko; Saya, Hideyuki; Nagano, Osamu

2018-03-04

The low turnover rate of thyroid follicular cells and the lack of a long-term thyroid cell culture system have hampered studies of thyroid carcinogenesis. We have now established a thyroid organoid culture system that supports thyroid cell proliferation in vitro. The established mouse thyroid organoids performed thyroid functions including thyroglobulin synthesis, iodide uptake, and the production and release of thyroid hormone. Furthermore, transplantation of the organoids into recipient mice resulted in the formation of normal thyroid-like tissue capable of iodide uptake and thyroglobulin production in vivo. Finally, forced expression of oncogenic NRAS (NRAS Q61R ) in thyroid organoids established from p53 knockout mice and transplantation of the manipulated organoids into mouse recipients generated a model of poorly differentiated thyroid cancer. Our findings suggest that this newly developed thyroid organoid culture system is a potential research tool for the study of thyroid physiology and pathology including thyroid cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

Novel aspects of live intestinal epithelial cell function revealed using a custom time-lapse video microscopy apparatus.

PubMed

Papetti, Michael; Kozlowski, Piotr

2018-04-01

Many aspects of cell physiology, including migration, membrane function, and cell division, are best understood by observing live cell dynamics over time using video microscopy. To probe these phenomena in colon epithelial cells using simple components with a limited budget, we have constructed an inexpensive (<$410) self-contained apparatus, consisting of a closed-loop, feedback-controlled system regulated by a PID (proportional-integrative-derivative) controller contained within a 0.077 m 3 insulated acrylic box. Temperature, humidity, pH, and proliferative capacity of colon epithelial cells in this system mimic those in a standard tissue culture incubator for over four days. Our system offers significant advantages over existing cost-prohibitive commercially available and custom-made devices because of its very low cost, use of PID temperature control, lack of reliance on constant infusion of external humidified, heated air or carbon dioxide, ability to directly measure cell culture medium temperature, and combination of exquisite cellular detail with minimal focus drift under physiological conditions for extended periods of time. Using this apparatus, coupled with an inverted microscope equipped with phase contrast optics and a programmable digital camera, we have observed many events in colon epithelial cells not visible by static imaging, including kinetics of normal and abnormal mitoses, dynamic membrane structures, intracellular vesicle movements, and cell migration. © 2018 International Society for Advancement of Cytometry. © 2018 International Society for Advancement of Cytometry.

Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications

PubMed Central

Yeo, Chew Chieng; Abu Bakar, Fauziah; Chan, Wai Ting; Espinosa, Manuel; Harikrishna, Jennifer Ann

2016-01-01

Toxin-antitoxin (TA) systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies. PMID:26907343

Three-dimensional hydrogel cell culture systems for modeling neural tissue

NASA Astrophysics Data System (ADS)

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 designed for use as a tool to predict the transport and processing that occurs prior to drug uptake in the central nervous system (CNS), and to predict BBB permeability. Electrochemical techniques and immunohistochemistry were used to validate this model and provide detailed information about cellular organization and function. Electrochemical impedance spectroscopy (EIS) provided evidence that endothelial cells cultured in the presence of astrocytes formed tight junctions capable of occluding the flow of electrical current. In a second series of experiments, a microglia-astrocyte co-culture system was developed to assess the effects of glial cells on electrode impedance recorded from neural prosthetic devices in vitro. Impedance measurements were compared with confocal images to determine the effects of glial cell density and cell type on electrode performance. The results indicate that EIS data can be used to model components of the reactive cell responses in brain tissue, and that impedance measurements recorded in vitro can be compared to measurements recorded in vivo. Taken together, these results demonstrate that alginate hydrogels can be used for the creation of 3-D neural cell scaffolds, and that such cell scaffolds can be used to model a variety of three-dimensional neural tissues in vitro, that cannot be studied in 2-D cultures.

Follicular helper T cells in immunity and systemic autoimmunity.

PubMed

Craft, Joseph E

2012-05-01

Follicular helper T (T(FH)) cells are essential for B-cell maturation and immunoglobulin production after immunization with thymus-dependent antigens. Nevertheless, the development and function of T(FH) cells have been less clearly defined than classic CD4(+) effector T-cell subsets, including T-helper-1 (T(H)1), T(H)2 and T(H)17 cells. As such, our understanding of the genesis of T(FH) cells in humans and their role in the development of autoimmunity remains incomplete. However, evidence from animal models of systemic lupus erythematosus (SLE) and patients with systemic autoimmune diseases suggests that these cells are necessary for pathogenic autoantibody production, in a manner analogous to their role in promotion of B-cell maturation during normal immune responses. In this Review, I discuss the findings that have increased our knowledge of T(FH)-cell development and function in normal and aberrant immune responses. Such information might improve our understanding of autoimmune diseases, such as SLE, and highlights the potential of T(FH) cells as therapeutic targets in these diseases.

Kill and spread the word: stimulation of antitumor immune responses in the context of radiotherapy.

PubMed

Gaipl, Udo S; Multhoff, Gabriele; Scheithauer, Heike; Lauber, Kirsten; Hehlgans, Stefanie; Frey, Benjamin; Rödel, Franz

2014-01-01

Besides the direct, targeted effects of ionizing irradiation (x-ray) on cancer cells, namely DNA damage and cell death induction, indirect, nontargeted ones exist, which are mediated in large part by the immune system. Immunogenic forms of tumor cell death induced by x-ray, including immune modulating danger signals like the heat shock protein 70, adenosine triphosphate, and high-mobility group box 1 protein are presented. Further, antitumor effects exerted by cells of the innate (natural killer cells) as well as adaptive immune system (T cells activated by dendritic cells) are outlined. Tumor cell death inhibiting molecules such as survivin are introduced as suitable target for molecularly tailored therapies in combination with x-ray. Finally, reasonable combinations of immune therapies with radiotherapy are discussed.

Fuel injection and mixing systems having piezoelectric elements and methods of using the same

DOEpatents

Mao, Chien-Pei [Clive, IA; Short, John [Norwalk, IA; Klemm, Jim [Des Moines, IA; Abbott, Royce [Des Moines, IA; Overman, Nick [West Des Moines, IA; Pack, Spencer [Urbandale, IA; Winebrenner, Audra [Des Moines, IA

2011-12-13

A fuel injection and mixing system is provided that is suitable for use with various types of fuel reformers. Preferably, the system includes a piezoelectric injector for delivering atomized fuel, a gas swirler, such as a steam swirler and/or an air swirler, a mixing chamber and a flow mixing device. The system utilizes ultrasonic vibrations to achieve fuel atomization. The fuel injection and mixing system can be used with a variety of fuel reformers and fuel cells, such as SOFC fuel cells.

CHECKPOINT INHIBITOR IMMUNE THERAPY: Systemic Indications and Ophthalmic Side Effects.

PubMed

Dalvin, Lauren A; Shields, Carol L; Orloff, Marlana; Sato, Takami; Shields, Jerry A

2018-06-01

To review immune checkpoint inhibitor indications and ophthalmic side effects. A literature review was performed using a PubMed search for publications between 1990 and 2017. Immune checkpoint inhibitors are designed to treat system malignancies by targeting one of three ligands, leading to T-cell activation for attack against malignant cells. These ligands (and targeted drug) include cytotoxic T-lymphocyte antigen-4 (CTLA-4, ipilimumab), programmed death protein 1 (PD-1, pembrolizumab, nivolumab), and programmed death ligand-1 (PD-L1, atezolizumab, avelumab, durvalumab). These medications upregulate the immune system and cause autoimmune-like side effects. Ophthalmic side effects most frequently manifest as uveitis (1%) and dry eye (1-24%). Other side effects include myasthenia gravis (n = 19 reports), inflammatory orbitopathy (n = 11), keratitis (n = 3), cranial nerve palsy (n = 3), optic neuropathy (n = 2), serous retinal detachment (n = 2), extraocular muscle myopathy (n = 1), atypical chorioretinal lesions (n = 1), immune retinopathy (n = 1), and neuroretinitis (n = 1). Most inflammatory side effects are managed with topical or periocular corticosteroids, but advanced cases require systemic corticosteroids and cessation of checkpoint inhibitor therapy. Checkpoint inhibitors enhance the immune system by releasing inhibition on T cells, with risk of autoimmune-like side effects. Ophthalmologists should include immune-related adverse events in their differential when examining cancer patients with new ocular symptoms.

Estrogen, Angiogenesis, Immunity and Cell Metabolism: Solving the Puzzle.

PubMed

Trenti, Annalisa; Tedesco, Serena; Boscaro, Carlotta; Trevisi, Lucia; Bolego, Chiara; Cignarella, Andrea

2018-03-15

Estrogen plays an important role in the regulation of cardiovascular physiology and the immune system by inducing direct effects on multiple cell types including immune and vascular cells. Sex steroid hormones are implicated in cardiovascular protection, including endothelial healing in case of arterial injury and collateral vessel formation in ischemic tissue. Estrogen can exert potent modulation effects at all levels of the innate and adaptive immune systems. Their action is mediated by interaction with classical estrogen receptors (ERs), ERα and ERβ, as well as the more recently identified G-protein coupled receptor 30/G-protein estrogen receptor 1 (GPER1), via both genomic and non-genomic mechanisms. Emerging data from the literature suggest that estrogen deficiency in menopause is associated with an increased potential for an unresolved inflammatory status. In this review, we provide an overview through the puzzle pieces of how 17β-estradiol can influence the cardiovascular and immune systems.

Isotachophoresis for fractionation and recovery of cytoplasmic RNA and nucleus from single cells.

PubMed

Kuriyama, Kentaro; Shintaku, Hirofumi; Santiago, Juan G

2015-07-01

There is a substantial need for simultaneous analyses of RNA and DNA from individual single cells. Such analysis provides unique evidence of cell-to-cell differences and the correlation between gene expression and genomic mutation in highly heterogeneous cell populations. We present a novel microfluidic system that leverages isotachophoresis to fractionate and isolate cytoplasmic RNA and genomic DNA (gDNA) from single cells. The system uniquely enables independent, sequence-specific analyses of these critical markers. Our system uses a microfluidic chip with a simple geometry and four end-channel electrodes, and completes the entire process in <5 min, including lysis, purification, fractionation, and delivery to DNA and RNA output reservoirs, each containing high quality and purity aliquots with no measurable cross-contamination of cytoplasmic RNA versus gDNA. We demonstrate our system with simultaneous, sequence-specific quantitation using off-chip RT-qPCR and qPCR for simultaneous cytoplasmic RNA and gDNA analyses, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cell death and survival signalling in the cardiovascular system.

PubMed

Tucka, Joanna; Bennett, Martin; Littlewood, Trevor

2012-01-01

The loss of cells is an important factor in many diseases, including those of the cardiovascular system. Whereas apoptosis is an essential process in development and tissue homeostasis, its occurrence is often associated with various pathologies. Apoptosis of neurons that fail to make appropriate connections is essential for the selection of correct neural signalling in the developing embryo, but its appearance in adults is often associated with neurodegenerative disease. Similarly, in the cardiovascular system, remodeling of the mammalian outflow tract during the transition from a single to dual series circulation with four chambers is accompanied by a precise pattern of cell death, but apoptosis of cardiomyocytes contributes to ischemia-reperfusion injury in the heart. In many cases, it is unclear whether apoptosis represents a causative association or merely a consequence of the disease itself. There are many excellent reviews on cell death in the cardiovascular system (1-5); in this review we outline the critical signalling pathways that promote the survival of cardiovascular cells, and their relevance to both physiological cell death and disease.

Disease-Associated Plasmacytoid Dendritic Cells

PubMed Central

Li, Shuang; Wu, Jing; Zhu, Shan; Liu, Yong-Jun; Chen, Jingtao

2017-01-01

Plasmacytoid dendritic cells (pDCs), also called natural interferon (IFN)-producing cells, represent a specialized cell type within the innate immune system. pDCs are specialized in sensing viral RNA and DNA by toll-like receptor-7 and -9 and have the ability to rapidly produce massive amounts of type 1 IFNs upon viral encounter. After producing type 1 IFNs, pDCs differentiate into professional antigen-presenting cells, which are capable of stimulating T cells of the adaptive immune system. Chronic activation of human pDCs by self-DNA or mitochondrial DNA contributes to the pathogenesis of systemic lupus erythematosis and IFN-related autoimmune diseases. Under steady-state conditions, pDCs play an important role in immune tolerance. In many types of human cancers, recruitment of pDCs to the tumor microenvironment contributes to the induction of immune tolerance. Here, we provide a systemic review of recent progress in studies on the role of pDCs in human diseases, including cancers and autoimmune/inflammatory diseases. PMID:29085361

System for controlling the operating temperature of a fuel cell

DOEpatents

Fabis, Thomas R.; Makiel, Joseph M.; Veyo, Stephen E.

2006-06-06

A method and system are provided for improved control of the operating temperature of a fuel cell (32) utilizing an improved temperature control system (30) that varies the flow rate of inlet air entering the fuel cell (32) in response to changes in the operating temperature of the fuel cell (32). Consistent with the invention an improved temperature control system (30) is provided that includes a controller (37) that receives an indication of the temperature of the inlet air from a temperature sensor (39) and varies the heat output by at least one heat source (34, 36) to maintain the temperature of the inlet air at a set-point T.sub.inset. The controller (37) also receives an indication of the operating temperature of the fuel cell (32) and varies the flow output by an adjustable air mover (33), within a predetermined range around a set-point F.sub.set, in order to maintain the operating temperature of the fuel cell (32) at a set-point T.sub.opset.

Material Challenges and Opportunities for Commercial Electric Aircraft

NASA Technical Reports Server (NTRS)

Misra, Ajay

2014-01-01

Significant reduction in carbon dioxide emission for future air transportation system will require adoption of electric propulsion system and more electric architectures. Various options for aircraft electric propulsion include hybrid electric, turboelectric, and full electric system. Realization of electric propulsion system for commercial aircraft applications will require significant increases in power density of electric motors and energy density of energy storage system, such as the batteries and fuel cells. In addition, transmission of MW of power in the aircraft will require high voltage power transmission system to reduce the weight of the power transmission system. Finally, there will be significant thermal management challenges. Significant advances in material technologies will be required to meet these challenges. Technologies of interest include materials with higher electrical conductivity than Cu, high thermal conductivity materials, and lightweight electrically insulating materials with high breakdown voltage, high temperature magnets, advanced battery and fuel cell materials, and multifunctional materials. The presentation will include various challenges for commercial electric aircraft and provide an overview of material improvements that will be required to meet these challenges.

A practical guide to microfluidic perfusion culture of adherent mammalian cells.

PubMed

Kim, Lily; Toh, Yi-Chin; Voldman, Joel; Yu, Hanry

2007-06-01

Culturing cells at microscales allows control over microenvironmental cues, such as cell-cell and cell-matrix interactions; the potential to scale experiments; the use of small culture volumes; and the ability to integrate with microsystem technologies for on-chip experimentation. Microfluidic perfusion culture in particular allows controlled delivery and removal of soluble biochemical molecules in the extracellular microenvironment, and controlled application of mechanical forces exerted via fluid flow. There are many challenges to designing and operating a robust microfluidic perfusion culture system for routine culture of adherent mammalian cells. The current literature on microfluidic perfusion culture treats microfluidic design, device fabrication, cell culture, and micro-assays independently. Here we systematically present and discuss important design considerations in the context of the entire microfluidic perfusion culture system. These design considerations include the choice of materials, culture configurations, microfluidic network fabrication and micro-assays. We also present technical issues such as sterilization; seeding cells in both 2D and 3D configurations; and operating the system under optimized mass transport and shear stress conditions, free of air-bubbles. The integrative and systematic treatment of the microfluidic system design and fabrication, cell culture, and micro-assays provides novices with an effective starting point to build and operate a robust microfludic perfusion culture system for various applications.

Role of Matricellular Proteins in Disorders of the Central Nervous System.

PubMed

Jayakumar, A R; Apeksha, A; Norenberg, M D

2017-03-01

Matricellular proteins (MCPs) are actively expressed non-structural proteins present in the extracellular matrix, which rapidly turnover and possess regulatory roles, as well as mediate cell-cell interactions. MCPs characteristically contain binding sites for other extracellular proteins, cell surface receptors, growth factors, cytokines and proteases, that provide structural support for surrounding cells. MCPs are present in most organs, including brain, and play a major role in cell-cell interactions and tissue repair. Among the MCPs found in brain include thrombospondin-1/2, secreted protein acidic and rich in cysteine family (SPARC), including Hevin/SC1, Tenascin C and CYR61/Connective Tissue Growth Factor/Nov family of proteins, glypicans, galectins, plasminogen activator inhibitor (PAI-1), autotaxin, fibulin and perisostin. This review summarizes the potential role of MCPs in the pathogenesis of major neurological disorders, including Alzheimer's disease, amyotrophic lateral sclerosis, ischemia, trauma, hepatic encephalopathy, Down's syndrome, autism, multiple sclerosis, brain neoplasms, Parkinson's disease and epilepsy. Potential therapeutic opportunities of MCP's for these disorders are also considered in this review.

Cellular Models: HD Patient-Derived Pluripotent Stem Cells.

PubMed

Geater, Charlene; Hernandez, Sarah; Thompson, Leslie; Mattis, Virginia B

2018-01-01

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by expanded polyglutamine (polyQ)-encoding repeats in the Huntingtin (HTT) gene. Traditionally, HD cellular models consisted of either patient cells not affected by disease or rodent neurons expressing expanded polyQ repeats in HTT. As these models can be limited in their disease manifestation or proper genetic context, respectively, human HD pluripotent stem cells (PSCs) are currently under investigation as a way to model disease in patient-derived neurons and other neural cell types. This chapter reviews embryonic stem cell (ESC) and induced pluripotent stem cell (iPSC) models of disease, including published differentiation paradigms for neurons and their associated phenotypes, as well as current challenges to the field such as validation of the PSCs and PSC-derived cells. Highlighted are potential future technical advances to HD PSC modeling, including transdifferentiation, complex in vitro multiorgan/system reconstruction, and personalized medicine. Using a human HD patient model of the central nervous system, hopefully one day researchers can tease out the consequences of mutant HTT (mHTT) expression on specific cell types within the brain in order to identify and test novel therapies for disease.

Tooth, hair and claw: comparing epithelial stem cell niches of ectodermal appendages

PubMed Central

Naveau, Adrien; Seidel, Kerstin; Klein, Ophir D.

2014-01-01

The vertebrate ectoderm gives rise to organs that produce mineralized or keratinized substances, including teeth, hair, and claws. Most of these ectodermal derivatives grow continuously throughout the animal’s life and have active pools of adult stem cells that generate all the necessary cell types. These organs provide powerful systems for understanding the mechanisms that enable stem cells to regenerate or renew ectodermally derived tissues, and remarkable progress in our understanding of these systems has been made in recent years using mouse models. We briefly compare what is known about stem cells and their niches in incisors, hair follicles, and claws, and we examine expression of Gli1 as a potential example of a shared stem cell marker. We summarize some of the features, structures, and functions of the stem cell niches in these ectodermal derivatives; definition of the basic elements of the stem cell niches in these organs will provide guiding principles for identification and characterization of the niche in similar systems. PMID:24530577

Therapeutic application of extracellular vesicles in acute and chronic renal injury.

PubMed

Rovira, Jordi; Diekmann, Fritz; Campistol, Josep M; Ramírez-Bajo, María José

A new cell-to-cell communication system was discovered in the 1990s, which involves the release of vesicles into the extracellular space. These vesicles shuttle bioactive particles, including proteins, mRNA, miRNA, metabolites, etc. This particular communication has been conserved throughout evolution, which explains why most cell types are capable of producing vesicles. Extracellular vesicles (EVs) are involved in the regulation of different physiological processes, as well as in the development and progression of several diseases. EVs have been widely studied over recent years, especially those produced by embryonic and adult stem cells, blood cells, immune system and nervous system cells, as well as tumour cells. EV analysis from bodily fluids has been used as a diagnostic tool for cancer and recently for different renal diseases. However, this review analyses the importance of EVs generated by stem cells, their function and possible clinical application in renal diseases and kidney transplantation. Copyright © 2016. Published by Elsevier España, S.L.U.

