Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen flight cells. An update

NASA Technical Reports Server (NTRS)

Smithrick, John J.; Hall, Stephen W.

1991-01-01

Validation testing of the NASA Lewis 125 Ah advanced design individual pressure vessel (IPV) nickel-hydrogen flight cells was conducted. Work consisted of characterization, storage, and cycle life testing. There was no capacity degradation after 52 days of storage with the cells in the discharged state, an open circuit, 0 C, and a hydrogen pressure of 14.5 psia. The catalyzed wall wick cells were cycled for over 11,000 cycles with no cell failures in the continuing test. One of the noncatalyzed wall wick cells failed.

Engineering Cell-Cell Signaling

PubMed Central

Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R.

2014-01-01

Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling based on quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilizing synthetic cells, advanced ‘chassis’ and predictive modeling to engineer the form and function of living tissues. PMID:23856592

The Implementation of Advanced Solar Array Technology in Future NASA Missions

NASA Technical Reports Server (NTRS)

Piszczor, Michael F.; Kerslake, Thomas W.; Hoffman, David J.; White, Steve; Douglas, Mark; Spence, Brian; Jones, P. Alan

2003-01-01

Advanced solar array technology is expected to be critical in achieving the mission goals on many future NASA space flight programs. Current PV cell development programs offer significant potential and performance improvements. However, in order to achieve the performance improvements promised by these devices, new solar array structures must be designed and developed to accommodate these new PV cell technologies. This paper will address the use of advanced solar array technology in future NASA space missions and specifically look at how newer solar cell technologies impact solar array designs and overall power system performance.

Evaluation of advanced high rate Li-SOCl2 cells

NASA Technical Reports Server (NTRS)

Deligiannis, F.; Ang, V.; Dawson, S.; Frank, H.; Subbarao, S.

1986-01-01

Under NASA sponsorship, JPL is developing advanced, high rate Li-SOCl2 cells for future space missions. As part of this effort, Li-SOCl2 cells of various designs were examined for performance and safety. The cells differed from one another in several aspects, such as: nature of carbon cathode, catalysts, cell configuration, case polarity, and safety devices. Performance evaluation included constant-current discharge over a range of currents and temperatures. Abuse-testing consisted of shortcircuiting, charging, and over-discharge. Energy densities greater than 300 Wh/Kg at the C/2 rate were found for some designs. A cell design featuring a high-surface-area carbon cathode was found to deliver nearly 500 Wh/Kg at moderate discharge rates. Temperature influenced the performance significantly.

The design analysis of a rechargeable lithium cell for space applications

NASA Technical Reports Server (NTRS)

Subba Rao, S.; Shen, D. H.; Yen, S. P. S.; Somoano, R. B.

1986-01-01

Ambient temperature rechargeable lithium batteries are needed by NASA for advanced space power applications for future missions. Specific energies of not less than 100 Wh/kg and long cycle life are critical performance goals. A design analysis of a 35 Ah Li-TiS2 cell was carried out using literature and experimental data to identify key design parameters governing specific energy. It is found that high specific energies are achievable in prismatic cells, especially with the use of advanced hardware materials. There is a serious need for a greatly expanded engineering database in order to enable more quantitative design analysis.

Development of advanced fuel cell system, phase 2

NASA Technical Reports Server (NTRS)

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

1973-01-01

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

Series II AMTEC cell development issues

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

Sievers, R.K.; Rasmussen, J.R.; Giglio, J.C.

1998-07-01

The Series II alkali metal thermal to electric converter (AMTEC) cell, developed over the last two year, represents a significant engineering advance in AMTEC technology, and major step toward spacecraft power systems. The PX-5 cell design was developed as an early prototype in stainless steel alloys. This design will evolve into the PX-6 engineering cell and finally into the EPX-1 to be used in the Advanced Radioisotope Power System (ARPS) program. The EPX-1 cell will be all-refractory metal. Late work on the PX-5 and early work on the PX-6 will be described.

Technology advancement of the electrochemical CO2 concentrating process

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Heppner, D. B.; Hallick, T. M.; Woods, R. R.

1979-01-01

Two multicell, liquid-cooled, advanced electrochemical depolarized carbon dioxide concentrator modules were fabricated. The cells utilized advanced, lightweight, plated anode current collectors, internal liquid cooling and lightweight cell frames. Both were designed to meet the carbon dioxide removal requirements of one-person, i.e., 1.0 kg/d (2.2 lb/d).

Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source

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

Wang, H; Ciovati, G; Clemens, W A

2011-03-01

We review the single-cell, superconducting crab cavity designs for the short-pulse x-ray (SPX) project at the Advanced Photon Source (APS). The 'on-cell' waveguide scheme is expected to have a more margin for the impedance budget of the APS storage ring, as well as offering a more compact design compared with the original design consisting of a low order mode damping waveguide on the beam pipe. We will report recent fabrication progress, cavity test performance on original and alternate prototypes, and concept designs and analysis for various cryomodule components.

Technology advancement of the electrochemical CO2 concentrating process

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Woods, R. R.; Hallick, T. M.; Heppner, D. B.

1977-01-01

A five-cell, liquid-cooled advanced electrochemical depolarized carbon dioxide concentrator module was fabricated. The cells utilized the advanced, lightweight, plated anode current collector concept and internal liquid-cooling. The five cell module was designed to meet the carbon dioxide removal requirements of one man and was assembled using plexiglass endplates. This one-man module was tested as part of an integrated oxygen generation and recovery subsystem.

Advanced technology for extended endurance alkaline fuel cells

NASA Technical Reports Server (NTRS)

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

1987-01-01

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

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

ERIC Educational Resources Information Center

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

2002-01-01

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

Photovoltaic options for solar electric propulsion

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Flood, Dennis J.

1990-01-01

During the past decade, a number of advances have occurred in solar cell and array technology. These advances have lead to performance improvement for both conventional space arrays and for advanced technology arrays. Performance enhancements have occurred in power density, specific power, and environmental capability. Both state-of-the-art and advanced development cells and array technology are discussed. Present technology will include rigid, rollout, and foldout flexible substrate designs, with silicon and GaAs solar cells. The use of concentrator array systems is also discussed based on both DOD and NASA efforts. 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 on germaniun substrates, indium phosphide, and thin film devices such as copper indium diselenide.

AMTEC radioisotope power system for the Pluto Express mission

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

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

1995-12-31

The Alkali Metal Thermal to Electric Converter (AMTEC) technology has made substantial advances in the last 3 years through design improvements and technical innovations. In 1993 programs began to produce an AMTEC cell specifically for the NASA Pluto Express Mission. A set of efficiency goals was established for this series of cells to be developed. According to this plan, cell {number_sign}8 would be 17% efficient but was actually 18% efficient. Achieving this goal, as well as design advances that allow the cell to be compact, has resulted in pushing the cell from an unexciting 2 W/kg and 2% efficiency tomore » very attractive 40 W/kg and 18% measured efficiency. This paper will describe the design and predict the performance of a radioisotope powered AMTEC system for the Pluto Express mission.« less

Cell Penetrating Bispecific Antibodies for Targeting Oncogenic Transcription Factors in Advanced Prostate Cancer

DTIC Science & Technology

2016-12-01

biochemical and biologic assay systems. The final specific aim was tol examine the ability of the bispecific antibody to perturb the growth of prostate ...designated by other documentation. TITLE: Cell-Penetrating Bispecific Antibodies for Targeting Oncogenic Transcription Factors in Advanced Prostate ...Bispecific Antibodies for Targeting Oncogenic Transcription Factors in Advanced Prostate Cancer Michael Lilly, MD Richard Weisbart, MD Medical

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

PubMed Central

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

2014-01-01

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

Design and fabrication of one piece in-situ ribbed cell walls for application in an advanced AMTEC cell

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

Kramer, D.P.; McDougal, J.R.; Booher, R.A.

1998-07-01

Alkali Metal Thermal to Electrical Conversion (AMTEC) technology has been identified as a promising advanced space power technology with a predicted thermal to electrical conversion efficiency of {approximately}20%. The AMTEC technology has been the focus of several research endeavors in recent years and in essence it utilizes sodium and beta-alumina solid electrolyte tubes placed within a metal housing (cell wall) forming an AMTEC cell. The future application of the AMTEC technology, as the basis of an advanced power system for future deep space missions, is dependent on the development of AMTEC cells which will have the appropriate long term physicalmore » and mechanical properties to ensure the successful completion of the mission. The emphasis of this paper is on the design and fabrication of one piece in-situ ribbed cell walls for application in AMTEC cells. Novel machining and laser welding processes were employed which allowed the successful fabrication of the one piece thin walled 0.10mm--0.25mm (0.004--0.010in) cells. In-situ ribbed cell walls have the advantage over other cell wall designs in that the number of piece parts and the total weld area is reduced greatly simplifying fabrication. Test results show that the fabricated one piece cell walls were hermetic (helium leak rates of less than 1 {times} 10{sup {minus}8} cm{sup 3}/s) and had sufficient compression strength to meet mission requirements.« less

Development of Large-Format Lithium-Ion Cells with Silicon Anode and Low Flammable Electrolyte

NASA Technical Reports Server (NTRS)

Wu, James J.; Hernandez-Lugo, D. M.; Smart, M. C.; Ratnakumar, B. V.; Miller, T. B.; Lvovich, V. F.; Lytle, J. K.

2014-01-01

NASA is developing safe, high energy and high capacity lithium-ion cell designs and batteries for future missions under NASAs Advanced Space Power System (ASPS) project. Advanced cell components, such as high specific capacity silicon anodes and low-flammable electrolytes have been developed for improving the cell specific energy and enhancing safety. To advance the technology readiness level, we have developed large-format flight-type hermetically sealed battery cells by incorporating high capacity silicon anodes, commercially available lithium nickel, cobalt, aluminum oxide (NCA) cathodes, and low-flammable electrolytes. In this report, we will present the performance results of these various battery cells. In addition, we will also discuss the post-test cell analysis results as well.

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.

Solid polymer electrolyte (SPE) fuel cell technology program, phase 1/1A. [design and fabrication

NASA Technical Reports Server (NTRS)

1975-01-01

A solid polymer electrolyte fuel cell was studied for the purpose of improving the characteristics of the technology. Several facets were evaluated, namely: (1) reduced fuel cell costs; (2) reduced fuel cell weight; (3) improved fuel cell efficiency; and (4) increased systems compatibility. Demonstrated advances were incorporated into a full scale hardware design. A single cell unit was fabricated. A substantial degree of success was demonstrated.

Chapter 16: Lignin Visualization: Advanced Microscopy Techniques for Lignin Characterization

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

Zeng, Yining; Donohoe, Bryon S

Visualization of lignin in plant cell walls, with both spatial and chemical resolution, is emerging as an important tool to understand lignin's role in the plant cell wall's nanoscale architecture and to understand and design processes intended to modify the lignin. As such, this chapter reviews recent advances in advanced imaging methods with respect to lignin in plant cell walls. This review focuses on the importance of lignin detection and localization for studies in both plant biology and biotechnology. Challenges going forward to identify and delineate lignin from other plant cell wall components and to quantitatively analyze lignin in wholemore » cell walls from native plant tissue and treated biomass are also discussed.« less

Preliminary flight test results from the advanced photovoltaic experiment

NASA Technical Reports Server (NTRS)

Brinker, David J.; Hickey, John R.

1990-01-01

The Advanced Photovoltaic Experiment is a space flight test designed to provide reference cell standards for photovoltaic measurement as well as to investigate the solar spectrum and the effect of the space environment on solar cells. After a flight of 69 months in low earth orbit as part of the Long Duration Exposure Facility set of experiments, it was retrieved in January, 1990. The electronic data acquisition system functioned as designed, measuring and recording cell performance data over the first 358 days of flight, limited by battery lifetime. Significant physical changes are also readily apparent, including erosion of front surface paint, micrometeoroid and debris catering and contamination.

Preliminary results from the advanced photovoltaic experiment flight test

NASA Technical Reports Server (NTRS)

Brinker, David J.; Hart, Russell E., Jr.; Hickey, John R.

1990-01-01

The Advanced Photovoltaic Experiment is a space flight test designed to provide reference cell standards for photovoltaic measurement as well as to investigate the solar spectrum and the effect of the space environment on solar cells. After a flight of 69 months in low earth orbit as part of the Long Duration Exposure Facility set of experiments, it was retrieved in January, 1990. The electronic data acquisition system functioned as designed, measuring and recording cell performance data over the first 358 days of flight; limited by battery lifetime. Significant physical changes are also readily apparent, including erosion of front surface paint, micrometeoroid and debris catering and contamination.

Advanced Solar Cells for Satellite Power Systems

NASA Technical Reports Server (NTRS)

Flood, Dennis J.; Weinberg, Irving

1994-01-01

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

Advanced solar cells for satellite power systems

NASA Astrophysics Data System (ADS)

Flood, Dennis J.; Weinberg, Irving

1994-11-01

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

Design principles for noninvasive, longitudinal and quantitative cell tracking with nanoparticle-based CT imaging.

PubMed

Meir, Rinat; Betzer, Oshra; Motiei, Menachem; Kronfeld, Noam; Brodie, Chaya; Popovtzer, Rachela

2017-02-01

Contradictory results in clinical trials are preventing the advancement and implementation of cell-based therapy. To explain such results, there is a need to uncover the mystery regarding the fate of the transplanted cells. To answer this need, we developed a technique for noninvasive in vivo cell tracking, which uses gold nanoparticles as contrast agents for CT imaging. Herein, we investigate the design principles of this technique for intramuscular transplantation of therapeutic cells. Longitudinal studies were performed, displaying the ability to track cells over long periods of time. As few as 500 cells could be detected and a way to quantify the number of cells visualized by CT was demonstrated. Moreover, monitoring of cell functionality was demonstrated on a mouse model of Duchenne muscular dystrophy. This cell-tracking technology has the potential to become an essential tool in pre-clinical as well as clinical trials and to advance the future of cell therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Space Electrochemical Research and Technology

NASA Technical Reports Server (NTRS)

Wilson, Richard M. (Compiler)

1996-01-01

Individual papers presented at the conference address the following topics: development of a micro-fiber nickel electrode for nickel-hydrogen cell, high performance nickel electrodes for space power application, bending properties of nickel electrodes for nickel-hydrogen batteries, effect of KOH concentration and anions on the performance of a Ni-H2 battery positive plate, advanced dependent pressure vessel nickel hydrogen spacecraft cell and battery design, electrolyte management considerations in modern nickel hydrogen and nickel cadmium cell and battery design, a novel unitized regenerative proton exchange membrane fuel cell, fuel cell systems for first lunar outpost - reactant storage options, the TMI regenerable solid oxide fuel cell, engineering development program of a closed aluminum-oxygen semi-cell system for an unmanned underwater vehicle, SPE OBOGS on-board oxygen generating system, hermetically sealed aluminum electrolytic capacitor, sol-gel technology and advanced electrochemical energy storage materials, development of electrochemical supercapacitors for EMA applications, and high energy density electrolytic capacitor.

The 4.5 inch diameter IPV Ni-H2 cell development program

NASA Technical Reports Server (NTRS)

Miller, L.

1986-01-01

Interest in larger capacity Ni-H2 battery cells for space applications has resulted in the initiation of a development/qualification/production program. Cell component design was completed and component hardware fabricated and/or delivered. Finished cell design projections demonstrate favorable specific energies in the range of 70 to 75 Whr/Kg (32 to 34 Whr/Lb) for capacities of 100 to 250 Ah. It is further planned during this effort to evaluate the advanced cell design technology which has evolved from the work conducted at the NASA/Lewis Research Center.

The 4.5 inch diameter IPV Ni-H2 cell development program

NASA Astrophysics Data System (ADS)

Miller, L.

1986-09-01

Interest in larger capacity Ni-H2 battery cells for space applications has resulted in the initiation of a development/qualification/production program. Cell component design was completed and component hardware fabricated and/or delivered. Finished cell design projections demonstrate favorable specific energies in the range of 70 to 75 Whr/Kg (32 to 34 Whr/Lb) for capacities of 100 to 250 Ah. It is further planned during this effort to evaluate the advanced cell design technology which has evolved from the work conducted at the NASA/Lewis Research Center.

Severe Accident Test Station Design Document

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

Snead, Mary A.; Yan, Yong; Howell, Michael

The purpose of the ORNL severe accident test station (SATS) is to provide a platform for evaluation of advanced fuels under projected beyond design basis accident (BDBA) conditions. The SATS delivers the capability to map the behavior of advanced fuels concepts under accident scenarios across various temperature and pressure profiles, steam and steam-hydrogen gas mixtures, and thermal shock. The overall facility will include parallel capabilities for examination of fuels and irradiated materials (in-cell) and non-irradiated materials (out-of-cell) at BDBA conditions as well as design basis accident (DBA) or loss of coolant accident (LOCA) conditions. Also, a supporting analytical infrastructure tomore » provide the data-needs for the fuel-modeling components of the Fuel Cycle Research and Development (FCRD) program will be put in place in a parallel manner. This design report contains the information for the first, second and third phases of design and construction of the SATS. The first phase consisted of the design and construction of an out-of-cell BDBA module intended for examination of non-irradiated materials. The second phase of this work was to construct the BDBA in-cell module to test irradiated fuels and materials as well as the module for DBA (i.e. LOCA) testing out-of-cell, The third phase was to build the in-cell DBA module. The details of the design constraints and requirements for the in-cell facility have been closely captured during the deployment of the out-of-cell SATS modules to ensure effective future implementation of the in-cell modules.« less

Elastin-like polypeptides: the power of design for smart cell encapsulation.

PubMed

Bandiera, Antonella

2017-01-01

Cell encapsulation technology is still a challenging issue. Innovative methodologies such as additive manufacturing, and alternative bioprocesses, such as cell therapeutic delivery, where cell encapsulation is a key tool are rapidly gaining importance for their potential in regenerative medicine. Responsive materials such as elastin-based recombinant expression products have features that are particularly attractive for cell encapsulation. They can be designed and tailored to meet desired requirements. Thus, they represent promising candidates for the development of new concept-based materials that can be employed in this field. Areas covered: An overview of the design and employment of elastin-like polypeptides for cell encapsulation is given to outline the state of the art. Special attention is paid to the design of the macromolecule employed as well as to the method of matrix formation and the biological system involved. Expert opinion: As a result of recent progress in regenerative medicine there is a compelling need for materials that provide specific properties and demonstrate defined functional features. Rationally designed materials that may adapt according to applied external stimuli and that are responsive to biological systems, such as elastin-like polypeptides, belong to this class of smart material. A run through the components described to date represents a good starting point for further advancement in this area. Employment of these components in cell encapsulation application will promote its advance toward 'smart cell encapsulation technology'.

Development of advanced fuel cell system

NASA Technical Reports Server (NTRS)

Grevstad, P. E.

1972-01-01

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

Advanced Solar Panel Designs

NASA Technical Reports Server (NTRS)

Ralph, E. L.; Linder, E. B.

1995-01-01

Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.

Bipolar nickel-hydrogen battery design

NASA Technical Reports Server (NTRS)

Koehler, C. W.; Applewhite, A. Z.; Kuo, Y.

1985-01-01

The initial design for the NASA-Lewis advanced nickel-hydrogen battery is discussed. Fabrication of two 10-cell boilerplate battery stacks will soon begin. The test batteries will undergo characterization testing and low Earth orbit life cycling. The design effectively deals with waste heat generated in the cell stack. Stack temperatures and temperature gradients are maintained to acceptable limits by utilizing the bipolar conduction plate as a heat path to the active cooling fluid panel external to the edge of the cell stack. The thermal design and mechanical design of the battery stack together maintain a materials balance within the cell. An electrolyte seal on each cell frame prohibits electrolyte bridging. An oxygen recombination site and electrolyte reservoir/separator design does not allow oxygen to leave the cell in which it was generated.

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

NASA Technical Reports Server (NTRS)

Coates, Dwaine; Wright, Doug; Repplinger, Ron

1995-01-01

The dependent pressure vessel (DPV) nickel-hydrogen (NiH2) battery is being developed as a potential spacecraft battery design for both military and commercial satellites. Individual pressure vessel (IPV) NiH2 batteries are currently flying on more than 70 Earth orbital satellites and have accumulated more than 140,000,000 cell-hours in actual spacecraft operation. The limitations of standard NiH2 IPV flight battery technology are primarily related to the internal cell design and the battery packaging issues associated with grouping multiple cylindrical cells. The DPV cell design offers higher specific energy and reduced cost, while retaining the established IPV NiH2 technology flight heritage and database. The advanced cell design offers a more efficient mechanical, electrical and thermal cell configuration and a reduced parts count. The internal electrode stack is a prismatic flat-plate arrangement. The flat individual cell pressure vessel provides a maximum direct thermal path for removing heat from the electrode stack. The cell geometry also minimizes multiple-cell battery packaging constraints by using an established end-plateltie-rod battery design. A major design advantage is that the battery support structure is efficiently required to restrain only the force applied to a portion of the end cell. As the cells are stacked in series to achieve the desired system voltage, this increment of the total battery weight becomes small. The geometry of the DPV cell promotes compact, minimum volume packaging and places all cell terminals along the length of the battery. The resulting ability to minimize intercell wiring offers additional design simplicity and significant weight savings. The DPV battery design offers significant cost and weight savings advantages while providing minimal design risks. Cell and battery level design issues will be addressed including mechanical, electrical and thermal design aspects. A design performance analysis will be presented at both the cell and battery level. The DPV is capable of delivering up to 76 Watt-hours per kilogram (Wh/kg) at the cell level and 70 Wh/kg at the full battery level. This represents a 40 percent increase in specific energy at the cell level and a 60 percent increase in specific energy at the battery level compared to current IPV NiH2 technology.

Multiplexed mRNA Sensing and Combinatorial-Targeted Drug Delivery Using DNA-Gold Nanoparticle Dimers.

PubMed

Kyriazi, Maria-Eleni; Giust, Davide; El-Sagheer, Afaf H; Lackie, Peter M; Muskens, Otto L; Brown, Tom; Kanaras, Antonios G

2018-04-24

The design of nanoparticulate systems which can perform multiple synergistic functions in cells with high specificity and selectivity is of great importance in applications. Here we combine recent advances in DNA-gold nanoparticle self-assembly and sensing to develop gold nanoparticle dimers that are able to perform multiplexed synergistic functions within a cellular environment. These dimers can sense two mRNA targets and simultaneously or independently deliver one or two DNA-intercalating anticancer drugs (doxorubicin and mitoxantrone) in live cells. Our study focuses on the design of sophisticated nanoparticle assemblies with multiple and synergistic functions that have the potential to advance sensing and drug delivery in cells.

Monolithically interconnected silicon-film™ module technology

NASA Astrophysics Data System (ADS)

DelleDonne, E. J.; Ford, D. H.; Hall, R. B.; Ingram, A. E.; Rand, J. A.; Barnett, A. M.

1999-03-01

AstroPower is developing an advanced thin-silicon-based, photovoltaic module product. A low-cost monolithic interconnected device is being integrated into a module that combines the design and process features of advanced light trapped, thin-silicon solar cells. This advanced product incorporates a low-cost substrate, a nominally 50-μm thick grown silicon layer with minority carrier diffusion lengths exceeding the active layer thickness, light trapping due to back-surface reflection, and back-surface passivation. The thin silicon layer enables high solar cell performance and can lead to a module conversion efficiency as high as 19%. These performance design features, combined with low-cost manufacturing using relatively low-cost capital equipment, continuous processing and a low-cost substrate, will lead to high-performance, low-cost photovoltaic panels.

Optical design considerations for high-concentration photovoltaics

NASA Astrophysics Data System (ADS)

Garboushian, Vahan; Gordon, Robert

2006-08-01

Over the past 15 years, major advances in Concentrating Photovoltaics (CPV) have been achieved. Ultra-efficient Si solar cells have produced commercial concentration systems which are being fielded today and are competitively priced. Advanced research has primarily focused on significantly more efficient multi-junction solar cells for tomorrow's systems. This effort has produced sophisticated solar cells that significantly improve power production. Additional performance and cost improvements, especially in the optical system area and system integration, must be made before CPV can realize its ultimate commercial potential. Structural integrity and reliability are vital for commercial success. As incremental technical improvements are made in solar cell technologies, evaluation and 'fine-tuning' of optical systems properly matched to the solar cell are becoming increasingly necessary. As we move forward, it is increasingly important to optimize all of the interrelated elements of a CPV system for high performance without sacrificing the marketable cost and structural requirements of the system. Areas such as wavelength absorption of refractive optics need to be carefully matched to the solar cell technology employed. Reflective optics require advanced engineering models to insure uniform flux distribution without excessive losses. In Situ measurement of the 'fine-grain' improvements are difficult as multiple variables such as solar insolation, temperature, wind, altitude, etc. infringe on analytical data. This paper discusses design considerations based on 10 years of field trials of high concentration systems and their relevance for tomorrow's advanced CPV systems.

Development of an alkaline fuel cell subsystem

NASA Technical Reports Server (NTRS)

1987-01-01

A two task program was initiated to develop advanced fuel cell components which could be assembled into an alkaline power section for the Space Station Prototype (SSP) fuel cell subsystem. The first task was to establish a preliminary SSP power section design to be representative of the 200 cell Space Station power section. The second task was to conduct tooling and fabrication trials and fabrication of selected cell stack components. A lightweight, reliable cell stack design suitable for the SSP regenerative fuel cell power plant was completed. The design meets NASA's preliminary requirements for future multikilowatt Space Station missions. Cell stack component fabrication and tooling trials demonstrated cell components of the SSP stack design of the 1.0 sq ft area can be manufactured using techniques and methods previously evaluated and developed.

Advanced nickel-hydrogen spacecraft battery development

NASA Technical Reports Server (NTRS)

Coates, Dwaine K.; Fox, Chris L.; Standlee, D. J.; Grindstaff, B. K.

1994-01-01

Eagle-Picher currently has several advanced nickel-hydrogen (NiH2) cell component and battery designs under development including common pressure vessel (CPV), single pressure vessel (SPV), and dependent pressure vessel (DPV) designs. A CPV NiH2 battery, utilizing low-cost 64 mm (2.5 in.) cell diameter technology, has been designed and built for multiple smallsat programs, including the TUBSAT B spacecraft which is currently scheduled (24 Nov. 93) for launch aboard a Russian Proton rocket. An advanced 90 mm (3.5 in.) NiH2 cell design is currently being manufactured for the Space Station Freedom program. Prototype 254 mm (10 in.) diameter SPV batteries are currently under construction and initial boilerplate testing has shown excellent results. NiH2 cycle life testing is being continued at Eagle-Picher and IPV cells have currently completed more than 89,000 accelerated LEO cycles at 15% DOD, 49,000 real-time LEO cycles at 30 percent DOD, 37,800 cycles under a real-time LEO profile, 30 eclipse seasons in accelerated GEO, and 6 eclipse seasons in real-time GEO testing at 75 percent DOD maximum. Nickel-metal hydride battery development is continuing for both aerospace and electric vehicle applications. Eagle-Picher has also developed an extensive range of battery evaluation, test, and analysis (BETA) measurement and control equipment and software, based on Hewlett-Packard computerized data acquisition/control hardware.

Advanced nickel-metal hydride cell development at Hughes: A joint work with US government

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

Lim, H.S.; Pickett, D.F.; Stockel, J.F.

1995-01-25

Hughes is currently engaged in the development of an advanced nickel-metal hydride (Ni/MHx) cell for spacecraft application with performance goals of 15 years of opertion in a geosynchronous earth orbit at 80% depth of discharge and over 30,000 cycles of life at 30% depth of discharge in a typical low earth orbit. We have developed the basic fabrication technique for a lightweight and potentially long life nickel electrode which is useable in space Ni/MHx cells. We have developed several attractive hydride alloys which are useable in hydride electrodes and basic fabrication techniques for lightweight, inexpensive, and potentially long life hydridemore » electrodes for a Ni/MHx cell. Utilizing Hughes extensive experiences in development of advanced Ni/Cd and Ni/H{sub 2} cells, we plan to develop a first generation space Ni/MHx cell design by 1995 and have the cell flight ready by 1997.« less

Fuel cell technology program contract summary report

NASA Technical Reports Server (NTRS)

1972-01-01

A fuel cell technology program which was established to advance the state-of-the-art of hydrogen-oxygen fuel cells using the P and WA PC8B technology as the base is reported. The major tasks of this program consisted of (1) fuel cell system studies of a space shuttle powerplant conceptual design (designated engineering model -1, EM-1) supported by liaison with the space shuttle prime contractors; (2) component and subsystem technology advancement and; (3) a demonstrator powerplant test. Fuel cell system studies, with the EM-1 as the focal point of design activities, included determination of voltage regulation, specific reactant consumption, weight, voltage level and performance characteristics. These studies provided the basis for coordination activities with the space shuttle vehicle prime contractor. Interface information, on-board checkout and in-flight monitoring requirements, and development cost data were also provided as part of this activity. Even though the two vehicles primes had different voltage requirements (115 volts in one case and 28 volts in the other), it was concluded that either option could be provided in the fuel cell power system by the electrical hook-up of the cells in the stack.