Radiogenic cell transformation and carcinogenesis

NASA Technical Reports Server (NTRS)

Yang, T. C.; Georgy, K. A.; Mei, M.; Durante, M.; Craise, L. M.

1995-01-01

Radiation carcinogenesis is one of the major biological effects considered important in the risk assessment for space travel. Various biological model systems, including both cultured cells and animals, have been found useful for studying the carcinogenic effects of space radiations, which consist of energetic electrons, protons and heavy ions. The development of techniques for studying neoplastic cell transformation in culture has made it possible to examine the cellular and molecular mechanisms of radiation carcinogenesis. Cultured cell systems are thus complementary to animal models. Many investigators have determined the oncogenic effects of ionizing and nonionizing radiation in cultured mammalian cells. One of the cell systems used most often for radiation transformation studies is mouse embryonic cells (C3H10T1/2), which are easy to culture and give good quantitative dose-response curves. Relative biological effectiveness (RBE) for heavy ions with various energies and linear energy transfer (LET) have been obtained with this cell system. Similar RBE and LET relationship was observed by investigators for other cell systems. In addition to RBE measurements, fundamental questions on repair of sub- and potential oncogenic lesions, direct and indirect effect, primary target and lesion, the importance of cell-cell interaction and the role of oncogenes and tumor suppressor genes in radiogenic carcinogenesis have been studied, and interesting results have been found. Recently several human epithelial cell systems have been developed, and ionizing radiation have been shown to transform these cells. Oncogenic transformation of these cells, however, requires a long expression time and/or multiple radiation exposures. Limited experimental data indicate high-LET heavy ions can be more effective than low-LET radiation in inducing cell transformation. Cytogenetic and molecular analyses can be performed with cloned transformants to provide insights into basic genetic mechanism(s) of radiogenic transformation of human epithelial cells.

Spaceflight bioreactor studies of cells and tissues.

PubMed

Freed, Lisa E; Vunjak-Novakovic, Gordana

2002-01-01

Studies of the fundamental role of gravity in the development and function of biological organisms are a central component of the human exploration of space. Microgravity affects numerous physical phenomena relevant to biological research, including the hydrostatic pressure in fluid filled vesicles, sedimentation of organelles, and buoyancy-driven convection of flow and heat. These physical phenomena can in turn directly and indirectly affect cellular morphology, metabolism, locomotion, secretion of extracellular matrix and soluble signals, and assembly into functional tissues. Studies aimed at distinguishing specific effects of gravity on biological systems require the ability to: (i) control and systematically vary gravity, e.g. by utilizing the microgravity environment of space in conjunction with an in-flight centrifuge; and (ii) maintain constant all other factors in the immediate environment, including in particular concentrations and exchange rates of biochemical species and hydrodynamic shear. The latter criteria imply the need for gravity-independent mechanisms to provide for mass transport between the cells and their environment. Available flight hardware has largely determined the experimental design and scientific objectives of spaceflight cell and tissue culture studies carried out to date. Simple culture vessels have yielded important quantitative data, and helped establish in vitro models of cell locomotion, growth and differentiation in various mammalian cell types including embryonic lung cells [6], lymphocytes [2,8], and renal cells [7,31]. Studies done using bacterial cells established the first correlations between gravity-dependent factors such as cell settling velocity and diffusional distance and the respective cell responses [12]. The development of advanced bioreactors for microgravity cell and tissue culture and for tissue engineering has benefited both research areas and provided relevant in vitro model systems for studies of astronaut well-being (loss of muscle and skeletal tissues [15-17]) and gene- and cell-level responses to the mechanical environment [13,14,18]. All five of the spaceflight bioreactor studies described above utilized three-dimensional cell culture systems in which the cells were associated with biodegradable polymer scaffolds [17], collagen gel [16], or microcarrier beads [13-15,18] in order to promote the expression of differentiated cell function. In four of the five spaceflight bioreactor studies [15-18], cells were cultured in perfused vessels (cartridges or rotating bioreactors) within recirculating loops designed to maintain medium composition within target ranges by a combination of gas exchange and fresh medium supply. Future spaceflight studies of cells and tissues are likely to involve a three-dimensional culture system, to promote cellular differentiation, and perfusion with or without rotation, to provide a gravity-independent mechanism for fluid mixing and mass transport. Previous spaceflight studies have guided the ongoing development of NASA flight hardware for the ISS (e.g. the EDU-2 and the CCU). This next generation of hardware will have extended operational capabilities including on-line microscopy, in-line sensors for the monitoring and control of metabolic parameters, modular design for replicate cultures, and, perhaps most importantly of all, compatibility with the ISS centrifuge. The latter will permit in-flight, 1 g control cultures, and thereby allow the experimental variable to be gravity itself rather than the more general "spaceflight environment". Technical limitations of spaceflight studies (e.g. allowable size, mass, and power) continue to motivate a creative approach to system design and to result in "spin-off" technologies (e.g. the STLV) for ground-based cell and tissue culture research. The increasing scientific and medical relevance of this work is evidenced by the growing number of publications in which advanced bioreactors are used for in vitro studies in physiologically relevant cell and tissue models.

PhysiCell: An open source physics-based cell simulator for 3-D multicellular systems.

PubMed

Ghaffarizadeh, Ahmadreza; Heiland, Randy; Friedman, Samuel H; Mumenthaler, Shannon M; Macklin, Paul

2018-02-01

Many multicellular systems problems can only be understood by studying how cells move, grow, divide, interact, and die. Tissue-scale dynamics emerge from systems of many interacting cells as they respond to and influence their microenvironment. The ideal "virtual laboratory" for such multicellular systems simulates both the biochemical microenvironment (the "stage") and many mechanically and biochemically interacting cells (the "players" upon the stage). PhysiCell-physics-based multicellular simulator-is an open source agent-based simulator that provides both the stage and the players for studying many interacting cells in dynamic tissue microenvironments. It builds upon a multi-substrate biotransport solver to link cell phenotype to multiple diffusing substrates and signaling factors. It includes biologically-driven sub-models for cell cycling, apoptosis, necrosis, solid and fluid volume changes, mechanics, and motility "out of the box." The C++ code has minimal dependencies, making it simple to maintain and deploy across platforms. PhysiCell has been parallelized with OpenMP, and its performance scales linearly with the number of cells. Simulations up to 105-106 cells are feasible on quad-core desktop workstations; larger simulations are attainable on single HPC compute nodes. We demonstrate PhysiCell by simulating the impact of necrotic core biomechanics, 3-D geometry, and stochasticity on the dynamics of hanging drop tumor spheroids and ductal carcinoma in situ (DCIS) of the breast. We demonstrate stochastic motility, chemical and contact-based interaction of multiple cell types, and the extensibility of PhysiCell with examples in synthetic multicellular systems (a "cellular cargo delivery" system, with application to anti-cancer treatments), cancer heterogeneity, and cancer immunology. PhysiCell is a powerful multicellular systems simulator that will be continually improved with new capabilities and performance improvements. It also represents a significant independent code base for replicating results from other simulation platforms. The PhysiCell source code, examples, documentation, and support are available under the BSD license at http://PhysiCell.MathCancer.org and http://PhysiCell.sf.net.

Feasibility study of a 110 watt per kilogram lightweight solar array system

NASA Technical Reports Server (NTRS)

Shepard, N. F.; Stahle, C. V.; Hanson, K. L.; Schneider, A.; Blomstrom, L. E.; Hansen, W. T.; Kirpich, A.

1973-01-01

The feasibility of a 10,000 watt solar array panel which has a minimum power-to-mass ratio of 110 watt/kg is discussed. The application of this ultralightweight solar array to three possible missions was investigated. With the interplanetary mission as a baseline, the constraining requirements for a geosynchronous mission and for a manned space station mission are presented. A review of existing lightweight solar array system concepts revealed that changes in the system approach are necessary to achieve the specified 110 watt/kg goal. A comprehensive review of existing component technology is presented in the areas of thin solar cells, solar cell covers, welded interconnectors, substrates and deployable booms. Advances in the state-of-the-art of solar cell and deployable boom technology were investigated. System level trade studies required to select the optimum boom bending stiffness, system aspect ratio, bus voltage level, and solar cell circuit arrangement are reported. Design analysis tasks included the thermal analysis of the solar cell blanket, thermal stress analysis of the solar cell interconnectors/substrate, and the thermostructural loading of the deployed boom.

Hydrogen Research for Spaceport and Space-Based Applications: Fuel Cell Projects

NASA Technical Reports Server (NTRS)

Anderson, Tim; Balaban, Canan

2008-01-01

The activities presented are a broad based approach to advancing key hydrogen related technologies in areas such as fuel cells, hydrogen production, and distributed sensors for hydrogen-leak detection, laser instrumentation for hydrogen-leak detection, and cryogenic transport and storage. Presented are the results from research projects, education and outreach activities, system and trade studies. The work will aid in advancing the state-of-the-art for several critical technologies related to the implementation of a hydrogen infrastructure. Activities conducted are relevant to a number of propulsion and power systems for terrestrial, aeronautics and aerospace applications. Fuel cell research focused on proton exchange membranes (PEM), solid oxide fuel cells (SOFC). Specific technologies included aircraft fuel cell reformers, new and improved electrodes, electrolytes, interconnect, and seals, modeling of fuel cells including CFD coupled with impedance spectroscopy. Research was conducted on new materials and designs for fuel cells, along with using embedded sensors with power management electronics to improve the power density delivered by fuel cells. Fuel cell applications considered were in-space operations, aviation, and ground-based fuel cells such as; powering auxiliary power units (APUs) in aircraft; high power density, long duration power supplies for interplanetary missions (space science probes and planetary rovers); regenerative capabilities for high altitude aircraft; and power supplies for reusable launch vehicles.

The Celution® System: Automated Processing of Adipose-Derived Regenerative Cells in a Functionally Closed System.

PubMed

Fraser, John K; Hicok, Kevin C; Shanahan, Rob; Zhu, Min; Miller, Scott; Arm, Douglas M

2014-01-01

Objective: To develop a closed, automated system that standardizes the processing of human adipose tissue to obtain and concentrate regenerative cells suitable for clinical treatment of thermal and radioactive burn wounds. Approach: A medical device was designed to automate processing of adipose tissue to obtain a clinical-grade cell output of stromal vascular cells that may be used immediately as a therapy for a number of conditions, including nonhealing wounds resulting from radiation damage. Results: The Celution ® System reliably and reproducibly generated adipose-derived regenerative cells (ADRCs) from tissue collected manually and from three commercial power-assisted liposuction devices. The entire process of introducing tissue into the system, tissue washing and proteolytic digestion, isolation and concentration of the nonadipocyte nucleated cell fraction, and return to the patient as a wound therapeutic, can be achieved in approximately 1.5 h. An alternative approach that applies ultrasound energy in place of enzymatic digestion demonstrates extremely poor efficiency cell extraction. Innovation: The Celution System is the first medical device validated and approved by multiple international regulatory authorities to generate autologous stromal vascular cells from adipose tissue that can be used in a real-time bedside manner. Conclusion: Initial preclinical and clinical studies using ADRCs obtained using the automated tissue processing Celution device described herein validate a safe and effective manner to obtain a promising novel cell-based treatment for wound healing.

Energy distributions exhibited during thermal runaway of commercial lithium ion batteries used for human spaceflight applications

NASA Astrophysics Data System (ADS)

Yayathi, Sandeep; Walker, William; Doughty, Daniel; Ardebili, Haleh

2016-10-01

Lithium ion (Li-ion) batteries provide low mass and energy dense solutions necessary for space exploration, but thermal related safety concerns impede the utilization of Li-ion technology for human applications. Experimental characterization of thermal runaway energy release with accelerated rate calorimetry supports safer thermal management systems. 'Standard' accelerated rate calorimetry setup provides means to measure the addition of energy exhibited through the body of a Li-ion cell. This study considers the total energy generated during thermal runaway as distributions between cell body and hot gases via inclusion of a unique secondary enclosure inside the calorimeter; this closed system not only contains the cell body and gaseous species, but also captures energy release associated with rapid heat transfer to the system unobserved by measurements taken on the cell body. Experiments include Boston Power Swing 5300, Samsung 18650-26F and MoliCel 18650-J Li-ion cells at varied states-of-charge. An inverse relationship between state-of-charge and onset temperature is observed. Energy contained in the cell body and gaseous species are successfully characterized; gaseous energy is minimal. Significant additional energy is measured with the heating of the secondary enclosure. Improved calorimeter apparatus including a secondary enclosure provides essential capability to measuring total energy release distributions during thermal runaway.

Fuel cell drives for road vehicles

NASA Astrophysics Data System (ADS)

Charnah, R. M.

For fuel-cell driven vehicles, including buses, the fuel cell may be the main, determining factor in the system but must be integrated into the complete design process. A Low-Floor Bus design is used to illustrate this point. The influence of advances in drive-train electronics is illustrated as are novel designs for motors and mechanical transmission of power to the wheels allowing the use of novel hub assemblies. A hybrid electric power system is being deployed in which Fuel Cells produce the energy needs but are coupled with batteries especially for acceleration phases and for recuperative braking.

Steam reforming of fuel to hydrogen in fuel cell

DOEpatents

Young, J.E.; Fraioli, A.V.

1983-07-13

A fuel cell is described capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

Identifying viable regulatory and innovation pathways for regenerative medicine: a case study of cultured red blood cells.

PubMed

Mittra, J; Tait, J; Mastroeni, M; Turner, M L; Mountford, J C; Bruce, K

2015-01-25

The creation of red blood cells for the blood transfusion markets represents a highly innovative application of regenerative medicine with a medium term (5-10 year) prospect for first clinical studies. This article describes a case study analysis of a project to derive red blood cells from human embryonic stem cells, including the systemic challenges arising from (i) the selection of appropriate and viable regulatory protocols and (ii) technological constraints related to stem cell manufacture and scale up to clinical Good Manufacturing Practice (GMP) standard. The method used for case study analysis (Analysis of Life Science Innovation Systems (ALSIS)) is also innovative, demonstrating a new approach to social and natural science collaboration to foresight product development pathways. Issues arising along the development pathway include cell manufacture and scale-up challenges, affected by regulatory demands emerging from the innovation ecosystem (preclinical testing and clinical trials). Our discussion reflects on the efforts being made by regulators to adapt the current pharmaceuticals-based regulatory model to an allogeneic regenerative medicine product and the broader lessons from this case study for successful innovation and translation of regenerative medicine therapies, including the role of methodological and regulatory innovation in future development in the field. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Proteomics show antigen presentation processes in human immune cells after AS03-H5N1 vaccination.

PubMed

Galassie, Allison C; Goll, Johannes B; Samir, Parimal; Jensen, Travis L; Hoek, Kristen L; Howard, Leigh M; Allos, Tara M; Niu, Xinnan; Gordy, Laura E; Creech, C Buddy; Hill, Heather; Joyce, Sebastian; Edwards, Kathryn M; Link, Andrew J

2017-06-01

Adjuvants enhance immunity elicited by vaccines through mechanisms that are poorly understood. Using a systems biology approach, we investigated temporal protein expression changes in five primary human immune cell populations: neutrophils, monocytes, natural killer cells, T cells, and B cells after administration of either an Adjuvant System 03 adjuvanted or unadjuvanted split-virus H5N1 influenza vaccine. Monocytes demonstrated the strongest differential signal between vaccine groups. On day 3 post-vaccination, several antigen presentation-related pathways, including MHC class I-mediated antigen processing and presentation, were enriched in monocytes and neutrophils and expression of HLA class I proteins was increased in the Adjuvant System 03 group. We identified several protein families whose proteomic responses predicted seroprotective antibody responses (>1:40 hemagglutination inhibition titer), including inflammation and oxidative stress proteins at day 1 as well as immunoproteasome subunit (PSME1 and PSME2) and HLA class I proteins at day 3 in monocytes. While comparison between temporal proteomic and transcriptomic results showed little overlap overall, enrichment of the MHC class I antigen processing and presentation pathway in monocytes and neutrophils was confirmed by both approaches. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Embryonic stem cells and the next generation of developmental toxicity testing.

PubMed

Kugler, Josephine; Huhse, Bettina; Tralau, Tewes; Luch, Andreas

2017-08-01

The advent of stem cell technology has seen the establishment of embryonic stem cells (ESCs) as molecular model systems and screening tools. Although ESCs are nowadays widely used in research, regulatory implementation for developmental toxicity testing is pending. Areas Covered: This review evaluates the performance of current ESC, including human (h)ESC testing systems, trying to elucidate their potential for developmental toxicity testing. It shall discuss defining parameters and mechanisms, their relevance and contemplate what can realistically be expected. Crucially this includes the question of how to ascertain the quality of currently employed cell lines and tests based thereon. Finally, the use of hESCs will raise ethical concerns which should be addressed early on. Expert Opinion: While the suitability of (h)ESCs as tools for research and development goes undisputed, any routine use for developmental toxicity testing currently still seems premature. The reasons for this comprise inherent biological deficiencies as well as cell line quality and system validation. Overcoming these issues will require collaboration of scientists, test developers and regulators. Also, validation needs to be made worthwhile for academia. Finally we have to continuously rethink existing strategies, making room for improved testing and innovative approaches.

Functionalized Nanostructures with Application in Regenerative Medicine

PubMed Central

Perán, Macarena; García, María A.; López-Ruiz, Elena; Bustamante, Milán; Jiménez, Gema; Madeddu, Roberto; Marchal, Juan A.

2012-01-01

In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application. PMID:22489186

Optoelectronic simulation of GaAs solar cells with angularly selective filters

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

Kraus, Tobias, E-mail: tobias.kraus@ise.fraunhofer.de; Höhn, Oliver; Hauser, Hubert

We discuss the influence of angularly selective filters on thin film gallium arsenide solar cells. For this reason, the detailed balance model was refined to fit our needs with respect to Auger recombination, reflection, transmission, and realistic absorption. For calculating real systems, an approach was made to include optical effects of angularly selective filters into electron-hole dynamic equations implemented in PC1D, a one dimensional solar cell calculation tool. With this approach, we find a relative V{sub oc} increase of 5% for an idealized 100 nm GaAs cell, including Auger recombination.

Purinergic signaling pathways in endocrine system.

PubMed

Bjelobaba, Ivana; Janjic, Marija M; Stojilkovic, Stanko S

2015-09-01

Adenosine-5'-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5'-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5'-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5'-triphosphate hydrolysis to adenosine-5'-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling. Published by Elsevier B.V.

Purinergic Signaling Pathways in Endocrine System

PubMed Central

Bjelobaba, Ivana; Janjic, Marija M.; Stojilkovic, Stanko S.

2015-01-01

Adenosine-5′-triphosphate is released by neuroendocrine, endocrine, and other cell types and acts as an extracellular agonist for ligand-gated P2X cationic channels and G protein-coupled P2Y receptors in numerous organs and tissues, including the endocrine system. The breakdown of ATP by ectonucleotidases not only terminates its extracellular messenger functions, but also provides a pathway for the generation of two additional agonists: adenosine 5′-diphosphate, acting via some P2Y receptors, and adenosine, a native agonist for G protein-coupled adenosine receptors, also expressed in the endocrine system. This article provides a review of purinergic signaling pathways in the hypothalamic magnocellular neurosecretory cells and neurohypophysis, hypothalamic parvocellular neuroendocrine system, adenohypophysis, and effector glands organized in five axes: hypothalamic-pituitary-gonadal, hypothalamic-pituitary-thyroid, hypothalamic-pituitary-adrenal, hypothalamic-pituitary-growth hormone, and hypothalamic-pituitary-prolactin. We attempted to summarize current knowledge of purinergic receptor subtypes expressed in the endocrine system, including their roles in intracellular signaling, hormone secretion, and other cell functions. We also briefly review the release mechanism for adenosine-5′-triphosphate by neuroendocrine, endocrine and surrounding cells, the enzymes involved in adenosine-5′-triphosphate hydrolysis to adenosine-5′-diphosphate and adenosine, and the relevance of this pathway for sequential activation of receptors and termination of signaling. PMID:25960051

Radio-frequency and microwave energies, magnetic and electric fields

NASA Technical Reports Server (NTRS)

Michaelson, S. M.

1975-01-01

The biological effects of radio frequency, including microwave, radiation are considered. Effects on body temperature, the eye, reproductive systems, internal organs, blood cells, the cardiovascular system, and the central nervous system are included. Generalized effects of electric and magnetic fields are also discussed. Experimentation with animals and clinical studies on humans are cited, and possible mechanisms of the effects observed are suggested.

Improvement and scale-up of the NASA Redox storage system

NASA Technical Reports Server (NTRS)

Reid, M. A.; Thaller, L. H.

1980-01-01

A preprototype 1.0 kW redox system (2 kW peak) with 11 kWh storage capacity was built and integrated with the NASA/DOE photovoltaic test facility at NASA Lewis. This full function redox system includes four substacks of 39 cells each (1/3 cu ft active area) which are connected hydraulically in parallel and electrically in series. An open circuit voltage cell and a set of rebalance cells are used to continuously monitor the system state of charge and automatically maintain the anode and cathode reactants electrochemically in balance. Recent membrane and electrode advances are summarized and the results of multicell stack tests of 1 cu ft are described.

Integration of photoswitchable proteins, photosynthetic reaction centers and semiconductor/biomolecule hybrids with electrode supports for optobioelectronic applications.

PubMed

Wang, Fuan; Liu, Xiaoqing; Willner, Itamar

2013-01-18

Light-triggered biological processes provide the principles for the development of man-made optobioelectronic systems. This Review addresses three recently developed topics in the area of optobioelectronics, while addressing the potential applications of these systems. The topics discussed include: (i) the reversible photoswitching of the bioelectrocatalytic functions of redox proteins by the modification of proteins with photoisomerizable units or by the integration of proteins with photoisomerizable environments; (ii) the integration of natural photosynthetic reaction centers with electrodes and the construction of photobioelectrochemical cells and photobiofuel cells; and (iii) the synthesis of biomolecule/semiconductor quantum dots hybrid systems and their immobilization on electrodes to yield photobioelectrochemical and photobiofuel cell elements. The fundamental challenge in the tailoring of optobioelectronic systems is the development of means to electrically contact photoactive biomolecular assemblies with the electrode supports. Different methods to establish electrical communication between the photoactive biomolecular assemblies and electrodes are discussed. These include the nanoscale engineering of the biomolecular nanostructures on surfaces, the development of photoactive molecular wires and the coupling of photoinduced electron transfer reactions with the redox functions of proteins. The different possible applications of optobioelectronic systems are discussed, including their use as photosensors, the design of biosensors, and the construction of solar energy conversion and storage systems. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chronic active EBV infection: the experience of the Samsung Medical Center in South Korea.

PubMed

Lee, Tae-Hee; Ko, Young-Hyeh

Chronic active EBV infection (CAEBV) of T-cell or NK-cell type is an EBV+ polyclonal, oligoclonal or often monoclonal lymphoproliferative disorder (LPD) recognized as representing the spectrum of EBV-associated T-cell and NK-cell LPD with different clinical presentations; one systemic and two cutaneous disorders including hydroa vacciniforme-like T-cell LPD and mosquito bite hypersensitivity. The systemic form of the disease is characterized by fever, persistent hepatitis, hepatosplenomegaly and lymphadenopathy, which shows varying degrees of clinical severity depending on the immune response of the host and the EBV viral load. We described the clinicopathological findings of two children with CAEBV with a brief review of the literature. Recognition of the disease is important for adequate management of the patient. EBV analysis should be included in the principal diagnostic tests for febrile children. Copyright © 2015 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Cell Phone-Based System (Chaak) for Surveillance of Immatures of Dengue Virus Mosquito Vectors

PubMed Central

LOZANO–FUENTES, SAUL; WEDYAN, FADI; HERNANDEZ–GARCIA, EDGAR; SADHU, DEVADATTA; GHOSH, SUDIPTO; BIEMAN, JAMES M.; TEP-CHEL, DIANA; GARCÍA–REJÓN, JULIÁN E.; EISEN, LARS

2014-01-01

Capture of surveillance data on mobile devices and rapid transfer of such data from these devices into an electronic database or data management and decision support systems promote timely data analyses and public health response during disease outbreaks. Mobile data capture is used increasingly for malaria surveillance and holds great promise for surveillance of other neglected tropical diseases. We focused on mosquito-borne dengue, with the primary aims of: 1) developing and field-testing a cell phone-based system (called Chaak) for capture of data relating to the surveillance of the mosquito immature stages, and 2) assessing, in the dengue endemic setting of Mérida, México, the cost-effectiveness of this new technology versus paper-based data collection. Chaak includes a desktop component, where a manager selects premises to be surveyed for mosquito immatures, and a cell phone component, where the surveyor receives the assigned tasks and captures the data. Data collected on the cell phone can be transferred to a central database through different modes of transmission, including near-real time where data are transferred immediately (e.g., over the Internet) or by first storing data on the cell phone for future transmission. Spatial data are handled in a novel, semantically driven, geographic information system. Compared with a pen-and-paper-based method, use of Chaak improved the accuracy and increased the speed of data transcription into an electronic database. The cost-effectiveness of using the Chaak system will depend largely on the up-front cost of purchasing cell phones and the recurring cost of data transfer over a cellular network. PMID:23926788

Design of a peptide-based vector, PepFect6, for efficient delivery of siRNA in cell culture and systemically in vivo

PubMed Central

EL Andaloussi, Samir; Lehto, Taavi; Mäger, Imre; Rosenthal-Aizman, Katri; Oprea, Iulian I.; Simonson, Oscar E.; Sork, Helena; Ezzat, Kariem; Copolovici, Dana M.; Kurrikoff, Kaido; Viola, Joana R.; Zaghloul, Eman M.; Sillard, Rannar; Johansson, Henrik J.; Said Hassane, Fatouma; Guterstam, Peter; Suhorutšenko, Julia; Moreno, Pedro M. D.; Oskolkov, Nikita; Hälldin, Jonas; Tedebark, Ulf; Metspalu, Andres; Lebleu, Bernard; Lehtiö, Janne; Smith, C. I. Edvard; Langel, Ülo

2011-01-01

While small interfering RNAs (siRNAs) have been rapidly appreciated to silence genes, efficient and non-toxic vectors for primary cells and for systemic in vivo delivery are lacking. Several siRNA-delivery vehicles, including cell-penetrating peptides (CPPs), have been developed but their utility is often restricted by entrapment following endocytosis. Hence, developing CPPs that promote endosomal escape is a prerequisite for successful siRNA implementation. We here present a novel CPP, PepFect 6 (PF6), comprising the previously reported stearyl-TP10 peptide, having pH titratable trifluoromethylquinoline moieties covalently incorporated to facilitate endosomal release. Stable PF6/siRNA nanoparticles enter entire cell populations and rapidly promote endosomal escape, resulting in robust RNAi responses in various cell types (including primary cells), with minimal associated transcriptomic or proteomic changes. Furthermore, PF6-mediated delivery is independent of cell confluence and, in most cases, not significantly hampered by serum proteins. Finally, these nanoparticles promote strong RNAi responses in different organs following systemic delivery in mice without any associated toxicity. Strikingly, similar knockdown in liver is achieved by PF6/siRNA nanoparticles and siRNA injected by hydrodynamic infusion, a golden standard technique for liver transfection. These results imply that the peptide, in addition to having utility for RNAi screens in vitro, displays therapeutic potential. PMID:21245043

Alkaline and non-aqueous proton-conducting pouch-cell batteries

DOEpatents

Young, Kwo-hsiung; Nei, Jean; Meng, Tiejun

2018-01-02

Provided are sealed pouch-cell batteries that are alkaline batteries or non-aqueous proton-conducing batteries. A pouch cell includes a flexible housing such as is used for pouch cell construction where the housing is in the form of a pouch, a cathode comprising a cathode active material suitable for use in an alkaline battery, an anode comprising an anode active material suitable for use in an alkaline battery, an electrolyte that is optionally an alkaline or proton-conducting electrolyte, and wherein the pouch does not include or require a safety vent or other gas absorbing or releasing system as the anode active material and the cathode active material do not increase the internal atmospheric pressure any more than 2 psig during cycling. The batteries provided function contrary to the art recognized belief that such battery systems were impossible due to unacceptable gas production during cycling.

Effect of load transients on SOFC operation—current reversal on loss of load

NASA Astrophysics Data System (ADS)

Gemmen, Randall S.; Johnson, Christopher D.

The dynamics of solid oxide fuel cell (SOFC) operation have been considered previously, but mainly through the use of one-dimensional codes applied to co-flow fuel cell systems. In this paper several geometries are considered, including cross-flow, co-flow, and counter-flow. The details of the model are provided, and the model is compared with some initial experimental data. For parameters typical of SOFC operation, a variety of transient cases are investigated, including representative load increase and decrease and system shutdown. Of particular note for large load decrease conditions (e.g., shutdown) is the occurrence of reverse current over significant portions of the cell, starting from the moment of load loss up to the point where equilibrated conditions again provide positive current. Consideration is given as to when such reverse current conditions might most significantly impact the reliability of the cell.

Realization of the Temperature Scale in the Range from 234.3 K (Hg Triple Point) to 1084.62°C (Cu Freezing Point) in Croatia

NASA Astrophysics Data System (ADS)

Zvizdic, Davor; Veliki, Tomislav; Grgec Bermanec, Lovorka

2008-06-01

This article describes the realization of the International Temperature Scale in the range from 234.3 K (mercury triple point) to 1084.62°C (copper freezing point) at the Laboratory for Process Measurement (LPM), Faculty of Mechanical Engineering and Naval Architecture (FSB), University of Zagreb. The system for the realization of the ITS-90 consists of the sealed fixed-point cells (mercury triple point, water triple point and gallium melting point) and the apparatus designed for the optimal realization of open fixed-point cells which include the gallium melting point, tin freezing point, zinc freezing point, aluminum freezing point, and copper freezing point. The maintenance of the open fixed-point cells is described, including the system for filling the cells with pure argon and for maintaining the pressure during the realization.

WASTE PACKAGE REMEDIATION SYSTEM DESCRIPTION DOCUMENT

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

N.D. Sudan

2000-06-22

The Waste Package Remediation System remediates waste packages (WPs) and disposal containers (DCs) in one of two ways: preparation of rejected DC closure welds for repair or opening of the DC/WP. DCs are brought to the Waste Package Remediation System for preparation of rejected closure welds if testing of the closure weld by the Disposal Container Handling System indicates an unacceptable, but repairable, welding flaw. DC preparation of rejected closure welds will require removal of the weld in such a way that the Disposal Container Handling System may resume and complete the closure welding process. DCs/WPs are brought to themore » Waste Package Remediation System for opening if the Disposal Container Handling System testing of the DC closure weld indicates an unrepairable welding flaw, or if a WP is recovered from the subsurface repository because suspected damage to the WP or failure of the WP has occurred. DC/WP opening will require cutting of the DC/WP such that a temporary seal may be installed and the waste inside the DC/WP removed by another system. The system operates in a Waste Package Remediation System hot cell located in the Waste Handling Building that has direct access to the Disposal Container Handling System. One DC/WP at a time can be handled in the hot cell. The DC/WP arrives on a transfer cart, is positioned within the cell for system operations, and exits the cell without being removed from the cart. The system includes a wide variety of remotely operated components including a manipulator with hoist and/or jib crane, viewing systems, machine tools for opening WPs, and equipment used to perform pressure and gas composition sampling. Remotely operated equipment is designed to facilitate DC/WP decontamination and hot cell equipment maintenance, and interchangeable components are provided where appropriate. The Waste Package Remediation System interfaces with the Disposal Container Handling System for the receipt and transport of WPs and DCs. The Waste Handling Building System houses the system, and provides the facility, safety, and auxiliary systems required to support operations. The system receives power from the Waste Handling Building Electrical System. The system also interfaces with the various DC systems.« less

Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

NASA Technical Reports Server (NTRS)

Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

1985-01-01

The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

Evaluation of a rat tracheal epithelial cell culture assay system to identify respiratory carcinogens

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

Steele, V.E.; Arnold, J.T.; Arnold, J.V.

1989-01-01

To evaluate a short-term epithelial cell assay system to detect respiratory carcinogens, primary cultures of rat tracheal epithelial cells were exposed to a series of 17 compounds and scored for morphologically transformed cell colonies 28 days later. The test compounds included known carcinogens and noncarcinogens in volatile or liquid form. Tracheal epithelial cells were isolate from F344 rats, plated onto collagen-coated dishes, and exposed to the test compounds on day 1 for 24 hours. At day 30 the cultures were fixed, stained, and scored for colonies having a density greater than 1,300 cells/mm{sup 2}. With standardized protocols, such colonies aremore » very infrequent in media and solvent control cultures. Concentration levels for each chemical were chosen over a range from nontoxic to toxic levels. Highly positive compounds in this assay included benzo(a)pyrene, benzo(l)aceanthrylene, 3-methylcholanthrene, and formaldehyde. Compounds which were negative in this assay included pyrene, benzo(e)pyrene, and 4-nitroquinoline-N-oxide. Examining the concordance of in vitro results with whole animal carcinogenesis studies revealed an accuracy of 88% with one false-positive and one false-negative compound. The results of these studies indicate that the rat tracheal epithelial cell assay may be useful in identifying potential respiratory carcinogens in our environment.« less

Mycoplasma pneumoniae, an Underutilized Model for Bacterial Cell Biology

PubMed Central

2014-01-01

In recent decades, bacterial cell biology has seen great advances, and numerous model systems have been developed to study a wide variety of cellular processes, including cell division, motility, assembly of macromolecular structures, and biogenesis of cell polarity. Considerable attention has been given to these model organisms, which include Escherichia coli, Bacillus subtilis, Caulobacter crescentus, and Myxococcus xanthus. Studies of these processes in the pathogenic bacterium Mycoplasma pneumoniae and its close relatives have also been carried out on a smaller scale, but this work is often overlooked, in part due to this organism's reputation as minimalistic and simple. In this minireview, I discuss recent work on the role of the M. pneumoniae attachment organelle (AO), a structure required for adherence to host cells, in these processes. The AO is constructed from proteins that generally lack homology to those found in other organisms, and this construction occurs in coordination with cell cycle events. The proteins of the M. pneumoniae AO share compositional features with proteins with related roles in model organisms. Once constructed, the AO becomes activated for its role in a form of gliding motility whose underlying mechanism appears to be distinct from that of other gliding bacteria, including Mycoplasma mobile. Together with the FtsZ cytoskeletal protein, motility participates in the cell division process. My intention is to bring this deceptively complex organism into alignment with the better-known model systems. PMID:25157081

Potential influences of complement factor H in autoimmune inflammatory and thrombotic disorders.

PubMed

Ferluga, Janez; Kouser, Lubna; Murugaiah, Valarmathy; Sim, Robert B; Kishore, Uday

2017-04-01

Complement system homeostasis is important for host self-protection and anti-microbial immune surveillance, and recent research indicates roles in tissue development and remodelling. Complement also appears to have several points of interaction with the blood coagulation system. Deficiency and altered function due to gene mutations and polymorphisms in complement effectors and regulators, including Factor H, have been associated with familial and sporadic autoimmune inflammatory - thrombotic disorders, in which autoantibodies play a part. These include systemic lupus erythematosus, rheumatoid arthritis, atypical haemolytic uremic syndrome, anti-phospholipid syndrome and age-related macular degeneration. Such diseases are generally complex - multigenic and heterogeneous in their symptoms and predisposition/susceptibility. They usually need to be triggered by vascular trauma, drugs or infection and non-complement genetic factors also play a part. Underlying events seem to include decline in peripheral regulatory T cells, dendritic cell, and B cell tolerance, associated with alterations in lymphoid organ microenvironment. Factor H is an abundant protein, synthesised in many cell types, and its reported binding to many different ligands, even if not of high affinity, may influence a large number of molecular interactions, together with the accepted role of Factor H within the complement system. Factor H is involved in mesenchymal stem cell mediated tolerance and also contributes to self-tolerance by augmenting iC3b production and opsonisation of apoptotic cells for their silent dendritic cell engulfment via complement receptor CR3, which mediates anti-inflammatory-tolerogenic effects in the apoptotic cell context. There may be co-operation with other phagocytic receptors, such as complement C1q receptors, and the Tim glycoprotein family, which specifically bind phosphatidylserine expressed on the apoptotic cell surface. Factor H is able to discriminate between self and nonself surfaces for self-protection and anti-microbe defence. Factor H, particularly as an abundant platelet protein, may also modulate blood coagulation, having an anti-thrombotic role. Here, we review a number of interaction pathways in coagulation and in immunity, together with associated diseases, and indicate where Factor H may be expected to exert an influence, based on reports of the diversity of ligands for Factor H. Copyright © 2017 Elsevier Ltd. All rights reserved.

The intersection of cancer, cancer stem cells, and the immune system: therapeutic opportunities.

PubMed

Silver, Daniel J; Sinyuk, Maksim; Vogelbaum, Michael A; Ahluwalia, Manmeet S; Lathia, Justin D

2016-02-01

During brain neoplasia, malignant cells subjugate the immune system to provide an environment that favors tumor growth. These mechanisms capitalize on tumor-promoting functions of various immune cell types and typically result in suppression of tumor immune rejection. Immunotherapy efforts are underway to disrupt these mechanisms and turn the immune system against developing tumors. While many of these therapies are already in early-stage clinical trials, understanding how these therapies impact various tumor cell populations, including self-renewing cancer stem cells, may help to predict their efficacy and clarify their mechanisms of action. Moreover, interrogating the biology of glioma cell, cancer stem cell, and immune cell interactions may provide additional therapeutic targets to leverage against disease progression. In this review, we begin by highlighting a series of investigations into immune cell-mediated tumor promotion that do not parse the tumor into stem and non-stem components. We then take a closer look at the immune-suppressive mechanisms derived specifically from cancer stem cell interactions with the immune system and end with an update on immunotherapy and cancer stem cell-directed clinical trials in glioblastoma. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Recent advances of in vitro culture systems for spermatogonial stem cells in mammals.

PubMed

Sahare, Mahesh G; Suyatno; Imai, Hiroshi

2018-04-01

Spermatogonial stem cells (SSCs) in the mammalian testis are unipotent stem cells for spermatozoa. They show unique cell characteristics as stem cells and germ cells after being isolated from the testis and cultured in vitro. This review introduces recent progress in the development of culture systems for the establishment of SSC lines in mammalian species, including humans. Based on the published reports, the isolation and purification of SSCs, identification and characteristics of SSCs, and culture system for mice, humans, and domestic animals have been summarized. In mice, cell lines from SSCs are established and can be reprogrammed to show pluripotent stem cell potency that is similar to embryonic stem cells. However, it is difficult to establish cell lines for animals other than mice because of the dearth of understanding about species-specific requirements for growth factors and mechanisms supporting the self-renewal of cultured SSCs. Among the factors that are associated with the development of culture systems, the enrichment of SSCs that are isolated from the testis and the combination of growth factors are essential. Providing an example of SSC culture in cattle, a rational consideration was made about how it can be possible to establish cell lines from neonatal and immature testes.

More than a Tad: spatiotemporal control of Caulobacter pili.

PubMed

Mignolet, Johann; Panis, Gaël; Viollier, Patrick H

2018-04-01

The Type IV pilus (T4P) is a powerful and sophisticated bacterial nanomachine involved in numerous cellular processes, including adhesion, DNA uptake and motility. Aside from the well-described subtype T4aP of the Gram-negative genera, including Myxococcus, Pseudomonas and Neisseria, the Tad (tight adherence) pilus secretion system re-shuffles homologous parts from other secretion systems along with uncharacterized components into a new type of protein translocation apparatus. A representative of the Tad apparatus, the Caulobacter crescentus pilus assembly (Cpa) machine is built exclusively at the newborn cell pole once per cell cycle. Recent comprehensive genetic analyses unearthed a myriad of spatiotemporal determinants acting on the Tad/Cpa system, many of which are conserved in other α-proteobacteria, including obligate intracellular pathogens and symbionts. Copyright © 2017 Elsevier Ltd. All rights reserved.

The complex simplicity of the brittle star nervous system.