Recent advances in Li/SO2 battery technology

NASA Astrophysics Data System (ADS)

Ralston, R. E.

The areas of improvement discussed are related to cell closure-hermetic seals, improved glass-to-metal seals, and lithium-limited cell design. Attention is given to the design of a Li/SO2 cell which can safely withstand discharge below zero volts into voltage reversal. The design characteristics of an unbalanced cell, the new lithium-limited or balanced cell, and a high rate unbalanced design are compared in a table for the 'D' size cell. It is concluded that the improvements in cell closure, glass seal stability, and cell balance have resulted in storability, reliability, and abuse resistance characteristics which make the performance of today's Li/SO2 battery without equal among competitive primary batteries. However, the Li/SO2 cell must not be used in applications where extreme electrical or environmental conditions can push the system beyond its recommended limits.

How Can Nanotechnology Help to Repair the Body? Advances in Cardiac, Skin, Bone, Cartilage and Nerve Tissue Regeneration

PubMed Central

Perán, Macarena; García, María Angel; Lopez-Ruiz, Elena; Jiménez, Gema; Marchal, Juan Antonio

2013-01-01

Nanotechnologists have become involved in regenerative medicine via creation of biomaterials and nanostructures with potential clinical implications. Their aim is to develop systems that can mimic, reinforce or even create in vivo tissue repair strategies. In fact, in the last decade, important advances in the field of tissue engineering, cell therapy and cell delivery have already been achieved. In this review, we will delve into the latest research advances and discuss whether cell and/or tissue repair devices are a possibility. Focusing on the application of nanotechnology in tissue engineering research, this review highlights recent advances in the application of nano-engineered scaffolds designed to replace or restore the followed tissues: (i) skin; (ii) cartilage; (iii) bone; (iv) nerve; and (v) cardiac. PMID:28809213

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.

High efficiency solar cell processing

NASA Technical Reports Server (NTRS)

Ho, F.; Iles, P. A.

1985-01-01

At the time of writing, cells made by several groups are approaching 19% efficiency. General aspects of the processing required for such cells are discussed. Most processing used for high efficiency cells is derived from space-cell or concentrator cell technology, and recent advances have been obtained from improved techniques rather than from better understanding of the limiting mechanisms. Theory and modeling are fairly well developed, and adequate to guide further asymptotic increases in performance of near conventional cells. There are several competitive cell designs with promise of higher performance ( 20%) but for these designs further improvements are required. The available cell processing technology to fabricate high efficiency cells is examined.

BBU design of linear induction accelerator cells for radiography application

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

Shang, C.C.; Chen, Y.J.; Gaporaso, G.J.

1997-05-06

There is an ongoing effort to develop accelerating modules for high-current electron accelerators for advanced radiography application. Accelerating modules with low beam-cavity coupling impedances along with gap designs with acceptable field stresses comprise a set of fundamental design criteria. We examine improved cell designs which have been developed for accelerator application in several radiographic operating regimes. We evaluate interaction impedances, analyze the effects of beam structure coupling on beam dynamics (beam break-up instability and corkscrew motion). We also provide estimates of coupling through interesting new high-gradient insulators and evaluate their potential future application in induction cells.

Programmable full-adder computations in communicating three-dimensional cell cultures.

PubMed

Ausländer, David; Ausländer, Simon; Pierrat, Xavier; Hellmann, Leon; Rachid, Leila; Fussenegger, Martin

2018-01-01

Synthetic biologists have advanced the design of trigger-inducible gene switches and their assembly into input-programmable circuits that enable engineered human cells to perform arithmetic calculations reminiscent of electronic circuits. By designing a versatile plug-and-play molecular-computation platform, we have engineered nine different cell populations with genetic programs, each of which encodes a defined computational instruction. When assembled into 3D cultures, these engineered cell consortia execute programmable multicellular full-adder logics in response to three trigger compounds.

Recent Advances in Wide-Bandgap Photovoltaic Polymers.

PubMed

Cai, Yunhao; Huo, Lijun; Sun, Yanming

2017-06-01

The past decade has witnessed significant advances in the field of organic solar cells (OSCs). Ongoing improvements in the power conversion efficiency of OSCs have been achieved, which were mainly attributed to the design and synthesis of novel conjugated polymers with different architectures and functional moieties. Among various conjugated polymers, the development of wide-bandgap (WBG) polymers has received less attention than that of low-bandgap and medium-bandgap polymers. Here, we briefly summarize recent advances in WBG polymers and their applications in organic photovoltaic (PV) devices, such as tandem, ternary, and non-fullerene solar cells. Addtionally, we also dissuss the application of high open-circuit voltage tandem solar cells in PV-driven electrochemical water dissociation. We mainly focus on the molecular design strategies, the structure-property correlations, and the photovoltaic performance of these WBG polymers. Finally, we extract empirical regularities and provide invigorating perspectives on the future development of WBG photovoltaic materials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced on-site power plant development technology program

NASA Technical Reports Server (NTRS)

Kemp, F. S.

1985-01-01

A 30-cell stack was tested for 7200 hours. At 6000 hours the stack was successfully refilled with acid with no loss of performance. A second stack containing the advanced Configuration B cell package was fabricated and assembled for testing in 1985. A 200-kW brassboard inverter was successfully evaluated, verifying the design of the two-bridge ASCR circuit design. A fuel processing catalyst train was tested for 2000 hours verifying the catalyst for use in a 200-kW development reformer. The development reformer was fabricated for evaluation in 1985. The initial test plan was prepared for a 200-kW verification test article.

Cell-laden hydrogels for osteochondral and cartilage tissue engineering.

PubMed

Yang, Jingzhou; Zhang, Yu Shrike; Yue, Kan; Khademhosseini, Ali

2017-07-15

Despite tremendous advances in the field of regenerative medicine, it still remains challenging to repair the osteochondral interface and full-thickness articular cartilage defects. This inefficiency largely originates from the lack of appropriate tissue-engineered artificial matrices that can replace the damaged regions and promote tissue regeneration. Hydrogels are emerging as a promising class of biomaterials for both soft and hard tissue regeneration. Many critical properties of hydrogels, such as mechanical stiffness, elasticity, water content, bioactivity, and degradation, can be rationally designed and conveniently tuned by proper selection of the material and chemistry. Particularly, advances in the development of cell-laden hydrogels have opened up new possibilities for cell therapy. In this article, we describe the problems encountered in this field and review recent progress in designing cell-hydrogel hybrid constructs for promoting the reestablishment of osteochondral/cartilage tissues. Our focus centers on the effects of hydrogel type, cell type, and growth factor delivery on achieving efficient chondrogenesis and osteogenesis. We give our perspective on developing next-generation matrices with improved physical and biological properties for osteochondral/cartilage tissue engineering. We also highlight recent advances in biomanufacturing technologies (e.g. molding, bioprinting, and assembly) for fabrication of hydrogel-based osteochondral and cartilage constructs with complex compositions and microarchitectures to mimic their native counterparts. Despite tremendous advances in the field of regenerative medicine, it still remains challenging to repair the osteochondral interface and full-thickness articular cartilage defects. This inefficiency largely originates from the lack of appropriate tissue-engineered biomaterials that replace the damaged regions and promote tissue regeneration. Cell-laden hydrogel systems have emerged as a promising tissue-engineering platform to address this issue. In this article, we describe the fundamental problems encountered in this field and review recent progress in designing cell-hydrogel constructs for promoting the reestablishment of osteochondral/cartilage tissues. Our focus centers on the effects of hydrogel composition, cell type, and growth factor delivery on achieving efficient chondrogenesis and osteogenesis. We give our perspective on developing next-generation hydrogel/inorganic particle/stem cell hybrid composites with improved physical and biological properties for osteochondral/cartilage tissue engineering. We also highlight recent advances in biomanufacturing and bioengineering technologies (e.g. 3D bioprinting) for fabrication of hydrogel-based osteochondral and cartilage constructs. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Microsystems Enabled Photovoltaics

ScienceCinema

Gupta, Vipin; Nielson, Greg; Okandan, Murat, Granata, Jennifer; Nelson, Jeff; Haney, Mike; Cruz-Campa, Jose Luiz

2018-06-07

Sandia's microsystems enabled photovoltaic advances combine mature technology and tools currently used in microsystem production with groundbreaking advances in photovoltaics cell design, decreasing production and system costs while improving energy conversion efficiency. The technology has potential applications in buildings, houses, clothing, portable electronics, vehicles, and other contoured structures.

Coal-Based Fuel-Cell Powerplants

NASA Technical Reports Server (NTRS)

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

1986-01-01

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

Advance prototype silver ion water bactericide system

NASA Technical Reports Server (NTRS)

Jasionowski, W. J.; Allen, E. T.

1974-01-01

An advance prototype unit was designed and fabricated to treat anticipated fuel cell water. The unit is a single canister that contains a membrane-type prefilter and a silver bromide contacting bed. A seven day baseline simulated mission test was performed; the performance was satisfactory and the effluent water was within all specifications for potability. After random vibrations another seven day simulated mission test was performed, and results indicate that simulated launch vibrations have no effects on the design and performance of the advanced prototype. Bench tests and accelerated breadboard tests were conducted to define the characteristics of an upgraded model of the advance prototype unit which would have 30 days of operating capability. A preliminary design of a silver ion generator for the shuttle orbiter was also prepared.

Design and Analysis of Single-Cell Sequencing Experiments.

PubMed

Grün, Dominic; van Oudenaarden, Alexander

2015-11-05

Recent advances in single-cell sequencing hold great potential for exploring biological systems with unprecedented resolution. Sequencing the genome of individual cells can reveal somatic mutations and allows the investigation of clonal dynamics. Single-cell transcriptome sequencing can elucidate the cell type composition of a sample. However, single-cell sequencing comes with major technical challenges and yields complex data output. In this Primer, we provide an overview of available methods and discuss experimental design and single-cell data analysis. We hope that these guidelines will enable a growing number of researchers to leverage the power of single-cell sequencing. Copyright © 2015 Elsevier Inc. All rights reserved.

Treatment of advanced gastrointestinal cancer with genetically modified autologous mesenchymal stem cells - TREAT-ME-1 - a phase I, first in human, first in class trial

PubMed Central

von Einem, Jobst C.; Peter, Sylvia; Günther, Christine; Volk, Hans-Dieter; Grütz, Gerald; Salat, Christoph; Stoetzer, Oliver; Nelson, Peter J.; Michl, Marlies; Modest, Dominik P.; Holch, Julian W.; Angele, Martin; Bruns, Christiane

2017-01-01

Purpose This phase I, first in human, first in class clinical study aimed at evaluating the safety, tolerability and efficacy of treatment with genetically modified mesenchymal stromal cells (MSC) in combination with ganciclovir (GCV). MSC_apceth_101 are genetically modified autologous MSCs used as vehicles for a cell-based gene therapy in patients with advanced gastrointestinal adenocarcinoma. Experimental design The study design consisted of a dose-escalation 3 + 3 design. All patients (n = 6) were treated with up to three applications of MSC_apceth_101, followed by GCV infusions given on three consecutive days starting 48 hours after injection of MSC_apceth_101. Three of six patients received a total dose of 1.5 × 106 cells/kg. Two patients received three doses of 1 × 106 cells/kg, while one patient received only two doses of 1 × 106 cells/kg due to a SADR. Results Six patients received MSC_apceth_101. No IMP-related serious adverse events occurred. Adverse-events related to IMP-injection were increased creatinine, cough, fever, and night sweat. TNF, IL-6, IL-8, IL-10 and sE-Selectin, showed that repeated application is immunologically safe, but induces a switch of the functional properties of monocytes to an inflammatory phenotype. Treatment induced stable disease in 4/6 patients, and progressive disease in 2/6 patients. Conclusion Treatment with MSC_apceth_101 in combination with GCV demonstrated acceptable safety and tolerability in patients with advanced gastrointestinal adenocarcinoma. PMID:29113291

Advances in the design of common pressure vessel nickel hydrogen batteries for aerospace applications

NASA Technical Reports Server (NTRS)

Zagrodnik, Jeffrey P.; Jones, Kenneth R.

1991-01-01

Over 7000 low-earth-orbit (LEO) cycles were demonstrated on a full-size aerospace common pressure vessel (CPV) prototype. The battery demonstrated the capability of the basic CPV design to meet the life and reliability requirements of aerospace missions. Subsequent design modifications have been employed to address the shortcomings of the original design and several new prototypes have been fabricated. These include a 12-cell 125 amp-hour geosynchronous earth-orbit (GEO) battery and a 22-cell 10.5 amp-hour LEO battery. Cells for an 80-cell battery intended to demonstrate the high voltage capability of the CPV design have also been fabricated. In addition, assembly of a 20-cell aircraft starting battery prototype is in progress, and testing of a group of 12-volt, 160 amp-hour terrestrial batteries is continuing.

Advanced nickel-metal hydride cell development at Hughes: A joint work with US government

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

Lim, H.S.; Pickett, D.F.; Stockel, J.F.

1995-07-01

Hughes is currently engaged in the development of an advanced nickel-metal hydride (Ni/MHx) cell for spacecraft application with performance goals of 15 years of operation in a geosynchronous earth orbit at 805 depth of discharge and over 30,000 cycles of life at 30% depth of discharge in a typical low earth orbit. The authors have developed the basic fabrication technique for a lightweight and potentially long life nickel electrode which is usable in space Ni/MHx cells. The authors have developed several attractive hydride alloys which are usable in hydride electrodes and basic fabrication techniques for lightweight, inexpensive, and potentially longmore » life hydride electrodes for a Ni/MHx cell. Utilizing Hughes extensive experiences in development of advanced Ni/Cd and Ni/H{sub 2} cells, the authors plan to develop a first generation space Ni/MHx cell design by 1995 and have the cell flight ready by 1997.« less

Computer-aided design of biological circuits using TinkerCell

PubMed Central

Bergmann, Frank T; Sauro, Herbert M

2010-01-01

Synthetic biology is an engineering discipline that builds on modeling practices from systems biology and wet-lab techniques from genetic engineering. As synthetic biology advances, efficient procedures will be developed that will allow a synthetic biologist to design, analyze and build biological networks. In this idealized pipeline, computer-aided design (CAD) is a necessary component. The role of a CAD application would be to allow efficient transition from a general design to a final product. TinkerCell is a design tool for serving this purpose in synthetic biology. In TinkerCell, users build biological networks using biological parts and modules. The network can be analyzed using one of several functions provided by TinkerCell or custom programs from third-party sources. Since best practices for modeling and constructing synthetic biology networks have not yet been established, TinkerCell is designed as a flexible and extensible application that can adjust itself to changes in the field. PMID:21327060

Advanced solar panel designs

NASA Technical Reports Server (NTRS)

Ralph, E. L.; Linder, E.

1995-01-01

This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

Systemic therapy for unresectable and metastatic transitional cell carcinoma of the urothelium: first-line and beyond.

PubMed

Cheng, Tina

2008-09-01

The review aims to provide an overview of recent advances and future research direction in the management of patients with advanced transitional cell carcinoma. Early data of the randomized phase III study comparing paclitaxel, cisplatin, and gemcitabine with gemcitabine plus cisplatin for advanced urothelial cancer detected no survival difference. A phase II study investigated the safety and efficacy of trastuzumab, carboplatin, gemcitabine, and paclitaxel in human epidermal growth factor receptor-2/neu-positive advanced urothelial carcinoma and reported promising results. Renal-sparing regimens are under active development. A nonrandomized comparison of the 3-week with the 4-week schedule for gemcitabine and cisplatin showed that the 3-week schedule had less hematological toxicity and better dose intensity. Potential molecular markers such as excision repair cross-complementation group 1, emmprin, and survivin for survival and/or platinum resistance in patients with transitional cell carcinoma showed promise. Recent data do not support change in the current standard of care for advanced transitional cell carcinoma. Clinical testing of emerging anticancer therapies using new agents, new combinations, and new approaches is under active investigation. Rational combination and new strategy in clinical trial design are critical for new drug development for transitional cell carcinoma.

A Low Cost Rad-Tolerant Standard Cell Library

NASA Technical Reports Server (NTRS)

Gambles, Jody W.; Maki, Gary K.

1997-01-01

This paper describes circuit design techniques developed at the NASA Institute of Advanced Microelectronics that have been shown to protect CMOS circuits from the deleterious effects of the natural space radiation environment. The IAuE is leading a program to incorporate these radiation-tolerance providing design techniques into a commercial standard cell library that will be used in conjunction with available Electronic Design Automation tools to produce space flight qualified microelectronics fabricated at modern commercial CMOS foundries.

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

PubMed Central

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

2014-01-01

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

Plasma chamber testing of advanced photovoltaic solar array coupons

NASA Technical Reports Server (NTRS)

Hillard, G. Barry

1994-01-01

The solar array module plasma interactions experiment is a space shuttle experiment designed to investigate and quantify the high voltage plasma interactions. One of the objectives of the experiment is to test the performance of the Advanced Photovoltaic Solar Array (APSA). The material properties of array blanket are also studied as electric insulators for APSA arrays in high voltage conditions. Three twelve cell prototype coupons of silicon cells were constructed and tested in a space simulation chamber.

Advanced space power PEM fuel cell systems

NASA Technical Reports Server (NTRS)

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

1989-01-01

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

Engineering in complex systems.

PubMed

Bujara, Matthias; Panke, Sven

2010-10-01

The implementation of the engineering design cycle of measure, model, manipulate would drastically enhance the success rate of biotechnological designs. Recent progress for the three elements suggests that the scope of the traditional engineering paradigm in biotechnology is expanding. Substantial advances were made in dynamic in vivo analysis of metabolism, which is essential for the accurate prediction of metabolic pathway behavior. Novel methods that require variable degrees of system knowledge facilitate metabolic system manipulation. The combinatorial testing of pre-characterized parts is particularly promising, because it can profit from automation and limits the search space. Finally, conceptual advances in orthogonalizing cells should enhance the reliability of engineering designs in the future. Coupled to improved in silico models of metabolism, these advances should allow a more rational design of metabolic systems. Copyright © 2010 Elsevier Ltd. All rights reserved.

Design and integration of a solar AMTEC power system with an advanced global positioning satellite

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

Johnson, G.; Hunt, M.E.; Determan, W.R.

1996-12-31

A 1,200-W solar AMTEC (alkali metal thermal-to-electric conversion) power system concept was developed and integrated with an advanced global positioning system (GPS) satellite. The critical integration issues for the SAMTEC with the GPS subsystems included (1) packaging within the Delta 2 launch vehicle envelope, (2) deployment and start-up operations for the SAMTEC, (3) SAMTEC operation during all mission phases, (4) satellite field of view restrictions with satellite operations, and (5) effect of the SAMTEC requirements on other satellite subsystems. The SAMTEC power system was compared with a conventional planar solar array/battery power system to assess the differences in system weight,more » size, and operations. Features of the design include the use of an advanced multitube, vapor anode AMTEC cell design with 24% conversion efficiency, and a direct solar insolation receiver design with integral LiF salt canisters for energy storage to generate power during the maximum solar eclipse cycle. The modular generator design consists of an array of multitube AMTEC cells arranged into a parallel/series electrical network with built-in cell redundancy. The preliminary assessment indicates that the solar generator design is scalable over a 500 to 2,500-W range. No battery power is required during the operational phase of the GPS mission. SAMTEC specific power levels greater than 5 We/kg and 160 We/m{sup 2} are anticipated for a mission duration of 10 to 12 yr in orbits with high natural radiation backgrounds.« less

Silicon solar cell efficiency improvement: Status and outlook

NASA Technical Reports Server (NTRS)

Wolf, M.

1985-01-01

Efficiency and operating life is an economic attribute in silicon solar cells application. The efficiency improvements made during the 30 year existence of the silicon solar cells, from about 6% efficiency at the beginning to 19% in the most recent experimental cells is illustrated. In the more stationary periods, the effort was oriented towards improving radiation resistance and yields on the production lines, while, in other periods, the emphasis was on reaching new levels of efficiency through better cell design and improved material processing. First results were forthcoming from the recent efforts. Considerably more efficiency advancement in silicon solar cells is expected, and the anticipated attainment of efficiencies significantly above 20% is discussed. Major advances in material processing and in the resulting material perfection are required.

Nanomaterials for renewable energy

DOE PAGES

Chen, Shimou; Li, Liang; Sun, Hanwen; ...

2015-05-19

With demand for sustainable energy, resource, and environment protection, new material technologies are constantly expanding during the last few couple of decades. An intensive attention has been given by the scientific communities. In particular, nanomaterials are increasingly playing an active role either by increasing the efficiency of the energy storage and conversion processes or by improving the device design and performance. This special issue presents recent research advances in various aspects of energy storage technologies, advanced batteries, fuel cells, solar cell, biofuels, and so on. Design and synthesis of novel materials have demonstrated great impact on the utilization of themore » sustainable energy, which need to solve the increasing shortage of resource and the issues of environmental pollution.« less

Design, analysis and test verification of advanced encapsulation systems

NASA Technical Reports Server (NTRS)

Garcia, A., III

1983-01-01

A preliminary reduced variable master was constructed for pressure loading. A study of cell thickness versus cell stress was completed. Work is continuing on encapsulation of qualification modules. A 4 ft x 4 ft 'credit card' construction laminate was made.

Design, analysis and test verification of advanced encapsulation systems

NASA Astrophysics Data System (ADS)

Garcia, A., III

1983-02-01

A preliminary reduced variable master was constructed for pressure loading. A study of cell thickness versus cell stress was completed. Work is continuing on encapsulation of qualification modules. A 4 ft x 4 ft 'credit card' construction laminate was made.

Research, development, and demonstration of lead-acid batteries for electric vehicle propulsion

NASA Astrophysics Data System (ADS)

1984-06-01

Research on electric motor vehicles is reported in the areas of active material utilization and active material integrity; design and fabrication of components, advanced cells, and modules; cell testing; and battery thermal management and electrolyte circulation subsystems.

APSA - A new generation of photovoltaic solar arrays

NASA Technical Reports Server (NTRS)

Stella, P. M.; Kurland, R. M.

1989-01-01

This paper provides details on the Advanced Photovoltaic Solar Array (APSA) wing design, fabrication, and testing. The impact of array size change on performance and mechanical characteristics is discussed. Projections for future performance enhancements that may be expected through the use of advanced solar cells presently under development are examined.

Unstructured viscous grid generation by advancing-front method

NASA Technical Reports Server (NTRS)

Pirzadeh, Shahyar

1993-01-01

A new method of generating unstructured triangular/tetrahedral grids with high-aspect-ratio cells is proposed. The method is based on new grid-marching strategy referred to as 'advancing-layers' for construction of highly stretched cells in the boundary layer and the conventional advancing-front technique for generation of regular, equilateral cells in the inviscid-flow region. Unlike the existing semi-structured viscous grid generation techniques, the new procedure relies on a totally unstructured advancing-front grid strategy resulting in a substantially enhanced grid flexibility and efficiency. The method is conceptually simple but powerful, capable of producing high quality viscous grids for complex configurations with ease. A number of two-dimensional, triangular grids are presented to demonstrate the methodology. The basic elements of the method, however, have been primarily designed with three-dimensional problems in mind, making it extendible for tetrahedral, viscous grid generation.

Management of advanced NK/T-cell lymphoma.

PubMed

Tse, Eric; Kwong, Yok-Lam

2014-09-01

NK/T-cell lymphomas are aggressive malignancies, and the outlook is poor when conventional anthracycline-containing regimens designed for B-cell lymphomas are used. With the advent of L-asparaginase-containing regimens, treatment outcome has significantly improved. L-asparaginase-containing regimens are now considered the standard in the management of NK/T-cell lymphomas. In advanced diseases, however, outcome remains unsatisfactory, with durable remission achieved in only about 50% of cases. Stratification of patients with advanced NK/T-cell lymphomas is needed, so that poor-risk patients can be given additional therapy to improve outcome. Conventional presentation parameters are untested and appear inadequate for prognostication when L-asparaginase-containing regimens are used. Recent evidence suggests that dynamic factors during treatment and interim assessment, including Epstein-Barr virus (EBV) DNA quantification and positron emission tomography computed tomography findings, are more useful in patient stratification. The role of high-dose chemotherapy and haematopoietic stem cell transplantation requires evaluation in an overall risk-adapted treatment algorithm.

Advanced high-temperature batteries

NASA Technical Reports Server (NTRS)

Nelson, P. A.

1989-01-01

Recent results for Li-Al/FeS2 cells and bipolar battery design have shown the possibility of achieving high specific energy (210 Wh/kg) and high specific power (239 W/kg) at the cell level for an electric vehicle application. Outstanding performance is also projected for sodium/metal chloride cells having large electrolyte areas and thin positive electrodes.

Evaluation of a Hydrogen Fuel Cell Powered Blended-Wing-Body Aircraft Concept for Reduced Noise and Emissions

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.

2004-01-01

This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.

NASA Lewis advanced IPV nickel-hydrogen technology

NASA Technical Reports Server (NTRS)

Smithrick, John J.; Britton, Doris L.

1993-01-01

Individual pressure vessel (IPV) nickel-hydrogen technology was advanced at NASA Lewis and under Lewis contracts. Some of the advancements are as follows: to use 26 percent potassium hydroxide electrolyte to improve cycle life and performance, to modify the state of the art cell design to eliminate identified failure modes and further improve cycle life, and to develop a lightweight nickel electrode to reduce battery mass, hence reduce launch and/or increase satellite payload. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen battery cells was reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 accelerated LEO cycles at 80 percent DOD compared to 3,500 cycles for cells containing 31 percent KOH. Results of the boiler plate cell tests have been validated at NWSC, Crane, Indiana. Forty-eight ampere-hour flight cells containing 26 and 31 percent KOH have undergone real time LEO cycle life testing at an 80 percent DOD, 10 C. The three cells containing 26 percent KOH failed on the average at cycle 19,500. The three cells containing 31 percent KOH failed on the average at cycle 6,400. Validation testing of NASA Lewis 125 Ah advanced design IPV nickel-hydrogen flight cells is also being conducted at NWSC, Crane, Indiana under a NASA Lewis contract. This consists of characterization, storage, and cycle life testing. There was no capacity degradation after 52 days of storage with the cells in the discharged state, on open circuit, 0 C, and a hydrogen pressure of 14.5 psia. The catalyzed wall wick cells have been cycled for over 22,694 cycles with no cell failures in the continuing test. All three of the non-catalyzed wall wick cells failed (cycles 9,588; 13,900; and 20,575). Cycle life test results of the Fibrex nickel electrode has demonstrated the feasibility of an improved nickel electrode giving a higher specific energy nickel-hydrogen cell. A nickel-hydrogen boiler plate cell using an 80 mil thick, 90 percent porous Fibrex nickel electrode has been cycled for 10,000 cycles at 40 percent DOD.

New advances in probing cell–extracellular matrix interactions

PubMed Central

2017-01-01

The extracellular matrix (ECM) provides structural and biochemical support to cells within tissues. An emerging body of evidence has established that the ECM plays a key role in cell mechanotransduction – the study of coupling between mechanical inputs and cellular phenotype – through either mediating transmission of forces to the cells, or presenting mechanical cues that guide cellular behaviors. Recent progress in cell mechanotransduction research has been facilitated by advances of experimental tools, particularly microtechnologies, engineered biomaterials, and imaging and analytical methods. Microtechnologies have enabled the design and fabrication of controlled physical microenvironments for the study and measurement of cell–ECM interactions. Advances in engineered biomaterials have allowed researchers to develop synthetic ECMs that mimic tissue microenvironments and investigate the impact of altered physicochemical properties on various cellular processes. Finally, advanced imaging and spectroscopy techniques have facilitated the visualization of the complex interaction between cells and ECM in vitro and in living tissues. This review will highlight the application of recent innovations in these areas to probing cell–ECM interactions. We believe cross-disciplinary approaches, combining aspects of the different technologies reviewed here, will inspire innovative ideas to further elucidate the secrets of ECM-mediated cell control. PMID:28352896

High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems

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

Kepler, Keith D.; Slater, Michael

This Li-ion cell technology development project had three objectives: to develop advanced electrode materials and cell components to enable stable high-voltage operation; to design and demonstrate a Li-ion cell using these materials that meets the PHEV40 performance targets; and to design and demonstrate a Li-ion cell using these materials that meets the EV performance targets. The major challenge to creating stable high energy cells with long cycle life is system integration. Although materials that can give high energy cells are known, stabilizing them towards long-term cycling in the presence of other novel cell components is a major challenge. The majormore » technical barriers addressed by this work include low cathode specific energy, poor electrolyte stability during high voltage operation, and insufficient capacity retention during deep discharge for Si-containing anodes. Through the course of this project, Farasis was able to improve capacity retention of NCM materials for 4.4+ V operation, through both surface treatment and bulk-doping approaches. Other material advances include increased rate capability and of HE-NCM materials through novel synthesis approach, doubling the relative capacity at 1C over materials synthesized using standard methods. Silicon active materials proved challenging throughout the project and ultimately were the limiting factor in the energy density vs. cycle life trade off. By avoiding silicon anodes for the lower energy PHEV design, we manufactured cells with intermediate energy density and long cycle life under high voltage operation for PHEV applications. Cells with high energy density for EV applications were manufactured targeting a 300 Wh/kg design and were able to achieve > 200 cycles.« less

Advanced spacecraft fuel cell systems

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1972-01-01

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

The effect of the low Earth orbit environment on space solar cells: Results of the advanced photovoltaic experiment (S0014)

NASA Technical Reports Server (NTRS)

Brinker, David J.; Hickey, John R.