PubMed

Zueva, Olga; Khoury, Maleana; Heinzeller, Thomas; Mashanova, Daria; Mashanov, Vladimir

2018-01-01

Brittle stars (Ophiuroidea, Echinodermata) have been increasingly used in studies of animal behavior, locomotion, regeneration, physiology, and bioluminescence. The success of these studies directly depends on good working knowledge of the ophiuroid nervous system. Here, we describe the arm nervous system at different levels of organization, including the microanatomy of the radial nerve cord and peripheral nerves, ultrastructure of the neural tissue, and localization of different cell types using specific antibody markers. We standardize the nomenclature of nerves and ganglia, and provide an anatomically accurate digital 3D model of the arm nervous system as a reference for future studies. Our results helped identify several general features characteristic to the adult echinoderm nervous system, including the extensive anatomical interconnections between the ectoneural and hyponeural components, neuroepithelial organization of the central nervous system, and the supporting scaffold of the neuroepithelium formed by radial glial cells. In addition, we provide further support to the notion that the echinoderm radial glia is a complex and diverse cell population. We also tested the suitability of a range of specific cell-type markers for studies of the brittle star nervous system and established that the radial glial cells are reliably labeled with the ERG1 antibodies, whereas the best neuronal markers are acetylated tubulin, ELAV, and synaptotagmin B. The transcription factor Brn1/2/4 - a marker of neuronal progenitors - is expressed not only in neurons, but also in a subpopulation of radial glia. For the first time, we describe putative ophiuroid proprioceptors associated with the hyponeural part of the central nervous system. Together, our data help establish both the general principles of neural architecture common to the phylum Echinodermata and the specific ophiuroid features.

The role of radiation hard solar cells in minimizing the costs of global satellite communication systems

NASA Technical Reports Server (NTRS)

Summers, Geoffrey P.; Walters, Robert J.; Messenger, Scott R.; Burke, Edward A.

1996-01-01

An analysis embodied in a PC computer program is presented, which quantitatively demonstrates how the availability of radiation hard solar cells can help minimize the cost of a global satellite communications system. An important distinction between the currently proposed systems, such as Iridium, Odyssey and Ellipsat, is the number of satellites employed and their operating altitudes. Analysis of the major costs associated with implementing these systems shows that operation at orbital altitudes within the earth's radiation belts (10(exp 3) to 10(exp 4)km) can reduce the total cost of a system by several hundred percent, so long as radiation hard components including solar cells can be used. A detailed evaluation of the predicted performance of photovoltaic arrays using several different planar solar cell technologies is given, including commercially available Si and GaAs/Ge, and InP/Si which is currently under development. Several examples of applying the program are given, which show that the end of life (EOL) power density of different technologies can vary by a factor of ten for certain missions. Therefore, although a relatively radiation-soft technology can usually provide the required EOL power by simply increasing the size of the array, the impact upon the total system budget could be unacceptable, due to increased launch and hardware costs. In aggregate, these factors can account for more than a 10% increase in the total system cost. Since the estimated total costs of proposed global-coverage systems range from $1B to $9B, the availability of radiation-hard solar cells could make a decisive difference in the selection of a particular constellation architecture.

Evaluating maturation and genetic modification of human dendritic cells in a new polyolefin cell culture bag system.

PubMed

Macke, Lars; Garritsen, Henk S P; Meyring, Wilhelm; Hannig, Horst; Pägelow, Ute; Wörmann, Bernhard; Piechaczek, Christoph; Geffers, Robert; Rohde, Manfred; Lindenmaier, Werner; Dittmar, Kurt E J

2010-04-01

Dendritic cells (DCs) are applied worldwide in several clinical studies of immune therapy of malignancies, autoimmune diseases, and transplantations. Most legislative bodies are demanding high standards for cultivation and transduction of cells. Closed-cell cultivating systems like cell culture bags would simplify and greatly improve the ability to reach these cultivation standards. We investigated if a new polyolefin cell culture bag enables maturation and adenoviral modification of human DCs in a closed system and compare the results with standard polystyrene flasks. Mononuclear cells were isolated from HLA-A*0201-positive blood donors by leukapheresis. A commercially available separation system (CliniMACS, Miltenyi Biotec) was used to isolate monocytes by positive selection using CD14-specific immunomagnetic beads. The essentially homogenous starting cell population was cultivated in the presence of granulocyte-macrophage-colony-stimulating factor and interleukin-4 in a closed-bag system in parallel to the standard flask cultivation system. Genetic modification was performed on Day 4. After induction of maturation on Day 5, mature DCs could be harvested and cryopreserved on Day 7. During the cultivation period comparative quality control was performed using flow cytometry, gene expression profiling, and functional assays. Both flasks and bags generated mature genetically modified DCs in similar yields. Surface membrane markers, expression profiles, and functional testing results were comparable. The use of a closed-bag system facilitated clinical applicability of genetically modified DCs. The polyolefin bag-based culture system yields DCs qualitatively and quantitatively comparable to the standard flask preparation. All steps including cryopreservation can be performed in a closed system facilitating standardized, safe, and reproducible preparation of therapeutic cells.

Interplay of differential cell mechanical properties, motility, and proliferation in emergent collective behavior of cell co-cultures

NASA Astrophysics Data System (ADS)

Sutter, Leo; Kolbman, Dan; Wu, Mingming; Ma, Minglin; Das, Moumita

The biophysics of cell co-cultures, i.e. binary systems of cell populations, is of great interest in many biological processes including formation of embryos, and tumor progression. During these processes, different types of cells with different physical properties are mixed with each other, with important consequences for cell-cell interaction, aggregation, and migration. The role of the differences in their physical properties in their collective behavior remains poorly understood. Furthermore, until recently most theoretical studies of collective cell migration have focused on two dimensional systems. Under physiological conditions, however, cells often have to navigate three dimensional and confined micro-environments. We study a confined, three-dimensional binary system of interacting, active, and deformable particles with different physical properties such as deformability, motility, adhesion, and division rates using Langevin Dynamics simulations. Our findings may provide insights into how the differences in and interplay between cell mechanical properties, division, and motility influence emergent collective behavior such as cell aggregation and segregation experimentally observed in co-cultures of breast cancer cells and healthy breast epithelial cells. This work was partially supported by a Cottrell College Science Award.

Li-ion battery thermal runaway suppression system using microchannel coolers and refrigerant injections

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

Bandhauer, Todd M.; Farmer, Joseph C.

A battery management system with thermally integrated fire suppression includes a multiplicity of individual battery cells in a housing; a multiplicity of cooling passages in the housing within or between the multiplicity of individual battery cells; a multiplicity of sensors operably connected to the individual battery cells, the sensors adapted to detect a thermal runaway event related to one or more of the multiplicity of individual battery cells; and a management system adapted to inject coolant into at least one of the multiplicity of cooling passages upon the detection of the thermal runaway event by the any one of themore » multiplicity of sensors, so that the thermal runaway event is rapidly quenched.« less

Solar-cell defect analyzer

NASA Technical Reports Server (NTRS)

Gauthier, M. K.; Miller, E. L.; Shumka, A.

1980-01-01

Laser-Scanning System pinpoints imperfections in solar cells. Entire solar panels containing large numbers of cells can be scanned. Although technique is similar to use of scanning electron microscope (SEM) to locate microscopic imperfections, it differs in that large areas may be examined, including entire solar panels, and it is not necessary to remove cover glass or encapsulants.

Childhood Central Nervous System Germ Cell Tumors Treatment (PDQ®)—Health Professional Version

Cancer.gov

CNS germ cell tumors can be diagnosed and classified based on histology, tumor markers, or a combination of both. Get detailed information about newly diagnosed and recurrent childhood CNS germ cell tumors including molecular features and clinical features, diagnostic and staging evaluation, and treatment in this summary for clinicians.

Direct methanol feed fuel cell and system

NASA Technical Reports Server (NTRS)

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

2008-01-01

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.

Direct methanol feed fuel cell and system

NASA Technical Reports Server (NTRS)

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

2004-01-01

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.

Direct methanol feed fuel cell and system

NASA Technical Reports Server (NTRS)

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

2000-01-01

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.

Direct methanol feed fuel cell and system

NASA Technical Reports Server (NTRS)

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

2001-01-01

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.

Microfluidic Devices for Drug Delivery Systems and Drug Screening

PubMed Central

Kompella, Uday B.; Damiati, Safa A.

2018-01-01

Microfluidic devices present unique advantages for the development of efficient drug carrier particles, cell-free protein synthesis systems, and rapid techniques for direct drug screening. Compared to bulk methods, by efficiently controlling the geometries of the fabricated chip and the flow rates of multiphase fluids, microfluidic technology enables the generation of highly stable, uniform, monodispersed particles with higher encapsulation efficiency. Since the existing preclinical models are inefficient drug screens for predicting clinical outcomes, microfluidic platforms might offer a more rapid and cost-effective alternative. Compared to 2D cell culture systems and in vivo animal models, microfluidic 3D platforms mimic the in vivo cell systems in a simple, inexpensive manner, which allows high throughput and multiplexed drug screening at the cell, organ, and whole-body levels. In this review, the generation of appropriate drug or gene carriers including different particle types using different configurations of microfluidic devices is highlighted. Additionally, this paper discusses the emergence of fabricated microfluidic cell-free protein synthesis systems for potential use at point of care as well as cell-, organ-, and human-on-a-chip models as smart, sensitive, and reproducible platforms, allowing the investigation of the effects of drugs under conditions imitating the biological system. PMID:29462948

A Portable Cell Maintenance System for Rapid Toxicity Monitoring Final Report CRADA No. TC-02081-04

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

Kane, S.; Zhou, P.

The Phase I STTR research project was targeted at meeting the objectives and requirements stated in STTR solicitation A04-T028 for a Portable Cell Maintenance System for Rapid Toxicity Monitoring. In accordance with the requirements for STTR programs, collaboration was formed between a small business, Kionix, Inc., and The Regents of the University of California, Lawrence Livermore National Laboratory (LLNL). The collaboration included CytoDiscovery, Inc. (CDI) which, in collaboration with Kionix, provided access to membrane chip technology and provided program support and coordination. The objective of the overall program (excerpted from the original solicitation) was: “To develop a small, portable cellmore » maintenance system for the transport, storage, and monitoring of viable vertebrate cells and tissues.” The goal of the Phase I project was to demonstrate the feasibility of achieving the program objectives utilizing a system comprised of a small-size, microfluidic chip-based cell maintenance cartridge (CMC) and a portable cell maintenance system (CMS) capable of housing a minimum of four CMCs. The system was designed to be capable of optimally maintaining multiple vertebrate cell types while supporting a wide variety of cellular assays.« less

Preparation of ubiquitin-conjugated proteins using an insect cell-free protein synthesis system.

PubMed

Suzuki, Takashi; Ezure, Toru; Ando, Eiji; Nishimura, Osamu; Utsumi, Toshihiko; Tsunasawa, Susumu

2010-01-01

Ubiquitination is one of the most significant posttranslational modifications (PTMs). To evaluate the ability of an insect cell-free protein synthesis system to carry out ubiquitin (Ub) conjugation to in vitro translated proteins, poly-Ub chain formation was studied in an insect cell-free protein synthesis system. Poly-Ub was generated in the presence of Ub aldehyde (UA), a de-ubiquitinating enzyme inhibitor. In vitro ubiquitination of the p53 tumor suppressor protein was also analyzed, and p53 was poly-ubiquitinated when Ub, UA, and Mdm2, an E3 Ub ligase (E3) for p53, were added to the in vitro reaction mixture. These results suggest that the insect cell-free protein synthesis system contains enzymatic activities capable of carrying out ubiquitination. CBB-detectable ubiquitinated p53 was easily purified from the insect cell-free protein synthesis system, allowing analysis of the Ub-conjugated proteins by mass spectrometry (MS). Lys 305 of p53 was identified as one of the Ub acceptor sites using this strategy. Thus, we conclude that the insect cell-free protein synthesis system is a powerful tool for studying various PTMs of eukaryotic proteins including ubiqutination presented here.

Orchestrating brain-cell renewal: the role of immune cells in adult neurogenesis in health and disease.

PubMed

Ziv, Yaniv; Schwartz, Michal

2008-11-01

Immune cells and immune molecules have recently been shown to support neurogenesis from neural stem and progenitor cells in the adult brain. This non-classical immune activity takes place constantly under normal physiological conditions and is extended under acute pathological conditions to include the attraction of progenitor cells and induction of neurogenesis in regions of the adult central nervous system (CNS) in which formation of new neurons does not normally occur. We suggest that the immune system should be viewed as a novel player in the adult neural stem cell niche and a coordinator of cell renewal processes after injury. We discuss these notions in light of the well-known facts that both immune-cell activity and cell renewal are inherently limited in the adult CNS and that immune and stem cells provide the body's mechanisms of repair.

Strategies to Maximize the Potential of Marine Biomaterials as a Platform for Cell Therapy

PubMed Central

Kim, Hyeongmin; Lee, Jaehwi

2016-01-01

Marine biopolymers have been explored as a promising cell therapy system for efficient cell delivery and tissue engineering. However, the marine biomaterial-based systems themselves have exhibited limited performance in terms of maintenance of cell viability and functions, promotion of cell proliferation and differentiation as well as cell delivery efficiency. Thus, numerous novel strategies have been devised to improve cell therapy outcomes. The strategies include optimization of physical and biochemical properties, provision of stimuli-responsive functions, and design of platforms for efficient cell delivery and tissue engineering. These approaches have demonstrated substantial improvement of therapeutic outcomes in a variety of research settings. In this review, therefore, research progress made with marine biomaterials as a platform for cell therapy is reported along with current research directions to further advance cell therapies as a tool to cure incurable diseases. PMID:26821034

Development of operational models of receptor activation including constitutive receptor activity and their use to determine the efficacy of the chemokine CCL17 at the CC chemokine receptor CCR4

PubMed Central

Slack, RJ; Hall, DA

2012-01-01

BACKGROUND AND PURPOSE The operational model provides a key conceptual framework for the analysis of pharmacological data. However, this model does not include constitutive receptor activity, a frequent phenomenon in modern pharmacology, particularly in recombinant systems. Here, we developed extensions of the operational model which include constitutive activity and applied them to effects of agonists at the chemokine receptor CCR4. EXPERIMENTAL APPROACH The effects of agonists of CCR4 on [35S]GTPγS binding to recombinant cell membranes and on the filamentous (F-) actin content of human CD4+ CCR4+ T cells were determined. The basal [35S]GTPγS binding was changed by varying the GDP concentration whilst the basal F-actin contents of the higher expressing T cell populations were elevated, suggesting constitutive activity of CCR4. Both sets of data were analysed using the mathematical models. RESULTS The affinity of CCL17 (also known as TARC) derived from analysis of the T cell data (pKa= 9.61 ± 0.17) was consistent with radioligand binding experiments (9.50 ± 0.11) while that from the [35S]GTPγS binding experiments was lower (8.27 ± 0.09). Its intrinsic efficacy differed between the two systems (110 in T cells vs. 11). CONCLUSIONS AND IMPLICATIONS The presence of constitutive receptor activity allows the absolute intrinsic efficacy of agonists to be determined without a contribution from the signal transduction system. Intrinsic efficacy estimated in this way is consistent with Furchgott's definition of this property. CCL17 may have a higher intrinsic efficacy at CCR4 in human T cells than that expressed recombinantly in CHO cells. PMID:22335621

2009 Fuel Cell Market Report

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

Vincent, Bill; Gangi, Jennifer; Curtin, Sandra

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States aremore » investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general.« less

2009 Fuel Cell Market Report, November 2010

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

Not Available

Fuel cells are electrochemical devices that combine hydrogen and oxygen to produce electricity, water, and heat. Unlike batteries, fuel cells continuously generate electricity, as long as a source of fuel is supplied. Moreover, fuel cells do not burn fuel, making the process quiet, pollution-free and two to three times more efficient than combustion. Fuel cell systems can be a truly zero-emission source of electricity, if the hydrogen is produced from non-polluting sources. Global concerns about climate change, energy security, and air pollution are driving demand for fuel cell technology. More than 630 companies and laboratories in the United States aremore » investing $1 billion a year in fuel cells or fuel cell component technologies. This report provides an overview of trends in the fuel cell industry and markets, including product shipments, market development, and corporate performance. It also provides snapshots of select fuel cell companies, including general.« less

Mutations in the Drosophila neuroglian cell adhesion molecule affect motor neuron pathfinding and peripheral nervous system patterning.

PubMed

Hall, S G; Bieber, A J

1997-03-01

We have identified and characterized three embryonic lethal mutations that alter or abolish expression of Drosophila Neuroglian and have used these mutations to analyze Neuroglian function during development. Neuroglian is a member of the immunoglobulin superfamily. It is expressed by a variety of cell types during embryonic development, including expression on motoneurons and the muscle cells that they innervate. Examination of the nervous systems of neuroglian mutant embryos reveals that motoneurons have altered pathfinding trajectories. Additionally, the sensory cell bodies of the peripheral nervous system display altered morphology and patterning. Using a temperature-sensitive mutation, the phenocritical period for Neuroglian function was determined to occur during late embryogenesis, an interval which coincides with the period during which neuromuscular connections and the peripheral nervous system pattern are established.

Immunology and Immunotherapy of Head and Neck Cancer

PubMed Central

Ferris, Robert L.

2015-01-01

The immune system plays a key role in the development, establishment, and progression of head and neck squamous cell carcinoma (HNSCC). A greater understanding of the dysregulation and evasion of the immune system in the evolution and progression of HNSCC provides the basis for improved therapies and outcomes for patients. HNSCC cells evade the host immune system through manipulation of their own immunogenicity, production of immunosuppressive mediators, and promotion of immunomodulatory cell types. Through the tumor's influence on the microenvironment, the immune system can be exploited to promote metastasis, angiogenesis, and growth. This article provides a brief overview of key components of the immune infiltrating cells in the tumor microenvironment, reviewing immunological principles related to head and neck cancer, including the concept of cancer immunosurveillance and immune escape. Current immunotherapeutic strategies and emerging results from ongoing clinical trials are presented. PMID:26351330

Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial

PubMed Central

2012-01-01

The immune system plays an important role in the regulation of tissue homeostasis ("tissue immune physiology"). Function of distinct tissues during adulthood, including the ovary, requires (1) Renewal from stem cells, (2) Preservation of tissue-specific cells in a proper differentiated state, which differs among distinct tissues, and (3) Regulation of tissue quantity. Such morphostasis can be executed by the tissue control system, consisting of immune system-related components, vascular pericytes, and autonomic innervation. Morphostasis is established epigenetically, during morphogenetic (developmental) immune adaptation, i.e., during the critical developmental period. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a “stop effect” of resident and self renewing monocyte-derived cells. The later normal tissue is programmed to emerge (e.g., late emergence of ovarian granulosa cells), the earlier its function ceases. Alteration of certain tissue differentiation during the critical developmental period causes persistent alteration of that tissue function, including premature ovarian failure (POF) and primary amenorrhea. In fetal and adult human ovaries the ovarian surface epithelium cells called ovarian stem cells (OSC) are bipotent stem cells for the formation of ovarian germ and granulosa cells. Recently termed oogonial stem cells are, in reality, not stem but already germ cells which have the ability to divide. Immune system-related cells and molecules accompany asymmetric division of OSC resulting in the emergence of secondary germ cells, symmetric division, and migration of secondary germ cells, formation of new granulosa cells and fetal and adult primordial follicles (follicular renewal), and selection and growth of primary/preantral, and dominant follicles. The number of selected follicles during each ovarian cycle is determined by autonomic innervation. Morphostasis is altered with advancing age, due to degenerative changes of the immune system. This causes cessation of oocyte and follicular renewal at 38 +/-2 years of age due to the lack of formation of new granulosa cells. Oocytes in primordial follicles persisting after the end of the prime reproductive period accumulate genetic alterations resulting in an exponentially growing incidence of fetal trisomies and other genetic abnormalities with advanced maternal age. The secondary germ cells also develop in the OSC cultures derived from POF and aging ovaries. In vitro conditions are free of immune mechanisms, which prevent neo-oogenesis in vivo. Such germ cells are capable of differentiating in vitro into functional oocytes. This may provide fresh oocytes and genetically related children to women lacking the ability to produce their own follicular oocytes. Further study of "immune physiology" may help us to better understand ovarian physiology and pathology, including ovarian infertility caused by POF or by a lack of ovarian follicles with functional oocytes in aging ovaries. The observations indicating involvement of immunoregulation in physiological neo-oogenesis and follicular renewal from OSC during the fetal and prime reproductive periods are reviewed as well as immune system and age-independent neo-oogenesis and oocyte maturation in OSC cultures, perimenopausal alteration of homeostasis causing disorders of many tissues, and the first OSC culture clinical trial. PMID:23176151

Modeling of indirect carbon fuel cell systems with steam and dry gasification

NASA Astrophysics Data System (ADS)

Ong, Katherine M.; Ghoniem, Ahmed F.