1992-01-01

The Advanced Photovoltaic Experiment (APEX), containing over 150 solar cells and sensors, was designed to generate laboratory reference standards as well as to explore the durability of a wide variety of space solar cells. Located on the leading edge of the Long Duration Exposure Facility (LDEF), APEX received the maximum possible dosage of atomic oxygen and ultraviolet radiation, as well as enormous numbers of impacts from micrometeoroids and debris. The effect of the low earth orbital (LEO) environment on the solar cells and materials of APEX will be discussed in this paper. The on-orbit performance of the solar cells, as well as a comparison of pre- and postflight laboratory performance measurements, will be presented.

Design of a small molecule against an oncogenic noncoding RNA.

PubMed

Velagapudi, Sai Pradeep; Cameron, Michael D; Haga, Christopher L; Rosenberg, Laura H; Lafitte, Marie; Duckett, Derek R; Phinney, Donald G; Disney, Matthew D

2016-05-24

The design of precision, preclinical therapeutics from sequence is difficult, but advances in this area, particularly those focused on rational design, could quickly transform the sequence of disease-causing gene products into lead modalities. Herein, we describe the use of Inforna, a computational approach that enables the rational design of small molecules targeting RNA to quickly provide a potent modulator of oncogenic microRNA-96 (miR-96). We mined the secondary structure of primary microRNA-96 (pri-miR-96) hairpin precursor against a database of RNA motif-small molecule interactions, which identified modules that bound RNA motifs nearby and in the Drosha processing site. Precise linking of these modules together provided Targaprimir-96 (3), which selectively modulates miR-96 production in cancer cells and triggers apoptosis. Importantly, the compound is ineffective on healthy breast cells, and exogenous overexpression of pri-miR-96 reduced compound potency in breast cancer cells. Chemical Cross-Linking and Isolation by Pull-Down (Chem-CLIP), a small-molecule RNA target validation approach, shows that 3 directly engages pri-miR-96 in breast cancer cells. In vivo, 3 has a favorable pharmacokinetic profile and decreases tumor burden in a mouse model of triple-negative breast cancer. Thus, rational design can quickly produce precision, in vivo bioactive lead small molecules against hard-to-treat cancers by targeting oncogenic noncoding RNAs, advancing a disease-to-gene-to-drug paradigm.

Cycle life test and failure model of nickel-hydrogen cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1983-01-01

Six ampere hour individual pressure vessel nickel hydrogen cells were charge/discharge cycled to failure. Failure as used here is defined to occur when the end of discharge voltage degraded to 0.9 volts. They were cycled under a low earth orbit cycle regime to a deep depth of discharge (80 percent of rated ampere hour capacity). Both cell designs were fabricated by the same manufacturer and represent current state of the art. A failure model was advanced which suggests both cell designs have inadequate volume tolerance characteristics. The limited existing data base at a deep depth of discharge (DOD) was expanded. Two cells of each design were cycled. One COMSAT cell failed at cycle 1712 and the other failed at cycle 1875. For the Air Force/Hughes cells, one cell failed at cycle 2250 and the other failed at cycle 2638. All cells, of both designs, failed due to low end of discharge voltage (0.9 volts). No cell failed due to electrical shorts. After cell failure, three different reconditioning tests (deep discharge, physical reorientation, and open circuit voltage stand) were conducted on all cells of each design. A fourth reconditioning test (electrolyte addition) was conducted on one cell of each design. In addition post cycle cell teardown and failure analysis were performed on the one cell of each design which did not have electrolyte added after failure.

Advanced coal gasifier-fuel cell power plant systems design

NASA Technical Reports Server (NTRS)

Heller, M. E.

1983-01-01

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

Versatile graphene biosensors for enhancing human cell therapy.

PubMed

Vlăsceanu, George M; Amărandi, Roxana-Maria; Ioniță, Mariana; Tite, Teddy; Iovu, Horia; Pilan, Luisa; Burns, Jorge S

2018-05-01

Technological advances in engineering and cell biology stimulate novel approaches for medical treatment, in particular cell-based therapy. The first cell-based gene therapy against cancer was recently approved by the US Food and Drug Administration. Progress in cancer diagnosis includes a blood test detecting five cancer types. Numerous stem cell phase I/II clinical trials showing safety and efficacy will soon pursue qualifying criteria for advanced therapy medicinal products (ATMP), aspiring to join the first stem-cell therapy approved by the European Medicines Agency. Cell based therapy requires extensive preclinical characterisation of biomarkers indicating mechanisms of action crucial to the desired therapeutic effect. Quantitative analyses monitoring critical functions for the manufacture of optimal cell and tissue-based clinical products include successful potency assays for implementation. The challenge to achieve high quality measurement is increasingly met by progress in biosensor design. We adopt a cell therapy perspective to highlight recent examples of graphene-enhanced biointerfaces for measurement of biomarkers relevant to cancer treatment, diagnosis and tissue regeneration. Graphene based biosensor design problems can thwart their use for health care transformative point of care testing and real-time applications. We discuss concerns to be addressed and emerging solutions for establishing clinical grade biosensors to accelerate human cell therapy. Copyright © 2018 Elsevier B.V. All rights reserved.

Advanced imaging research and development at DARPA

NASA Astrophysics Data System (ADS)

Dhar, Nibir K.; Dat, Ravi

2012-06-01

Advances in imaging technology have huge impact on our daily lives. Innovations in optics, focal plane arrays (FPA), microelectronics and computation have revolutionized camera design. As a result, new approaches to camera design and low cost manufacturing is now possible. These advances are clearly evident in visible wavelength band due to pixel scaling, improvements in silicon material and CMOS technology. CMOS cameras are available in cell phones and many other consumer products. Advances in infrared imaging technology have been slow due to market volume and many technological barriers in detector materials, optics and fundamental limits imposed by the scaling laws of optics. There is of course much room for improvements in both, visible and infrared imaging technology. This paper highlights various technology development projects at DARPA to advance the imaging technology for both, visible and infrared. Challenges and potentials solutions are highlighted in areas related to wide field-of-view camera design, small pitch pixel, broadband and multiband detectors and focal plane arrays.

Parallel multipoint recording of aligned and cultured neurons on corresponding Micro Channel Array toward on-chip cell analysis.

PubMed

Tonomura, W; Moriguchi, H; Jimbo, Y; Konishi, S

2008-01-01

This paper describes an advanced Micro Channel Array (MCA) so as to record neuronal network at multiple points simultaneously. Developed MCA is designed for neuronal network analysis which has been studied by co-authors using MEA (Micro Electrode Arrays) system. The MCA employs the principle of the extracellular recording. Presented MCA has the following advantages. First of all, the electrodes integrated around individual micro channels are electrically isolated for parallel multipoint recording. Sucking and clamping of cells through micro channels is expected to improve the cellular selectivity and S/N ratio. In this study, hippocampal neurons were cultured on the developed MCA. As a result, the spontaneous and evoked spike potential could be recorded by sucking and clamping the cells at multiple points. Herein, we describe the successful experimental results together with the design and fabrication of the advanced MCA toward on-chip analysis of neuronal network.

NREL Achieves World Record Performance For Thin Film Solar Cell Technology

Science.gov Websites

World Record Performance For Thin Film Solar Cell Technology Golden, Colo., May 10, 1996 world record in the performance of an advanced solar cell technology designed to have a major impact on the cost of electricity from the sun. NREL established a new world record "sunlight-to

Low Cost Design of an Advanced Encryption Standard (AES) Processor Using a New Common-Subexpression-Elimination Algorithm

NASA Astrophysics Data System (ADS)

Chen, Ming-Chih; Hsiao, Shen-Fu

In this paper, we propose an area-efficient design of Advanced Encryption Standard (AES) processor by applying a new common-expression-elimination (CSE) method to the sub-functions of various transformations required in AES. The proposed method reduces the area cost of realizing the sub-functions by extracting the common factors in the bit-level XOR/AND-based sum-of-product expressions of these sub-functions using a new CSE algorithm. Cell-based implementation results show that the AES processor with our proposed CSE method has significant area improvement compared with previous designs.

Material Science for High-Efficiency Photovoltaics: From Advanced Optical Coatings to Cell Design for High-Temperature Applications

NASA Astrophysics Data System (ADS)

Perl, Emmett Edward

Solar cells based on III-V compound semiconductors are ideally suited to convert solar energy into electricity. The highest efficiency single-junction solar cells are made of gallium arsenide, and have attained an efficiency of 28.8%. Multiple III-V materials can be combined to construct multijunction solar cells, which have reached record efficiencies greater than 45% under concentration. III-V solar cells are also well suited to operate efficiently at elevated temperatures, due in large part to their high material quality. These properties make III-V solar cells an excellent choice for use in concentrator systems. Concentrator photovoltaic systems have attained module efficiencies that exceed 40%, and have the potential to reach the lowest levelized cost of electricity in sunny places like the desert southwest. Hybrid photovoltaic-thermal solar energy systems can utilize high-temperature III-V solar cells to simultaneously achieve dispatchability and a high sunlight-to-electricity efficiency. This dissertation explores material science to advance the state of III-V multijunction solar cells for use in concentrator photovoltaic and hybrid photovoltaic-thermal solar energy systems. The first half of this dissertation describes work on advanced optical designs to improve the efficiency of multijunction solar cells. As multijunction solar cells move to configurations with four or more subcells, they utilize a larger portion of the solar spectrum. Broadband antireflection coatings are essential to realizing efficiency gains for these state-of-the-art cells. A hybrid design consisting of antireflective nanostructures placed on top of multilayer interference-based optical coatings is developed. Antireflection coatings that utilize this hybrid approach yield unparalleled performance, minimizing reflection losses to just 0.2% on sapphire and 0.6% on gallium nitride for 300-1800nm light. Dichroic mirrors are developed for bonded 5-junction solar cells that utilize InGaN as a top junction. These designs maximize reflection of high-energy light for an InGaN top junction while minimizing reflection of low-energy light that would be absorbed by the lower four junctions. Increasing the reflectivity of high-energy photons enables a second pass of light through the InGaN cell, leading to increased absorption and a higher photocurrent. These optical designs enhanced the efficiency of a 2.65eV InGaN solar cell to a value of 3.3% under the AM0 spectrum, the highest reported efficiency for a standalone InGaN solar cell. The second half of the dissertation describes the development of III-V solar cells for high-temperature applications. As the operating temperature of a solar cell is increased, the ideal bandgap of the top junction increases. AlGaInP solar cells with bandgaps ranging from 1.9eV to 2.2eV are developed. A 2.03eV AlGaInP solar cell is demonstrated with a bandgap-voltage offset of 440mV, the lowest of any AlGaInP solar cell reported to date. Single-junction AlGaInP, GaInP, and GaAs solar cells designed for high-temperature operation are characterized up to a temperature of 400°C. The cell properties are compared to an analytical drift-diffusion model, and we find that a fundamental increase in the intrinsic carrier concentration, ni, dominates the temperature dependence of the dark currents, open-circuit voltage, and cell efficiency. These findings provide a valuable guide to the design of any system that requires high-temperature solar cell operation.

Computer-aided design of biological circuits using TinkerCell.

PubMed

Chandran, Deepak; Bergmann, Frank T; Sauro, Herbert M

2010-01-01

Synthetic biology is an engineering discipline that builds on modeling practices from systems biology and wet-lab techniques from genetic engineering. As synthetic biology advances, efficient procedures will be developed that will allow a synthetic biologist to design, analyze, and build biological networks. In this idealized pipeline, computer-aided design (CAD) is a necessary component. The role of a CAD application would be to allow efficient transition from a general design to a final product. TinkerCell is a design tool for serving this purpose in synthetic biology. In TinkerCell, users build biological networks using biological parts and modules. The network can be analyzed using one of several functions provided by TinkerCell or custom programs from third-party sources. Since best practices for modeling and constructing synthetic biology networks have not yet been established, TinkerCell is designed as a flexible and extensible application that can adjust itself to changes in the field. © 2010 Landes Bioscience

By-Pass Diode Temperature Tests of a Solar Array Coupon under Space Thermal Environment Conditions

NASA Technical Reports Server (NTRS)

Wright, Kenneth H.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie; Wu, Gordon

2016-01-01

By-Pass diodes are a key design feature of solar arrays and system design must be robust against local heating, especially with implementation of larger solar cells. By-Pass diode testing was performed to aid thermal model development for use in future array designs that utilize larger cell sizes that result in higher string currents. Testing was performed on a 56-cell Advanced Triple Junction solar array coupon provided by SSL. Test conditions were vacuum with cold array backside using discrete by-pass diode current steps of 0.25 A ranging from 0 A to 2.0 A.

Targeted polymeric nanoparticles for cancer gene therapy

PubMed Central

Kim, Jayoung; Wilson, David R.; Zamboni, Camila G.; Green, Jordan J.

2015-01-01

In this article, advances in designing polymeric nanoparticles for targeted cancer gene therapy are reviewed. Characterization and evaluation of biomaterials, targeting ligands, and transcriptional elements are each discussed. Advances in biomaterials have driven improvements to nanoparticle stability and tissue targeting, conjugation of ligands to the surface of polymeric nanoparticles enable binding to specific cancer cells, and the design of transcriptional elements has enabled selective DNA expression specific to the cancer cells. Together, these features have improved the performance of polymeric nanoparticles as targeted non-viral gene delivery vectors to treat cancer. As polymeric nanoparticles can be designed to be biodegradable, non-toxic, and to have reduced immunogenicity and tumorigenicity compared to viral platforms, they have significant potential for clinical use. Results of polymeric gene therapy in clinical trials and future directions for the engineering of nanoparticle systems for targeted cancer gene therapy are also presented. PMID:26061296

The cancer-immunity cycle as rational design for synthetic cancer drugs: Novel DC vaccines and CAR T-cells.

PubMed

Ramachandran, Mohanraj; Dimberg, Anna; Essand, Magnus

2017-08-01

Cell therapy is an advanced form of cancer immunotherapy that has had remarkable clinical progress in the past decade in the search for cure of cancer. Most success has been achieved for chimeric antigen receptor (CAR) T-cells where CAR T-cells targeting CD19 show very high complete response rates for patients with refractory acute B-cell acute lymphoblastic leukemia (ALL) and are close to approval for this indication. CD19 CAR T-cells are also effective against B-cell chronic lymphoblastic leukemia (CLL) and B-cell lymphomas. Although encouraging, CAR T-cells have not yet proven clinically effective for solid tumors. This is mainly due to the lack of specific and homogenously expressed targets to direct the T-cells against and a hostile immunosuppressive tumor microenvironment in solid tumors. Cancer vaccines based on dendritic cells (DC) are also making progress although clinical efficacy is still lacking. The likelihood of success is however increasing now when individual tumors can be sequences and patient-specific neoepitopes identified. Neoepitopes and/or neoantigens can then be included in patient-based DC vaccines. This review discusses recent advancements of DC vaccines and CAR T-cells with emphasis on the cancer-immunity cycle, and current efforts to design novel cell therapies. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Improved specific energy Ni-H2 cell

NASA Astrophysics Data System (ADS)

Miller, L. E.

1985-12-01

Significant improvements in specific energy for Ni-H2 battery cells have been and will be achieved. Current flight cell designs in operation on multiple satellites have achieved a specific energy of 52 Whr/Kg (this value may be compared to 45 Whr/Kg for advanced, light-weight Ni-Cd space cells). Battery cells operating at increased pressures (61 atm/900 psi) have been manufactured and successfully tested demonstrating a specific energy of 70 Whr/Kg. Further optimization of electrode substrate, pressure vessel wall thickness and cell terminal/conductor assembly designs will permit achievement of specific energies between 75-80 Whr/Kg. Energy density (outline volume) will be improved from 49 Whr/L to 79 Whr/L.

CAPSTONE SENIOR DESIGN - SUPRAMOLECULAR PROTON EXCHANGE MEMBRANES FOR FUEL CELLS

EPA Science Inventory

In order to assume a leading role in the burgeoning hydrogen economy, new infrastructure will be required for fuel cell manufacturing and R&D capabilities. The objective of this proposal is the development of a new generation of advanced proton exchange membrane (PEM) technol...

Protein and genome evolution in Mammalian cells for biotechnology applications.

PubMed

Majors, Brian S; Chiang, Gisela G; Betenbaugh, Michael J

2009-06-01

Mutation and selection are the essential steps of evolution. Researchers have long used in vitro mutagenesis, expression, and selection techniques in laboratory bacteria and yeast cultures to evolve proteins with new properties, termed directed evolution. Unfortunately, the nature of mammalian cells makes applying these mutagenesis and whole-organism evolution techniques to mammalian protein expression systems laborious and time consuming. Mammalian evolution systems would be useful to test unique mammalian cell proteins and protein characteristics, such as complex glycosylation. Protein evolution in mammalian cells would allow for generation of novel diagnostic tools and designer polypeptides that can only be tested in a mammalian expression system. Recent advances have shown that mammalian cells of the immune system can be utilized to evolve transgenes during their natural mutagenesis processes, thus creating proteins with unique properties, such as fluorescence. On a more global level, researchers have shown that mutation systems that affect the entire genome of a mammalian cell can give rise to cells with unique phenotypes suitable for commercial processes. This review examines the advances in mammalian cell and protein evolution and the application of this work toward advances in commercial mammalian cell biotechnology.

A high specific power solar array for low to mid-power spacecraft

NASA Technical Reports Server (NTRS)

Jones, P. Alan; White, Stephen F.; Harvey, T. Jeffery; Smith, Brian S.

1993-01-01

UltraFlex is the generic term for a solar array system which delivers on-orbit power in the 400 to 6,000 watt per wing sizes with end-of-life specific power performance ranging to 150 watts-per-kilogram. Such performance is accomplished with off-the-shelf solar cells and state-of the-art materials and processes. Much of the recent work in photovoltaics is centered on advanced solar cell development. Successful as such work has been, no integrated solar array system has emerged which meets NASA's stated goals of 'increasing the end-of-life performance of space solar cells and arrays while minimizing their mass and cost.' This issue is addressed; namely, is there an array design that satisfies the usual requirements for space-rated hardware and that is inherently reliable, inexpensive, easily manufactured and simple, which can be used with both advanced cells currently in development and with inexpensive silicon cells? The answer is yes. The UltraFlex array described incorporates use of a blanket substrate which is thermally compatible with silicon and other materials typical of advanced multi-junction devices. The blanket materials are intrinsically insensitive to atomic oxygen degradation, are space rated, and are compatible with standard cell bonding processes. The deployment mechanism is simple and reliable and the structure is inherently stiff (high natural frequency). Mechanical vibration modes are also readily damped. The basic design is presented as well as supporting analysis and development tests.

A high specific power solar array for low to mid-power spacecraft

NASA Astrophysics Data System (ADS)

Jones, P. Alan; White, Stephen F.; Harvey, T. Jeffery; Smith, Brian S.

1993-05-01

UltraFlex is the generic term for a solar array system which delivers on-orbit power in the 400 to 6,000 watt per wing sizes with end-of-life specific power performance ranging to 150 watts-per-kilogram. Such performance is accomplished with off-the-shelf solar cells and state-of the-art materials and processes. Much of the recent work in photovoltaics is centered on advanced solar cell development. Successful as such work has been, no integrated solar array system has emerged which meets NASA's stated goals of 'increasing the end-of-life performance of space solar cells and arrays while minimizing their mass and cost.' This issue is addressed; namely, is there an array design that satisfies the usual requirements for space-rated hardware and that is inherently reliable, inexpensive, easily manufactured and simple, which can be used with both advanced cells currently in development and with inexpensive silicon cells? The answer is yes. The UltraFlex array described incorporates use of a blanket substrate which is thermally compatible with silicon and other materials typical of advanced multi-junction devices. The blanket materials are intrinsically insensitive to atomic oxygen degradation, are space rated, and are compatible with standard cell bonding processes. The deployment mechanism is simple and reliable and the structure is inherently stiff (high natural frequency). Mechanical vibration modes are also readily damped. The basic design is presented as well as supporting analysis and development tests.

Evaluation of solar cells and arrays for potential solar power satellite applications

NASA Technical Reports Server (NTRS)

Almgren, D. W.; Csigi, K.; Gaudet, A. D.

1978-01-01

Proposed solar array designs and manufacturing methods are evaluated to identify options which show the greatest promise of leading up to the develpment of a cost-effective SPS solar cell array design. The key program elements which have to be accomplished as part of an SPS solar cell array development program are defined. The issues focussed on are: (1) definition of one or more designs of a candidate SPS solar array module, using results from current system studies; (2) development of the necessary manufacturing requirements for the candidate SPS solar cell arrays and an assessment of the market size, timing, and industry infrastructure needed to produce the arrays for the SPS program; (3) evaluation of current DOE, NASA and DOD photovoltaic programs to determine the impacts of recent advances in solar cell materials, array designs and manufacturing technology on the candidate SPS solar cell arrays; and (4) definition of key program elements for the development of the most promising solar cell arrays for the SPS program.

Automatic microscopy for mitotic cell location.

NASA Technical Reports Server (NTRS)

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

1972-01-01

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

Alkaline RFC Space Station prototype - 'Next step Space Station'. [Regenerative Fuel Cells

NASA Technical Reports Server (NTRS)

Hackler, I. M.

1986-01-01

The regenerative fuel cell, a candidate technology for the Space Station's energy storage system, is described. An advanced development program was initiated to design, manufacture, and integrate a regenerative fuel cell Space Station prototype (RFC SSP). The RFC SSP incorporates long-life fuel cell technology, increased cell area for the fuel cells, and high voltage cell stacks for both units. The RFC SSP's potential for integration with the Space Station's life support and propulsion systems is discussed.

Recent advances in Echinococcus genomics and stem cell research.

PubMed

Koziol, U; Brehm, K

2015-10-30

Alveolar and cystic echinococcosis, caused by the metacestode larval stages of the tapeworms Echinococcus multilocularis and Echinococcus granulosus, respectively, are life-threatening diseases and very difficult to treat. The introduction of benzimidazole-based chemotherapy, which targets parasite β-tubulin, has significantly improved the life-span and prognosis of echinococcosis patients. However, benzimidazoles show only parasitostatic activity, are associated with serious adverse side effects and have to be administered for very long time periods, underlining the need for new drugs. Very recently, the nuclear genomes of E. multilocularis and E. granulosus have been characterised, revealing a plethora of data for gaining a deeper understanding of host-parasite interaction, parasite development and parasite evolution. Combined with extensive transcriptome analyses of Echinococcus life cycle stages these investigations also yielded novel clues for targeted drug design. Recent years also witnessed significant advancements in the molecular and cellular characterisation of the Echinococcus 'germinative cell' population, which forms a unique stem cell system that differs from stem cells of other organisms in the expression of several genes associated with the maintenance of pluripotency. As the only parasite cell type capable of undergoing mitosis, the germinative cells are central to all developmental transitions of Echinococcus within the host and to parasite expansion via asexual proliferation. In the present article, we will briefly introduce and discuss recent advances in Echinococcus genomics and stem cell research in the context of drug design and development. Interestingly, it turns out that benzimidazoles seem to have very limited effects on Echinococcus germinative cells, which could explain the high recurrence rates observed after chemotherapeutic treatment of echinococcosis patients. This clearly indicates that future efforts into the development of parasitocidal drugs should also target the parasite's stem cell system. Copyright © 2015 Elsevier B.V. All rights reserved.

Genome engineering in cattle: recent technological advancements.

PubMed

Wang, Zhongde

2015-02-01

Great strides in technological advancements have been made in the past decade in cattle genome engineering. First, the success of cloning cattle by somatic cell nuclear transfer (SCNT) or chromatin transfer (CT) is a significant advancement that has made obsolete the need for using embryonic stem (ES) cells to conduct cell-mediated genome engineering, whereby site-specific genetic modifications can be conducted in bovine somatic cells via DNA homologous recombination (HR) and whereby genetically engineered cattle can subsequently be produced by animal cloning from the genetically modified cells. With this approach, a chosen bovine genomic locus can be precisely modified in somatic cells, such as to knock out (KO) or knock in (KI) a gene via HR, a gene-targeting strategy that had almost exclusively been used in mouse ES cells. Furthermore, by the creative application of embryonic cloning to rejuvenate somatic cells, cattle genome can be sequentially modified in the same line of somatic cells and complex genetic modifications have been achieved in cattle. Very recently, the development of designer nucleases-such as zinc finger nucleases (ZFNs) and transcription activator-like effector nuclease (TALENs), and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-has enabled highly efficient and more facile genome engineering in cattle. Most notably, by employing such designer nucleases, genomes can be engineered at single-nucleotide precision; this process is now often referred to as genome or gene editing. The above achievements are a drastic departure from the traditional methods of creating genetically modified cattle, where foreign DNAs are randomly integrated into the animal genome, most often along with the integrations of bacterial or viral DNAs. Here, I review the most recent technological developments in cattle genome engineering by highlighting some of the major achievements in creating genetically engineered cattle for agricultural and biomedical applications.

Nanomedicine: de novo design of nanodrugs

NASA Astrophysics Data System (ADS)

Yang, Zaixing; Kang, Seung-Gu; Zhou, Ruhong

2013-12-01

Phenomenal advances in nanotechnology and nanoscience have been accompanied by exciting progress in de novo design of nanomedicines. Nanoparticles with their large space of structural amenability and excellent mechanical and electrical properties have become ideal candidates for high efficacy nanomedicines in both diagnostics and therapeutics. The therapeutic nanomedicines can be further categorized into nanocarriers for conventional drugs and nanodrugs with direct curing of target diseases. Here we review some of the recent advances in de novo design of nanodrugs, with an emphasis on the molecular level understanding of their interactions with biological systems including key proteins and cell membranes. We also include some of the latest advances in the development of nanocarriers with both passive and active targeting for completeness. These studies may shed light on a better understanding of the molecular mechanisms behind these nanodrugs, and also provide new insights and direction for the future design of nanomedicines.

Nanomedicine: de novo design of nanodrugs.

PubMed

Yang, Zaixing; Kang, Seung-gu; Zhou, Ruhong

2014-01-21

Phenomenal advances in nanotechnology and nanoscience have been accompanied by exciting progress in de novo design of nanomedicines. Nanoparticles with their large space of structural amenability and excellent mechanical and electrical properties have become ideal candidates for high efficacy nanomedicines in both diagnostics and therapeutics. The therapeutic nanomedicines can be further categorized into nanocarriers for conventional drugs and nanodrugs with direct curing of target diseases. Here we review some of the recent advances in de novo design of nanodrugs, with an emphasis on the molecular level understanding of their interactions with biological systems including key proteins and cell membranes. We also include some of the latest advances in the development of nanocarriers with both passive and active targeting for completeness. These studies may shed light on a better understanding of the molecular mechanisms behind these nanodrugs, and also provide new insights and direction for the future design of nanomedicines.

A Space Testbed for Photovoltaics

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Bailey, Sheila G.

1998-01-01

The Ohio Aerospace Institute and the NASA Lewis Research Center are designing and building a solar-cell calibration facility, the Photovoltaic Engineering Testbed (PET) to fly on the International Space Station to test advanced solar cell types in the space environment. A wide variety of advanced solar cell types have become available in the last decade. Some of these solar cells offer more than twice the power per unit area of the silicon cells used for the space station power system. They also offer the possibilities of lower cost, lighter weight, and longer lifetime. The purpose of the PET facility is to reduce the cost of validating new technologies and bringing them to spaceflight readiness. The facility will be used for three primary functions: calibration, measurement, and qualification. It is scheduled to be launched in June of 2002.

A novel Smac mimetic APG-1387 demonstrates potent antitumor activity in nasopharyngeal carcinoma cells by inducing apoptosis.

PubMed

Li, Ning; Feng, Lin; Han, Hui-Qiong; Yuan, Jing; Qi, Xue-Kang; Lian, Yi-Fan; Kuang, Bo-Hua; Zhang, Yu-Chen; Deng, Cheng-Cheng; Zhang, Hao-Jiong; Yao, You-Yuan; Xu, Miao; He, Gui-Ping; Zhao, Bing-Chun; Gao, Ling; Feng, Qi-Sheng; Chen, Li-Zhen; Yang, Lu; Yang, Dajun; Zeng, Yi-Xin

2016-10-10

Despite advances in the development of radiation against nasopharyngeal carcinoma (NPC), the management of advanced NPC remains a challenge. Smac mimetics are designed to neutralize inhibitor of apoptosis (IAP) proteins, thus reactivating the apoptotic program in cancer cells. In this study, we investigated the effect of a novel bivalent Smac mimetic APG-1387 in NPC. In vitro, APG-1387 in combination with TNF-α potently decreased NPC cell viability by inducing apoptosis in majority of NPC cell lines. The in vitro antitumor effect was RIPK1-dependent, whereas it was independent on IAPs, USP11, or EBV. Of note, the inhibition of NF-κB or AKT pathway rendered resistant NPC cells responsive to the treatment of APG-1387/TNF-α. In vivo, APG-1387 displayed antitumor activity as a single agent at well-tolerated doses, even in an in vitro resistant cell line. In summary, our results demonstrate that APG-1387 exerts a potent antitumor effect on NPC. These findings support clinical evaluation of APG-1387 as a potential treatment for advanced NPC. Copyright © 2016. Published by Elsevier Ireland Ltd.

Recent Advances in Superparamagnetic Iron Oxide Nanoparticles for Cellular Imaging and Targeted Therapy Research

PubMed Central

Wang, Yi-Xiang J.; Xuan, Shouhu; Port, Marc; Idee, Jean-Marc

2013-01-01

Advances of nanotechnology have led to the development of nanomaterials with both potential diagnostic and therapeutic applications. Among them, superparamagnetic iron oxide (SPIO) nanoparticles have received particular attention. Over the past decade, various SPIOs with unique physicochemical and biological properties have been designed by modifying the particle structure, size and coating. This article reviews the recent advances in preparing SPIOs with novel properties, the way these physicochemical properties of SPIOs influence their interaction with cells, and the development of SPIOs in liver and lymph nodes magnetic resonance imaging (MRI) contrast. Cellular uptake of SPIO can be exploited in a variety of potential clinical applications, including stem cell and inflammation cell tracking and intra-cellular drug delivery to cancerous cells which offers higher intra-cellular concentration. When SPIOs are used as carrier vehicle, additional advantages can be achieved including magnetic targeting and hyperthermia options, as well as monitoring with MRI. Other potential applications of SPIO include magnetofection and gene delivery, targeted retention of labeled stem cells, sentinel lymph nodes mapping, and magnetic force targeting and cell orientation for tissue engineering. PMID:23621536

What Undergraduates Misunderstand about Stem Cell Research

ERIC Educational Resources Information Center

Halverson, Kristy Lynn; Freyermuth, Sharyn K.; Siegel, Marcelle A.; Clark, Catharine G.

2010-01-01

As biotechnology-related scientific advances, such as stem cell research (SCR), are increasingly permeating the popular media, it has become ever more important to understand students' ideas about this issue. Very few studies have investigated learners' ideas about biotechnology. Our study was designed to understand the types of alternative…

Gold nanoparticles for non-invasive cell tracking with CT imaging

NASA Astrophysics Data System (ADS)

Meir, Rinat; Betzer, Oshra; Barnoy, Eran; Motiei, Menachem; Popovtzer, Rachela

2018-02-01

Cell-based therapies use living cells with therapeutic traits to treat various diseases. This is a beneficial alternative for diseases that existing medicine cannot cure efficiently. However, inconsistent results in clinical trials are preventing the advancement and implementation of cell-based therapy. In order to explain such results, there is a need to discover the fate of the transplanted cells. To answer this need, we developed a technique for noninvasive in vivo cell tracking, which uses gold nanoparticles as contrast agents for CT imaging. Herein, we investigate the design principles of this technique for intramuscular transplantation of therapeutic cells. Longitudinal studies were performed, demonstrating the ability to track cells over long periods of time. As few as 500 cells could be detected and a way to quantify the number of cells visualized by CT was demonstrated. This cell-tracking technology has the potential to become an essential tool in pre-clinical studies as well as in clinical trials and advance cell therapy.

The 1985 Goddard Space Flight Center Battery Workshop

NASA Technical Reports Server (NTRS)

Morrow, G. (Editor)

1986-01-01

The subjects covered include: advanced energy storage, lithium cell technology, nickel-cadmium design evaluation and component testing, simulated orbital cycling and flight experience, and nickel-hydrogen technology.

Advances in genetic circuit design: novel biochemistries, deep part mining, and precision gene expression.

PubMed

Nielsen, Alec A K; Segall-Shapiro, Thomas H; Voigt, Christopher A

2013-12-01

Cells use regulatory networks to perform computational operations to respond to their environment. Reliably manipulating such networks would be valuable for many applications in biotechnology; for example, in having genes turn on only under a defined set of conditions or implementing dynamic or temporal control of expression. Still, building such synthetic regulatory circuits remains one of the most difficult challenges in genetic engineering and as a result they have not found widespread application. Here, we review recent advances that address the key challenges in the forward design of genetic circuits. First, we look at new design concepts, including the construction of layered digital and analog circuits, and new approaches to control circuit response functions. Second, we review recent work to apply part mining and computational design to expand the number of regulators that can be used together within one cell. Finally, we describe new approaches to obtain precise gene expression and to reduce context dependence that will accelerate circuit design by more reliably balancing regulators while reducing toxicity. Copyright © 2013. Published by Elsevier Ltd.

A novel approach of ensuring layout regularity correct by construction in advanced technologies

NASA Astrophysics Data System (ADS)

Ahmed, Shafquat Jahan; Vaderiya, Yagnesh; Gupta, Radhika; Parthasarathy, Chittoor; Marin, Jean-Claude; Robert, Frederic

2017-03-01

In advanced technology nodes, layout regularity has become a mandatory prerequisite to create robust designs less sensitive to variations in manufacturing process in order to improve yield and minimizing electrical variability. In this paper we describe a method for designing regular full custom layouts based on design and process co-optimization. The method includes various design rule checks that can be used on-the-fly during leaf-cell layout development. We extract a Layout Regularity Index (LRI) from the layouts based on the jogs, alignments and pitches used in the design for any given metal layer. Regularity Index of a layout is the direct indicator of manufacturing yield and is used to compare the relative health of different layout blocks in terms of process friendliness. The method has been deployed for 28nm and 40nm technology nodes for Memory IP and is being extended to other IPs (IO, standard-cell). We have quantified the gain of layout regularity with the deployed method on printability and electrical characteristics by process-variation (PV) band simulation analysis and have achieved up-to 5nm reduction in PV band.

The journey from discoveries in fundamental immunology to cancer immunotherapy.

PubMed

Miller, Jacques F A P; Sadelain, Michel

2015-04-13

Recent advances in cancer immunotherapy have directly built on 50 years of fundamental and technological advances that made checkpoint blockade and T cell engineering possible. In this review, we intend to show that research, not specifically designed to bring relief or cure to any particular disease, can, when creatively exploited, lead to spectacular results in the management of cancer. The discovery of thymus immune function, T cells, and immune surveillance bore the seeds for today's targeted immune interventions and chimeric antigen receptors. Copyright © 2015 Elsevier Inc. All rights reserved.

Flight Weight Design Nickel-Hydrogen Cells Using Lightweight Nickel Fiber Electrodes

NASA Technical Reports Server (NTRS)

Britton, Doris L.; Willis, Bob; Pickett, David F.

2003-01-01

The goal of this program is to develop a lightweight nickel electrode for advanced aerospace nickel-hydrogen cells and batteries with improved specific energy and specific volume. The lightweight nickel electrode will improve the specific energy of a nickel-hydrogen cell by >50%. These near-term advanced batteries will reduce power system mass and volume, while decreasing the cost, thus increasing mission capabilities and enabling small spacecraft missions. This development also offers a cost savings over the traditional sinter development methods for fabrication. The technology has been transferred to Eagle-Picher, a major aerospace battery manufacturer, who has scaled up the process developed at NASA GRC and fabricated electrodes for incorporation into flight-weight nickel-hydrogen cells.

Innovative manufacturing technologies for low-cost, high efficiency PERC-based PV modules

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

Yelundur, Vijay

2017-04-19

The goal this project was to accelerate the deployment of innovative solar cell and module technologies that reduce the cost of PERC-based modules to best-in-class. New module integration technology was to be used to reduce the cost and reliance on conventional silver bus bar pastes and enhance cell efficiency. On the cell manufacturing front, the cost of PERC solar cells was to be reduced by introducing advanced metallization approaches to increase cell efficiency. These advancements will be combined with process optimization to target cell efficiencies in the range of 21 to 21.5%. This project will also explore the viability ofmore » a bifacial PERC solar cell design to enable cost savings through the use of thin silicon wafers. This project was terminated on 4/30/17 after four months of activity due financial challenges facing the recipient.« less

Design of a small molecule against an oncogenic noncoding RNA

PubMed Central

Velagapudi, Sai Pradeep; Cameron, Michael D.; Haga, Christopher L.; Rosenberg, Laura H.; Lafitte, Marie; Duckett, Derek R.; Phinney, Donald G.; Disney, Matthew D.

2016-01-01

The design of precision, preclinical therapeutics from sequence is difficult, but advances in this area, particularly those focused on rational design, could quickly transform the sequence of disease-causing gene products into lead modalities. Herein, we describe the use of Inforna, a computational approach that enables the rational design of small molecules targeting RNA to quickly provide a potent modulator of oncogenic microRNA-96 (miR-96). We mined the secondary structure of primary microRNA-96 (pri-miR-96) hairpin precursor against a database of RNA motif–small molecule interactions, which identified modules that bound RNA motifs nearby and in the Drosha processing site. Precise linking of these modules together provided Targaprimir-96 (3), which selectively modulates miR-96 production in cancer cells and triggers apoptosis. Importantly, the compound is ineffective on healthy breast cells, and exogenous overexpression of pri-miR-96 reduced compound potency in breast cancer cells. Chemical Cross-Linking and Isolation by Pull-Down (Chem-CLIP), a small-molecule RNA target validation approach, shows that 3 directly engages pri-miR-96 in breast cancer cells. In vivo, 3 has a favorable pharmacokinetic profile and decreases tumor burden in a mouse model of triple-negative breast cancer. Thus, rational design can quickly produce precision, in vivo bioactive lead small molecules against hard-to-treat cancers by targeting oncogenic noncoding RNAs, advancing a disease-to-gene-to-drug paradigm. PMID:27170187

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

Final Report: Mass Production Cost Estimation of Direct H2 PEM Fuel Cell Systems for Transportation Applications (2012-2016)

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

James, Brian David; Huya-Kouadio, Jennie Moton; Houchins, Cassidy

This report summarizes project activities for Strategic Analysis, Inc. (SA) Contract Number DE-EE0005236 to the U.S. Department of Energy titled “Transportation Fuel Cell System Cost Assessment”. The project defined and projected the mass production costs of direct hydrogen Proton Exchange Membrane fuel cell power systems for light-duty vehicles (automobiles) and 40-foot transit buses. In each year of the five-year contract, the fuel cell power system designs and cost projections were updated to reflect technology advances. System schematics, design assumptions, manufacturing assumptions, and cost results are presented.

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

NASA Astrophysics Data System (ADS)

Barricklow, Keegan Corey

CdTe solar cells have been commercialized at the Gigawatt/year level. The development of volume manufacturing processes for next generation CdTe photovoltaics (PV) with higher efficiencies requires research systems with flexibility, scalability, repeatability and automation. The Advanced Research Deposition Systems (ARDS) developed by the Materials Engineering Laboratory (MEL) provides such a platform for the investigation of materials and manufacturing processes necessary to produce the next generation of CdTe PV. Limited by previous research systems, the ARDS was developed to provide process and hardware flexibility, accommodating advanced processing techniques, and capable of producing device quality films. The ARDS is a unique, in-line process tool with nine processing stations. The system was designed, built and assembled at the Materials Engineering Laboratory. Final assembly, startup, characterization and process development are the focus of this research. Many technical challenges encountered during the startup of the ARDS were addressed in this research. In this study, several hardware modifications needed for the reliable operation of the ARDS were designed, constructed and successfully incorporated into the ARDS. The effect of process condition on film properties for each process step was quantified. Process development to achieve 12% efficient baseline solar cell required investigation of discrete processing steps, troubleshooting process variation, and developing performance correlations. Subsequent to this research, many advances have been demonstrated with the ARDS. The ARDS consistently produces devices of 12% +/-.5% by the process of record (POR). The champion cell produced to date utilizing the ARDS has an efficiency of 16.2% on low cost commercial sodalime glass and utilizes advanced films. The ARDS has enabled investigation of advanced concepts for processing CdTe devices including, Plasma Cleaning, Plasma Enhanced Closed Space Sublimation (PECSS), Electron Reflector (ER) using Cd1-xMgxTe (CMT) structure and alternative device structures. The ARDS has been instrumental in the collaborative research with many institutions.

Using technology to promote mobile learning: engaging students with cell phones in the classroom.

PubMed

Robb, Meigan; Shellenbarger, Teresa

2012-01-01

Advancements in cell phone technology have impacted every aspect of society. Individuals have instant access to social networks, Web sites, and applications. Faculty need to consider using these mobile devices to enrich the classroom. The authors discuss how they successfully designed and incorporated cell phone learning activities into their classrooms. Teaching-learning strategies using cell phone technology and recommendations for overcoming challenges associated with cell phone use in the classroom are discussed.

Effect of LEO cycling on 125 Ah advanced design IPV nickel-hydrogen flight cells - An update

NASA Technical Reports Server (NTRS)

Smithrick, John J.; Hall, Stephen W.

1991-01-01

An update of validation test results confirming the breakthrough in LEO cycle life of nickel-hydrogen cells containing 26 percent potassium hydroxide (KOH) electrolyte is presented. A breakthrough in the LEO cycle life of individual pressure vessel nickel-hydrogen cells is reported. The cycle life of boiler plate cells containing 26 percent KOH electrolyte was about 40,000 LEO cycles compared to 3500 cycles for cells containing 31 percent KOH.

The Performance of Advanced III-V Solar Cells

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

Cell encapsulation in biodegradable hydrogels for tissue engineering applications.

PubMed

Nicodemus, Garret D; Bryant, Stephanie J

2008-06-01

Encapsulating cells in biodegradable hydrogels offers numerous attractive features for tissue engineering, including ease of handling, a highly hydrated tissue-like environment for cell and tissue growth, and the ability to form in vivo. Many properties important to the design of a hydrogel scaffold, such as swelling, mechanical properties, degradation, and diffusion, are closely linked to the crosslinked structure of the hydrogel, which is controlled through a variety of different processing conditions. Degradation may be tuned by incorporating hydrolytically or enzymatically labile segments into the hydrogel or by using natural biopolymers that are susceptible to enzymatic degradation. Because cells are present during the gelation process, the number of suitable chemistries and formulations are limited. In this review, we describe important considerations for designing biodegradable hydrogels for cell encapsulation and highlight recent advances in material design and their applications in tissue engineering.

Advancements in rationally designed PGM-free fuel cell catalysts derived from metal–organic frameworks

DOE PAGES

Barkholtz, Heather M.; Liu, Di -Jia

2016-11-14

Over the past several years, metal-organic framework (MOF)-derived platinum group metal free (PGM-free) electrocatalysts have gained considerable attention due to their high efficiency and low cost as potential replacement for platinum in catalyzing oxygen reduction reaction (ORR). In this review, we summarize the recent advancements in design, synthesis and characterization of MOF-derived ORR catalysts and their performances in acidic and alkaline media. As a result, we also discuss the key challenges such as durability and activity enhancement critical in moving forward this emerging electrocatalyst science.

Advances in fuel cell vehicle design

NASA Astrophysics Data System (ADS)

Bauman, Jennifer

Factors such as global warming, dwindling fossil fuel reserves, and energy security concerns combine to indicate that a replacement for the internal combustion engine (ICE) vehicle is needed. Fuel cell vehicles have the potential to address the problems surrounding the ICE vehicle without imposing any significant restrictions on vehicle performance, driving range, or refuelling time. Though there are currently some obstacles to overcome before attaining the widespread commercialization of fuel cell vehicles, such as improvements in fuel cell and battery durability, development of a hydrogen infrastructure, and reduction of high costs, the fundamental concept of the fuel cell vehicle is strong: it is efficient, emits zero harmful emissions, and the hydrogen fuel can be produced from various renewable sources. Therefore, research on fuel cell vehicle design is imperative in order to improve vehicle performance and durability, increase efficiency, and reduce costs. This thesis makes a number of key contributions to the advancement of fuel cell vehicle design within two main research areas: powertrain design and DC/DC converters. With regards to powertrain design, this research first analyzes various powertrain topologies and energy storage system types. Then, a novel fuel cell-battery-ultracapacitor topology is presented which shows reduced mass and cost, and increased efficiency, over other promising topologies found in the literature. A detailed vehicle simulator is created in MATLAB/Simulink in order to simulate and compare the novel topology with other fuel cell vehicle powertrain options. A parametric study is performed to optimize each powertrain and general conclusions for optimal topologies, as well as component types and sizes, for fuel cell vehicles are presented. Next, an analytical method to optimize the novel battery-ultracapacitor energy storage system based on maximizing efficiency, and minimizing cost and mass, is developed. This method can be applied to any system utilizing the novel battery-ultracapacitor energy storage system and is not limited in application to only fuel cell vehicles. With regards to DC/DC converters, it is important to design efficient and light-weight converters for use in fuel cell and other electric vehicles to improve overall vehicle fuel economy. Thus, this research presents a novel soft-switching method, the capacitor-switched regenerative snubber, for the high-power DC/DC boost converters commonly used in fuel cell vehicles. This circuit is shown to increase the efficiency and reduce the overall mass of the DC/DC boost converter.

The Recent Revolution in the Design and Manufacture of Cranial Implants: Modern Advancements and Future Directions

PubMed Central

Bonda, David J.; Manjila, Sunil; Selman, Warren R.; Dean, David

2015-01-01

Large format (i.e., > 25 cm2) cranioplasty is a challenging procedure not only from a cosmesis standpoint, but also in terms of ensuring that the patient's brain will be well-protected from direct trauma. Until recently, when a patient's own cranial flap was unavailable, these goals were unattainable. Recent advances in implant Computer Aided Design and 3-D printing are leveraging other advances in regenerative medicine. It is now possible to 3-D-print patient-specific implants from a variety of polymer, ceramic, or metal components. A skull template may be used to design the external shape of an implant that will become well integrated in the skull, while also providing beneficial distribution of mechanical force distribution in the event of trauma. Furthermore, an internal pore geometry can be utilized to facilitate the seeding of banked allograft cells. Implants may be cultured in a bioreactor along with recombinant growth factors to produce implants coated with bone progenitor cells and extracellular matrix that appear to the body as a graft, albeit a tissue-engineered graft. The growth factors would be left behind in the bioreactor and the graft would resorb as new host bone invades the space and is remodeled into strong bone. As we describe in this review, such advancements will lead to optimal replacement of cranial defects that are both patient-specific and regenerative. PMID:26171578

Aerodynamic performance of conventional and advanced design labyrinth seals with solid-smooth abradable, and honeycomb lands. [gas turbine engines

NASA Technical Reports Server (NTRS)

Stocker, H. L.; Cox, D. M.; Holle, G. F.

1977-01-01

Labyrinth air seal static and dynamic performance was evaluated using solid, abradable, and honeycomb lands with standard and advanced seal designs. The effects on leakage of land surface roughness, abradable land porosity, rub grooves in abradable lands, and honeycomb land cell size and depth were studied using a standard labyrinth seal. The effects of rotation on the optimum seal knife pitch were also investigated. Selected geometric and aerodynamic parameters for an advanced seal design were evaluated to derive an optimized performance configuration. The rotational energy requirements were also measured to determine the inherent friction and pumping energy absorbed by the various seal knife and land configurations tested in order to properly assess the net seal system performance level. Results indicate that: (1) seal leakage can be significantly affected with honeycomb or abradable lands; (2) rotational energy absorption does not vary significantly with the use of a solid-smooth, an abradable, or a honeycomb land; and (3) optimization of an advanced lab seal design produced a configuration that had leakage 25% below a conventional stepped seal.

On-Demand Cell Internal Short Circuit Device

NASA Technical Reports Server (NTRS)

Darcy, Eric; Keyser, Matthew

2014-01-01

A device implantable in Li-ion cells that can generate a hard internal short circuit on-demand by exposing the cell to 60?C has been demonstrated to be valuable for expanding our understanding of cell responses. The device provides a negligible impact to cell performance and enables the instigation of the 4 general categories of cell internal shorts to determine relative severity and cell design susceptibility. Tests with a 18650 cell design indicates that the anode active material short to the aluminum cathode current collector tends to be more catastrophic than the 3 other types of internal shorts. Advanced safety features (such as shutdown separators) to prevent or mitigate the severity of cell internal shorts can be verified with this device. The hard short success rate achieved to date in 18650 cells is about 80%, which is sufficient for using these cells in battery assemblies for field-failure-relevant, cell-cell thermal runaway propagation verification tests

New Advanced Technologies in Stem Cell Therapy

DTIC Science & Technology

2012-09-01

directions for this project include investigating modulation of the IKK/NF-kB pathway as a means to rejuvenate the phenotype of aged muscle stem and...Reference 1. Conboy IM, Conboy MJ, Wagers AJ, Girma ER, Weissman IL, Rando TA. Rejuvenation of aged progenitor cells by exposure to a young...the influence that age plays on the regeneration capacity of the cells. Study Design: We will investigate the effects of cell survival, proliferation

New Advanced Technologies In Stem Cell Therapy

DTIC Science & Technology

2011-09-01

rejuvenate the phenotype of aged muscle stem and progenitor cells. Clinical research should be conducted to test the efficacy of p65 inhibition...entothelial cells or pericytes). Finally we will investigate the influence that age plays on the regeneration capacity of the cells. Study Design: We...skeletal muscle when compared to male MDSCs, we will determine the influence that sex has on the hMDCs. Due to the fact that MDSCs isolated from aged

Advanced manufacturing of microdisk vaccines for uniform control of material properties and immune cell function.

PubMed

Zeng, Qin; Zhang, Peipei; Zeng, Xiangbin; Tostanoski, Lisa H; Jewell, Christopher M

2017-12-19

The continued challenges facing vaccines in infectious disease and cancer highlight a need for better control over the features of vaccines and the responses they generate. Biomaterials offer unique advantages to achieve this goal through features such as controlled release and co-delivery of antigens and adjuvants. However, many synthesis strategies lead to particles with heterogeneity in diameter, shape, loading level, or other properties. In contrast, advanced manufacturing techniques allow precision control of material properties at the micro- and nano-scale. These capabilities in vaccines and immunotherapies could allow more rational design to speed efficient design and clinical translation. Here we employed soft lithography to generate polymer microdisk vaccines with uniform structures and tunable compositions of vaccine antigens and toll like receptor agonists (TLRas) that serve as molecular adjuvants. Compared to conventional PLGA particles formed by emulsion, microdisks provided a dramatic improvement in the consistency of properties such as diameter. During culture with primary dendritic cells (DCs) from mice, microdisks were internalized by the cells without toxicity, while promoting co-delivery of antigen and TLRa to the same cell. Analysis of DC surface activation markers by flow cytometry revealed microdisk vaccines activated dendritic cells in a manner that depended on the level of TLRa, while antigen processing and presentation depended on the amount of antigen in the microdisks. Together, this work demonstrates the use of advanced manufacturing techniques to produce uniform vaccines that direct DC function depending on the composition in the disks.

Considerations for Estimating Electrode Performance in Li-Ion Cells

NASA Technical Reports Server (NTRS)

Bennett, William R.

2012-01-01

Advanced electrode materials with increased specific capacity and voltage performance are critical to the development of Li-ion batteries with increased specific energy and energy density. Although performance metrics for individual electrodes are critically important, a fundamental understanding of the interactions of electrodes in a full cell is essential to achieving the desired performance, and for establishing meaningful goals for electrode performance. This paper presents practical design considerations for matching positive and negative electrodes in a viable design. Methods for predicting cell-level discharge voltage, based on laboratory data for individual electrodes, are presented and discussed.

An Innovative Carbonate Fuel Cell Matrix, Abstract #188

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

Hilmi, Abdelkader; Surendranath, Arun; Yuh, Chao-Yi

2015-05-28

The electrolyte matrix in direct carbonate fuel cell (DFC) is a microporous ceramic structure sandwiched between the electrodes to isolate the fuel from the oxidant, store electrolyte and facilitate ionic transport. FCE has advanced DFC electrolyte matrix over the years and demonstrated that the matrix meets the requirements for greater than 5 year life based on accelerated tests and field stack operations. However, development of advanced designs and materials that can further increase the performance and extend cell life will enable accelerated MCFC deployment. This paper will report the progress on the development of an unique and innovative matrix designmore » that offers numerous benefits to the carbonate fuel cell performance and durability. In addition, this paper will also review parameters that affect matrix material stability and approaches to extend cell life.« less

Tilted pillar array fabrication by the combination of proton beam writing and soft lithography for microfluidic cell capture: Part 1 Design and feasibility.

PubMed

Rajta, Istvan; Huszánk, Robert; Szabó, Atilla T T; Nagy, Gyula U L; Szilasi, Szabolcs; Fürjes, Peter; Holczer, Eszter; Fekete, Zoltan; Járvás, Gabor; Szigeti, Marton; Hajba, Laszlo; Bodnár, Judit; Guttman, Andras

2016-02-01

Design, fabrication, integration, and feasibility test results of a novel microfluidic cell capture device is presented, exploiting the advantages of proton beam writing to make lithographic irradiations under multiple target tilting angles and UV lithography to easily reproduce large area structures. A cell capture device is demonstrated with a unique doubly tilted micropillar array design for cell manipulation in microfluidic applications. Tilting the pillars increased their functional surface, therefore, enhanced fluidic interaction when special bioaffinity coating was used, and improved fluid dynamic behavior regarding cell culture injection. The proposed microstructures were capable to support adequate distribution of body fluids, such as blood, spinal fluid, etc., between the inlet and outlet of the microfluidic sample reservoirs, offering advanced cell capture capability on the functionalized surfaces. The hydrodynamic characteristics of the microfluidic systems were tested with yeast cells (similar size as red blood cells) for efficient capture. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Treatment of advanced gastrointestinal cancer with genetically modified autologous mesenchymal stem cells - TREAT-ME-1 - a phase I, first in human, first in class trial.

PubMed

von Einem, Jobst C; Peter, Sylvia; Günther, Christine; Volk, Hans-Dieter; Grütz, Gerald; Salat, Christoph; Stoetzer, Oliver; Nelson, Peter J; Michl, Marlies; Modest, Dominik P; Holch, Julian W; Angele, Martin; Bruns, Christiane; Niess, Hanno; Heinemann, Volker

2017-10-06

This phase I, first in human, first in class clinical study aimed at evaluating the safety, tolerability and efficacy of treatment with genetically modified mesenchymal stromal cells (MSC) in combination with ganciclovir (GCV). MSC_apceth_101 are genetically modified autologous MSCs used as vehicles for a cell-based gene therapy in patients with advanced gastrointestinal adenocarcinoma. The study design consisted of a dose-escalation 3 + 3 design. All patients ( n = 6) were treated with up to three applications of MSC_apceth_101, followed by GCV infusions given on three consecutive days starting 48 hours after injection of MSC_apceth_101. Three of six patients received a total dose of 1.5 × 10 6 cells/kg. Two patients received three doses of 1 × 10 6 cells/kg, while one patient received only two doses of 1 × 10 6 cells/kg due to a SADR. Six patients received MSC_apceth_101. No IMP-related serious adverse events occurred. Adverse-events related to IMP-injection were increased creatinine, cough, fever, and night sweat. TNF, IL-6, IL-8, IL-10 and sE-Selectin, showed that repeated application is immunologically safe, but induces a switch of the functional properties of monocytes to an inflammatory phenotype. Treatment induced stable disease in 4/6 patients, and progressive disease in 2/6 patients. Treatment with MSC_apceth_101 in combination with GCV demonstrated acceptable safety and tolerability in patients with advanced gastrointestinal adenocarcinoma.

Biology and clinical application of CAR T cells for B cell malignancies.