2016-05-01

An indirect carbon fuel cell (ICFC) system that couples coal gasification to a solid oxide fuel cell (SOFC) is a promising candidate for high efficiency stationary power. This study couples an equilibrium gasifier model to a detailed 1D MEA model to study the theoretical performance of an ICFC system run on steam or carbon dioxide. Results show that the fuel cell in the ICFC system is capable of power densities greater than 1.0 W cm-2 with H2O recycle, and power densities ranging from 0.2 to 0.4 W cm-2 with CO2 recycle. This result indicates that the ICFC system performs better with steam than with CO2 gasification as a result of the faster electro-oxidation kinetics of H2 relative to CO. The ICFC system is then shown to reach higher current densities and efficiencies than a thermally decoupled gasifier + fuel cell (G + FC) system because it does not include combustion losses associated with autothermal gasification. 55-60% efficiency is predicted for the ICFC system coupled to a bottoming cycle, making this technology competitive with other state-of-the-art stationary power candidates.

A combination HIV reporter virus system for measuring post-entry event efficiency and viral outcome in primary CD4+ T cell subsets.

PubMed

Tilton, Carisa A; Tabler, Caroline O; Lucera, Mark B; Marek, Samantha L; Haqqani, Aiman A; Tilton, John C

2014-01-01

Fusion between the viral membrane of human immunodeficiency virus (HIV) and the host cell marks the end of the HIV entry process and the beginning of a series of post-entry events including uncoating, reverse transcription, integration, and viral gene expression. The efficiency of post-entry events can be modulated by cellular factors including viral restriction factors and can lead to several distinct outcomes: productive, latent, or abortive infection. Understanding host and viral proteins impacting post-entry event efficiency and viral outcome is critical for strategies to reduce HIV infectivity and to optimize transduction of HIV-based gene therapy vectors. Here, we report a combination reporter virus system measuring both membrane fusion and viral promoter-driven gene expression. This system enables precise determination of unstimulated primary CD4+ T cell subsets targeted by HIV, the efficiency of post-entry viral events, and viral outcome and is compatible with high-throughput screening and cell-sorting methods. Copyright © 2013 Elsevier B.V. All rights reserved.

Current-Controlled Electrical Point-Source Stimulation of Embryonic Stem Cells

PubMed Central

Chen, Michael Q.; Xie, Xiaoyan; Wilson, Kitchener D.; Sun, Ning; Wu, Joseph C.; Giovangrandi, Laurent; Kovacs, Gregory T. A.

2010-01-01

Stem cell therapy is emerging as a promising clinical approach for myocardial repair. However, the interactions between the graft and host, resulting in inconsistent levels of integration, remain largely unknown. In particular, the influence of electrical activity of the surrounding host tissue on graft differentiation and integration is poorly understood. In order to study this influence under controlled conditions, an in vitro system was developed. Electrical pacing of differentiating murine embryonic stem (ES) cells was performed at physiologically relevant levels through direct contact with microelectrodes, simulating the local activation resulting from contact with surrounding electroactive tissue. Cells stimulated with a charged balanced voltage-controlled current source for up to 4 days were analyzed for cardiac and ES cell gene expression using real-time PCR, immunofluorescent imaging, and genome microarray analysis. Results varied between ES cells from three progressive differentiation stages and stimulation amplitudes (nine conditions), indicating a high sensitivity to electrical pacing. Conditions that maximally encouraged cardiomyocyte differentiation were found with Day 7 EBs stimulated at 30 µA. The resulting gene expression included a sixfold increase in troponin-T and a twofold increase in β-MHCwithout increasing ES cell proliferation marker Nanog. Subsequent genome microarray analysis revealed broad transcriptome changes after pacing. Concurrent to upregulation of mature gene programs including cardiovascular, neurological, and musculoskeletal systems is the apparent downregulation of important self-renewal and pluripotency genes. Overall, a robust system capable of long-term stimulation of ES cells is demonstrated, and specific conditions are outlined that most encourage cardiomyocyte differentiation. PMID:20652088

Analysis of Stationary, Photovoltaic-based Surface Power System Designs at the Lunar South Pole

NASA Technical Reports Server (NTRS)

Freeh, Joshua E.

2009-01-01

Combinations of solar arrays and either batteries or regenerative fuel cells are analyzed for a surface power system module at the lunar south pole. The systems are required to produce 5 kW of net electrical power in sunlight and 2 kW of net electrical power during lunar night periods for a 10-year period between 2020 and 2030. Systems-level models for energy conservation, performance, degradation, and mass are used to compare to various systems. The sensitivities of important and/or uncertain variables including battery specific energy, fuel cell operating voltage, and DC-DC converter efficiency are compared to better understand the system. Switching unit efficiency, battery specific energy, and fuel cell operating voltage appear to be important system-level variables for this system. With reasonably sized solar arrays, the regenerative fuel cell system has significantly lower mass than the battery system based on the requirements and assumptions made herein. The total operational time is estimated at about 10,000 hours in battery discharge/fuel cell mode and about 4,000 and 8,000 hours for the battery charge and electrolyzer modes, respectively. The estimated number of significant depth-of-discharge cycles for either energy storage system is less than 100 for the 10-year period.

Effects of exercise training on chronic inflammation in obesity : current evidence and potential mechanisms.

PubMed

You, Tongjian; Arsenis, Nicole C; Disanzo, Beth L; Lamonte, Michael J

2013-04-01

Chronic, systemic inflammation is an independent risk factor for several major clinical diseases. In obesity, circulating levels of inflammatory markers are elevated, possibly due to increased production of pro-inflammatory cytokines from several tissues/cells, including macrophages within adipose tissue, vascular endothelial cells and peripheral blood mononuclear cells. Recent evidence supports that adipose tissue hypoxia may be an important mechanism through which enlarged adipose tissue elicits local tissue inflammation and further contributes to systemic inflammation. Current evidence supports that exercise training, such as aerobic and resistance exercise, reduces chronic inflammation, especially in obese individuals with high levels of inflammatory biomarkers undergoing a longer-term intervention. Several studies have reported that this effect is independent of the exercise-induced weight loss. There are several mechanisms through which exercise training reduces chronic inflammation, including its effect on muscle tissue to generate muscle-derived, anti-inflammatory 'myokine', its effect on adipose tissue to improve hypoxia and reduce local adipose tissue inflammation, its effect on endothelial cells to reduce leukocyte adhesion and cytokine production systemically, and its effect on the immune system to lower the number of pro-inflammatory cells and reduce pro-inflammatory cytokine production per cell. Of these potential mechanisms, the effect of exercise training on adipose tissue oxygenation is worth further investigation, as it is very likely that exercise training stimulates adipose tissue angiogenesis and increases blood flow, thereby reducing hypoxia and the associated chronic inflammation in adipose tissue of obese individuals.

The emerging CHO systems biology era: harnessing the 'omics revolution for biotechnology.

PubMed

Kildegaard, Helene Faustrup; Baycin-Hizal, Deniz; Lewis, Nathan E; Betenbaugh, Michael J

2013-12-01

Chinese hamster ovary (CHO) cells are the primary factories for biopharmaceuticals because of their capacity to correctly fold and post-translationally modify recombinant proteins compatible with humans. New opportunities are arising to enhance these cell factories, especially since the CHO-K1 cell line was recently sequenced. Now, the CHO systems biology era is underway. Critical 'omics data sets, including proteomics, transcriptomics, metabolomics, fluxomics, and glycomics, are emerging, allowing the elucidation of the molecular basis of CHO cell physiology. The incorporation of these data sets into mathematical models that describe CHO phenotypes will provide crucial biotechnology insights. As 'omics technologies and computational systems biology mature, genome-scale approaches will lead to major innovations in cell line development and metabolic engineering, thereby improving protein production and bioprocessing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multi-processor including data flow accelerator module

DOEpatents

Davidson, George S.; Pierce, Paul E.

1990-01-01

An accelerator module for a data flow computer includes an intelligent memory. The module is added to a multiprocessor arrangement and uses a shared tagged memory architecture in the data flow computer. The intelligent memory module assigns locations for holding data values in correspondence with arcs leading to a node in a data dependency graph. Each primitive computation is associated with a corresponding memory cell, including a number of slots for operands needed to execute a primitive computation, a primitive identifying pointer, and linking slots for distributing the result of the cell computation to other cells requiring that result as an operand. Circuitry is provided for utilizing tag bits to determine automatically when all operands required by a processor are available and for scheduling the primitive for execution in a queue. Each memory cell of the module may be associated with any of the primitives, and the particular primitive to be executed by the processor associated with the cell is identified by providing an index, such as the cell number for the primitive, to the primitive lookup table of starting addresses. The module thus serves to perform functions previously performed by a number of sections of data flow architectures and coexists with conventional shared memory therein. A multiprocessing system including the module operates in a hybrid mode, wherein the same processing modules are used to perform some processing in a sequential mode, under immediate control of an operating system, while performing other processing in a data flow mode.

Eustachian Tube Function.

PubMed

Ars, Bernard; Dirckx, Joris

2016-10-01

The fibrocartilaginous eustachian tube is part of a system of contiguous organs including the nose, palate, rhinopharynx, and middle ear cleft. The middle ear cleft consists of the tympanic cavity, which includes the bony eustachian tube (protympanum) and the mastoid gas cells system. The tympanic cavity and mastoid gas cells are interconnected and allow gaseous exchange and pressure regulation. The fibrocartilaginous eustachian tube is a complex organ consisting of a dynamic conduit with its mucosa, cartilage, surrounding soft tissue, peritubal muscles (ie, tensor and levator veli palatine, salpingopharyngeus and tensor tympani), and superior bony support (the sphenoid sulcus). Copyright © 2016 Elsevier Inc. All rights reserved.

Three-Dimensional Cell Printing of Large-Volume Tissues: Application to Ear Regeneration.

PubMed

Lee, Jung-Seob; Kim, Byoung Soo; Seo, Donghwan; Park, Jeong Hun; Cho, Dong-Woo

2017-03-01

The three-dimensional (3D) printing of large-volume cells, printed in a clinically relevant size, is one of the most important challenges in the field of tissue engineering. However, few studies have reported the fabrication of large-volume cell-printed constructs (LCCs). To create LCCs, appropriate fabrication conditions should be established: Factors involved include fabrication time, residence time, and temperature control of the cell-laden hydrogel in the syringe to ensure high cell viability and functionality. The prolonged time required for 3D printing of LCCs can reduce cell viability and result in insufficient functionality of the construct, because the cells are exposed to a harsh environment during the printing process. In this regard, we present an advanced 3D cell-printing system composed of a clean air workstation, a humidifier, and a Peltier system, which provides a suitable printing environment for the production of LCCs with high cell viability. We confirmed that the advanced 3D cell-printing system was capable of providing enhanced printability of hydrogels and fabricating an ear-shaped LCC with high cell viability. In vivo results for the ear-shaped LCC also showed that printed chondrocytes proliferated sufficiently and differentiated into cartilage tissue. Thus, we conclude that the advanced 3D cell-printing system is a versatile tool to create cell-printed constructs for the generation of large-volume tissues.

Advancing Small Satellite Electronics Heritage for Microfluidic Biological Experiments

NASA Technical Reports Server (NTRS)

White, Bruce; Mazmanian, Edward; Tapio, Eric

2016-01-01

DLR's Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) mission, launching in 2017, will carry multiple biological payloads into a sun-synchronous orbit, including NASA Ames' PowerCell experiment. PowerCell will attempt to characterize the viability of synthetic biology at micro-g, Lunar, and Martian gravity levels. PowerCell experiment requirements demand an electronic system similar to previous microfluidic biology payloads, but with an expanded feature set. As such, the system was based on PharmaSat (Diaz-Aguado et al. 2009), a previous successful biology payload from NASA Ames, and improved upon. Newer, more miniaturized electronics allow for greater capability with a lower part count and smaller size. Two identical PowerCell enclosures will fly. Each enclosure contains two separate and identical experiments with a 48-segment optical density measurement system, grow light system, microfluidic system for nutrient delivery and waste flushing, plus thermal control and environmental sensing/housekeeping including temperature, pressure, humidity, and acceleration. Electronics consist of a single Master PCB that interfaces to the spacecraft bus and regulates power and communication, plus LED, Detector, and Valve Manifold PCBs for each experiment. To facilitate ease of reuse on future missions, experiment electronics were designed to be compatible with a standard 3U small sat form factor and power bus, or to interface with a Master power/comm PCB for use in a larger satellite as in the case of PowerCell's flight on Eu:CROPIS.

Yeast Immobilization Systems for Alcoholic Wine Fermentations: Actual Trends and Future Perspectives

PubMed Central

Moreno-García, Jaime; García-Martínez, Teresa; Mauricio, Juan C.; Moreno, Juan

2018-01-01

Yeast immobilization is defined as the physical confinement of intact cells to a region of space with conservation of biological activity. The use of these methodologies for alcoholic fermentation (AF) offers many advantages over the use of the conventional free yeast cell method and different immobilization systems have been proposed so far for different applications, like winemaking. The most studied methods for yeast immobilization include the use of natural supports (e.g., fruit pieces), organic supports (e.g., alginate), inorganic (e.g., porous ceramics), membrane systems, and multi-functional agents. Some advantages of the yeast-immobilization systems include: high cell densities, product yield improvement, lowered risk of microbial contamination, better control and reproducibility of the processes, as well as reuse of the immobilization system for batch fermentations and continuous fermentation technologies. However, these methods have some consequences on the behavior of the yeasts, affecting the final products of the fermentative metabolism. This review compiles current information about cell immobilizer requirements for winemaking purposes, the immobilization methods applied to the production of fermented beverages to date, and yeast physiological consequences of immobilization strategies. Finally, a recent inter-species immobilization methodology has been revised, where yeast cells are attached to the hyphae of a Generally Recognized As Safe fungus and remain adhered following loss of viability of the fungus. The bio-capsules formed with this method open new and promising strategies for alcoholic beverage production (wine and low ethanol content beverages). PMID:29497415

Multipotent Caudal Neural Progenitors Derived from Human Pluripotent Stem Cells That Give Rise to Lineages of the Central and Peripheral Nervous System

PubMed Central

Hasegawa, Kouichi; Menheniott, Trevelyan; Rollo, Ben; Zhang, Dongcheng; Hough, Shelley; Alshawaf, Abdullah; Febbraro, Fabia; Ighaniyan, Samiramis; Leung, Jessie; Elliott, David A.; Newgreen, Donald F.; Pera, Martin F.

2015-01-01

Abstract The caudal neural plate is a distinct region of the embryo that gives rise to major progenitor lineages of the developing central and peripheral nervous system, including neural crest and floor plate cells. We show that dual inhibition of the glycogen synthase kinase 3β and activin/nodal pathways by small molecules differentiate human pluripotent stem cells (hPSCs) directly into a preneuroepithelial progenitor population we named “caudal neural progenitors” (CNPs). CNPs coexpress caudal neural plate and mesoderm markers, and, share high similarities to embryonic caudal neural plate cells in their lineage differentiation potential. Exposure of CNPs to BMP2/4, sonic hedgehog, or FGF2 signaling efficiently directs their fate to neural crest/roof plate cells, floor plate cells, and caudally specified neuroepithelial cells, respectively. Neural crest derived from CNPs differentiated to neural crest derivatives and demonstrated extensive migratory properties in vivo. Importantly, we also determined the key extrinsic factors specifying CNPs from human embryonic stem cell include FGF8, canonical WNT, and IGF1. Our studies are the first to identify a multipotent neural progenitor derived from hPSCs, that is the precursor for major neural lineages of the embryonic caudal neural tube. Stem Cells 2015;33:1759–1770 PMID:25753817

Medical Research System

NASA Technical Reports Server (NTRS)

1993-01-01

Based on Johnson Space Flight Center's development of a rotating bioreactor cell culture apparatus for Space Shuttle medical research, Johnson Space Flight Center engineers who worked on the original project formed a company called Synthecon, with the intention of commercializing the bioreactor technology. Synthecon grows three dimensional tissues in the bioreactor. These are superior to previous two-dimensional tissue samples in the study of human cell growth. A refined version of the Johnson Space Center technology, Synthecon's Rotary Cell Culture System includes a cell culture chamber that rotates around a horizontal axis. The cells establish an orbit that approximates free fall through the liquid medium in the chamber. The technology has significant applications for cancer research and treatment as well as AIDS research.

Develop and test fuel cell powered on-site integrated total energy systems: Phase 3: Full-scale power plant development

NASA Technical Reports Server (NTRS)

1982-01-01

The development of a commercially viable and cost-effective phospheric acid fuel cell powered on-site integrated energy system (OS/IES) is described. The fuel cell offers energy efficients in the range of 35-40% of the higher heating value of available fuels in the form of electrical energy. In addition, by utilizing the thermal energy generated for heating, ventilating and air-conditioning (HVAC), a fuel cell OS/IES could provide total energy efficiencies in the neighborhood of 80%. Also, the Engelhard fuel cell OS/IES offers the important incentive of replacing imported oil with domestically produced methanol, including coal-derived methanol.

Non-Hermitian Operator Modelling of Basic Cancer Cell Dynamics

NASA Astrophysics Data System (ADS)

Bagarello, Fabio; Gargano, Francesco

2018-04-01

We propose a dynamical system of tumor cells proliferation based on operatorial methods. The approach we propose is quantum-like: we use ladder and number operators to describe healthy and tumor cells birth and death, and the evolution is ruled by a non-hermitian Hamiltonian which includes, in a non reversible way, the basic biological mechanisms we consider for the system. We show that this approach is rather efficient in describing some processes of the cells. We further add some medical treatment, described by adding a suitable term in the Hamiltonian, which controls and limits the growth of tumor cells, and we propose an optimal approach to stop, and reverse, this growth.

A plasmid-based reporter system for live cell imaging of dengue virus infected cells.

PubMed

Medin, Carey L; Valois, Sierra; Patkar, Chinmay G; Rothman, Alan L

2015-01-01

Cell culture models are used widely to study the effects of dengue virus (DENV) on host cell function. Current methods of identification of cells infected with an unmodified DENV requires fixation and permeablization of cells to allow DENV-specific antibody staining. This method does not permit imaging of viable cells over time. In this report, a plasmid-based reporter was developed to allow non-destructive identification of DENV-infected cells. The plasmid-based reporter was demonstrated to be broadly applicable to the four DENV serotypes, including low-passaged strains, and was specifically cleaved by the viral protease with minimal interference on viral production. This study reveals the potential for this novel reporter system to advance the studies of virus-host interactions during DENV infection. Copyright © 2014 Elsevier B.V. All rights reserved.

Inhibitory effect of hot-water extract from dried fruit of Crataegus pinnatifida on low-density lipoprotein (LDL) oxidation in cell and cell-free systems.

PubMed

Chu, Chia-Yih; Lee, Miao-Jane; Liao, Chuen-Lan; Lin, Wea-Lung; Yin, Yu-Fang; Tseng, Tsui-Hwa

2003-12-17

The dried fruit of Crataegus pinnatifida, a local soft drink material and medical herb, was found to possess potential against oxidative stress. In the preliminary study, the antioxidant potential of a hot-water extract obtained from the dried fruit of C. pinnatifida (CF-H) was evaluated in terms of its capacity of quenching 1,1-diphenyl-2-picrylhydrazyl free radicals (EC(50) = 0.118 mg/mL). After content analysis, it was found that CF-H is mainly composed of polyphenols including flavonoids (6.9%), procyanidins (2.2%), (+)-catechin (0.5%), and (-)-epicatechin (0.2%). The antioxidative bioactivity of CF-H had been assess previously using the models of CuSO(4) as cell-free system and sodium nitroprusside (SNP) plus macrophage RAW 264.7 cells as cell system to induce human low-density lipoprotein oxidation. CF-H was found to inhibit relative electrophoretic mobility and thiobarbituric acid reactive substances at the concentration of 0.5-1.0 mg/mL in the cell-free system and at 0.01-0.10 mg/mL in the cell system. Furthermore, it was found that CF-H decreased the SNP-induced cell lipid peroxidation and reduced glutathione depletion.