PubMed

Davila, Marco L; Sadelain, Michel

2016-07-01

Chimeric antigen receptor (CAR)-modified T cells have generated broad interest in oncology following a series of dramatic clinical successes in patients with chemorefractory B cell malignancies. CAR therapy now appears to be on the cusp of regulatory approval as a cell-based immunotherapy. We review here the T cell biology and cell engineering research that led to the development of second generation CARs, the selection of CD19 as a CAR target, and the preclinical studies in animal models that laid the foundation for clinical trials targeting CD19+ malignancies. We further summarize the status of CD19 CAR clinical therapy for non-Hodgkin lymphoma and B cell acute lymphoblastic leukemia, including their efficacy, toxicities (cytokine release syndrome, neurotoxicity and B cell aplasia) and current management in humans. We conclude with an overview of recent pre-clinical advances in CAR design that argues favorably for the advancement of CAR therapy to tackle other hematological malignancies as well as solid tumors.

Biology and clinical application of CAR T Cells for B cell malignancies

PubMed Central

Davila, Marco L; Sadelain, Michel

2017-01-01

Chimeric antigen receptor (CAR)-modified T cells have generated broad interest in oncology following a series of dramatic clinical successes in patients with chemorefractory B cell malignancies. CAR therapy now appears to be on the cusp of regulatory approval as a cell-based immunotherapy. We review here the T cell biology and cell engineering research that led to the development of second generation CARs, the selection of CD19 as a CAR target, and the preclinical studies in animal models that laid the foundation for clinical trials targeting CD19+ malignancies. We further summarize the status of CD19 CAR clinical therapy for non-Hodgkin lymphoma (NHL) and B cell acute lymphoblastic leukemia (B-ALL), including their efficacy, toxicities (cytokine release syndrome, neurotoxicity and B cell aplasia) and current management in humans. We conclude with an overview of recent pre-clinical advances in CAR design that argues favorably for the advancement of CAR therapy to tackle other hematological malignancies as well as solid tumors. PMID:27262700

Biosensor-based engineering of biosynthetic pathways

DOE PAGES

Rogers, Jameson K.; Taylor, Noah D.; Church, George M.

2016-03-18

Biosynthetic pathways provide an enzymatic route from inexpensive renewable resources to valuable metabolic products such as pharmaceuticals and plastics. However, designing these pathways is challenging due to the complexities of biology. Advances in the design and construction of genetic variants has enabled billions of cells, each possessing a slightly different metabolic design, to be rapidly generated. However, our ability to measure the quality of these designs lags by several orders of magnitude. Recent research has enabled cells to report their own success in chemical production through the use of genetically encoded biosensors. A new engineering discipline is emerging around themore » creation and application of biosensors. Biosensors, implemented in selections and screens to identify productive cells, are paving the way for a new era of biotechnological progress.« less

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

PubMed Central

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

2002-01-01

The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors. PMID:12587031

Biotechnology apprenticeship for secondary-level students: teaching advanced cell culture techniques for research.

PubMed

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

2002-01-01

The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors.

Functional Architecture of the Retina: Development and Disease

PubMed Central

Hoon, Mrinalini; Okawa, Haruhisa; Santina, Luca Della; Wong, Rachel O.L.

2014-01-01

Structure and function are highly correlated in the vertebrate retina, a sensory tissue that is organized into cell layers with microcircuits working in parallel and together to encode visual information. All vertebrate retinas share a fundamental plan, comprising five major neuronal cell classes with cell body distributions and connectivity arranged in stereotypic patterns. Conserved features in retinal design have enabled detailed analysis and comparisons of structure, connectivity and function across species. Each species, however, can adopt structural and/or functional retinal specializations, implementing variations to the basic design in order to satisfy unique requirements in visual function. Recent advances in molecular tools, imaging and electrophysiological approaches have greatly facilitated identification of the cellular and molecular mechanisms that establish the fundamental organization of the retina and the specializations of its microcircuits during development. Here, we review advances in our understanding of how these mechanisms act to shape structure and function at the single cell level, to coordinate the assembly of cell populations, and to define their specific circuitry. We also highlight how structure is rearranged and function is disrupted in disease, and discuss current approaches to re-establish the intricate functional architecture of the retina. PMID:24984227

Functional architecture of the retina: development and disease.

PubMed

Hoon, Mrinalini; Okawa, Haruhisa; Della Santina, Luca; Wong, Rachel O L

2014-09-01

Structure and function are highly correlated in the vertebrate retina, a sensory tissue that is organized into cell layers with microcircuits working in parallel and together to encode visual information. All vertebrate retinas share a fundamental plan, comprising five major neuronal cell classes with cell body distributions and connectivity arranged in stereotypic patterns. Conserved features in retinal design have enabled detailed analysis and comparisons of structure, connectivity and function across species. Each species, however, can adopt structural and/or functional retinal specializations, implementing variations to the basic design in order to satisfy unique requirements in visual function. Recent advances in molecular tools, imaging and electrophysiological approaches have greatly facilitated identification of the cellular and molecular mechanisms that establish the fundamental organization of the retina and the specializations of its microcircuits during development. Here, we review advances in our understanding of how these mechanisms act to shape structure and function at the single cell level, to coordinate the assembly of cell populations, and to define their specific circuitry. We also highlight how structure is rearranged and function is disrupted in disease, and discuss current approaches to re-establish the intricate functional architecture of the retina. Copyright © 2014 Elsevier Ltd. All rights reserved.

Recent Advances of Cell-Cycle Inhibitor Therapies for Pediatric Cancer.

PubMed

Mills, Christopher C; Kolb, E A; Sampson, Valerie B

2017-12-01

This review describes the pivotal roles of cell-cycle and checkpoint regulators and discusses development of specific cell-cycle inhibitors for therapeutic use for pediatric cancer. The mechanism of action as well as the safety and tolerability of drugs in pediatric patients, including compounds that target CDK4/CDK6 (palbociclib, ribociclib, and abemaciclib), aurora kinases (AT9283 and MLN8237), Wee1 kinase (MK-1775), KSP (ispinesib), and tubulin (taxanes, vinca alkaloids), are presented. The design of mechanism-based combinations that exploit the cross-talk of signals activated by cell-cycle arrest, as well as pediatric-focused drug development, are critical for the advancement of drugs for rare childhood diseases. Cancer Res; 77(23); 6489-98. ©2017 AACR . ©2017 American Association for Cancer Research.

Advanced solar panel designs

NASA Technical Reports Server (NTRS)

Ralph, E. L.; Linder, E. B.

1996-01-01

Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 cm(exp 2) coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 cm(exp 2) coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg. This paper will address the construction details for the GaAs/isogrid and dual-junction GaAs/carbon mesh panel configurations. These are ultimately sized to provide 75 Watts and 119 Watts respectively for smallsats or may be used as modular building blocks for larger systems. GaAs/isogrid and dual-junction GaAs/carbon mesh coupons have been fabricated and tested to successfully demonstrate critical performance parameters and results are also provided here.

New bioproduction systems: from molecular circuits to novel reactor concepts in cell-free biotechnology.

PubMed

Rupp, Steffen

2013-01-01

: The last decades witnessed a strong growth in several areas of biotechnology, especially in fields related to health, as well as in industrial biotechnology. Advances in molecular engineering now enable biotechnologists to design more efficient pathways in order to convert a larger spectrum of renewable resources into industrially used biofuels and chemicals as well as into new pharmaceuticals and therapeutic proteins. In addition material sciences advanced significantly making it more and more possible to integrate biology and engineering. One of the key questions currently is how to develop new ways of engineering biological systems to cope with the complexity and limitations given by the cell. The options to integrate biology with classical engineering advanced cell free technologies in the recent years significantly. Cell free protein production using cellular extracts is now a well-established universal technology for production of proteins derived from many organisms even at the milligram scale. Among other applications it has the potential to supply the demand for a multitude of enzymes and enzyme variants facilitating in vitro metabolic engineering. This review will briefly address the recent achievements and limitations of cell free conversions. Especially, the requirements for reactor systems in cell free biotechnology, a currently underdeveloped field, are reviewed and some perspectives are given on how material sciences and biotechnology might be able to advance these new developments in the future.

Advancing the Oxygen Generation Assembly Design to Increase Reliability and Reduce Costs for a Future Long Duration Mission

NASA Technical Reports Server (NTRS)

Takada, Kevin C.; Ghariani, Ahmed E.; Van Keuren,

2015-01-01

The state-of-the-art Oxygen Generation Assembly (OGA) has been reliably producing breathing oxygen for the crew aboard the International Space Station (ISS) for over eight years. Lessons learned from operating the ISS OGA have led to proposing incremental improvements to advance the baseline design for use in a future long duration mission. These improvements are intended to reduce system weight, crew maintenance time and resupply mass from Earth while increasing reliability. The proposed improvements include replacing the cell stack membrane material, deleting the nitrogen purge equipment, replacing the hydrogen sensors, deleting the wastewater interface, replacing the hydrogen dome and redesigning the cell stack power supply. The development work to date will be discussed and forward work will be outlined. Additionally, a redesigned system architecture will be proposed.

Molecular engineering of sensitizers for dye-sensitized solar cell applications.

PubMed

Giribabu, Lingamallu; Kanaparthi, Ravi Kumar; Velkannan, Veerapandian

2012-06-01

Dye-sensitized solar cells (DSSCs) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy. This account focuses on recent advances in molecular design and technological aspects of sensitizers based on metal complexes, metal-free organics and tetrapyrrolic compounds which include porphyrins, phthalocyanines as well as corroles. Special attention has been paid to the design principles of these dyes, and co-sensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device. This account also focuses on recent advances of efficient ruthenium sensitizers as well as other metal complexes and their applications in DSSCs. Recent developments in the area of metal-free organic and tetrapyrrolic sensitizers are also discussed. Copyright © 2012 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Recent Progress in the Design of Advanced Cathode Materials and Battery Models for High-Performance Lithium-X (X = O2 , S, Se, Te, I2 , Br2 ) Batteries.

PubMed

Xu, Jiantie; Ma, Jianmin; Fan, Qinghua; Guo, Shaojun; Dou, Shixue

2017-07-01

Recent advances and achievements in emerging Li-X (X = O 2 , S, Se, Te, I 2 , Br 2 ) batteries with promising cathode materials open up new opportunities for the development of high-performance lithium-ion battery alternatives. In this review, we focus on an overview of recent important progress in the design of advanced cathode materials and battery models for developing high-performance Li-X (X = O 2 , S, Se, Te, I 2 , Br 2 ) batteries. We start with a brief introduction to explain why Li-X batteries are important for future renewable energy devices. Then, we summarize the existing drawbacks, major progress and emerging challenges in the development of cathode materials for Li-O 2 (S) batteries. In terms of the emerging Li-X (Se, Te, I 2 , Br 2 ) batteries, we systematically summarize their advantages/disadvantages and recent progress. Specifically, we review the electrochemical performance of Li-Se (Te) batteries using carbonate-/ether-based electrolytes, made with different electrode fabrication techniques, and of Li-I 2 (Br 2 ) batteries with various cell designs (e.g., dual electrolyte, all-organic electrolyte, with/without cathode-flow mode, and fuel cell/solar cell integration). Finally, the perspective on and challenges for the development of cathode materials for the promising Li-X (X = O 2 , S, Se, Te, I 2 , Br 2 ) batteries is presented. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Developmental engineering: a new paradigm for the design and manufacturing of cell-based products. Part I: from three-dimensional cell growth to biomimetics of in vivo development.

PubMed

Lenas, Petros; Moos, Malcolm; Luyten, Frank P

2009-12-01

Recent advances in developmental biology, systems biology, and network science are converging to poise the heretofore largely empirical field of tissue engineering on the brink of a metamorphosis into a rigorous discipline based on universally accepted engineering principles of quality by design. Failure of more simplistic approaches to the manufacture of cell-based therapies has led to increasing appreciation of the need to imitate, at least to some degree, natural mechanisms that control cell fate and differentiation. The identification of many of these mechanisms, which in general are based on cell signaling pathways, is an important step in this direction. Some well-accepted empirical concepts of developmental biology, such as path-dependence, robustness, modularity, and semiautonomy of intermediate tissue forms, that appear sequentially during tissue development are starting to be incorporated in process design.

Looking into the Future: Toward Advanced 3D Biomaterials for Stem-Cell-Based Regenerative Medicine.

PubMed

Liu, Zhongmin; Tang, Mingliang; Zhao, Jinping; Chai, Renjie; Kang, Jiuhong

2018-04-01

Stem-cell-based therapies have the potential to provide novel solutions for the treatment of a variety of diseases, but the main obstacles to such therapies lie in the uncontrolled differentiation and functional engraftment of implanted tissues. The physicochemical microenvironment controls the self-renewal and differentiation of stem cells, and the key step in mimicking the stem cell microenvironment is to construct a more physiologically relevant 3D culture system. Material-based 3D assemblies of stem cells facilitate the cellular interactions that promote morphogenesis and tissue organization in a similar manner to that which occurs during embryogenesis. Both natural and artificial materials can be used to create 3D scaffolds, and synthetic organic and inorganic porous materials are the two main kinds of artificial materials. Nanotechnology provides new opportunities to design novel advanced materials with special physicochemical properties for 3D stem cell culture and transplantation. Herein, the advances and advantages of 3D scaffold materials, especially with respect to stem-cell-based therapies, are first outlined. Second, the stem cell biology in 3D scaffold materials is reviewed. Third, the progress and basic principles of developing 3D scaffold materials for clinical applications in tissue engineering and regenerative medicine are reviewed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid prototype fabrication processes for high-performance thrust cells

NASA Technical Reports Server (NTRS)

Hunt, K.; Chwiedor, T.; Diab, J.; Williams, R.

1994-01-01

The Thrust Cell Technologies Program (Air Force Phillips Laboratory Contract No. F04611-92-C-0050) is currently being performed by Rocketdyne to demonstrate advanced materials and fabrication technologies which can be utilized to produce low-cost, high-performance thrust cells for launch and space transportation rocket engines. Under Phase 2 of the Thrust Cell Technologies Program (TCTP), rapid prototyping and investment casting techniques are being employed to fabricate a 12,000-lbf thrust class combustion chamber for delivery and hot-fire testing at Phillips Lab. The integrated process of investment casting directly from rapid prototype patterns dramatically reduces design-to-delivery cycle time, and greatly enhances design flexibility over conventionally processed cast or machined parts.

NREL - Advanced Vehicles and Fuels Basics - Center for Transportation Technologies and Systems 2010

ScienceCinema

Dan; Arvizu; Barbara; Goodman; Robert; McCormick; Tony; Markel; Matt; Keyser; Sreekant; Narumanchi; Rob; Farrington

2017-12-09

We can improve the fuel economy of our cars, trucks, and buses by designing them to use the energy in fuels more efficiently. Researchers at the National Renewable Energy Laboratory (NREL) are helping the nation achieve these goals by developing transportation technologies like: advanced vehicle systems and components; alternative fuels; as well as fuel cells, hybrid electric, and plug-in hybrid vehicles.

High Current ESD Test of Advanced Triple Junction Solar Array Coupon

NASA Technical Reports Server (NTRS)

Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie

2015-01-01

A test was conducted on an Advanced Triple Junction (ATJ) coupon that was part of a risk reduction effort in the development of a high-powered solar array design by SSL. The ATJ coupon was a small, 4-cell, two-string configuration that has served as the basic test coupon design used in previous SSL environmental aging campaigns. The coupon has many attributes of the flight design; e.g., substrate structure with graphite face sheets, integrated by-pass diodes, cell interconnects, RTV grout, wire routing, etc. The objective of the present test was to evaluate the performance of the coupon after being subjected to induced electrostatic discharge testing at two string voltages (100 V, 150 V) and four array current (1.65 A, 2.0 A, 2.475 A, and 3.3 A). An ESD test circuit, unique to SSL solar array design, was built that simulates the effect of missing cells and strings in a full solar panel with special primary arc flashover circuitry. A total of 73 primary arcs were obtained that included 7 temporary sustained arcs (TSA) events. The durations of the TSAs ranged from 50 micros to 2.9 ms. All TSAs occurred at a string voltage of 150 V. Post-test Large Area Pulsed Solar Simulator (LAPSS), Dark I-V, and By-Pass Diode tests showed that no degradation occurred due to the TSA events. In addition, the post-test insulation resistance measured was > 50 G-ohms between cells and substrate. These test results indicate a robust design for application to a high-current, high-power mission application.

High Current ESD Test of Advanced Triple Junction Solar Array Coupon

NASA Technical Reports Server (NTRS)

Wright, K. H.; Schneider, T. A.; Vaughn, J. A.; Hoang, B.; Wong, F.

2014-01-01

A test was conducted on an Advanced Triple Junction (ATJ) coupon that was part of a risk reduction effort in the development of a high-powered solar array design by SSL. The ATJ coupon was a small, 4-cell, two-string configuration that has served as the basic test coupon design used in previous SSL environmental aging campaigns. The coupon has many attributes of the flight design; e.g., substrate structure with graphite face sheets, integrated by-pass diodes, cell interconnects, RTV grout, wire routing, etc. The objective of the present test was to evaluate the performance of the coupon after being subjected to induced electrostatic discharge testing at two string voltages (100 V, 150 V) and four array current (1.65 A, 2.0 A, 2.475 A, and 3.3 A). An ESD test circuit, unique to SSL solar array design, was built that simulates the effect of missing cells and strings in a full solar panel with special primary arc flashover circuitry. A total of 73 primary arcs were obtained that included 7 temporary sustained arcs (TSA) events. The durations of the TSAs ranged from 50 µs to 2.9 ms. All TSAs occurred at a string voltage of 150 V. Post-test Large Area Pulsed Solar Simulator (LAPSS), Dark I-V, and By-Pass Diode tests showed that no degradation occurred due to the TSA events. In addition, the post-test insulation resistance measured was > 50 G-ohms between cells and substrate. These test results indicate a robust design for application to a high-current, high-power mission application.

High Current ESD Test of Advanced Triple Junction Solar Array Coupon

NASA Technical Reports Server (NTRS)

Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie

2014-01-01

Testing was conducted on an Advanced Triple Junction (ATJ) coupon that was part of a risk reduction effort in the development of a high-powered solar array design by Space Systems/Loral, LLC (SSL). The ATJ coupon was a small, 4-cell, two-string configuration that has served as the basic test coupon design used in previous SSL environmental aging campaigns. The coupon has many attributes of the flight design; e.g., substrate structure with graphite face sheets, integrated by-pass diodes, cell interconnects, RTV grout, wire routing, etc. The objective of the present test was to evaluate the performance of the coupon after being subjected to induced electrostatic discharge (ESD) testing at two string voltages (100 V, 150 V) and four array currents (1.65 A, 2.0 A, 2.475 A, and 3.3 A). An ESD test circuit, unique to SSL solar array design, was built that simulates the effect of missing cells and strings in a full solar panel with special primary arc flashover circuitry. A total of 73 primary arcs were obtained that included 7 temporary sustained arcs (TSA) events. The durations of the TSAs ranged from 50 micro-seconds to 2.75 milli-seconds. All TSAs occurred at a string voltage of 150 V. Post-test Large Area Pulsed Solar Simulator (LAPSS), Dark I-V, and By-Pass Diode tests showed that no degradation occurred due to the TSA events. In addition, the post-test insulation resistance measured was > 50 G-ohms between cells and substrate. These test results indicate a robust design for application to a high-current, high-power mission.

Solid Oxide Fuel Cell Seal Development at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M.; Bansal, Narottam P.; Dynys, Fred W.; Lang, Jerry; Daniels, Christopher C.; Palko, Joeseph L.; Choi, S. R.

2004-01-01

Researchers at NASA GRC are confronting the seal durability challenges of Solid Oxide Fuel Cells by pursuing an integrated and multidisciplinary development effort incorporating thermo-structural analyses, advanced materials, experimentation, and novel seal design concepts. The successful development of durable hermetic SOFC seals is essential to reliably producing the high power densities required for aerospace applications.

Th1/Th2 Cytokines: An Easy Model to Study Gene Expression in Immune Cells

ERIC Educational Resources Information Center

Moran, Jose M.; Gonzalez-Polo, Rosa A.; Soler, German; Fuentes, Jose M.

2006-01-01

This report describes a laboratory exercise that was incorporated into a Cell Biology and Molecular Biology advanced course. The exercise was made for a class size with eight students and was designed to reinforce the understanding of basic molecular biology techniques. Students used the techniques of reverse transcription and arginase activity…

Cancer and Radiation Therapy: Current Advances and Future Directions

PubMed Central

Baskar, Rajamanickam; Lee, Kuo Ann; Yeo, Richard; Yeoh, Kheng-Wei

2012-01-01

In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. However with its increasing incidence, the clinical management of cancer continues to be a challenge for the 21st century. Treatment modalities comprise of radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy during their course of illness; it contributes towards 40% of curative treatment for cancer. The main goal of radiation therapy is to deprive cancer cells of their multiplication (cell division) potential. Celebrating a century of advances since Marie Curie won her second Nobel Prize for her research into radium, 2011 has been designated the Year of Radiation therapy in the UK. Over the last 100 years, ongoing advances in the techniques of radiation treatment and progress made in understanding the biology of cancer cell responses to radiation will endeavor to increase the survival and reduce treatment side effects for cancer patients. In this review, principles, application and advances in radiation therapy with their biological end points are discussed. PMID:22408567

Cancer and radiation therapy: current advances and future directions.

PubMed

Baskar, Rajamanickam; Lee, Kuo Ann; Yeo, Richard; Yeoh, Kheng-Wei

2012-01-01

In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. However with its increasing incidence, the clinical management of cancer continues to be a challenge for the 21st century. Treatment modalities comprise of radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Radiation therapy remains an important component of cancer treatment with approximately 50% of all cancer patients receiving radiation therapy during their course of illness; it contributes towards 40% of curative treatment for cancer. The main goal of radiation therapy is to deprive cancer cells of their multiplication (cell division) potential. Celebrating a century of advances since Marie Curie won her second Nobel Prize for her research into radium, 2011 has been designated the Year of Radiation therapy in the UK. Over the last 100 years, ongoing advances in the techniques of radiation treatment and progress made in understanding the biology of cancer cell responses to radiation will endeavor to increase the survival and reduce treatment side effects for cancer patients. In this review, principles, application and advances in radiation therapy with their biological end points are discussed.

Metal-free organic dyes for dye-sensitized solar cells: from structure: property relationships to design rules.

PubMed

Mishra, Amaresh; Fischer, Markus K R; Bäuerle, Peter

2009-01-01

Dye-sensitized solar cells (DSSC) have attracted considerable attention in recent years as they offer the possibility of low-cost conversion of photovoltaic energy. This Review focuses on recent advances in molecular design and technological aspects of metal-free organic dyes for applications in dye-sensitized solar cells. Special attention has been paid to the design principles of these dyes and on the effect of various electrolyte systems. Cosensitization, an emerging technique to extend the absorption range, is also discussed as a way to improve the performance of the device. In addition, we report on inverted dyes for photocathodes, which constitutes a relatively new approach for the production of tandem cells. Special consideration has been paid to the correlation between the molecular structure and physical properties to their performance in DSSCs.

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.

Design considerations for advanced battery concepts

NASA Technical Reports Server (NTRS)

Leibecki, H. F.; Thaller, L. H.

1986-01-01

A mathematical representation for the charge and discharge of a sodium-sulfur cell is developed. These equations are then used as the basis for a computerized model to examine the effects of cell arrangement in the design of a large multi-kilowatt battery from a group of hypothetical individual cells with known variations in their ampere hour capacity and internal resistance. The cycling characteristics of 216 individual cells arranged in six different configurations are evaluated with the view towards minimizing the adverse effects that are introduced due to the stoichastic aspects of groupings of cells, as well as the possibility of cell failures in both the open and shorted mode. Although battery systems based on sodium-sulfur cells are described in this example, any of the newer electrochemical systems can be fitted into this framework by making appropriate modifications to the basic equations.

Design considerations for advanced battery concepts

NASA Technical Reports Server (NTRS)

Leibecki, H. F.; Thaller, L. H.

1986-01-01

A mathematical representation for the charge and discharge of a sodium-sulfur cell is developed. These equations are then used as the basis for a computerized model to examine the effects of cell arrangement in the design of a large multi-kilowatt battery from a group of hypothetical individual cells with known variations in their ampere hour capacity and internal resistance. The cycling characteristics of 216 individual cells arranged in six different configurations are evaluated with the view towards minimizing the adverse effects that are introduced due to the stochastic aspects of groupings of cells, as well as the possibility of cell failures in both the open and shorted mode. Although battery systems based on sodium-sulfur cells are described in this example, any of the newer electrochemical systems can be fitted into this framework by making appropriate modifications to the basic equations.

Design considerations for a 10-kW integrated hydrogen-oxygen regenerative fuel cell system

NASA Technical Reports Server (NTRS)

Hoberecht, M. A.; Miller, T. B.; Rieker, L. L.; Gonzalez-Sanabria, O. D.

1984-01-01

Integration of an alkaline fuel cell subsystem with an alkaline electrolysis subsystem to form a regenerative fuel cell (RFC) system for low earth orbit (LEO) applications characterized by relatively high overall round trip electrical efficiency, long life, and high reliability is possible with present state of the art technology. A hypothetical 10 kW system computer modeled and studied based on data from ongoing contractual efforts in both the alkaline fuel cell and alkaline water electrolysis areas. The alkaline fuel cell technology is under development utilizing advanced cell components and standard Shuttle Orbiter system hardware. The alkaline electrolysis technology uses a static water vapor feed technique and scaled up cell hardware is developed. The computer aided study of the performance, operating, and design parameters of the hypothetical system is addressed.

Osimertinib in patients with advanced epidermal growth factor receptor T790M mutation-positive non-small cell lung cancer: rationale, evidence and place in therapy

PubMed Central

Ricciuti, Biagio; Baglivo, Sara; Paglialunga, Luca; De Giglio, Andrea; Bellezza, Guido; Chiari, Rita; Crinò, Lucio; Metro, Giulio

2017-01-01

The identification of epidermal growth factor receptor (EGFR) mutations represented a fundamental step forward in the treatment of advanced non-small cell lung cancer (NSCLC) as they define a subset of patients who benefit from the administration of specifically designed targeted therapies. The inhibition of mutant EGFR through EGFR-tyrosine kinase inhibitors (TKIs), either reversible, first-generation gefitinib and erlotinib, or irreversible, second-generation afatinib, has dramatically improved the prognosis of patients harboring this specific genetic alteration, leading to unexpected clinical benefit. Unfortunately, virtually all patients who initially respond to treatment develop acquired resistance to EGFR-TKIs within 9–14 months. The EGFR T790M secondary mutation has emerged as a cause of treatment failure in approximately 60% of resistant cases. To date, several compounds designed with the aim to overcome T790M-mediated resistance are under clinical investigation. The aim of this review is to discuss emerging data regarding the third-generation EGFR-TKI, osimertinib, for the treatment of EGFR T790M mutant advanced NSCLC. PMID:28607578

Progression-free survival as primary endpoint in randomized clinical trials of targeted agents for advanced renal cell carcinoma. Correlation with overall survival, benchmarking and power analysis.

PubMed

Bria, Emilio; Massari, Francesco; Maines, Francesca; Pilotto, Sara; Bonomi, Maria; Porta, Camillo; Bracarda, Sergio; Heng, Daniel; Santini, Daniele; Sperduti, Isabella; Giannarelli, Diana; Cognetti, Francesco; Tortora, Giampaolo; Milella, Michele

2015-01-01

A correlation, power and benchmarking analysis between progression-free and overall survival (PFS, OS) of randomized trials with targeted agents or immunotherapy for advanced renal cell carcinoma (RCC) was performed to provide a practical tool for clinical trial design. For 1st-line of treatment, a significant correlation was observed between 6-month PFS and 12-month OS, between 3-month PFS and 9-month OS and between the distributions of the cumulative PFS and OS estimates. According to the regression equation derived for 1st-line targeted agents, 7859, 2873, 712, and 190 patients would be required to determine a 3%, 5%, 10% and 20% PFS advantage at 6 months, corresponding to an absolute increase in 12-month OS rates of 2%, 3%, 6% and 11%, respectively. These data support PFS as a reliable endpoint for advanced RCC receiving up-front therapies. Benchmarking and power analyses, on the basis of the updated survival expectations, may represent practical tools for future trial' design. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Advanced generation anti-prostate specific membrane antigen designer T cells for prostate cancer immunotherapy.