Imaging of musculoskeletal manifestations in sickle cell disease patients.

PubMed

Kosaraju, Vijaya; Harwani, Alok; Partovi, Sasan; Bhojwani, Nicholas; Garg, Vasant; Ayyappan, Sabarish; Kosmas, Christos; Robbin, Mark

2017-05-01

Sickle cell disease (SCD) is a hereditary red cell disorder with clinical manifestations secondary to sickling or crescent-shaped distortion of the red blood cells. Major clinical manifestations of SCD include haemolytic anaemia and vaso-occlusive phenomena resulting in ischaemic tissue injury and organ damage. Chronic sequelae of the anaemia and vaso-occlusive processes involving the musculoskeletal system include complications related to extramedullary haematopoiesis, osteonecrosis, myonecrosis and osteomyelitis. Sickle cell bone disease is one of the commonest clinical presentations. Awareness and knowledge of the imaging features related to these complications are essential for early diagnosis and prompt management. In this article, the pathophysiology and key imaging findings related to these complications are reviewed.

Using low-risk factors to generate non-integrated human induced pluripotent stem cells from urine-derived cells.

PubMed

Wang, Linli; Chen, Yuehua; Guan, Chunyan; Zhao, Zhiju; Li, Qiang; Yang, Jianguo; Mo, Jian; Wang, Bin; Wu, Wei; Yang, Xiaohui; Song, Libing; Li, Jun

2017-11-02

Because the lack of an induced pluripotent stem cell (iPSC) induction system with optimal safety and efficiency limits the application of these cells, development of such a system is important. To create such an induction system, we screened a variety of reprogrammed plasmid combinations and multiple compounds and then verified the system's feasibility using urine cells from different individuals. We also compared large-scale iPSC chromosomal variations and expression of genes associated with genomic stability between this system and the traditional episomal system using karyotype and quantitative reverse transcription polymerase chain reaction analyses. We developed a high-efficiency episomal system, the 6F/BM1-4C system, lacking tumorigenic factors for human urine-derived cell (hUC) reprogramming. This system includes six low-risk factors (6F), Oct4, Glis1, Klf4, Sox2, L-Myc, and the miR-302 cluster. Transfected hUCs were treated with four compounds (4C), inhibitor of lysine-demethylase1, methyl ethyl ketone, glycogen synthase kinase 3 beta, and histone deacetylase, within a short time period. Comparative analysis revealed significantly decreased chromosomal variation in iPSCs and significantly increased Sirt1 expression compared with iPSCs induced using the traditional episomal system. The 6F/BM1-4C system effectively induces reprogramming of urine cells in samples obtained from different individuals. iPSCs induced using the 6F/BM1-4C system are more stable at the cytogenetic level and have potential value for clinical application.

Gas venting system

DOEpatents

Khan, Amjad; Dreier, Ken Wayne; Moulthrop, Lawrence Clinton; White, Erik James

2010-06-29

A system to vent a moist gas stream is disclosed. The system includes an enclosure and an electrochemical cell disposed within the enclosure, the electrochemical cell productive of the moist gas stream. A first vent is in fluid communication with the electrochemical cell for venting the moist gas stream to an exterior of the enclosure, and a second vent is in fluid communication with an interior of the enclosure and in thermal communication with the first vent for discharging heated air to the exterior of the enclosure. At least a portion of the discharging heated air is for preventing freezing of the moist gas stream within the first vent.

Monitoring Cellular Events in Living Mast Cells Stimulated with an Extremely Small Amount of Fluid on a Microchip

NASA Astrophysics Data System (ADS)

Munaka, Tatsuya; Abe, Hirohisa; Kanai, Masaki; Sakamoto, Takashi; Nakanishi, Hiroaki; Yamaoka, Tetsuji; Shoji, Shuichi; Murakami, Akira

2006-07-01

We successfully developed a measurement system for real-time analysis of cellular function using a newly designed microchip. This microchip was equipped with a micro cell incubation chamber (240 nl) and was stimulated by a very small amount of stimuli (as small as 24 nl). Using the microchip system, cultivation of mast cells was successfully carried out. Monitoring of the cellular events after stimulation with an extremely small amount of fluid on a microchip was performed. This system could be applicable for various types of cellular analysis including real-time monitoring of cellular response by stimulation.

Non-conventional expression systems for the production of vaccine proteins and immunotherapeutic molecules

PubMed Central

Legastelois, Isabelle; Buffin, Sophie; Peubez, Isabelle; Mignon, Charlotte; Sodoyer, Régis; Werle, Bettina

2017-01-01

ABSTRACT The increasing demand for recombinant vaccine antigens or immunotherapeutic molecules calls into question the universality of current protein expression systems. Vaccine production can require relatively low amounts of expressed materials, but represents an extremely diverse category consisting of different target antigens with marked structural differences. In contrast, monoclonal antibodies, by definition share key molecular characteristics and require a production system capable of very large outputs, which drives the quest for highly efficient and cost-effective systems. In discussing expression systems, the primary assumption is that a universal production platform for vaccines and immunotherapeutics will unlikely exist. This review provides an overview of the evolution of traditional expression systems, including mammalian cells, yeast and E.coli, but also alternative systems such as other bacteria than E. coli, transgenic animals, insect cells, plants and microalgae, Tetrahymena thermophila, Leishmania tarentolae, filamentous fungi, cell free systems, and the incorporation of non-natural amino acids. PMID:27905833

Lithium-ion battery diagnostic and prognostic techniques

DOEpatents

Singh, Harmohan N.

2009-11-03

Embodiments provide a method and a system for determining cell imbalance condition of a multi-cell battery including a plurality of cell strings. To determine a cell imbalance condition, a charge current is applied to the battery and is monitored during charging. The charging time for each cell string is determined based on the monitor of the charge current. A charge time difference of any two cell strings in the battery is used to determine the cell imbalance condition by comparing with a predetermined acceptable charge time difference for the cell strings.

Plasmodesmata in integrated cell signalling: insights from development and environmental signals and stresses

PubMed Central

Sager, Ross; Lee, Jung-Youn

2014-01-01

To survive as sedentary organisms built of immobile cells, plants require an effective intercellular communication system, both locally between neighbouring cells within each tissue and systemically across distantly located organs. Such a system enables cells to coordinate their intracellular activities and produce concerted responses to internal and external stimuli. Plasmodesmata, membrane-lined intercellular channels, are essential for direct cell-to-cell communication involving exchange of diffusible factors, including signalling and information molecules. Recent advances corroborate that plasmodesmata are not passive but rather highly dynamic channels, in that their density in the cell walls and gating activities are tightly linked to developmental and physiological processes. Moreover, it is becoming clear that specific hormonal signalling pathways play crucial roles in relaying primary cellular signals to plasmodesmata. In this review, we examine a number of studies in which plasmodesmal structure, occurrence, and/or permeability responses are found to be altered upon given cellular or environmental signals, and discuss common themes illustrating how plasmodesmal regulation is integrated into specific cellular signalling pathways. PMID:25262225

Apollo Lunar Module Electrical Power System Overview

NASA Technical Reports Server (NTRS)

Interbartolo, Michael

2009-01-01

Objectives include: a) Describe LM Electrical System original specifications; b) Describe the decision to change from fuel cells to batteries and other changes; c) Describe the Electrical system; and d) Describe the Apollo 13 failure from the LM perspective.

The effects of Candida albicans cell wall protein fraction on dendritic cell maturation.

PubMed

Roudbary, Maryam; Roudbar Mohammadi, Shahla; Bozorgmehr, Mahmood; Moazzeni, Seyed Mohammad

2009-06-01

Candida albicans is a member of the normal human microflora. C. albicans cell wall is composed of several protein and carbohydrate components which have been shown to play a crucial role in C. albicans interaction with the host immune system. Major components of C. albican cell wall are carbohydrates such as mannans, beta glucans and chitins, and proteins that partially modulate the host immune responses. Dendritic cells (DC), as the most important antigen-presenting cells of the immune system, play a critical role in inducing immune responses against different pathogens. We investigated the effect of the cell wall protein fraction (CPF) of C. albicans on DC maturation. The CPF of C. albicans cells was extracted by a lysis buffer containing sodium dodecyl sulphate, 2-mercaptoethanol and phosphate-buffered saline. The extract was dialyzed and its protein pattern was evaluated by electrophoresis. Dendritic cells were purified from Balb/c mice spleens through a three-step method including mononuclear cell separation, as well as 2-h and overnight cultures. The purified CPF was added at different concentrations to DC. The purity and maturation status of DC were determined by flow cytometry using monoclonal antibodies against CD11c, MHC-II, CD40 and CD86. Treatment of DC with 10 microg/ml of CPF increased the expression of maturation markers including MHC-II, CD86 and CD40 on DC compared to the control group. In this study we used C. albicans CPF with the molecular weight of 40-45 kDa for pulsing and maturation of dendritic cells. Since according to our results CPF significantly increased the expression of maturation markers on DC, we suggest that CPF may act as an efficient immunomodulator, or may be used as a potential adjuvant to boost the host immune system against infections.

The aryl hydrocarbon receptor and food allergy.

PubMed

Schulz, V J; Smit, J J; Pieters, R H H

2013-06-01

The immune system is important for protection against pathogens and malignant cells. However, malfunction of the immune system can also result in detrimental auto-immune diseases, inflammatory diseases, cancers and allergies. The aryl hydrocarbon receptor (AhR), present in numerous tissues and cell subsets, including cells of the immune system, plays an important role in the functioning of the immune system. Activation of the AhR is for example associated with various effects on dendritic cells (DCs), regulatory T cells and the Th1/Th2 cell balance. These cells play a major role in the development of food allergy. Food allergy is an increasing health problem in both humans and animals. Despite the knowledge in risk factors and cellular mechanisms for food allergy, no approved treatments are available yet. Recently, it has been shown that activation of the AhR by dioxin-like compounds suppresses allergic sensitization by suppressing the absolute number of precursor and effector T cells, by preserving CD4(+)CD25(+)Foxp3(+) Treg cells and by affecting DCs and their interaction with effector T cells. Future research should elucidate whether and how AhR activation can be used to interfere in food allergic responses in humans and in animals. This may lead to new prevention strategies and therapeutic possibilities for food allergy.

Development of a high-throughput screening system for identification of novel reagents regulating DNA damage in human dermal fibroblasts.

PubMed

Bae, Seunghee; An, In-Sook; An, Sungkwan

2015-09-01

Ultraviolet (UV) radiation is a major inducer of skin aging and accumulated exposure to UV radiation increases DNA damage in skin cells, including dermal fibroblasts. In the present study, we developed a novel DNA repair regulating material discovery (DREAM) system for the high-throughput screening and identification of putative materials regulating DNA repair in skin cells. First, we established a modified lentivirus expressing the luciferase and hypoxanthine phosphoribosyl transferase (HPRT) genes. Then, human dermal fibroblast WS-1 cells were infected with the modified lentivirus and selected with puromycin to establish cells that stably expressed luciferase and HPRT (DREAM-F cells). The first step in the DREAM protocol was a 96-well-based screening procedure, involving the analysis of cell viability and luciferase activity after pretreatment of DREAM-F cells with reagents of interest and post-treatment with UVB radiation, and vice versa. In the second step, we validated certain effective reagents identified in the first step by analyzing the cell cycle, evaluating cell death, and performing HPRT-DNA sequencing in DREAM-F cells treated with these reagents and UVB. This DREAM system is scalable and forms a time-saving high-throughput screening system for identifying novel anti-photoaging reagents regulating DNA damage in dermal fibroblasts.

System, device, and methods for real-time screening of live cells, biomarkers, and chemical signatures

DOEpatents

Sundaram, S Kamakshi [Richland, WA; Riley, Brian J [West Richland, WA; Weber, Thomas J [Richland, WA; Sacksteder, Colette A [West Richland, WA; Addleman, R Shane [Benton City, WA

2011-06-07

An ATR-FTIR device and system are described that defect live-cell responses to stimuli and perturbations in real-time. The system and device can monitor perturbations resulting from exposures to various physical, chemical, and biological materials in real-time, as well as those sustained over a long period of time, including those associated with stimuli having unknown modes-of-action (e.g. nanoparticles). The device and system can also be used to identify specific chemical species or substances that profile cellular responses to these perturbations.

Three-dimensional slice cultures from murine fetal gut for investigations of the enteric nervous system.

PubMed

Metzger, Marco; Bareiss, Petra M; Nikolov, Ivan; Skutella, Thomas; Just, Lothar

2007-01-01

Three-dimensional intestinal cultures offer new possibilities for the examination of growth potential, analysis of time specific gene expression, and spatial cellular arrangement of enteric nervous system in an organotypical environment. We present an easy to produce in vitro model of the enteric nervous system for analysis and manipulation of cellular differentiation processes. Slice cultures of murine fetal colon were cultured on membrane inserts for up to 2 weeks without loss of autonomous contractility. After slice preparation, cultured tissue reorganized within the first days in vitro. Afterward, the culture possessed more than 35 cell layers, including high prismatic epithelial cells, smooth muscle cells, glial cells, and neurons analyzed by immunohistochemistry. The contraction frequency of intestinal slice culture could be modulated by the neurotransmitter serotonin and the sodium channel blocker tetrodotoxin. Coculture experiments with cultured neurospheres isolated from enhanced green fluorescent protein (eGFP) transgenic mice demonstrated that differentiating eGFP-positive neurons were integrated into the intestinal tissue culture. This slice culture model of enteric nervous system proved to be useful for studying cell-cell interactions, cellular signaling, and cell differentiation processes in a three-dimensional cell arrangement.

Automated microscopy system for detection and genetic characterization of fetal nucleated red blood cells on slides

NASA Astrophysics Data System (ADS)

Ravkin, Ilya; Temov, Vladimir

1998-04-01

The detection and genetic analysis of fetal cells in maternal blood will permit noninvasive prenatal screening for genetic defects. Applied Imaging has developed and is currently evaluating a system for semiautomatic detection of fetal nucleated red blood cells on slides and acquisition of their DNA probe FISH images. The specimens are blood smears from pregnant women (9 - 16 weeks gestation) enriched for nucleated red blood cells (NRBC). The cells are identified by using labeled monoclonal antibodies directed to different types of hemoglobin chains (gamma, epsilon); the nuclei are stained with DAPI. The Applied Imaging system has been implemented with both Olympus BX and Nikon Eclipse series microscopes which were equipped with transmission and fluorescence optics. The system includes the following motorized components: stage, focus, transmission, and fluorescence filter wheels. A video camera with light integration (COHU 4910) permits low light imaging. The software capabilities include scanning, relocation, autofocusing, feature extraction, facilities for operator review, and data analysis. Detection of fetal NRBCs is achieved by employing a combination of brightfield and fluorescence images of nuclear and cytoplasmic markers. The brightfield and fluorescence images are all obtained with a single multi-bandpass dichroic mirror. A Z-stack of DNA probe FISH images is acquired by moving focus and switching excitation filters. This stack is combined to produce an enhanced image for presentation and spot counting.

Advances in mechanisms of allergy.

PubMed

Bochner, Bruce S; Busse, William W

2004-05-01

This review summarizes selected Mechanisms of Allergy articles appearing between 2002 and 2003 in the Journal of Allergy and Clinical Immunology. Articles chosen include those dealing with human airways disease pathophysiology, pharmacology, cell biology, cell recruitment, and genetics, as well as information from allergen challenge models in both human and nonhuman systems. When appropriate, articles from other journals have been included to supplement the topics being presented.

40 CFR 1037.615 - Hybrid vehicles and other advanced technologies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... system by chassis testing a vehicle equipped with the advanced system and an equivalent conventional vehicle, or by testing the hybrid systems and the equivalent non-hybrid systems as described in § 1037.550... include regenerative braking (or the equivalent) and energy storage systems, fuel cell vehicles, and...

Air Force electrochemical power research and technology program for space applications

NASA Technical Reports Server (NTRS)

Allen, Douglas

1987-01-01

An overview is presented of the existing Air Force electrochemical power, battery, and fuel cell programs for space application. Present thrusts are described along with anticipated technology availability dates. Critical problems to be solved before system applications occur are highlighted. Areas of needed performance improvement of batteries and fuel cells presently used are outlined including target dates for key demonstrations of advanced technology. Anticipated performance and current schedules for present technology programs are reviewed. Programs that support conventional military satellite power systems and special high power applications are reviewed. Battery types include bipolar lead-acid, nickel-cadmium, silver-zinc, nickel-hydrogen, sodium-sulfur, and some candidate advanced couples. Fuel cells for pulsed and transportation power applications are discussed as are some candidate advanced regenerative concepts.

Synergistic interaction of the cannabinoid and death receptor systems - a potential target for future cancer therapies?

PubMed

Keresztes, Attila; Streicher, John M

2017-10-01

Cannabinoid receptors have been shown to interact with other receptors, including tumor necrosis factor receptor superfamily (TNFRS) members, to induce cancer cell death. When cannabinoids and death-inducing ligands (including TNF-related apoptosis-inducing ligand) are administered together, they have been shown to synergize and demonstrate enhanced antitumor activity in vitro. Certain cannabinoid ligands have been shown to sensitize cancer cells and synergistically interact with members of the TNFRS, thus suggesting that the combination of cannabinoids with death receptor (DR) ligands induces additive or synergistic tumor cell death. This review summarizes recent findings on the interaction of the cannabinoid and DR systems and suggests possible clinical co-application of cannabinoids and DR ligands in the treatment of various malignancies. © 2017 Federation of European Biochemical Societies.

Immune regulation of systemic hypertension, pulmonary arterial hypertension, and preeclampsia: shared disease mechanisms and translational opportunities.

PubMed

Jafri, Salema; Ormiston, Mark L

2017-12-01

Systemic hypertension, preeclampsia, and pulmonary arterial hypertension (PAH) are diseases of high blood pressure in the systemic or pulmonary circulation. Beyond the well-defined contribution of more traditional pathophysiological mechanisms, such as changes in the renin-angiotensin-aldosterone system, to the development of these hypertensive disorders, there is substantial clinical evidence supporting an important role for inflammation and immunity in the pathogenesis of each of these three conditions. Over the last decade, work in small animal models, bearing targeted deficiencies in specific cytokines or immune cell subsets, has begun to clarify the immune-mediated mechanisms that drive changes in vascular structure and tone in hypertensive disease. By summarizing the clinical and experimental evidence supporting a contribution of the immune system to systemic hypertension, preeclampsia, and PAH, the current review highlights the cellular and molecular pathways that are common to all three hypertensive disorders. These mechanisms are centered on an imbalance in CD4 + helper T cell populations, defined by excessive Th17 responses and impaired T reg activity, as well as the excessive activation or impairment of additional immune cell types, including macrophages, dendritic cells, CD8 + T cells, B cells, and natural killer cells. The identification of common immune mechanisms in systemic hypertension, preeclampsia, and PAH raises the possibility of new therapeutic strategies that target the immune component of hypertension across multiple disorders. Copyright © 2017 the American Physiological Society.

Zoledronate Triggers Vδ2 T Cells to Destroy and Kill Spheroids of Colon Carcinoma: Quantitative Image Analysis of Three-Dimensional Cultures.