PubMed

Ma, Qiangzhong; Gomes, Erica M; Lo, Agnes Shuk-Yee; Junghans, Richard P

2014-02-01

Adoptive immunotherapy by infusion of designer T cells (dTc) engineered with chimeric antigen receptors (CARs) for tumoricidal activity represents a potentially highly specific modality for the treatment of cancer. In this study, 2nd generation (gen) anti-prostate specific membrane antigen (PSMA) dTc were developed for improving the efficacy of previously developed 1st gen dTc for prostate cancer immunotherapy. The 1st gen dTc are modified with chimeric immunoglobulin-T cell receptor (IgTCR) while the 2nd gen dTc are engineered with an immunoglobulin-CD28-T cell receptor (IgCD28TCR), which incorporates a CD28 costimulatory signal for optimal T cell activation. A 2nd gen anti-PSMA IgCD28TCR CAR was constructed by inserting the CD28 signal domain into the 1st gen CAR. 1st and 2nd gen anti-PSMA dTc were created by transducing human T cells with anti-PSMA CARs and their antitumor efficacy was compared for specific activation on PSMA-expressing tumor contact, cytotoxicity against PSMA-expressing tumor cells in vitro, and suppression of tumor growth in an animal model. The 2nd gen dTc can be optimally activated to secrete larger amounts of cytokines such as IL2 and IFNγ than 1st gen and to proliferate more vigorously on PSMA-expressing tumor contact. More importantly, the 2nd gen dTc preserve the PSMA-specific cytotoxicity in vitro and suppress tumor growth in animal models with significant higher potency. Our results demonstrate that 2nd gen anti-PSMA designer T cells exhibit superior antitumor functions versus 1st gen, providing a rationale for advancing this improved agent toward clinical application in prostate cancer immunotherapy. © 2013 Wiley Periodicals, Inc.

Advanced Bioinks for 3D Printing: A Materials Science Perspective.

PubMed

Chimene, David; Lennox, Kimberly K; Kaunas, Roland R; Gaharwar, Akhilesh K

2016-06-01

Advanced bioinks for 3D printing are rationally designed materials intended to improve the functionality of printed scaffolds outside the traditional paradigm of the "biofabrication window". While the biofabrication window paradigm necessitates compromise between suitability for fabrication and ability to accommodate encapsulated cells, recent developments in advanced bioinks have resulted in improved designs for a range of biofabrication platforms without this tradeoff. This has resulted in a new generation of bioinks with high print fidelity, shear-thinning characteristics, and crosslinked scaffolds with high mechanical strength, high cytocompatibility, and the ability to modulate cellular functions. In this review, we describe some of the promising strategies being pursued to achieve these goals, including multimaterial, interpenetrating network, nanocomposite, and supramolecular bioinks. We also provide an overview of current and emerging trends in advanced bioink synthesis and biofabrication, and evaluate the potential applications of these novel biomaterials to clinical use.

Leveraging advances in biology to design biomaterials

NASA Astrophysics Data System (ADS)

Darnell, Max; Mooney, David J.

2017-12-01

Biomaterials have dramatically increased in functionality and complexity, allowing unprecedented control over the cells that interact with them. From these engineering advances arises the prospect of improved biomaterial-based therapies, yet practical constraints favour simplicity. Tools from the biology community are enabling high-resolution and high-throughput bioassays that, if incorporated into a biomaterial design framework, could help achieve unprecedented functionality while minimizing the complexity of designs by identifying the most important material parameters and biological outputs. However, to avoid data explosions and to effectively match the information content of an assay with the goal of the experiment, material screens and bioassays must be arranged in specific ways. By borrowing methods to design experiments and workflows from the bioprocess engineering community, we outline a framework for the incorporation of next-generation bioassays into biomaterials design to effectively optimize function while minimizing complexity. This framework can inspire biomaterials designs that maximize functionality and translatability.

Immune drug discovery from venoms.

PubMed

Jimenez, Rocio; Ikonomopoulou, Maria P; Lopez, J Alejandro; Miles, John J

2018-01-01

This review catalogues recent advances in knowledge on venoms as standalone therapeutic agents or as blueprints for drug design, with an emphasis on venom-derived compounds that affects the immune system. We discuss venoms and venom-derived compounds that affect total immune cell numbers, immune cell proliferation, immune cell migration, immune cell phenotype and cytokine secretion. Identifying novel compounds that 'tune' the system, up-regulating the immune response during infectious disease and cancer and down-regulating the immune response during autoimmunity, will greatly expand the tool kit of human immunotherapeutics. Targeting these pathways may also open therapeutic options that alleviate symptoms of envenomation. Finally, combining recent advances in venomics with progress in low cost, high-throughput screening platforms will no doubt yield hundreds of prototype immune modulating compounds in the coming years. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Logan, B.G.

A recently completed two-year study of a commercial tandem mirror reactor design (Mirror Advanced Reactor Study (MARS)) is briefly reviewed. The end plugs are designed for trapped particle stability, MHD ballooning, balanced geodesic curvature, and small radial electric fields in the central cell. New technologies such as lithium-lead blankets, 24T hybrid coils, gridless direct converters and plasma halo vacuum pumps are highlighted.

The Computing And Interdisciplinary Systems Office: Annual Review and Planning Meeting

NASA Technical Reports Server (NTRS)

Lytle, John K.

2003-01-01

The goal of this research is to develop an advanced engineering analysis system that enables high-fidelity, multi-disciplinary, full propulsion system simulations to be performed early in the design process (a virtual test cell that integrates propulsion and information technologies). This will enable rapid, high-confidence, cost-effective design of revolutionary systems.

Study of low speed flow cytometry for diffraction imaging with different chamber and nozzle designs.

PubMed

Sa, Yu; Feng, Yuanming; Jacobs, Kenneth M; Yang, Jun; Pan, Ran; Gkigkitzis, Ioannis; Lu, Jun Q; Hu, Xin-Hua

2013-11-01

Achieving effective hydrodynamic focusing and flow stability at low speed presents a challenging design task in flow cytometry for studying phenomena such as cell adhesion and diffraction imaging of cells with low-cost cameras. We have developed different designs of flow chamber and sheath nozzle to accomplish the above goal. A 3D computational model of the chambers has been established to simulate the fluid dynamics in different chamber designs and measurements have been performed to determine the velocity and size distributions of the core fluid from the nozzle. Comparison of the simulation data with experimental results shows good agreement. With the computational model significant insights were gained for optimization of the chamber design and improvement of the cell positioning accuracy for study of slow moving cells. The benefit of low flow speed has been demonstrated also by reduced blurring in the diffraction images of single cells. Based on these results, we concluded that the new designs of chamber and sheath nozzle produce stable hydrodynamic focusing of the core fluid at low speed and allow detailed study of cellular morphology under various rheological conditions using the diffraction imaging method. © 2013 International Society for Advancement of Cytometry.

Electrochemical carbon dioxide concentrator advanced technology tasks

NASA Technical Reports Server (NTRS)

Schneider, J. J.; Schubert, F. H.; Hallick, T. M.; Woods, R. R.

1975-01-01

Technology advancement studies are reported on the basic electrochemical CO2 removal process to provide a basis for the design of the next generation cell, module and subsystem hardware. An Advanced Electrochemical Depolarized Concentrator Module (AEDCM) is developed that has the characteristics of low weight, low volume, high CO2, removal, good electrical performance and low process air pressure drop. Component weight and noise reduction for the hardware of a six man capacity CO2 collection subsystem was developed for the air revitalization group of the Space Station Prototype (SSP).

Modeling studies of electrolyte flow and bubble behavior in advanced Hall cells

NASA Astrophysics Data System (ADS)

Shekhar, R.; Evans, J. W.

Much research was performed in recent years by corporations and university/government labs on materials for use in advanced Hall-Heroult cells. Attention has focussed on materials for use as wettable cathodes and inert anodes and much was achieved in terms of material development. Comparatively less attention was devoted to how these materials might be incorporated in new or existing cells, i.e., to how the cells should be designed and redesigned, to take full advantage of these materials. The effort, supported by the U.S. Department of Energy, to address this issue, is described. The primary objectives are cell design where electrolyte flow can be managed to promote both the removal of the anode gas bubbles and the convection of dissolved alumina in the inter-electrode region, under conditions where the anode-cathode distance is small. The principal experimental tool was a water model consisting of a large tank in which simulated anodes can be suspended in either the horizontal or vertical configurations. Gas generation was by forcing compressed air through porous graphite and the fine bubbles characteristic of inert anodes were produced by adding butanol to the water. Velocities were measured using a laser Doppler velocimeter. Velocity measurements with two different anode designs (one that is flat and the other that has grooves) are presented. The results show that the electrode configuration has a significant effect on the fluid flow pattern in the inter-electrode region. Furthermore, it is shown that rapid fluid flow is obtained when the cell is operated with a submerged anode.

Three-Dimensional Coculture Of Human Small-Intestine Cells

NASA Technical Reports Server (NTRS)

Wolf, David; Spaulding, Glen; Goodwin, Thomas J.; Prewett, Tracy

1994-01-01

Complex three-dimensional masses of normal human epithelial and mesenchymal small-intestine cells cocultured in process involving specially designed bioreactors. Useful as tissued models for studies of growth, regulatory, and differentiation processes in normal intestinal tissues; diseases of small intestine; and interactions between cells of small intestine and viruses causing disease both in small intestine and elsewhere in body. Process used to produce other tissue models, leading to advances in understanding of growth and differentiation in developing organisms, of renewal of tissue, and of treatment of myriad of clinical conditions. Prior articles describing design and use of rotating-wall culture vessels include "Growing And Assembling Cells Into Tissues" (MSC-21559), "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662), and "In Vitro, Matrix-Free Formation Of Solid Tumor Spheroids" (MSC-21843).

Fuel cell technology program

NASA Technical Reports Server (NTRS)

1972-01-01

A fuel cell technology program was established to advance the state-of-the art of hydrogen oxygen fuel cells using low temperature, potassium hydroxide electrolyte technology as the base. Cell and component testing confirmed that low temperature, potassium hydroxide electrolyte technology is compatible with the requirements of the space shuttle Phase B contractors. Testing of the DM-1 powerplant demonstrated all of the important requirements of the shuttle except operating life. Testing also identified DM-1 powerplant life limiting mechanisms; hydrogen pump gear wear and pressurization of the cell stack over its design limits.

Nickel-hydrogen cell low-Earth life test update

NASA Technical Reports Server (NTRS)

Frate, David T.

1991-01-01

When individual pressure vessel (IPV) nickel-hydrogen (Ni/H2) cells were selected as the energy storage system for the Space Station Freedom in March of 1986, a limited database existed on life and performance characteristics of these cells in a low earth orbit (LEO) regime. Therefore, NASA LeRC initiated a Ni/H2 cell test program with the primary objectives of building a test facility, procuring cells from existing NASA contracts, and screening several cell designs by life testing in a LEO 35 percent depth of discharge (DOD) scenario. A total of 40 cells incorporating 13 designs were purchased from Yardney, Hughes, and Eagle-Picher. Thirty-two of the cells purchased were 65 A-hr nameplate capacity and eight cells were 50 A-hr. Yardney and Eagle-Picher cells were built with both the Air Force recirculating and the advanced back-to-back electrode stack configurations and incorporated 31 and 26 percent KOH. Acceptance testing of the first delivered cells began in March of 1988, with life testing following in September of that year.Performance comparisons of these cells are made here while specifically addressing life test data relative to the design differences.

Nickel-hydrogen cell low-earth-orbit life test update

NASA Technical Reports Server (NTRS)

Frate, David T.

1991-01-01

When individual pressure vessel (IPV) nickel-hydrogen (Ni/H2) cells were selected as the energy storage system for Space Station Freedom in March of 1986, a limited database existed on life and performance characteristics of these cells in a low earth orbit (LEO) regime. Therefore, NASA LeRC initiated a Ni/H2 cell test program with the primary objectives of building a test facility, procuring cells from existing NASA contracts, and screening several cell designs by life testing in a LEO 35 percent depth of discharge (DOD) scenario. A total of 40 cells incorporating 13 designs were purchased from Yardney, Hughes, and Eagle-Picher. Thirty-two of the cells purchased were 65 A-hr nameplate capacity and eight cells were 50 A-Hr. Yardney and Eagle-Picher cells were built with both the Air Force recirculating and the advanced back-to-back electrode stack configurations and incorporated 31 and 26 percent KOH. Acceptance testing of the first delivered cells began in March of 1988, with life testing following in September of that year. Performance comparisons of these cells are made here while specifically addressing life test data relative to the design differences.

Advanced Energy Storage and Conversion Devices

DTIC Science & Technology

2008-12-01

determined lithium-ion insertion mechanisms. 3.1 Background and Objectives Polymer electrolyte membrane fuel cells ( PEMFCs ) function by permitting...is one of the most critical components in the polymer electrolyte fuel cells. In recent years, PEMFCs have been identified as promising power...and residual hydrocarbons that are commonly produced by internal combustion engines. PEMFCs , due to their high efficiency and modularity of design

Design strategies and applications of circulating cell-mediated drug delivery systems.

PubMed

Su, Yixue; Xie, Zhiwei; Kim, Gloria B; Dong, Cheng; Yang, Jian

2015-01-01

Drug delivery systems, particularly nanomaterial-based drug delivery systems, possess a tremendous amount of potential to improve diagnostic and therapeutic effects of drugs. Controlled drug delivery targeted to a specific disease is designed to significantly improve the pharmaceutical effects of drugs and reduce their side effects. Unfortunately, only a few targeted drug delivery systems can achieve high targeting efficiency after intravenous injection, even with the development of numerous surface markers and targeting modalities. Thus, alternative drug and nanomedicine targeting approaches are desired. Circulating cells, such as erythrocytes, leukocytes, and stem cells, present innate disease sensing and homing properties. Hence, using living cells as drug delivery carriers has gained increasing interest in recent years. This review highlights the recent advances in the design of cell-mediated drug delivery systems and targeting mechanisms. The approaches of drug encapsulation/conjugation to cell-carriers, cell-mediated targeting mechanisms, and the methods of controlled drug release are elaborated here. Cell-based "live" targeting and delivery could be used to facilitate a more specific, robust, and smart payload distribution for the next-generation drug delivery systems.

Rare cell isolation and analysis in microfluidics

PubMed Central

Chen, Yuchao; Li, Peng; Huang, Po-Hsun; Xie, Yuliang; Mai, John D.; Wang, Lin; Nguyen, Nam-Trung; Huang, Tony Jun

2014-01-01

Rare cells are low-abundance cells in a much larger population of background cells. Conventional benchtop techniques have limited capabilities to isolate and analyze rare cells because of their generally low selectivity and significant sample loss. Recent rapid advances in microfluidics have been providing robust solutions to the challenges in the isolation and analysis of rare cells. In addition to the apparent performance enhancements resulting in higher efficiencies and sensitivity levels, microfluidics provides other advanced features such as simpler handling of small sample volumes and multiplexing capabilities for high-throughput processing. All of these advantages make microfluidics an excellent platform to deal with the transport, isolation, and analysis of rare cells. Various cellular biomarkers, including physical properties, dielectric properties, as well as immunoaffinities, have been explored for isolating rare cells. In this Focus article, we discuss the design considerations of representative microfluidic devices for rare cell isolation and analysis. Examples from recently published works are discussed to highlight the advantages and limitations of the different techniques. Various applications of these techniques are then introduced. Finally, a perspective on the development trends and promising research directions in this field are proposed. PMID:24406985

Driving CAR-Based T-Cell Therapy to Success

PubMed Central

Jena, Bipulendu; Moyes, Judy S; Huls, Helen; Cooper, Laurence JN

2014-01-01

T-cells that have been genetically modified, activated, and propagated ex vivo can be infused to control tumor progression in patients who are refractory to conventional treatments. Early-phase clinical trials demonstrate that the tumor-associated antigen (TAA) CD19 can be therapeutically engaged through the enforced expression of a chimeric antigen receptor (CAR) on clinical-grade T-cells. Advances in vector design, the architecture of the CAR molecule especially as associated with T-cell co-stimulatory pathways, and understanding of the tumor microenvironment, play significant roles in the successful treatment of medically fragile patients. However, some recipients of CAR+ T-cells demonstrate incomplete responses. Understanding the potential for treatment failure provides a pathway to improve the potency of adoptive transfer of CAR+ T-cells. High throughput single-cell analyses to understand the complexity of the inoculum coupled with animal models may provide insight into the therapeutic potential of genetically modified T-cells. This review focusses on recent advances regarding the human application of C19-specific CAR+ T-cells and explores how their success for hematologic cancers can provide a framework for investigational treatment of solid tumor malignancies. PMID:24488441

Design of multifunctional nanoparticles for combined in-vivo imaging and advanced drug delivery

NASA Astrophysics Data System (ADS)

Leary, James F.

2018-02-01

Design of multifunctional nanoparticles for multimodal in-vivo imaging and advanced targeting to diseased single cells for massive parallel processing nanomedicine approaches requires careful overall design and a multilayered approach. Initial core materials can include non-toxic metals which not only serve as an x-ray contrast agent for CAT scan imaging, but can contain T1 or T2 contrast agents for MRI imaging. One choice is superparamagnetic iron oxide NPs which also allow for convenient magnetic manipulation during manufacturing but also for re-positioning inside the body and for single cell hyperthermia therapies. To permit real-time fluorescence-guided surgery, fluorescence molecules can be included. Advanced targeting can be achieved by attaching antibodies, peptides, aptamers, or other targeting molecules to the nanoparticle in a multilayered approach producing "programmable nanoparticles" whereby the "programming" means controlling a sequence of multi-step targeting methods. Addition of membrane permeating peptides can facilitate uptake by the cell. Addition of "stealth" molecules (e.g. PEG or chitosan) to the outer surfaces of the nanoparticles can permit greatly enhanced circulation times in-vivo which in turn lead to lower amounts of drug exposure to the patient which can reduce undesirable side effects. Nanoparticles with incomplete layers can be removed by affinity purification methods to minimize mistargeting events in-vivo. Nanoscale imaging of these manufactured, multifunctional nanoparticles can be achieved either directly through superresolution microscopy or indirectly through single nanoparticle zeta-sizing or x-ray correlation microscopy. Since these multifunctional nanoparticles are best analyzed by technologies permitting analysis in aqueous environments, superresolution microscopy is, in most cases, the preferred method.

Live-cell imaging of cell signaling using genetically encoded fluorescent reporters.

PubMed

Ni, Qiang; Mehta, Sohum; Zhang, Jin

2018-01-01

Synergistic advances in fluorescent protein engineering and live-cell imaging techniques in recent years have fueled the concurrent development and application of genetically encoded fluorescent reporters that are tailored for tracking signaling dynamics in living systems over multiple length and time scales. These biosensors are uniquely suited for this challenging task, owing to their specificity, sensitivity, and versatility, as well as to the noninvasive and nondestructive nature of fluorescence and the power of genetic encoding. Over the past 10 years, a growing number of fluorescent reporters have been developed for tracking a wide range of biological signals in living cells and animals, including second messenger and metabolite dynamics, enzyme activation and activity, and cell cycle progression and neuronal activity. Many of these biosensors are gaining wide use and are proving to be indispensable for unraveling the complex biological functions of individual signaling molecules in their native environment, the living cell, shedding new light on the structural and molecular underpinnings of cell signaling. In this review, we highlight recent advances in protein engineering that are likely to help expand and improve the design and application of these valuable tools. We then turn our focus to specific examples of live-cell imaging using genetically encoded fluorescent reporters as an important platform for advancing our understanding of G protein-coupled receptor signaling and neuronal activity. © 2017 Federation of European Biochemical Societies.

Status of Diffused Junction p(+)n InP Solar Cells for Space Applications

NASA Technical Reports Server (NTRS)

Faur, Mircea; Faur, Maria; Flood, D. J.; Brinker, D. J.; Goradia, C.; Fatemi, N. S.; Jenkins, P. P.; Wilt, D. M.; Bailey, S.

1994-01-01

Recently, we have succeeded in fabricating diffused junction p(+)n(Cd,S) InP solar cells with measured AMO, 25 C open circuit voltage (V(sub OC)) of 887.6 mV, which, to the best of our knowledge, is higher than previously reported V(sub OC) values for any InP homojunction solar cells. The experiment-based projected achievable efficiency of these cells using LEC grown substrates is 21.3%. The maximum AMO, 25 C efficiency recorded to date on bare cells is, however, only 13.2%. This is because of large external and internal losses due to non-optimized front grid design, antireflection (AR) coating and emitter thickness. This paper summarizes recent advances in the technology of fabrication of p(+)n InP diffused structures and solar cells, resulted from a study undertaken in an effort to increase the cell efficiency. The topics discussed in this paper include advances in: 1) the formation of thin p(+) InP:Cd emitter layers, 2) electroplated front contacts, 3) surface passivation and 4) the design of a new native oxide/AI203/MgF2 three layer AR coating using a chemically-grown P-rich passivating oxide as a first layer. Based on the high radiation resistance and the excellent post-irradiation annealing and recovery demonstrated in the early tests done to date, as well as the projected high efficiency and low-cost high-volume fabricability, these cells show a very good potential for space photovoltaic applications.

Electrochemical Energy Storage for an Orbiting Space Station

NASA Technical Reports Server (NTRS)

Martin, R. E.

1981-01-01

The system weight of a multi hundred kilowatt fuel cell electrolysis cell energy storage system based upon alkaline electrochemical cell technology for use in a future orbiting space station in low Earth orbit (LEO) was studied. Preliminary system conceptual design, fuel cell module performance characteristics, subsystem and system weights, and overall system efficiency are identified. The impact of fuel cell module operating temperature and efficiency upon energy storage system weight is investigated. The weight of an advanced technology system featuring high strength filament wound reactant tanks and a fuel cell module employing lightweight graphite electrolyte reservoir plates is defined.

Processing technology for high efficiency silicon solar cells

NASA Technical Reports Server (NTRS)

Spitzer, M. B.; Keavney, C. J.

1985-01-01

Recent advances in silicon solar cell processing have led to attainment of conversion efficiency approaching 20%. The basic cell design is investigated and features of greatest importance to achievement of 20% efficiency are indicated. Experiments to separately optimize high efficiency design features in test structures are discussed. The integration of these features in a high efficiency cell is examined. Ion implantation has been used to achieve optimal concentrations of emitter dopant and junction depth. The optimization reflects the trade-off between high sheet conductivity, necessary for high fill factor, and heavy doping effects, which must be minimized for high open circuit voltage. A second important aspect of the design experiments is the development of a passivation process to minimize front surface recombination velocity. The manner in which a thin SiO2 layer may be used for this purpose is indicated without increasing reflection losses, if the antireflection coating is properly designed. Details are presented of processing intended to reduce recombination at the contact/Si interface. Data on cell performance (including CZ and ribbon) and analysis of loss mechanisms are also presented.

Test Results of a Ten Cell Bipolar Nickel-hydrogen Battery

NASA Technical Reports Server (NTRS)

Cataldo, R. L.

1984-01-01

A study was initiated to design and evaluate a new design concept for nickel-hydrogen cells. This concept involved constructing a battery in a bipolar stack with cells consisting of a one plate for each nickel and hydrogen electrode. Preliminary designs at the system level of this concept promised improvements in both volumetric and gravimetric energy densities, thermal management, life extension, costs, and peak power capability over more conventional designs. Test results were most encouraging. This preprototype battery, built with less than ideal components and hardware, exceeded expectations. A total of 2000 LEO cycles at 80 percent depth of discharge were accrued. A cycle life goal of 30,000 cycles appears achievable with minor design changes. These improvements include advanced technology nickel electrodes, insulated bipolar plates and specifically designed frames to minimize shunt currents. The discharge rate capability of this design exceeds 25C. At the 10C discharge rate, 80% of the battery capacity can be withdrawn in six minutes. This data shows that the bipolar design is well suited for those applications requiring high peak power pulses.

WholeCellSimDB: a hybrid relational/HDF database for whole-cell model predictions

PubMed Central

Karr, Jonathan R.; Phillips, Nolan C.; Covert, Markus W.

2014-01-01

Mechanistic ‘whole-cell’ models are needed to develop a complete understanding of cell physiology. However, extracting biological insights from whole-cell models requires running and analyzing large numbers of simulations. We developed WholeCellSimDB, a database for organizing whole-cell simulations. WholeCellSimDB was designed to enable researchers to search simulation metadata to identify simulations for further analysis, and quickly slice and aggregate simulation results data. In addition, WholeCellSimDB enables users to share simulations with the broader research community. The database uses a hybrid relational/hierarchical data format architecture to efficiently store and retrieve both simulation setup metadata and results data. WholeCellSimDB provides a graphical Web-based interface to search, browse, plot and export simulations; a JavaScript Object Notation (JSON) Web service to retrieve data for Web-based visualizations; a command-line interface to deposit simulations; and a Python API to retrieve data for advanced analysis. Overall, we believe WholeCellSimDB will help researchers use whole-cell models to advance basic biological science and bioengineering. Database URL: http://www.wholecellsimdb.org Source code repository URL: http://github.com/CovertLab/WholeCellSimDB PMID:25231498

Modeling to Optimize Terminal Stem Cell Differentiation

PubMed Central

Gallicano, G. Ian

2013-01-01

Embryonic stem cell (ESC), iPCs, and adult stem cells (ASCs) all are among the most promising potential treatments for heart failure, spinal cord injury, neurodegenerative diseases, and diabetes. However, considerable uncertainty in the production of ESC-derived terminally differentiated cell types has limited the efficiency of their development. To address this uncertainty, we and other investigators have begun to employ a comprehensive statistical model of ESC differentiation for determining the role of intracellular pathways (e.g., STAT3) in ESC differentiation and determination of germ layer fate. The approach discussed here applies the Baysian statistical model to cell/developmental biology combining traditional flow cytometry methodology and specific morphological observations with advanced statistical and probabilistic modeling and experimental design. The final result of this study is a unique tool and model that enhances the understanding of how and when specific cell fates are determined during differentiation. This model provides a guideline for increasing the production efficiency of therapeutically viable ESCs/iPSCs/ASC derived neurons or any other cell type and will eventually lead to advances in stem cell therapy. PMID:24278782

Determination of the robot location in a workcell of a flexible production line

NASA Astrophysics Data System (ADS)

Banas, W.; Sekala, A.; Gwiazda, A.; Foit, K.; Hryniewicz, P.; Kost, G.

2015-11-01

Location of components of a manufacturing cell is apparently an easy task but even during the constructing of a manufacturing cell, in which is planned a production of one, simple component it is necessary, among others, to check access to all required points. The robot in a manufacturing cell must handle both machine tools located in a manufacturing cell and parts store (input and output one). It handles also transport equipment and auxiliary stands. Sometimes, during the design phase, the changes of robot location are necessary due to the limitation of access to its required working positions. Often succeeding changes of a manufacturing cell configuration are realized. They occur at the stages of visualization and simulation of robot program functioning. In special cases, it is even necessary to replace the planned robot with a robot of greater range or of a different configuration type. This article presents and describes the parameters and components which should be taken into consideration during designing robotised manufacturing cells. The main idea bases on application of advanced engineering programs to adding the designing process. Using this approach it could be possible to present the designing process of an exemplar flexible manufacturing cell intended to manufacture two similar components. The proposed model of such designed manufacturing cell could be easily extended to the manufacturing cell model in which it is possible to produce components belonging the one technological group of chosen similarity level. In particular, during the design process, one should take into consideration components which limit the ability of robot foundation. It is also important to show the method of determining the best location of robot foundation. The presented design method could also support the designing process of other robotised manufacturing cells.

Advanced photovoltaic solar array development

NASA Technical Reports Server (NTRS)

Kurland, Richard M.; Stella, Paul

1989-01-01

Phase 2 of the Advanced Photovoltaic Solar Array (APSA) program, started in mid-1987, is currently in progress to fabricate prototype wing hardware that will lead to wing integration and testing in 1989. The design configuration and key details are reviewed. A status of prototype hardware fabricated to date is provided. Results from key component-level tests are discussed. Revised estimates of array-level performance as a function of solar cell device technology for geosynchronous missions are given.

Quality by control: Towards model predictive control of mammalian cell culture bioprocesses.

PubMed

Sommeregger, Wolfgang; Sissolak, Bernhard; Kandra, Kulwant; von Stosch, Moritz; Mayer, Martin; Striedner, Gerald

2017-07-01

The industrial production of complex biopharmaceuticals using recombinant mammalian cell lines is still mainly built on a quality by testing approach, which is represented by fixed process conditions and extensive testing of the end-product. In 2004 the FDA launched the process analytical technology initiative, aiming to guide the industry towards advanced process monitoring and better understanding of how critical process parameters affect the critical quality attributes. Implementation of process analytical technology into the bio-production process enables moving from the quality by testing to a more flexible quality by design approach. The application of advanced sensor systems in combination with mathematical modelling techniques offers enhanced process understanding, allows on-line prediction of critical quality attributes and subsequently real-time product quality control. In this review opportunities and unsolved issues on the road to a successful quality by design and dynamic control implementation are discussed. A major focus is directed on the preconditions for the application of model predictive control for mammalian cell culture bioprocesses. Design of experiments providing information about the process dynamics upon parameter change, dynamic process models, on-line process state predictions and powerful software environments seem to be a prerequisite for quality by control realization. © 2017 The Authors. Biotechnology Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Non-immune cells equipped with T cell receptor-like signaling for cancer cell ablation

PubMed Central

Kojima, Ryosuke; Scheller, Leo; Fussenegger, Martin

2017-01-01

The ability to engineer custom cell-contact-sensing output devices into human non-immune cells would be useful for extending the applicability of cell-based cancer therapies and avoiding risks associated with engineered immune cells. Here, we have developed a new class of synthetic T-cell receptor-like signal-transduction device that functions efficiently in human non-immune cells and triggers release of output molecules specifically upon sensing contact with a target cell. This device employs an interleukin signaling cascade, whose OFF/ON switching is controlled by biophysical segregation of a transmembrane signal-inhibitory protein from the sensor cell/target cell interface. We further showed that designer non-immune cells equipped with this device driving expression of a membrane-penetrator/prodrug-activating enzyme construct could specifically kill target cells in the presence of the prodrug, indicating its potential usefulness for target-cell-specific, cell-based enzyme-prodrug cancer therapy. Our study also contributes to advancement of synthetic biology by extending available design principles to transmit extracellular information to cells. PMID:29131143

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.

High Current ESD Test of Advanced Triple Junction Solar Array Coupon

NASA Technical Reports Server (NTRS)

Wright, Kenneth H., Jr.; Schneider, Todd A.; Vaughn, Jason A.; Hoang, Bao; Wong, Frankie

2014-01-01

Testing was conducted on an Advanced Triple Junction (ATJ) coupon that was part of a risk reduction effort in the development of a high-powered solar array design by Space Systems Loral, LLC (SSL). The ATJ coupon was a small, 4-cell, two-string configuration of flight-type design that has served as the basic test coupon design used in previous SSL environmental aging campaigns. The objective of the present test was to evaluate the performance of the coupon after being subjected to induced electrostatic discharge (ESD) testing at two string voltages (100 V, 150 V) and four string currents (1.65 A, 2.0 A, 2.475 A, and 3.3 A). An ESD test circuit, unique to SSL solar array design, was built that simulates the effect of missing cells and strings in a full solar panel with special primary arc flashover circuitry. A total of 73 primary arcs were obtained that included 7 temporary sustained arcs (TSA) events. The durations of the TSAs ranged from 50 micro-seconds to 2.75 milli-seconds. All TSAs occurred at a string voltage of 150 V. Post-ESD functional testing showed that no degradation occurred due to the TSA events. These test results point to a robust design for application to a high-current, high-power mission.

Exploiting Advanced Hydrogel Technologies to Address Key Challenges in Regenerative Medicine

PubMed Central

Gentleman, Eileen

2018-01-01

Regenerative medicine aims to tackle a panoply of challenges, from repairing focal damage to articular cartilage to preventing pathological tissue remodelling after myocardial infarction. Hydrogels are water-swollen networks formed from synthetic or naturally derived polymers, and are emerging as important tools to address these challenges. Recent advances in hydrogel chemistries are enabling researchers to create hydrogels that can act as 3D ex vivo tissue models, allowing them to explore fundamental questions in cell biology by replicating tissues’ dynamic and non-linear physical properties. Enabled by emerging techniques such as 3D bioprinting, cell-laden hydrogels are also being developed with highly controlled tissue-specific architectures, vasculature, and biological functions that together can direct tissue repair. Moreover, advanced in situ forming and acellular hydrogels are increasingly finding use as delivery vehicles for bioactive compounds and in mediating host cell response. Here, we review advances in the design and fabrication of hydrogels for regenerative medicine. We also address how controlled chemistries are allowing for precise engineering of spatial and time-dependent properties in hydrogels with a look to how these materials will eventually translate to clinical applications. PMID:29316363

Computational model-informed design and bioprinting of cell-patterned constructs for bone tissue engineering.

PubMed

Carlier, Aurélie; Skvortsov, Gözde Akdeniz; Hafezi, Forough; Ferraris, Eleonora; Patterson, Jennifer; Koç, Bahattin; Van Oosterwyck, Hans

2016-05-17

Three-dimensional (3D) bioprinting is a rapidly advancing tissue engineering technology that holds great promise for the regeneration of several tissues, including bone. However, to generate a successful 3D bone tissue engineering construct, additional complexities should be taken into account such as nutrient and oxygen delivery, which is often insufficient after implantation in large bone defects. We propose that a well-designed tissue engineering construct, that is, an implant with a specific spatial pattern of cells in a matrix, will improve the healing outcome. By using a computational model of bone regeneration we show that particular cell patterns in tissue engineering constructs are able to enhance bone regeneration compared to uniform ones. We successfully bioprinted one of the most promising cell-gradient patterns by using cell-laden hydrogels with varying cell densities and observed a high cell viability for three days following the bioprinting process. In summary, we present a novel strategy for the biofabrication of bone tissue engineering constructs by designing cell-gradient patterns based on a computational model of bone regeneration, and successfully bioprinting the chosen design. This integrated approach may increase the success rate of implanted tissue engineering constructs for critical size bone defects and also can find a wider application in the biofabrication of other types of tissue engineering constructs.

Emerging Semitransparent Solar Cells: Materials and Device Design.

PubMed

Tai, Qidong; Yan, Feng

2017-09-01

Semitransparent solar cells can provide not only efficient power-generation but also appealing images and show promising applications in building integrated photovoltaics, wearable electronics, photovoltaic vehicles and so forth in the future. Such devices have been successfully realized by incorporating transparent electrodes in new generation low-cost solar cells, including organic solar cells (OSCs), dye-sensitized solar cells (DSCs) and organometal halide perovskite solar cells (PSCs). In this review, the advances in the preparation of semitransparent OSCs, DSCs, and PSCs are summarized, focusing on the top transparent electrode materials and device designs, which are all crucial to the performance of these devices. Techniques for optimizing the efficiency, color and transparency of the devices are addressed in detail. Finally, a summary of the research field and an outlook into the future development in this area are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

MATERIALS SCIENCE: New Tigers in the Fuel Cell Tank.

PubMed

Service, R F

2000-06-16

After decades of incremental advances, a spurt of findings suggests that fuel cells that run on good old fossil fuels are almost ready for prime time. Although conventional ceramic cells, known as solid oxide fuel cells, require expensive heat-resistant materials, a new generation of SOFCs, including one featured on page 2031, converts hydrocarbons directly into electricity at lower temperatures. And a recent demonstration of a system of standard SOFCs large enough to light up more than 200 homes showed that it is the most efficient large-scale electrical generator ever designed.

Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 1: Cell embedding method and performance

NASA Astrophysics Data System (ADS)

Raghavan, Ajay; Kiesel, Peter; Sommer, Lars Wilko; Schwartz, Julian; Lochbaum, Alexander; Hegyi, Alex; Schuh, Andreas; Arakaki, Kyle; Saha, Bhaskar; Ganguli, Anurag; Kim, Kyung Ho; Kim, ChaeAh; Hah, Hoe Jin; Kim, SeokKoo; Hwang, Gyu-Ok; Chung, Geun-Chang; Choi, Bokkyu; Alamgir, Mohamed

2017-02-01

A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic sensors. High-performance large-format pouch cells with embedded fiber-optic sensors were fabricated. The first of this two-part paper focuses on the embedding method details and performance of these cells. The seal integrity, capacity retention, cycle life, compatibility with existing module designs, and mass-volume cost estimates indicate their suitability for xEV and other advanced battery applications. The second part of the paper focuses on the internal strain and temperature signals obtained from these sensors under various conditions and their utility for high-accuracy cell state estimation algorithms.

Fuel Cell Development for NASA's Human Exploration Program: Benchmarking with "The Hydrogen Economy"

NASA Technical Reports Server (NTRS)

Scott, John H.

2007-01-01

The theoretically high efficiency and low temperature operation of hydrogen-oxygen fuel cells has motivated them to be the subject of much study since their invention in the 19th Century, but their relatively high life cycle costs kept them as a "solution in search of a problem" for many years. The first problem for which fuel cells presented a truly cost effective solution was that of providing a power source for NASA's human spaceflight vehicles in the 1960 s. NASA thus invested, and continues to invest, in the development of fuel cell power plants for this application. This development program continues to place its highest priorities on requirements for minimum system mass and maximum durability and reliability. These priorities drive fuel cell power plant design decisions at all levels, even that of catalyst support. However, since the mid-1990's, prospective environmental regulations have driven increased governmental and industrial interest in "green power" and the "Hydrogen Economy." This has in turn stimulated greatly increased investment in fuel cell development for a variety of commercial applications. This investment is bringing about notable advances in fuel cell technology, but, as these development efforts place their highest priority on requirements for minimum life cycle cost and field safety, these advances are yielding design solutions quite different at almost every level from those needed for spacecraft applications. This environment thus presents both opportunities and challenges for NASA's Human Exploration Program

Recent developments in microfluidics for cell studies.

PubMed

Xiong, Bin; Ren, Kangning; Shu, Yiwei; Chen, Yin; Shen, Bo; Wu, Hongkai

2014-08-20

As a technique for precisely manipulating fluid at the micrometer scale, the field of microfluidics has experienced an explosive growth over the past two decades, particularly owing to the advances in device design and fabrication. With the inherent advantages associated with its scale of operation, and its flexibility in being incorporated with other microscale techniques for manipulation and detection, microfluidics has become a major enabling technology, which has introduced new paradigms in various fields involving biological cells. A microfluidic device is able to realize functions that are not easily imaginable in conventional biological analysis, such as highly parallel, sophisticated high-throughput analysis, single-cell analysis in a well-defined manner, and tissue engineering with the capability of manipulation at the single-cell level. Major advancements in microfluidic device fabrication and the growing trend of implementing microfluidics in cell studies are presented, with a focus on biological research and clinical diagnostics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

Fuel cell technology program

NASA Technical Reports Server (NTRS)

1972-01-01

A program to advance the technology for a cost-effective hydrogen/oxygen fuel cell system for future manned spacecraft is discussed. The evaluation of base line design concepts and the development of product improvements in the areas of life, power, specific weight and volume, versatility of operation, field maintenance and thermal control were conducted from the material and component level through the fabrication and test of an engineering model of the fuel cell system. The program was to be accomplished in a 13 month period.

Fabrication Method for Laboratory-Scale High-Performance Membrane Electrode Assemblies for Fuel Cells.

PubMed

Sassin, Megan B; Garsany, Yannick; Gould, Benjamin D; Swider-Lyons, Karen E

2017-01-03

Custom catalyst-coated membranes (CCMs) and membrane electrode assemblies (MEAs) are necessary for the evaluation of advanced electrocatalysts, gas diffusion media (GDM), ionomers, polymer electrolyte membranes (PEMs), and electrode structures designed for use in next-generation fuel cells, electrolyzers, or flow batteries. This Feature provides a reliable and reproducible fabrication protocol for laboratory scale (10 cm 2 ) fuel cells based on ultrasonic spray deposition of a standard Pt/carbon electrocatalyst directly onto a perfluorosulfonic acid PEM.

Application of pixel-cell detector technology for Advanced Neutron Beam Monitors

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

Kopp, Daniel M.

2011-01-11

Application of Pixel-Cell Detector Technology for Advanced Neutron Beam Monitors Specifications of currently available neutron beam detectors limit their usefulness at intense neutron beams of large-scale national user facilities used for the advanced study of materials. A large number of neutron-scattering experiments require beam monitors to operate in an intense neutron beam flux of >10E+7 neutrons per second per square centimeter. For instance, a 4 cm x 4 cm intense beam flux of 6.25 x 10E+7 n/s/cm2 at the Spallation Neutron Source will put a flux of 1.00 x 10E+9 n/s at the beam monitor. Currently available beam monitors withmore » a typical efficiency of 1 x 10E-4 will need to be replaced in less than two years of operation due to wire and gas degradation issues. There is also a need at some instruments for beam position information that are beyond the capabilities of currently available He-3 and BF3 neutron beam monitors. ORDELA, Inc.’s research under USDOE SBIR Grant (DE-FG02-07ER84844) studied the feasibility of using pixel-cell technology for developing a new generation of stable, long-life neutron beam monitors. The research effort has led to the development and commercialization of advanced neutron beam detectors that will directly benefit the Spallation Neutron Source and other intense neutron sources such as the High Flux Isotope Reactor. A prototypical Pixel-Cell Neutron Beam Monitor was designed and constructed during this research effort. This prototype beam monitor was exposed to an intense neutron beam at the HFIR SNS HB-2 test beam site. Initial measurements on efficiency, uniformity across the detector, and position resolution yielded excellent results. The development and test results have provided the required data to initiate the fabrication and commercialization of this next generation of neutron-detector systems. ORDELA, Inc. has (1) identified low-cost design and fabrication strategies, (2) developed and built pixel-cell detectors and instrumented a 64-pixel-cell detector to specifications for the Cold-Neutron Chopper Spectrometer and POWGEN instruments, (3) investigated the general characteristics of this technology, (4) studied pixel-cell configurations and arrived at an optimized modular design, and (5) evaluated fabrication costs of mass production for these configurations. The resulting technology will enable a complete line of pixel-cell-based neutron detectors to be commercially under available. ORDELA, Inc has a good track history of application of innovative technology into the marketplace. Our commercialization record reflects this. For additional information, please contact Daniel Kopp at ORDELA, Inc. at +1 (865) 483-8675 or check our website at www.ordela.com.« less

Influence of nanomaterials on stem cell differentiation: designing an appropriate nanobiointerface

PubMed Central

Ilie, Ioana; Ilie, Razvan; Mocan, Teodora; Bartos, Dana; Mocan, Lucian

2012-01-01

During the last decade, due to advances in functionalization chemistry, novel nanobiomaterials with applications in tissue engineering and regenerative medicine have been developed. These novel materials with their unique physical and chemical properties are bioactive hierarchical structures that hold great promise for future development of human tissues. Thus, various nanomaterials are currently being intensively explored in the directed differentiation of stem cells, the design of novel bioactive scaffolds, and new research avenues towards tissue regeneration. This paper illustrates the latest achievements in the applications of nanotechnology in tissue engineering in the field of regenerative medicine. PMID:22619557

Advanced U.S. military aircraft battery systems

NASA Astrophysics Data System (ADS)

Flake, Richard A.; Eskra, Michael D.

1990-04-01

While most USAF aircraft currently use vented Ni-Cd for dc electrical power and emergency power, as well as the powering of lights and instruments prior to engine starting, these batteries have high maintenance requirements, low reliability, and no built-in testing capability with which to check battery health prior to flight. The USAF Wright R&D Center accordingly initiated its Advanced Maintenance-Free NiCd Battery System development program in 1986, in order to develop a sealed Ni-Cd battery which would remain maintenance-free over a period of three years. Attention is being given to a high power bipolar battery design in which there are no individual cell cases or cell interconnects.

Optical Coherence Microscopy

NASA Astrophysics Data System (ADS)

Aguirre, Aaron D.; Zhou, Chao; Lee, Hsiang-Chieh; Ahsen, Osman O.; Fujimoto, James G.

Cellular imaging of human tissues remains an important advance for many clinical applications of optical coherence tomography (OCT). Imaging cells with traditional OCT systems has not been possible due to the limited transverse resolution of such techniques. Optical coherence microscopy (OCM) refers to OCT methods that achieve high transverse resolution to visualize cells and subcellular features. This chapter provides a comprehensive discussion of the rationale for cellular imaging in human tissues as well as a review of the key technological advances required to achieve it. Time domain and Fourier domain OCM approaches are described with an emphasis on state of the art system designs, including miniaturized endoscopic imaging probes. Clinical applications are discussed and multiple examples of cellular imaging in human tissues are provided.

Back-Up/ Peak Shaving Fuel Cell System

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

Staudt, Rhonda L.

2008-05-28

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

Engineering Enriched Microenvironments with Gradients of Platelet Lysate in Hydrogel Fibers.

PubMed

Santo, Vítor E; Babo, Pedro; Amador, Miguel; Correia, Cláudia; Cunha, Bárbara; Coutinho, Daniela F; Neves, Nuno M; Mano, João F; Reis, Rui L; Gomes, Manuela E

2016-06-13

Gradients of physical and chemical cues are characteristic of specific tissue microenvironments and contribute toward morphogenesis and tissue regeneration upon injury. Recent advances on microfluidics and hydrogel manipulation raised the possibility of generating biomimetic biomaterials enriched with bioactive factors and encapsulating cells following designs specifically tailored for a target application. The novelty of this work relies on the combination of methacrylated gellan gum (MeGG) with platelet lysate (PL), aiming to generate novel advanced 3D PL-enriched photo-cross-linkable hydrogels and overcoming the lack of adhesion sites provided by the native MeGG hydrogels. This combination takes advantage of the availability, enriched growth factor composition, and potential autologous application of PL while simultaneously preserving the ability provided by MeGG to tailor mechanical properties, protein release kinetics, and shape of the construct according to the desired goal. Incorporation of PL in the hydrogels significantly improved cellular adhesion and viability in the constructs. The use of microfluidic tools allowed the design of a fiber-like hydrogel incorporating a gradient of PL along the length of the fiber. These spatial protein gradients led to the viability and cell number gradients caused by maintenance of human umbilical vein endothelial cells (HUVECs) survival in the fibers toward the PL-enriched sections in comparison with the nonloaded MeGG sections of the fibers. Altogether, we propose a proof of concept strategy to design a PL gradient biomaterial with potential in tissue engineering approaches and analysis of cell-microenvironment interactions.

Summary of flat-plate solar array project documentation. Abstracts of published documents, 1975 to June 1982

NASA Technical Reports Server (NTRS)

1982-01-01

Technologies that will enable the private sector to manufacture and widely use photovoltaic systems for the generation of electricity in residential, commercial, industrial, and government applications at a cost per watt that is competitive with other means is investigated. Silicon refinement processes, advanced silicon sheet growth techniques, solar cell development, encapsulation, automated fabrication process technology, advanced module/array design, and module/array test and evaluation techniques are developed.

A programmable synthetic lineage-control network that differentiates human IPSCs into glucose-sensitive insulin-secreting beta-like cells

PubMed Central

Saxena, Pratik; Heng, Boon Chin; Bai, Peng; Folcher, Marc; Zulewski, Henryk; Fussenegger, Martin

2016-01-01

Synthetic biology has advanced the design of standardized transcription control devices that programme cellular behaviour. By coupling synthetic signalling cascade- and transcription factor-based gene switches with reverse and differential sensitivity to the licensed food additive vanillic acid, we designed a synthetic lineage-control network combining vanillic acid-triggered mutually exclusive expression switches for the transcription factors Ngn3 (neurogenin 3; OFF-ON-OFF) and Pdx1 (pancreatic and duodenal homeobox 1; ON-OFF-ON) with the concomitant induction of MafA (V-maf musculoaponeurotic fibrosarcoma oncogene homologue A; OFF-ON). This designer network consisting of different network topologies orchestrating the timely control of transgenic and genomic Ngn3, Pdx1 and MafA variants is able to programme human induced pluripotent stem cells (hIPSCs)-derived pancreatic progenitor cells into glucose-sensitive insulin-secreting beta-like cells, whose glucose-stimulated insulin-release dynamics are comparable to human pancreatic islets. Synthetic lineage-control networks may provide the missing link to genetically programme somatic cells into autologous cell phenotypes for regenerative medicine. PMID:27063289

The impact of solar cell technology on planar solar array performance

NASA Technical Reports Server (NTRS)

Mills, Michael W.; Kurland, Richard M.

1989-01-01

The results of a study into the potential impact of advanced solar cell technologies on the characteristics (weight, cost, area) of typical planar solar arrays designed for low, medium and geosynchronous altitude earth orbits are discussed. The study considered planar solar array substrate designs of lightweight, rigid-panel graphite epoxy and ultra-lightweight Kapton. The study proposed to answer the following questions: Do improved cell characteristics translate into array-level weight, size and cost improvements; What is the relative importance of cell efficiency, weight and cost with respect to array-level performance; How does mission orbital environment affect array-level performance. Comparisons were made at the array level including all mechanisms, hinges, booms, and harnesses. Array designs were sized to provide 5kW of array power (not spacecraft bus power, which is system dependent but can be scaled from given values). The study used important grass roots issues such as use of the GaAs radiation damage coefficients as determined by Anspaugh. Detailed costing was prepared, including cell and cover costs, and manufacturing attrition rates for the various cell types.

Small Portable PEM Fuel Cell Systems for NASA Exploration Missions

NASA Technical Reports Server (NTRS)

Burke, Kenneth A.

2005-01-01

Oxygen-Hydrogen PEM-based fuel cell systems are being examined as a portable power source alternative in addition to advanced battery technology. Fuel cell power systems have been used by the Gemini, Apollo, and Space Shuttle programs. These systems have not been portable, but have been integral parts of their spacecraft, and have used reactants from a separate cryogenic supply. These systems typically have been higher in power. They also have had significant ancillary equipment sections that perform the pumping of reactants and coolant through the fuel cell stack and the separation of the product water from the unused reactant streams. The design of small portable fuel cell systems will be a significant departure from these previous designs. These smaller designs will have very limited ancillary equipment, relying on passive techniques for reactant and thermal management, and the reactant storage will be an integral part of the fuel cell system. An analysis of the mass and volume for small portable fuel cell systems was done to evaluate and quantify areas of technological improvement. A review of current fuel cell technology as well as reactant storage and management technology was completed to validate the analysis and to identify technology challenges

Latest developments in the Advanced Photovoltaic Solar Array Program

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Kurland, Richard M.

1990-01-01

In 1985, the Advanced Photovoltaic Solar Array (APSA) Program was established to demonstrate a producible array system with a specific power greater than 130 W/kg at a 10-kW (BOL) power level. The latest program phase completed fabrication and initial functional testing of a prototype wing representative of a full-scale 5-kW (BOL) wing (except truncated in length to about 1 kW), with weight characteristics that could meet the 130-W/kg (BOL) specific power goal using thin silicon solar cell modules and weight-efficient structural components. The wing configuration and key design details are reviewed, along with results from key component-level and wing-level tests. Projections for future enhancements that may be expected through the use of advanced solar cells and structural components are shown. Performance estimates are given for solar electric propulsion orbital transfer missions through the Van Allen radiation belts. The latest APSA program plans are presented.

An Overview of Advanced SILAC-Labeling Strategies for Quantitative Proteomics.

PubMed

Terzi, F; Cambridge, S

2017-01-01

Comparative, quantitative mass spectrometry of proteins provides great insight to protein abundance and function, but some molecular characteristics related to protein dynamics are not so easily obtained. Because the metabolic incorporation of stable amino acid isotopes allows the extraction of distinct temporal and spatial aspects of protein dynamics, the SILAC methodology is uniquely suited to be adapted for advanced labeling strategies. New SILAC strategies have emerged that allow deeper foraging into the complexity of cellular proteomes. Here, we review a few advanced SILAC-labeling strategies that have been published during last the years. Among them, different subsaturating-labeling as well as dual-labeling schemes are most prominent for a range of analyses including those of neuronal proteomes, secretion, or cell-cell-induced stimulations. These recent developments suggest that much more information can be gained from proteomic analyses if the labeling strategies are specifically tailored toward the experimental design. © 2017 Elsevier Inc. All rights reserved.

Development of Advanced Fuel Cell System (Phase 4)

NASA Technical Reports Server (NTRS)

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

1976-01-01

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

Model-based design of experiments for cellular processes.

PubMed

Chakrabarty, Ankush; Buzzard, Gregery T; Rundell, Ann E

2013-01-01

Model-based design of experiments (MBDOE) assists in the planning of highly effective and efficient experiments. Although the foundations of this field are well-established, the application of these techniques to understand cellular processes is a fertile and rapidly advancing area as the community seeks to understand ever more complex cellular processes and systems. This review discusses the MBDOE paradigm along with applications and challenges within the context of cellular processes and systems. It also provides a brief tutorial on Fisher information matrix (FIM)-based and Bayesian experiment design methods along with an overview of existing software packages and computational advances that support MBDOE application and adoption within the Systems Biology community. As cell-based products and biologics progress into the commercial sector, it is anticipated that MBDOE will become an essential practice for design, quality control, and production. Copyright © 2013 Wiley Periodicals, Inc.

Status of diffused junction p+n InP solar cells for space applications

NASA Technical Reports Server (NTRS)

Faur, Mircea; Goradia, C.; Faur, Maria; Fatemi, N. S.; Jenkins, P. P.; Flood, D. J.; Brinker, D. J.; Wilt, D. M.; Bailey, S.; Goradia, M.

1994-01-01

Recently, we have succeeded in fabricating diffused junction p(sup +)n(Cd,S) InP solar cells with measured AMO, 25 C open circuit voltage (V(sub OC)) of 887.6 mV, which, to the best of our knowledge, is higher than previously reported V(sub OC) values for any InP homojunction solar cells. The experiment-based projected achievable efficiency of these cells using LEC grown substrates is 21.3 percent. The maximum AMO, 25 C internal losses due to date on bare cells is, however, only 13.2 percent. This is because of large external and internal losses due to non-optimized front grid design, antireflection (AR) coating and emitter thickness. This paper summarizes recent advances in the technology of fabrication of p(sup +)n InP diffused structures and solar cells, resulted from a study undertaken in an effort to increase the cell efficiency. The topics discussed in this paper include advances in: (1) the formation on thin p(sup +) InP:Cd emitter layers, (2) electroplated front contacts, (3) surface passivation and (4) the design of a new native oxide/Al2O3/MgF2 tree layer AR coating using a chemically-grown P-rich passivating oxide as a first layer. Based on the high radiation resistance and the excellent post-irradiation annealing and recovery demonstrated in the early tests done to date, as well as the projected high efficiency and low-cost high-volume fabricability, these cells show a very good potential for space photovoltaic applications.

Status of diffused junction p+n InP solar cells for space applications

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

Faur, M.; Goradia, C.; Faur, M.

1994-09-01

Recently, the authors have succeeded in fabricating diffused junction p{sup +}n(Cd,S) InP solar cells with measured AMO, 25 C open circuit voltage (V{sub OC}) of 887.6 mV, which, to the best of their knowledge, is higher than previously reported V{sub OC} values for any InP homojunction solar cells. The experiment-based projected achievable efficiency of these cells using LEC grown substrates is 21.3 percent. The maximum AMO, 25 C internal losses due to date on bare cells is, however, only 13.2 percent. This is because of large external and internal losses due to non-optimized front grid design, antireflection (AR) coating andmore » emitter thickness. This paper summarizes recent advances in the technology of fabrication of p{sup +}n InP diffused structures and solar cells, resulted from a study undertaken in an effort to increase the cell efficiency. The topics discussed in this paper include advances in: (1) the formation on thin p{sup +} InP:Cd emitter layers, (2) electroplated front contacts, (3) surface passivation and (4) the design of a new native oxide/Al2O3/MgF2 tree layer AR coating using a chemically-grown P-rich passivating oxide as a first layer. Based on the high radiation resistance and the excellent post-irradiation annealing and recovery demonstrated in the early tests done to date, as well as the projected high efficiency and low-cost high-volume fabricability, these cells show a very good potential for space photovoltaic applications.« less

Development of hydrogels for regenerative engineering.

PubMed

Guan, Xiaofei; Avci-Adali, Meltem; Alarçin, Emine; Cheng, Hao; Kashaf, Sara Saheb; Li, Yuxiao; Chawla, Aditya; Jang, Hae Lin; Khademhosseini, Ali

2017-05-01

The aim of regenerative engineering is to restore complex tissues and biological systems through convergence in the fields of advanced biomaterials, stem cell science, and developmental biology. Hydrogels are one of the most attractive biomaterials for regenerative engineering, since they can be engineered into tissue mimetic 3D scaffolds to support cell growth due to their similarity to native extracellular matrix. Advanced nano- and micro-technologies have dramatically increased the ability to control properties and functionalities of hydrogel materials by facilitating biomimetic fabrication of more sophisticated compositions and architectures, thus extending our understanding of cell-matrix interactions at the nanoscale. With this perspective, this review discusses the most commonly used hydrogel materials and their fabrication strategies for regenerative engineering. We highlight the physical, chemical, and functional modulation of hydrogels to design and engineer biomimetic tissues based on recent achievements in nano- and micro-technologies. In addition, current hydrogel-based regenerative engineering strategies for treating multiple tissues, such as musculoskeletal, nervous and cardiac tissue, are also covered in this review. The interaction of multiple disciplines including materials science, cell biology, and chemistry, will further play an important role in the design of functional hydrogels for the regeneration of complex tissues. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diesel fuel to dc power: Navy & Marine Corps Applications

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

Bloomfield, D.P.