PubMed

Varesano, Serena; Zocchi, Maria Raffaella; Poggi, Alessandro

2018-01-01

New successful anti-cancer strategies are based on the stimulation of immune reaction against tumors: however, preclinical testing of such treatments is still a challenge. To improve the screening of anti-cancer drugs, three-dimensional (3D) culture systems, including spheroids, have been validated as preclinical models. We propose the spheroid 3D system to test anti-tumor drug-induced immune responses. We show that colorectal carcinoma (CRC) spheroids, generated with the epithelial growth factor (EGF), can be co-cultured with Vδ2 T cells to evaluate the anti-tumor activity of these effector lymphocytes. By computerized image analysis, the precise and unbiased measure of perimeters and areas of tumor spheroids is achievable, beside the calculation of their volume. CRC spheroid size is related to ATP content and cell number, as parameters for cell metabolism and proliferation; in turn, crystal violet staining can check the viability of cells inside the spheroids to detect tumor killing by Vδ2 T cells. In this 3D cultures, we tested (a) zoledronate that is known to activate Vδ2 T cells and (b) the therapeutic anti-EGF receptor humanized antibody cetuximab that can elicit the antibody-dependent cytotoxicity of tumor cells by effector lymphocytes. Zoledronate triggers Vδ2 T cells to kill and degrade CRC spheroids; we detected the T-cell receptor dependency of zoledronate effect, conceivably due to the recognition of phosphoantigens produced as a drug effect on target cell metabolism. In addition, cetuximab triggered Vδ2 T lymphocytes to exert the antibody-dependent cellular cytotoxicity of CRC spheroids. Finally, the system reveals differences in the sensitivity of CRC cell lines to the action of Vδ2 T lymphocytes and in the efficiency of anti-tumor effectors from distinct donors. A limitation of this model is the absence of cells, including fibroblasts, that compose tumor microenvironment and influence drug response. Nevertheless, the system can be improved by setting mixed spheroids, made of stromal and cancer cells. We conclude that this type of spheroid 3D culture is a feasible and reliable system to evaluate and measure anti-tumor drug-induced immune responses beside direct anti-cancer drug effect.

Space Photovoltaic Research and Technology, 1989

NASA Technical Reports Server (NTRS)

1991-01-01

Remarkable progress on a wide variety of approaches in space photovoltaics, for both near and far term applications is reported. Papers were presented in a variety of technical areas, including multi-junction cell technology, GaAs and InP cells, system studies, cell and array development, and non-solar direct conversion. Five workshops were held to discuss the following topics: mechanical versus monolithic multi-junction cells; strategy in space flight experiments; non-solar direct conversion; indium phosphide cells; and space cell theory and modeling.

Self-Regulating Water-Separator System for Fuel Cells

NASA Technical Reports Server (NTRS)

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 compressibility would be sensed, and an increase in compressibility beyond a preset point (signifying a decrease in water content below an optimum low level) would cause the outflow from the reciprocating pump to be diverted back to the separator to recycle some water.

Biotechnological and biomedical applications of mesenchymal stem cells as a therapeutic system.

PubMed

Rahimzadeh, Amirbahman; Mirakabad, Fatemeh Sadat Tabatabaei; Movassaghpour, Aliakbar; Shamsasenjan, Karim; Kariminekoo, Saber; Talebi, Mehdi; Shekari, Abolfazl; Zeighamian, Vahideh; Ghalhar, Masoud Gandomkar; Akbarzadeh, Abolfazl

2016-01-01

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.

High resolution light-sheet based high-throughput imaging cytometry system enables visualization of intra-cellular organelles

NASA Astrophysics Data System (ADS)

Regmi, Raju; Mohan, Kavya; Mondal, Partha Pratim

2014-09-01

Visualization of intracellular organelles is achieved using a newly developed high throughput imaging cytometry system. This system interrogates the microfluidic channel using a sheet of light rather than the existing point-based scanning techniques. The advantages of the developed system are many, including, single-shot scanning of specimens flowing through the microfluidic channel at flow rate ranging from micro- to nano- lit./min. Moreover, this opens-up in-vivo imaging of sub-cellular structures and simultaneous cell counting in an imaging cytometry system. We recorded a maximum count of 2400 cells/min at a flow-rate of 700 nl/min, and simultaneous visualization of fluorescently-labeled mitochondrial network in HeLa cells during flow. The developed imaging cytometry system may find immediate application in biotechnology, fluorescence microscopy and nano-medicine.

Redox flow batteries having multiple electroactive elements

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

Wang, Wei; Li, Liyu; Yang, Zhenguo

Introducing multiple redox reactions with a suitable voltage range can improve the energy density of redox flow battery (RFB) systems. One example includes RFB systems utilizing multiple redox pairs in the positive half cell, the negative half cell, or in both. Such RFB systems can have a negative electrolyte, a positive electrolyte, and a membrane between the negative electrolyte and the positive electrolyte, in which at least two electrochemically active elements exist in the negative electrolyte, the positive electrolyte, or both.

Localized surface plasmon resonance mercury detection system and methods

DOEpatents

James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

2016-03-22

A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

A Microfluidic Device for Continuous Sensing of Systemic Acute Toxicants in Drinking Water

PubMed Central

Zhao, Xinyan; Dong, Tao

2013-01-01

A bioluminescent-cell-based microfluidic device for sensing toxicants in drinking water was designed and fabricated. The system employed Vibrio fischeri cells as broad-spectrum sensors to monitor potential systemic cell toxicants in water, such as heavy metal ions and phenol. Specifically, the chip was designed for continuous detection. The chip design included two counter-flow micromixers, a T-junction droplet generator and six spiral microchannels. The cell suspension and water sample were introduced into the micromixers and dispersed into droplets in the air flow. This guaranteed sufficient oxygen supply for the cell sensors. Copper (Cu2+), zinc (Zn2+), potassium dichromate and 3,5-dichlorophenol were selected as typical toxicants to validate the sensing system. Preliminary tests verified that the system was an effective screening tool for acute toxicants although it could not recognize or quantify specific toxicants. A distinct non-linear relationship was observed between the zinc ion concentration and the Relative Luminescence Units (RLU) obtained during testing. Thus, the concentration of simple toxic chemicals in water can be roughly estimated by this system. The proposed device shows great promise for an early warning system for water safety. PMID:24300075

Application of stem cell/growth factor system, as a multimodal therapy approach in regenerative medicine to improve cell therapy yields.

PubMed

Pourrajab, Fatemeh; Babaei Zarch, Mojtaba; Baghi Yazdi, Mohammad; Rahimi Zarchi, Abolfazl; Vakili Zarch, Abbas

2014-04-15

Stem cells hold a great promise for regenerative medicine, especially for replacing cells in infarcted organ that hardly have any intrinsic renewal capacity, including heart and brain. Signaling pathways that regulate pluripotency or lineage-specific gene and protein expression have been the major focus of stem cell research. Between them, there are some well known signaling pathways such as GF/GFR systems, SDF-1α/CXC4 ligand receptor interaction and PI3K/Akt signaling, and cytokines may regulate cell fate decisions, and can be utilized to positively influence cell therapy outcomes or accentuate synergistic compliance. For example, contributing factors in the progression of heart failure are both the loss of cardiomyocytes after myocardial infarction, and the absence of an adequate endogenous repair signaling. Combining cell engraftment with therapeutic signaling factor delivery is more exciting in terms of host progenitor/donor stem cell survival and proliferation. Thus stem cell-based therapy, besides triggering signaling pathways through GF/GFR systems can become a realistic option in regenerative processes for replacing lost cells and reconstituting the damaged organ, as before. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Architecture and inherent robustness of a bacterial cell-cycle control system.

PubMed

Shen, Xiling; Collier, Justine; Dill, David; Shapiro, Lucy; Horowitz, Mark; McAdams, Harley H

2008-08-12

A closed-loop control system drives progression of the coupled stalked and swarmer cell cycles of the bacterium Caulobacter crescentus in a near-mechanical step-like fashion. The cell-cycle control has a cyclical genetic circuit composed of four regulatory proteins with tight coupling to processive chromosome replication and cell division subsystems. We report a hybrid simulation of the coupled cell-cycle control system, including asymmetric cell division and responses to external starvation signals, that replicates mRNA and protein concentration patterns and is consistent with observed mutant phenotypes. An asynchronous sequential digital circuit model equivalent to the validated simulation model was created. Formal model-checking analysis of the digital circuit showed that the cell-cycle control is robust to intrinsic stochastic variations in reaction rates and nutrient supply, and that it reliably stops and restarts to accommodate nutrient starvation. Model checking also showed that mechanisms involving methylation-state changes in regulatory promoter regions during DNA replication increase the robustness of the cell-cycle control. The hybrid cell-cycle simulation implementation is inherently extensible and provides a promising approach for development of whole-cell behavioral models that can replicate the observed functionality of the cell and its responses to changing environmental conditions.

Induced Pluripotent Stem Cell Models to Enable In Vitro Models for Screening in the Central Nervous System.

PubMed

Hunsberger, Joshua G; Efthymiou, Anastasia G; Malik, Nasir; Behl, Mamta; Mead, Ivy L; Zeng, Xianmin; Simeonov, Anton; Rao, Mahendra

2015-08-15

There is great need to develop more predictive drug discovery tools to identify new therapies to treat diseases of the central nervous system (CNS). Current nonpluripotent stem cell-based models often utilize non-CNS immortalized cell lines and do not enable the development of personalized models of disease. In this review, we discuss why in vitro models are necessary for translational research and outline the unique advantages of induced pluripotent stem cell (iPSC)-based models over those of current systems. We suggest that iPSC-based models can be patient specific and isogenic lines can be differentiated into many neural cell types for detailed comparisons. iPSC-derived cells can be combined to form small organoids, or large panels of lines can be developed that enable new forms of analysis. iPSC and embryonic stem cell-derived cells can be readily engineered to develop reporters for lineage studies or mechanism of action experiments further extending the utility of iPSC-based systems. We conclude by describing novel technologies that include strategies for the development of diversity panels, novel genomic engineering tools, new three-dimensional organoid systems, and modified high-content screens that may bring toxicology into the 21st century. The strategic integration of these technologies with the advantages of iPSC-derived cell technology, we believe, will be a paradigm shift for toxicology and drug discovery efforts.

The dormant cells of Mycobacterium tuberculosis may be resuscitated by targeting-expression system of recombinant mycobacteriophage-Rpf: implication of shorter course of TB chemotherapy in the future.

PubMed

Gan, Yiling; Yao, Yiyong; Guo, Shuliang

2015-05-01

Here we hypothesized that dormant cells of Mycobacterium tuberculosis (M. tuberculosis) may be resuscitated by a new expression system of recombinant mycobacteriophage-resuscitation-promoting factor (Rpf). In this system, gene of targeted Rpf was cloned into mycobacteriophage genome, since mycobacteriophages possess several characteristics, including automatic identification and specific infection of M. tuberculosis. Thus the targeted delivery and endogenous expression of Rpf to the infected area of M. tuberculosis can be realized, followed by resuscitating the dormant cells of M. tuberculosis. Finally, these resuscitated M. tuberculosis can be thoroughly killed by a strong short-term subsequent chemotherapy, which makes the course of TB chemotherapy much shorter in the future compared to simple chemotherapy. Early studies have confirmed that dormant cells of M. tuberculosis can be resuscitated by Rpf in vitro, but so far, there is no report that Rpf can succeed in resuscitating dormant cells of M. tuberculosis in vivo, the reason may be that it is difficult for purified Rpf to remain active in vivo, especially to achieve targeted delivery of exogenous Rpf to the infected area of dormant cells of M. tuberculosis. Mycobacteriophage is a virus, capable of specifically identifying and infecting mycobacterium, such as M. tuberculosis. Several studies show that motif 3-containing proteins have peptidoglycan-hydrolysing activity and that while this activity is not required for mycobacteriophage viability, it facilitates efficient infection and DNA injection of mycobacteriophage (including motif 3 protein) into stationary phase cells. Thus this expression system can achieve targeted delivery and endogenous expression of Rpf to infected area of dormant cells of M. tuberculosis. Finally, we discuss the implication of this recombinant expression system for shortening the course of TB chemotherapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Celution® System: Automated Processing of Adipose-Derived Regenerative Cells in a Functionally Closed System

PubMed Central

Fraser, John K.; Hicok, Kevin C.; Shanahan, Rob; Zhu, Min; Miller, Scott; Arm, Douglas M.

2014-01-01

Objective: To develop a closed, automated system that standardizes the processing of human adipose tissue to obtain and concentrate regenerative cells suitable for clinical treatment of thermal and radioactive burn wounds. Approach: A medical device was designed to automate processing of adipose tissue to obtain a clinical-grade cell output of stromal vascular cells that may be used immediately as a therapy for a number of conditions, including nonhealing wounds resulting from radiation damage. Results: The Celution® System reliably and reproducibly generated adipose-derived regenerative cells (ADRCs) from tissue collected manually and from three commercial power-assisted liposuction devices. The entire process of introducing tissue into the system, tissue washing and proteolytic digestion, isolation and concentration of the nonadipocyte nucleated cell fraction, and return to the patient as a wound therapeutic, can be achieved in approximately 1.5 h. An alternative approach that applies ultrasound energy in place of enzymatic digestion demonstrates extremely poor efficiency cell extraction. Innovation: The Celution System is the first medical device validated and approved by multiple international regulatory authorities to generate autologous stromal vascular cells from adipose tissue that can be used in a real-time bedside manner. Conclusion: Initial preclinical and clinical studies using ADRCs obtained using the automated tissue processing Celution device described herein validate a safe and effective manner to obtain a promising novel cell-based treatment for wound healing. PMID:24761343

Photovoltaic energy technologies: Health and environmental effects document

NASA Astrophysics Data System (ADS)

Moskowitz, P. D.; Hamilton, L. D.; Morris, S. C.; Rowe, M. D.

1980-09-01

The potential health and environmental consequences of producing electricity by photovoltaic energy systems was analyzed. Potential health and environmental risks are identified in representative fuel and material supply cycles including extraction, processing, refining, fabrication, installation, operation, and isposal for four photovoltaic energy systems (silicon N/P single crystal, silicon metal/insulator/semiconductor (MIS) cell, cadmium sulfide/copper sulfide backwall cell, and gallium arsenide heterojunction cell) delivering equal amounts of useful energy. Each step of the fuel and material supply cycles, materials demands, byproducts, public health, occupational health, and environmental hazards is identified.

Annexins in plasma membrane repair.

PubMed

Boye, Theresa Louise; Nylandsted, Jesper

2016-10-01

Disruption of the plasma membrane poses deadly threat to eukaryotic cells and survival requires a rapid membrane repair system. Recent evidence reveal various plasma membrane repair mechanisms, which are required for cells to cope with membrane lesions including membrane fusion and replacement strategies, remodeling of cortical actin cytoskeleton and vesicle wound patching. Members of the annexin protein family, which are Ca2+-triggered phospholipid-binding proteins emerge as important components of the plasma membrane repair system. Here, we discuss the mechanisms of plasma membrane repair involving annexins spanning from yeast to human cancer cells.

Electrostatically actuatable light modulating device

DOEpatents

Koehler, Dale R.

1991-01-01

The electrostatically actuatable light modulator utilizes an opaque substrate plate patterned with an array of aperture cells, the cells comprised of physically positionable dielectric shutters and electrostatic actuators. With incorporation of a light source and a viewing screen, a projection display system is effected. Inclusion of a color filter array aligned with the aperture cells accomplishes a color display. The system is realized in terms of a silicon based manufacturing technology allowing fabrication of a high resolution capability in a physically small device which with the utilization of included magnification optics allows both large and small projection displays.

Translational Cellular Research on the International Space Station

NASA Technical Reports Server (NTRS)

Love, John; Cooley, Vic

2016-01-01

The emerging field of Translational Research aims to coalesce interdisciplinary findings from basic science for biomedical applications. To complement spaceflight research using human subjects, translational studies can be designed to address aspects of space-related human health risks and help develop countermeasures to prevent or mitigate them, with therapeutical benefits for analogous conditions experienced on Earth. Translational research with cells and model organisms is being conducted onboard the International Space Station (ISS) in connection with various human systems impacted by spaceflight, such as the cardiovascular, musculoskeletal, and immune systems. Examples of recent cell-based translational investigations on the ISS include the following. The JAXA investigation Cell Mechanosensing seeks to identify gravity sensors in skeletal muscle cells to develop muscle atrophy countermeasures by analyzing tension fluctuations in the plasma membrane, which changes the expression of key proteins and genes. Earth applications of this study include therapeutic approaches for some forms of muscular dystrophy, which appear to parallel aspects of muscle wasting in space. Spheroids is an ESA investigation examining the system of endothelial cells lining the inner surface of all blood vessels in terms of vessel formation, cellular proliferation, and programmed cell death, because injury to the endothelium has been implicated as underpinning various cardiovascular and musculoskeletal problems arising during spaceflight. Since endothelial cells are involved in the functional integrity of the vascular wall, this research has applications to Earth diseases such as atherosclerosis, diabetes, and hypertension. The goal of the T-Cell Activation in Aging NASA investigation is to understand human immune system depression in microgravity by identifying gene expression patterns of candidate molecular regulators, which will provide further insight into factors that may play a critical role in immune function loss during aging. In addition, Omics investigations with cells have synergistic applications ranging from the evaluation of pharmacological countermeasures to drug discovery. Thus, cell-based translational research onboard the ISS is bidirectionally bridging cutting-edge cellular and molecular approaches with space bioastronautics and human health methodologies on Earth.

The extraction of simple relationships in growth factor-specific multiple-input and multiple-output systems in cell-fate decisions by backward elimination PLS regression.

PubMed

Akimoto, Yuki; Yugi, Katsuyuki; Uda, Shinsuke; Kudo, Takamasa; Komori, Yasunori; Kubota, Hiroyuki; Kuroda, Shinya

2013-01-01

Cells use common signaling molecules for the selective control of downstream gene expression and cell-fate decisions. The relationship between signaling molecules and downstream gene expression and cellular phenotypes is a multiple-input and multiple-output (MIMO) system and is difficult to understand due to its complexity. For example, it has been reported that, in PC12 cells, different types of growth factors activate MAP kinases (MAPKs) including ERK, JNK, and p38, and CREB, for selective protein expression of immediate early genes (IEGs) such as c-FOS, c-JUN, EGR1, JUNB, and FOSB, leading to cell differentiation, proliferation and cell death; however, how multiple-inputs such as MAPKs and CREB regulate multiple-outputs such as expression of the IEGs and cellular phenotypes remains unclear. To address this issue, we employed a statistical method called partial least squares (PLS) regression, which involves a reduction of the dimensionality of the inputs and outputs into latent variables and a linear regression between these latent variables. We measured 1,200 data points for MAPKs and CREB as the inputs and 1,900 data points for IEGs and cellular phenotypes as the outputs, and we constructed the PLS model from these data. The PLS model highlighted the complexity of the MIMO system and growth factor-specific input-output relationships of cell-fate decisions in PC12 cells. Furthermore, to reduce the complexity, we applied a backward elimination method to the PLS regression, in which 60 input variables were reduced to 5 variables, including the phosphorylation of ERK at 10 min, CREB at 5 min and 60 min, AKT at 5 min and JNK at 30 min. The simple PLS model with only 5 input variables demonstrated a predictive ability comparable to that of the full PLS model. The 5 input variables effectively extracted the growth factor-specific simple relationships within the MIMO system in cell-fate decisions in PC12 cells.

Potential immunologic targets for treating fibrosis in systemic sclerosis: a review focused on leukocytes and cytokines.

PubMed

Hasegawa, Minoru; Takehara, Kazuhiko

2012-12-01

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis. Although the pathogenesis remains unclear, a variety of cells contribute to the fibrotic process via interactions with each other and production of various cytokines. Recent literature related to the immunologic pathogenesis and future strategies for treating the fibrosis of SSc are discussed and, especially, this literature-based review that includes the authors' perspective, focused on leukocytes and cytokines. A PubMed search for articles published between January 2005 and January 2012 was conducted using the following keywords: systemic sclerosis, leukocyte, cytokine, growth factor, and chemokine. The reference lists of identified articles were searched for further articles. Targeting profibrogenic cytokines, including transforming growth factor-β, is still a very active area of research in SSc and most cellular studies have focused on the roles of fibroblasts in SSc. However, a growing number of recent studies indicate a role for B cells in the development of SSc and other autoimmune diseases such as systemic lupus erythematosus. Therefore, B-cell-targeted therapies, including currently available monoclonal antibodies against CD19, CD20, CD22, and B-cell-activating factor, belonging to the tumor necrosis factor family represent possible treatment options. Furthermore, the modulation of T-cell costimulatory molecules such as a recombinant fusion protein of cytotoxic T-lymphocyte antigen-4 may be as effective in SSc as it is in treating other autoimmune diseases. Approaches to antagonize interleukin (IL)-1, IL-6, or IL-17A signaling may also be attractive. This review describes recent advances in the treatment of fibrosis in SSc patients focused on immunologic strategies, such as leukocyte- or cytokine-targeted therapies. Copyright © 2012 Elsevier Inc. All rights reserved.

Reactor Power for Large Displacement Autonomous Underwater Vehicles

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

McClure, Patrick Ray; Reid, Robert Stowers; Poston, David Irvin

This is a PentaChart on reactor power for large displacement autonomous underwater vehicles. Currently AUVs use batteries or combinations of batteries and fuel cells for power. Battery/fuel cell technology is limited by duration. Batteries and cell fuels are a good match for some missions, but other missions could benefit greatly by a longer duration. The goal is the following: to design nuclear systems to power an AUV and meet design constraints including non-proliferation issues, power level, size constraints, and power conversion limitations. The action plan is to continue development of a range of systems for terrestrial systems and focus onmore » a system for Titan Moon as alternative to Pu-238 for NASA.« less

NREL and Fraunhofer ISE to Collaborate on Hydrogen and Fuel Cell Research |

Science.gov Websites

(R&D) activities to accelerate progress in these fields. NREL's long-term research and accelerate progress toward shared R&D goals and to ensure sustainable use of hydrogen and fuel cell Fraunhofer ISE in the following areas: Electrolysis, including cell, stack, and system R&D and

Liquid-Feed Methanol Fuel Cell With Membrane Electrolyte

NASA Technical Reports Server (NTRS)

Surampudi, Subbarao; Narayanan, S. R.; Halpert, Gerald; Frank, Harvey; Vamos, Eugene

1995-01-01

Fuel cell generates electricity from direct liquid feed stream of methanol/water solution circulated in contact with anode, plus direct gaseous feed stream of air or oxygen in contact with cathode. Advantages include relative simplicity and elimination of corrosive electrolytic solutions. Offers potential for reductions in size, weight, and complexity, and for increases in safety of fuel-cell systems.

Candidate space processing techniques for biomaterials other than preparative electrophoresis

NASA Technical Reports Server (NTRS)

Brooks, D. E.

1976-01-01

The advantages of performing the partition and countercurrent distribution (CCD) of cells in phase separated aqueous polymer systems under reduced gravity were assessed. Other possible applications considered for the space processing program include the freezing front separation of cells, adsorption of cells at the air-water interface, and the macrophage electrophoretic mobility test for cancer.

Antigen discovery and delivery of subunit vaccines by nonliving bacterial ghost vectors.

PubMed

Walcher, Petra; Mayr, Ulrike B; Azimpour-Tabrizi, Chakameh; Eko, Francis O; Jechlinger, Wolfgang; Mayrhofer, Peter; Alefantis, Tim; Mujer, Cesar V; DelVecchio, Vito G; Lubitz, Werner

2004-12-01

The bacterial ghost (BG) platform system is a novel vaccine delivery system endowed with intrinsic adjuvant properties. BGs are nonliving Gram-negative bacterial cell envelopes which are devoid of their cytoplasmic contents, yet maintain their cellular morphology and antigenic structures, including bioadhesive properties. The main advantages of BGs as carriers of subunit vaccines include their ability to stimulate a high immune response and to target the carrier itself to primary antigen-presenting cells. The intrinsic adjuvant properties of BGs enhance the immune response to target antigens, including T-cell activation and mucosal immunity. Since native and foreign antigens can be carried in the envelope complex of BGs, combination vaccines with multiple antigens of diverse origin can be presented to the immune system simultaneously. Beside the capacity of BGs to function as carriers of protein antigens, they also have a high loading capacity for DNA. Thus, loading BGs with recombinant DNA takes advantage of the excellent bioavailability for DNA-based vaccines and the high expression rates of the DNA-encoded antigens in target cell types such as macrophages and dendritic cells. There are many spaces within BGs including the inner and outer membranes, the periplasmic space and the internal lumen which can carry antigens, DNA or mediators of the immune response. All can be used for subunit antigen to design new vaccine candidates with particle presentation technology. In addition, the fact that BGs can also carry piggyback large-size foreign antigen particles, increases the technologic usefulness of BGs as combination vaccines against viral and bacterial pathogens. Furthermore, the BG antigen carriers can be stored as freeze-dried preparations at room temperature for extended periods without loss of efficacy. The potency, safety and relatively low production cost of BGs offer a significant technical advantage over currently utilized vaccine technologies.

Microfluidic devices for cell cultivation and proliferation

PubMed Central

Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

2013-01-01

Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell culture in microperfusion systems to deliver continuous nutrient supplies for long term cell culture. It offers many opportunities to mimic the cell-cell and cell-extracellular matrix interactions of tissues by creating gradient concentrations of biochemical signals such as growth factors, chemokines, and hormones. Other applications of cell cultivation in microfluidic systems include high resolution cell patterning on a modified substrate with adhesive patterns and the reconstruction of complicated tissue architectures. In this review, recent advances in microfluidic platforms for cell culturing and proliferation, for both simple monolayer (2D) cell seeding processes and 3D configurations as accurate models of in vivo conditions, are examined. PMID:24273628

Nutrient requirements and other factors involved in the culture of human kidney cells on microcarrier beads

NASA Technical Reports Server (NTRS)

Lewis, Marian L.; Morrison, Dennis R.

1987-01-01

The culture of human kidney cells on microcarrier beads in the Bioprocessing Laboratory at the Johnson Space Center is described. These were the first series of studies performed before and during 1983 to determine optimum conditions, including medium type, bead type and density. The composition of several medium types and the molecular weights of some common culture medium supplements and cellular proteins are included. The microgravity cell-to-bead attachment experiment performed on Space Transportation System Flight 8 is described.

Photovoltaic options for solar electric propulsion

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Flood, Dennis J.

1990-01-01

This paper discusses both state-of-the-art and advanced development cell and array technology. Present technology includes rigid, roll-out, and foldout flexible substrate designs, with silicon and GaAs solar cells. The use of concentrator array systems is discussed based on both DOD efforts and NASA work. The benefits of advanced lightweight array technology, for both near term and far term utilization, and of advanced high efficiency thin radiation resistant cells is examined. This includes gallium arsenide/germanium, indium phosphide, and thin film devices such as copper indium disclenide.

ARC Cell Science Validation (CS-V) Payload Overview

NASA Technical Reports Server (NTRS)

Gilkerson, Nikita

2017-01-01

Automated cell biology system for laboratory and International Space Station (ISS) National Laboratory research. Enhanced cell culture platform that provides undisturbed culture maintenance, including feedback temperature control, medical grade gas supply, perfusion nutrient delivery and removal of waste, and automated experiment manipulations. Programmable manipulations include: media feeds change out, injections, fraction collections, fixation, flow rate, and temperature modification within a one-piece sterile barrier flow path. Cassette provides 3 levels of containment and allows Crew access to the bioculture chamber and flow path assembly for experiment initiation, refurbishment, or sample retrieval and preservation.

Stretchy Proteins on Stretchy Substrates: The Important Elements of Integrin-Mediated Rigidity Sensing

PubMed Central

Moore, Simon W.; Roca-Cusachs, Pere; Sheetz, Michael P.

2013-01-01

Matrix and tissue rigidity guides many cellular processes, including the differentiation of stem cells and the migration of cells in health and disease. Cells actively and transiently test rigidity using mechanisms limited by inherent physical parameters that include the strength of extracellular attachments, the pulling capacity on these attachments, and the sensitivity of the mechanotransduction system. Here we focus on rigidity sensing mediated through the integrin family of extracellular matrix receptors and linked proteins, and discuss the evidence supporting these proteins as mechanosensors. PMID:20708583

New applications for phosphoric acid fuel cells

NASA Astrophysics Data System (ADS)

Stickles, R. P.; Breuer, C. T.

1983-11-01

New applications for phosphoric acid fuel cells were identified and evaluated. Candidates considered included all possibilities except grid connected electric utility applications, on site total energy systems, industrial cogeneration, opportunistic use of waste hydrogen, space and military applications, and applications smaller than 10 kW. Applications identified were screened, with the most promising subjected to technical and economic evaluation using a fuel cell and conventional power system data base developed in the study. The most promising applications appear to be the underground mine locomotive and the railroad locomotive. Also interesting are power for robotic submersibles and Arctic villages. The mine locomotive is particularly attractive since it is expected that the fuel cell could command a very high price and still be competitive with the conventionally used battery system. The railroad locomotive's attractiveness results from the (smaller) premium price which the fuel cell could command over the conventional diesel electric system based on its superior fuel efficiency, and on the large size of this market and the accompanying opportunities for manufacturing economy.

Design and development of hyaluronan-functionalized polybenzofulvene nanoparticles as CD44 receptor mediated drug delivery system

NASA Astrophysics Data System (ADS)

Licciardi, Mariano; Scialabba, Cinzia; Giammona, Gaetano; Paolino, Marco; Razzano, Vincenzo; Grisci, Giorgio; Giuliani, Germano; Makovec, Francesco; Cappelli, Andrea

2017-06-01

A tri-component polymer brush (TCPB ), composed of a polybenzofulvene copolymer bearing low molecular weight hyaluronic acid (HA) on the surface of its cylindrical brush-like backbone and oligo-PEG fractions, was employed in the preparation of 350 nm nanostructured drug delivery systems capable of delivering the anticancer drug doxorubicin. The obtained drug delivery systems were characterized on the basis of drug loading and release, dimensions and zeta potential, morphology and in vitro cell activity, and uptake on three different human cell lines, namely the bronchial epithelial 16HBE, the breast adenocarcinoma MCF-7, and the colon cancer HCT116 cells. Finally, the ability of doxorubicin-loaded TCPB nanoparticles (DOXO-TCPB) to be internalized into cancer cells by CD44 receptor mediated uptake was assessed by means of uptake studies in HCT cells. These data were supported by anti-CD44-FITC staining assay. The proposed TCPB nanostructured drug delivery systems have many potential applications in nanomedicine, including cancer targeted drug delivery.

New applications for phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Stickles, R. P.; Breuer, C. T.

1983-01-01

New applications for phosphoric acid fuel cells were identified and evaluated. Candidates considered included all possibilities except grid connected electric utility applications, on site total energy systems, industrial cogeneration, opportunistic use of waste hydrogen, space and military applications, and applications smaller than 10 kW. Applications identified were screened, with the most promising subjected to technical and economic evaluation using a fuel cell and conventional power system data base developed in the study. The most promising applications appear to be the underground mine locomotive and the railroad locomotive. Also interesting are power for robotic submersibles and Arctic villages. The mine locomotive is particularly attractive since it is expected that the fuel cell could command a very high price and still be competitive with the conventionally used battery system. The railroad locomotive's attractiveness results from the (smaller) premium price which the fuel cell could command over the conventional diesel electric system based on its superior fuel efficiency, and on the large size of this market and the accompanying opportunities for manufacturing economy.

The clock is ticking. Ageing of the circadian system: From physiology to cell cycle.

PubMed

Terzibasi-Tozzini, Eva; Martinez-Nicolas, Antonio; Lucas-Sánchez, Alejandro

2017-10-01

The circadian system is the responsible to organise the internal temporal order in relation to the environment of every process of the organisms producing the circadian rhythms. These rhythms have a fixed phase relationship among them and with the environment in order to optimise the available energy and resources. From a cellular level, circadian rhythms are controlled by genetic positive and negative auto-regulated transcriptional and translational feedback loops, which generate 24h rhythms in mRNA and protein levels of the clock components. It has been described about 10% of the genome is controlled by clock genes, with special relevance, due to its implications, to the cell cycle. Ageing is a deleterious process which affects all the organisms' structures including circadian system. The circadian system's ageing may produce a disorganisation among the circadian rhythms, arrhythmicity and, even, disconnection from the environment, resulting in a detrimental situation to the organism. In addition, some environmental conditions can produce circadian disruption, also called chronodisruption, which may produce many pathologies including accelerated ageing. Finally, some strategies to prevent, palliate or counteract chronodisruption effects have been proposed to enhance the circadian system, also called chronoenhancement. This review tries to gather recent advances in the chronobiology of the ageing process, including cell cycle, neurogenesis process and physiology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antimicrobial outcomes in plasma medicine

NASA Astrophysics Data System (ADS)

Ryan, Thomas P.; Stalder, Kenneth R.; Woloszko, Jean

2015-03-01

Plasma is referred to as the fourth state of matter and is frequently generated in the environment of a strong electric field. The result consists of highly reactive species--ions, electrons, reactive atoms and molecules, and UV radiation. Plasma Medicine unites a number of fields, including Physics, Plasma Chemistry, Cell Biology, Biochemistry, and Medicine. The treatment modality utilizes Cold Atmospheric Plasma (CAP), which is able to sterilize and treat microbes in a nonthermal manner. These gas-based plasma systems operate at close to room temperature and atmospheric pressure, making them very practical for a range of potential treatments and are highly portable for clinical use throughout the health care system. The hypothesis is that gas based plasma kills bacteria, fungus, and viruses but spares mammalian cells. This paper will review systematic work which shows examples of systems and performance in regards to antimicrobial effects and the sparing of mammalian cells. The mechanism of action will be discussed, as well as dosing for the treatment of microbial targets, including sterilization processes, another important healthcare need. In addition, commercial systems will be overviewed and compared, along with evidence-based, patient results. The range of treatments cover wound treatment and biofilms, as well as antimicrobial treatment, with little chance for resistance and tolerance, as in drug regimens. Current clinical studies include applications in dentistry, food treatment, cancer treatment, wound treatment for bacteria and biofilms, and systems to combat health care related infections.

Die another way – non-apoptotic mechanisms of cell death

PubMed Central

Tait, Stephen W. G.; Ichim, Gabriel; Green, Douglas R.

2014-01-01

ABSTRACT Regulated, programmed cell death is crucial for all multicellular organisms. Cell death is essential in many processes, including tissue sculpting during embryogenesis, development of the immune system and destruction of damaged cells. The best-studied form of programmed cell death is apoptosis, a process that requires activation of caspase proteases. Recently it has been appreciated that various non-apoptotic forms of cell death also exist, such as necroptosis and pyroptosis. These non-apoptotic cell death modalities can be either triggered independently of apoptosis or are engaged should apoptosis fail to execute. In this Commentary, we discuss several regulated non-apoptotic forms of cell death including necroptosis, autophagic cell death, pyroptosis and caspase-independent cell death. We outline what we know about their mechanism, potential roles in vivo and define outstanding questions. Finally, we review data arguing that the means by which a cell dies actually matters, focusing our discussion on inflammatory aspects of cell death. PMID:24833670

Selective effects of quercetin on the cell growth and antioxidant defense system in normal versus transformed mouse hepatic cell lines.

PubMed

Son, Young-Ok; Lee, Kyung-Yeol; Kook, Sung-Ho; Lee, Jeong-Chae; Kim, Jong-Ghee; Jeon, Young-Mi; Jang, Yong-Suk

2004-10-19

Quercetin is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. However, little is known about its biological effect on nonmalignant cells, although the effect is one of the critical criteria to evaluate the clinical efficacy of the anticancer agent. In this study, we investigated the effects of quercetin on cell growth and apoptosis using embryonic normal hepatic cell line (BNL CL.2) and its SV40-transformed cell line (BNL SV A.8). We also evaluated the effects of quercetin on the antioxidant defense system in those cells. BNL SV A.8 cells were more sensitive to quercetin-mediated cytotoxicity than BNL CL.2 cells. In addition, the enzyme assays showed that quercetin actively stimulated the antioxidant defense systems including superoxide dismutase, catalase, glutathione, and glutathione reductase only in the BNL CL.2 cells. In particular, quercetin significantly reduced superoxide dismutase activity and increased the malonaldehyde content in BNL SV A.8 cells. These are thought to be closely related to quercetin-mediated apoptosis. Our findings suggest that quercetin is a dietary flavonoid that is capable of inducing selective growth inhibition and apoptosis in hepatic tumor cells, but not in normal cells.

Activity-dependent self-regulation of viscous length scales in biological systems

NASA Astrophysics Data System (ADS)

Nandi, Saroj Kumar

2018-05-01

The cellular cortex, which is a highly viscous thin cytoplasmic layer just below the cell membrane, controls the cell's mechanical properties, which can be characterized by a hydrodynamic length scale ℓ . Cells actively regulate ℓ via the activity of force-generating molecules, such as myosin II. Here we develop a general theory for such systems through a coarse-grained hydrodynamic approach including activity in the static description of the system providing an experimentally accessible parameter and elucidate the detailed mechanism of how a living system can actively self-regulate its hydrodynamic length scale, controlling the rigidity of the system. Remarkably, we find that ℓ , as a function of activity, behaves universally and roughly inversely proportional to the activity of the system. Our theory rationalizes a number of experimental findings on diverse systems, and comparison of our theory with existing experimental data shows good agreement.

A thermodynamic approach for selecting operating conditions in the design of reversible solid oxide cell energy systems

NASA Astrophysics Data System (ADS)

Wendel, Christopher H.; Kazempoor, Pejman; Braun, Robert J.

2016-01-01

Reversible solid oxide cell (ReSOC) systems are being increasingly considered for electrical energy storage, although much work remains before they can be realized, including cell materials development and system design optimization. These systems store electricity by generating a synthetic fuel in electrolysis mode and subsequently recover electricity by electrochemically oxidizing the stored fuel in fuel cell mode. System thermal management is improved by promoting methane synthesis internal to the ReSOC stack. Within this strategy, the cell-stack operating conditions are highly impactful on system performance and optimizing these parameters to suit both operating modes is critical to achieving high roundtrip efficiency. Preliminary analysis shows the thermoneutral voltage to be a useful parameter for analyzing ReSOC systems and the focus of this study is to quantitatively examine how it is affected by ReSOC operating conditions. The results reveal that the thermoneutral voltage is generally reduced by increased pressure, and reductions in temperature, fuel utilization, and hydrogen-to-carbon ratio. Based on the thermodynamic analysis, many different combinations of these operating conditions are expected to promote efficient energy storage. Pressurized systems can achieve high efficiency at higher temperature and fuel utilization, while non-pressurized systems may require lower stack temperature and suffer from reduced energy density.

Development and epithelial organisation of muscle cells in the sea anemone Nematostella vectensis.

PubMed

Jahnel, Stefan M; Walzl, Manfred; Technau, Ulrich

2014-01-01

Nematostella vectensis, a member of the cnidarian class Anthozoa, has been established as a promising model system in developmental biology, but while information about the genetic regulation of embryonic development is rapidly increasing, little is known about the cellular organization of the various cell types in the adult. Here, we studied the anatomy and development of the muscular system of N. vectensis to obtain further insights into the evolution of muscle cells. The muscular system of N. vectensis is comprised of five distinct muscle groups, which are differentiated into a tentacle and a body column system. Both systems house longitudinal as well as circular portions. With the exception of the ectodermal tentacle longitudinal muscle, all muscle groups are of endodermal origin. The shape and epithelial organization of muscle cells vary considerably between different muscle groups. Ring muscle cells are formed as epitheliomuscular cells in which the myofilaments are housed in the basal part of the cell, while the apical part is connected to neighboring cells by apical cell-cell junctions. In the longitudinal muscles of the column, the muscular part at the basal side is connected to the apical part by a long and narrow cytoplasmic bridge. The organization of these cells, however, remains epitheliomuscular. A third type of muscle cell is represented in the longitudinal muscle of the tentacle. Using transgenic animals we show that the apical cell-cell junctions are lost during differentiation, resulting in a detachment of the muscle cells to a basiepithelial position. These muscle cells are still located within the epithelium and outside of the basal matrix, therefore constituting basiepithelial myocytes. We demonstrate that all muscle cells, including the longitudinal basiepithelial muscle cells of the tentacle, initially differentiate from regular epithelial cells before they alter their epithelial organisation. A wide range of different muscle cell morphologies can already be found in a single animal. This suggests how a transition from an epithelially organized muscle system to a mesenchymal could have occurred. Our study on N. vectensis provides new insights into the organisation of a muscle system in a non-bilaterian organism.