1996-12-31

During the past year Analytic Power has tested fuel cell stacks and diesel fuel processors for US Navy and Marine Corps applications. The units are 10 kW demonstration power plants. The USN power plant was built to demonstrate the feasibility of diesel fueled PEM fuel cell power plants for 250 kW and 2.5 MW shipboard power systems. We designed and tested a ten cell, 1 kW USMC substack and fuel processor. The complete 10 kW prototype power plant, which has application to both power and hydrogen generation, is now under construction. The USN and USMC fuel cell stacks have beenmore » tested on both actual and simulated reformate. Analytic Power has accumulated operating experience with autothermal reforming based fuel processors operating on sulfur bearing diesel fuel, jet fuel, propane and natural gas. We have also completed the design and fabrication of an advanced regenerative ATR for the USMC. One of the significant problems with small fuel processors is heat loss which limits its ability to operate with the high steam to carbon ratios required for coke free high efficiency operation. The new USMC unit specifically addresses these heat transfer issues. The advances in the mill programs have been incorporated into Analytic Power`s commercial units which are now under test.« less

WholeCellSimDB: a hybrid relational/HDF database for whole-cell model predictions.

PubMed

Karr, Jonathan R; Phillips, Nolan C; Covert, Markus W

2014-01-01

Mechanistic 'whole-cell' models are needed to develop a complete understanding of cell physiology. However, extracting biological insights from whole-cell models requires running and analyzing large numbers of simulations. We developed WholeCellSimDB, a database for organizing whole-cell simulations. WholeCellSimDB was designed to enable researchers to search simulation metadata to identify simulations for further analysis, and quickly slice and aggregate simulation results data. In addition, WholeCellSimDB enables users to share simulations with the broader research community. The database uses a hybrid relational/hierarchical data format architecture to efficiently store and retrieve both simulation setup metadata and results data. WholeCellSimDB provides a graphical Web-based interface to search, browse, plot and export simulations; a JavaScript Object Notation (JSON) Web service to retrieve data for Web-based visualizations; a command-line interface to deposit simulations; and a Python API to retrieve data for advanced analysis. Overall, we believe WholeCellSimDB will help researchers use whole-cell models to advance basic biological science and bioengineering. http://www.wholecellsimdb.org SOURCE CODE REPOSITORY: URL: http://github.com/CovertLab/WholeCellSimDB. © The Author(s) 2014. Published by Oxford University Press.

Immunologic "vaccination" for the prevention of autoimmune diabetes (type 1A).

PubMed

Simone, E A; Wegmann, D R; Eisenbarth, G S

1999-03-01

Diabetes type 1A is an autoimmune condition characterized by lymphocytic infiltration of islets and selective destruction of insulin-secreting beta-cells. Numerous investigators have prevented diabetes in animal models with a variety of antigens and routes of administration. It is also now possible to identify high-risk individuals even before the appearance of autoantibodies. These advances have created the opportunity to design and begin human prevention trials. This review focuses on a variety of immunomodulatory approaches (including administration of adjuvants, autoantigens, T-cells, T-cell receptors, and DNA) that we have collectively termed immunologic "vaccination." In addition, we discuss the potential benefits and dangers of these approaches and issues relating to the design of human trials.

HYDROGEL-BASED NANOCOMPOSITES OF THERAPEUTIC PROTEINS FOR TISSUE REPAIR

PubMed Central

Zhu, Suwei; Segura, Tatiana

2014-01-01

The ability to design artificial extracellular matrices as cell instructive scaffolds has opened the door to technologies capable of studying cell fates in vitro and to guide tissue repair in vivo. One main component of the design of artificial extracellular matrices is the incorporation of protein-based biochemical cues to guide cell phenotypes and multicellular organizations. However, promoting the long-term bioactivity, controlling the bioavailability and understanding how the physical presentations of these proteins impacts cellular fates are among the challenges of the field. Nanotechnolgy has advanced to meet the challenges of protein therapeutics. For example, the approaches to incorporating proteins into tissue repairing scaffolds have ranged from bulk encapsulations to smart nanodepots that protect proteins from degradations and allow opportunities for controlled release. PMID:24778979

HYDROGEL-BASED NANOCOMPOSITES OF THERAPEUTIC PROTEINS FOR TISSUE REPAIR.

PubMed

Zhu, Suwei; Segura, Tatiana

2014-05-01

The ability to design artificial extracellular matrices as cell instructive scaffolds has opened the door to technologies capable of studying cell fates in vitro and to guide tissue repair in vivo . One main component of the design of artificial extracellular matrices is the incorporation of protein-based biochemical cues to guide cell phenotypes and multicellular organizations. However, promoting the long-term bioactivity, controlling the bioavailability and understanding how the physical presentations of these proteins impacts cellular fates are among the challenges of the field. Nanotechnolgy has advanced to meet the challenges of protein therapeutics. For example, the approaches to incorporating proteins into tissue repairing scaffolds have ranged from bulk encapsulations to smart nanodepots that protect proteins from degradations and allow opportunities for controlled release.

Design and implementation of adoptive therapy with chimeric antigen receptor-modified T cells.

PubMed

Jensen, Michael C; Riddell, Stanley R

2014-01-01

A major advance in adoptive T-cell therapy (ACT) is the ability to efficiently endow patient's T cells with reactivity for tumor antigens through the stable or regulated introduction of genes that encode high affinity tumor-targeting T-cell receptors (TCRs) or synthetic chimeric antigen receptors (CARs). Case reports and small series of patients treated with TCR- or CAR-modified T cells have shown durable responses in a subset of patients, particularly with B-cell malignancies treated with T cells modified to express a CAR that targets the CD19 molecule. However, many patients do not respond to therapy and serious on and off-target toxicities have been observed with TCR- and CAR-modified T cells. Thus, challenges remain to make ACT with gene-modified T cells a reproducibly effective and safe therapy and to expand the breadth of patients that can be treated to include those with common epithelial malignancies. This review discusses research topics in our laboratories that focus on the design and implementation of ACT with CAR-modified T cells. These include cell intrinsic properties of distinct T-cell subsets that may facilitate preparing therapeutic T-cell products of defined composition for reproducible efficacy and safety, the design of tumor targeting receptors that optimize signaling of T-cell effector functions and facilitate tracking of migration of CAR-modified T cells in vivo, and novel CAR designs that have alternative ligand binding domains or confer regulated function and/or survival of transduced T cells. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Regenerative Fuel Cell Power Systems for Lunar and Martian Surface Exploration

NASA Technical Reports Server (NTRS)

Guzik, Monica C.; Jakupca, Ian J.; Gilligan, Ryan P.; Bennett, William R.; Smith, Phillip J.; Fincannon, James

2017-01-01

This paper presents the preliminary results of a recent National Aeronautics and Space Administration (NASA) study funded under the Advanced Exploration Systems (AES) Modular Power Systems (AMPS) project. This study evaluated multiple surface locations on both the Moon and Mars, with the goal of establishing a common approach towards technology development and system design for surface power systems that use Regenerative Fuel Cell (RFC) energy storage methods. One RFC design may not be applicable to all surface locations; however, AMPS seeks to find a unified architecture, or series of architectures, that leverages a single development approach to answer the technology need for RFC systems. Early system trades were performed to select the most effective fuel cell and electrolyzer architectures based on current state-of-the-art technology, whereas later trades will establish a detailed system design to enable a near-term ground (non-flight) demonstration. This paper focuses on the initial trade studies, presents the selected fuel cell and electrolyzer architectures for follow-on system design studies, and suggests areas for further technology investment.

Advances and challenges in logical modeling of cell cycle regulation: perspective for multi-scale, integrative yeast cell models

PubMed Central

Todd, Robert G.; van der Zee, Lucas

2016-01-01

Abstract The eukaryotic cell cycle is robustly designed, with interacting molecules organized within a definite topology that ensures temporal precision of its phase transitions. Its underlying dynamics are regulated by molecular switches, for which remarkable insights have been provided by genetic and molecular biology efforts. In a number of cases, this information has been made predictive, through computational models. These models have allowed for the identification of novel molecular mechanisms, later validated experimentally. Logical modeling represents one of the youngest approaches to address cell cycle regulation. We summarize the advances that this type of modeling has achieved to reproduce and predict cell cycle dynamics. Furthermore, we present the challenge that this type of modeling is now ready to tackle: its integration with intracellular networks, and its formalisms, to understand crosstalks underlying systems level properties, ultimate aim of multi-scale models. Specifically, we discuss and illustrate how such an integration may be realized, by integrating a minimal logical model of the cell cycle with a metabolic network. PMID:27993914

New Whole-House Solutions Case Study: Shaw Construction, Aspen, Colorado

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

none,

This builder worked with Building Science Corporation to design affordable HERS-54 townhouses with central solar radiator space heating, PV, R-28 closed-cell spray foam under slab and R-26 in advanced framed walls, and rigid polyiso on inside of basement walls

Modeling Signaling Networks to Advance New Cancer Therapies.

PubMed

Saez-Rodriguez, Julio; MacNamara, Aidan; Cook, Simon

2015-01-01

Cell signaling pathways control cells' responses to their environment through an intricate network of proteins and small molecules partitioned by intracellular structures, such as the cytoskeleton and nucleus. Our understanding of these pathways has been revised recently with the advent of more advanced experimental techniques; no longer are signaling pathways viewed as linear cascades of information flowing from membrane-bound receptors to the nucleus. Instead, such pathways must be understood in the context of networks, and studying such networks requires an integration of computational and experimental approaches. This understanding is becoming more important in designing novel therapies for diseases such as cancer. Using the MAPK (mitogen-activated protein kinase) and PI3K (class I phosphoinositide-3' kinase) pathways as case studies of cellular signaling, we give an overview of these pathways and their functions. We then describe, using a number of case studies, how computational modeling has aided in understanding these pathways' deregulation in cancer, and how such understanding can be used to optimally tailor current therapies or help design new therapies against cancer.

Functional and Biomimetic Materials for Engineering of the Three-Dimensional Cell Microenvironment.

PubMed

Huang, Guoyou; Li, Fei; Zhao, Xin; Ma, Yufei; Li, Yuhui; Lin, Min; Jin, Guorui; Lu, Tian Jian; Genin, Guy M; Xu, Feng

2017-10-25

The cell microenvironment has emerged as a key determinant of cell behavior and function in development, physiology, and pathophysiology. The extracellular matrix (ECM) within the cell microenvironment serves not only as a structural foundation for cells but also as a source of three-dimensional (3D) biochemical and biophysical cues that trigger and regulate cell behaviors. Increasing evidence suggests that the 3D character of the microenvironment is required for development of many critical cell responses observed in vivo, fueling a surge in the development of functional and biomimetic materials for engineering the 3D cell microenvironment. Progress in the design of such materials has improved control of cell behaviors in 3D and advanced the fields of tissue regeneration, in vitro tissue models, large-scale cell differentiation, immunotherapy, and gene therapy. However, the field is still in its infancy, and discoveries about the nature of cell-microenvironment interactions continue to overturn much early progress in the field. Key challenges continue to be dissecting the roles of chemistry, structure, mechanics, and electrophysiology in the cell microenvironment, and understanding and harnessing the roles of periodicity and drift in these factors. This review encapsulates where recent advances appear to leave the ever-shifting state of the art, and it highlights areas in which substantial potential and uncertainty remain.

Refining the treatment of advanced nonsmall cell lung cancer

PubMed Central

Ogita, Shin; Wozniak, Antoinette J

2010-01-01

Metastatic nonsmall cell lung cancer (NSCLC) is a debilitating and deadly disease with virtually no chance for long-term survival. Chemotherapy has improved both survival and quality of life for patients with advanced disease. Overall survival of patients with metastatic NSCLC has gradually increased from 8 to 12 months over the past three decades with the introduction of new chemotherapeutic drugs and agents directed at novel targets in the cancer cell. Epidermal growth factor receptor and vascular endothelial growth factor are two such targets. Recent developments also include treatment based on histology and the use of maintenance therapy. It has been recognized that lung cancer is a very complex disease. It is common practice to include a number of scientific correlative studies in the design of clinical trials in order to determine predictive markers of benefit from treatment. This article will review the current approach to the treatment of advanced NSCLC including the use of chemotherapy and molecularly targeted agents. Future directions including the use of potentially predictive biomarkers and innovative clinical trials aimed at a more individualized approach to treatment will also be discussed. PMID:28210103

Biofunctionalized Plants as Diverse Biomaterials for Human Cell Culture.

PubMed

Fontana, Gianluca; Gershlak, Joshua; Adamski, Michal; Lee, Jae-Sung; Matsumoto, Shion; Le, Hau D; Binder, Bernard; Wirth, John; Gaudette, Glenn; Murphy, William L

2017-04-01

The commercial success of tissue engineering products requires efficacy, cost effectiveness, and the possibility of scaleup. Advances in tissue engineering require increased sophistication in the design of biomaterials, often challenging the current manufacturing techniques. Interestingly, several of the properties that are desirable for biomaterial design are embodied in the structure and function of plants. This study demonstrates that decellularized plant tissues can be used as adaptable scaffolds for culture of human cells. With simple biofunctionalization technique, it is possible to enable adhesion of human cells on a diverse set of plant tissues. The elevated hydrophilicity and excellent water transport abilities of plant tissues allow cell expansion over prolonged periods of culture. Moreover, cells are able to conform to the microstructure of the plant frameworks, resulting in cell alignment and pattern registration. In conclusion, the current study shows that it is feasible to use plant tissues as an alternative feedstock of scaffolds for mammalian cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Designed cell consortia as fragrance-programmable analog-to-digital converters.

PubMed

Müller, Marius; Ausländer, Simon; Spinnler, Andrea; Ausländer, David; Sikorski, Julian; Folcher, Marc; Fussenegger, Martin

2017-03-01

Synthetic biology advances the rational engineering of mammalian cells to achieve cell-based therapy goals. Synthetic gene networks have nearly reached the complexity of digital electronic circuits and enable single cells to perform programmable arithmetic calculations or to provide dynamic remote control of transgenes through electromagnetic waves. We designed a synthetic multilayered gaseous-fragrance-programmable analog-to-digital converter (ADC) allowing for remote control of digital gene expression with 2-bit AND-, OR- and NOR-gate logic in synchronized cell consortia. The ADC consists of multiple sampling-and-quantization modules sensing analog gaseous fragrance inputs; a gas-to-liquid transducer converting fragrance intensity into diffusible cell-to-cell signaling compounds; a digitization unit with a genetic amplifier circuit to improve the signal-to-noise ratio; and recombinase-based digital expression switches enabling 2-bit processing of logic gates. Synthetic ADCs that can remotely control cellular activities with digital precision may enable the development of novel biosensors and may provide bioelectronic interfaces synchronizing analog metabolic pathways with digital electronics.

Recent Advances in Bioink Design for 3D Bioprinting of Tissues and Organs.

PubMed

Ji, Shen; Guvendiren, Murat

2017-01-01

There is a growing demand for alternative fabrication approaches to develop tissues and organs as conventional techniques are not capable of fabricating constructs with required structural, mechanical, and biological complexity. 3D bioprinting offers great potential to fabricate highly complex constructs with precise control of structure, mechanics, and biological matter [i.e., cells and extracellular matrix (ECM) components]. 3D bioprinting is an additive manufacturing approach that utilizes a "bioink" to fabricate devices and scaffolds in a layer-by-layer manner. 3D bioprinting allows printing of a cell suspension into a tissue construct with or without a scaffold support. The most common bioinks are cell-laden hydrogels, decellulerized ECM-based solutions, and cell suspensions. In this mini review, a brief description and comparison of the bioprinting methods, including extrusion-based, droplet-based, and laser-based bioprinting, with particular focus on bioink design requirements are presented. We also present the current state of the art in bioink design including the challenges and future directions.

Recent Advances in Bioink Design for 3D Bioprinting of Tissues and Organs

PubMed Central

Ji, Shen; Guvendiren, Murat

2017-01-01

There is a growing demand for alternative fabrication approaches to develop tissues and organs as conventional techniques are not capable of fabricating constructs with required structural, mechanical, and biological complexity. 3D bioprinting offers great potential to fabricate highly complex constructs with precise control of structure, mechanics, and biological matter [i.e., cells and extracellular matrix (ECM) components]. 3D bioprinting is an additive manufacturing approach that utilizes a “bioink” to fabricate devices and scaffolds in a layer-by-layer manner. 3D bioprinting allows printing of a cell suspension into a tissue construct with or without a scaffold support. The most common bioinks are cell-laden hydrogels, decellulerized ECM-based solutions, and cell suspensions. In this mini review, a brief description and comparison of the bioprinting methods, including extrusion-based, droplet-based, and laser-based bioprinting, with particular focus on bioink design requirements are presented. We also present the current state of the art in bioink design including the challenges and future directions. PMID:28424770

A microfluidic chaotic mixer platform for cancer stem cell immunocapture and release

NASA Astrophysics Data System (ADS)

Shaner, Sebastian Wesley

Isolation of exceedingly rare and ambiguous cells, like cancer stem cells (CSCs), from a pool of other abundant cells is a daunting task primarily due to the inadequately defined properties of such cells. With phenotypes of different CSCs fairly well-defined, immunocapturing of CSCs is a desirable cell-specific capture technique. A microfluidic device is a proven candidate that offers the platform for user-constrained microenvironments that can be optimized for small-scale volumetric flow experimentation. In this study, we show how a well-known passive micromixer design (staggered herringbone mixer - SHM) can be optimized to induce maximum chaotic mixing within antibody-laced microchannels and, ultimately, promote CSC capture. The device's (Cancer Stem Cell Capture Chip - CSC3 (TM)) principle design configuration is called: Single-Walled Staggered Herringbone (SWaSH). The CSC3 (TM) was constructed of a polydimethylsiloxane (PDMS) foundation and thinly coated with an alginate hydrogel derivatized with streptavidin. The results of our work showed that the non-stickiness of alginate and antigen-specific antibodies allowed for superb target-specific cell isolation and negligible non-specific cell binding. Future engineering design directions include developing new configurations (e.g. Staggered High-Low Herringbone (SHiLoH) and offset SHiLoH) to optimize microvortex generation within the microchannels. This study's qualitative and quantitative results can help stimulate progress into refinements in device design and prospective advancements in cancer stem cell isolation and more comprehensive single-cell and cluster analysis.

Will advances in fish immunology change vaccination strategies?

PubMed

Secombes, Chris

2008-10-01

This review will discuss some of the recent advances in discovering immune genes in fish, in terms of their relevance to vaccine design and development. Particular emphasis will be placed on the many cytokine and costimulatory molecules now known, with examples drawn from the mammalian literature as to their potential value for fish vaccinology. A new area of vaccine research will also be touched upon, where efficacious responses are elicited by inhibiting the natural negative regulators of immune responses, such as Treg cell products and SOCS proteins.

Advanced Fabrication Techniques for Precisely Controlled Micro and Nano Scale Environments for Complex Tissue Regeneration and Biomedical Applications

NASA Astrophysics Data System (ADS)

Holmes, Benjamin

As modern medicine advances, it is still very challenging to cure joint defects due to their poor inherent regenerative capacity, complex stratified architecture, and disparate biomechanical properties. The current clinical standard for catastrophic or late stage joint degradation is a total joint implant, where the damaged joint is completely excised and replaced with a metallic or artificial joint. However, these procedures still only lasts for 10-15 years, and there are hosts of recovery complications which can occur. Thus, these studies have sought to employ advanced biomaterials and scaffold fabricated techniques to effectively regrow joint tissue, instead of merely replacing it with artificial materials. We can hypothesize here that the inclusion of biomimetic and bioactive nanomaterials with highly functional electrospun and 3D printed scaffold can improve physical characteristics (mechanical strength, surface interactions and nanotexture) enhance cellular growth and direct stem cell differentiation for bone, cartilage and vascular growth as well as cancer metastasis modeling. Nanomaterial inclusion and controlled 3D printed features effectively increased nano surface roughness, Young's Modulus and provided effective flow paths for simulated arterial blood. All of the approaches explored proved highly effective for increasing cell growth, as a result of increasing micro-complexity and nanomaterial incorporation. Additionally, chondrogenic and osteogenic differentiation, cell migration, cell to cell interaction and vascular formation were enhanced. Finally, growth-factor(gf)-loaded polymer nanospheres greatly improved vascular cell behavior, and provided a highly bioactive scaffold for mesenchymal stem cell (MSC) and human umbilical vein endothelial cell (HUVEC) co-culture and bone formation. In conclusion, electrospinning and 3D printing when combined effectively with biomimetic and bioactive nanomaterials (i.e. carbon nanomaterials, collagen, nHA, polymer drug delivery nanospheres) can provide high performance, functional materials that also serve as effective tissue forming 3D environments. Both general science knowledge and the translational potential of tissue engineered constructs were advanced by original contributions to the fields for tissue engineering and orthopedic medicine. The most original advancement of general science comes from a successful combination of advanced nanomaterials and biomaterials with existing 3D printing and CAD design to support multiple types of cells and tissues. Future translation of these technologies was advanced due to the highly functional nature of these constructs (i.e. mechanical and hydrodynamic characteristics). Future work would involve more evaluation of vascular neogenesis, small animal models to evaluate bioactivity and biocompatibility and large clinically relevant animals to measure gross tissue formation and biomechanical performance.

Computational design and refinement of self-heating lithium ion batteries

NASA Astrophysics Data System (ADS)

Yang, Xiao-Guang; Zhang, Guangsheng; Wang, Chao-Yang

2016-10-01

The recently discovered self-heating lithium ion battery has shown rapid self-heating from subzero temperatures and superior power thereafter, delivering a practical solution to poor battery performance at low temperatures. Here, we describe and validate an electrochemical-thermal coupled model developed specifically for computational design and improvement of the self-heating Li-ion battery (SHLB) where nickel foils are embedded in its structure. Predicting internal cell characteristics, such as current, temperature and Li-concentration distributions, the model is used to discover key design factors affecting the time and energy needed for self-heating and to explore advanced cell designs with the highest self-heating efficiency. It is found that ohmic heat generated in the nickel foil accounts for the majority of internal heat generation, resulting in a large internal temperature gradient from the nickel foil toward the outer cell surface. The large through-plane temperature gradient leads to highly non-uniform current distribution, and more importantly, is found to be the decisive factor affecting the heating time and energy consumption. A multi-sheet cell design is thus proposed and demonstrated to substantially minimize the temperature gradient, achieving 30% more rapid self-heating with 27% less energy consumption than those reported in the literature.

Small capacity, low cost (Ni-H2) design concept for commercial, military, and higher-volume aerospace applications

NASA Technical Reports Server (NTRS)

Wheeler, James R.; Cook, William D.; Smith, Ron

1991-01-01

Nickel Hydrogen (Ni/H2) batteries have become the technology of choice for both commercial and defense related satellites in geosynchronous orbits. Their use for low earth orbit (LEO) applications is not as advanced, but seems just as inevitable because of their inherent advantages over nickel cadmium batteries. These include superior energy density, longer cycle life, and better tolerance to over-charge and reversal. Ni/H2 cells have the added advantage in both construction and operation of not presenting the environmental possibility of cadmium pollution. Unfortunately, but necessarily, the design of these cells has been driven to high cost by the sophistication of the satellites and their uses. Now, using most of the same concepts but less costly materials and techniques, a low cost, small cell design was developed. Combined with the concept of the common pressure vessel, this new design promises to be ideal for the small-sat and commercial markets which, increasingly, are calling for large numbers of less expensive satellites.

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.

Challenges and Opportunities to Harnessing the (Hematopoietic) Stem Cell Niche

PubMed Central

Choi, Ji Sun; Harley, Brendan A. C.

2016-01-01

In our body, stem cells reside in a microenvironment termed the niche. While the exact composition and therefore the level of complexity of a stem cell niche can vary significantly tissue-to-tissue, the stem cell niche microenvironment is dynamic, typically containing spatial and temporal variations in both cellular, extracellular matrix, and biomolecular components. This complex flow of secreted or bound biomolecules, cytokines, extracellular matrix components, and cellular constituents all contribute to the regulation of stem cell fate specification events, making engineering approaches at the nano- and micro-scale of particular interest for creating an artificial niche environment in vitro. Recent advances in fabrication approaches have enabled biomedical researchers to capture and recreate the complexity of stem cell niche microenvironments in vitro. Such engineered platforms show promise as a means to enhance our understanding of the mechanisms underlying niche-mediated stem cell regulation as well as offer opportunities to precisely control stem cell expansion and differentiation events for clinical applications. While these principles generally apply to all adult stem cells and niches, in this review, we focus on recent developments in engineering synthetic niche microenvironments for one of the best-characterized stem cell populations, hematopoietic stem cells (HSC). Specifically, we highlight recent advances in platforms designed to facilitate the extrinsic control of HSC fate decisions. PMID:27134819

Infusing CD19-directed T cells to augment disease control in patients undergoing autologous hematopoietic stem-cell transplantation for advanced B-lymphoid malignancies.

PubMed

Kebriaei, Partow; Huls, Helen; Jena, Bipulendu; Munsell, Mark; Jackson, Rineka; Lee, Dean A; Hackett, Perry B; Rondon, Gabriela; Shpall, Elizabeth; Champlin, Richard E; Cooper, Laurence J N

2012-05-01

Limited curative treatment options exist for patients with advanced B-lymphoid malignancies, and new therapeutic approaches are needed to augment the efficacy of hematopoietic stem-cell transplantation (HSCT). Cellular therapies, such as adoptive transfer of T cells that are being evaluated to target malignant disease, use mechanisms independent of chemo- and radiotherapy with nonoverlapping toxicities. Gene therapy is employed to generate tumor-specific T cells, as specificity can be redirected through enforced expression of a chimeric antigen receptor (CAR) to achieve antigen recognition based on the specificity of a monoclonal antibody. By combining cell and gene therapies, we have opened a new Phase I protocol at the MD Anderson Cancer Center (Houston, TX) to examine the safety and feasibility of administering autologous genetically modified T cells expressing a CD19-specific CAR (capable of signaling through chimeric CD28 and CD3-ζ) into patients with high-risk B-lymphoid malignancies undergoing autologous HSCT. The T cells are genetically modified by nonviral gene transfer of the Sleeping Beauty system and CAR(+) T cells selectively propagated in a CAR-dependent manner on designer artificial antigen-presenting cells. The results of this study will lay the foundation for future protocols including CAR(+) T-cell infusions derived from allogeneic sources.

Mechanical design of an intracranial stent for treating cerebral aneurysms.

PubMed

Shobayashi, Yasuhiro; Tanoue, Tetsuya; Tateshima, Satoshi; Tanishita, Kazuo

2010-11-01

Endovascular treatment of cerebral aneurysms using stents has advanced markedly in recent years. Mechanically, a cerebrovascular stent must be very flexible longitudinally and have low radial stiffness. However, no study has examined the stress distribution and deformation of cerebrovascular stents using the finite element method (FEM) and experiments. Stents can have open- and closed-cell structures, and open-cell stents are used clinically in the cerebrovasculature because of their high flexibility. However, the open-cell structure confers a risk of in-stent stenosis due to protrusion of stent struts into the normal parent artery. Therefore, a flexible stent with a closed-cell structure is required. To design a clinically useful, highly flexible, closed-cell stent, one must examine the mechanical properties of the closed-cell structure. In this study, we investigated the relationship between mesh patterns and the mechanical properties of closed-cell stents. Several mesh patterns were designed and their characteristics were studied using numerical simulation. The results showed that the bending stiffness of a closed-cell stent depends on the geometric configuration of the stent cell. It decreases when the stent cell is stretched in the circumferential direction. Mechanical flexibility equal to an open-cell structure was obtained in a closed-cell structure by varying the geometric configuration of the stent cell. Copyright © 2010 IPEM. Published by Elsevier Ltd. All rights reserved.

Status of shuttle fuel cell technology program.

NASA Technical Reports Server (NTRS)

Rice, W. E.; Bell, D., III

1972-01-01

The hydrogen-oxygen fuel cell has been proved as an efficient and reliable electrical power supply for NASA manned-space-flight vehicles. It has thus ensured a role in the Space Shuttle Program as the primary electrical power supply for the Orbiter vehicle. The advanced fuel cell technology programs conducted under the management of the NASA Manned Spacecraft Center over the past two years have resulted in a high level of technical readiness in fuel cell power generation to support shuttle mission requirements. These programs have taken advantage of technological developments that have occurred since the designs were completed for the Gemini and Apollo fuel cells.

Design, Optimization and Application of Small Molecule Biosensor in Metabolic Engineering.

PubMed

Liu, Yang; Liu, Ye; Wang, Meng

2017-01-01

The development of synthetic biology and metabolic engineering has painted a great future for the bio-based economy, including fuels, chemicals, and drugs produced from renewable feedstocks. With the rapid advance of genome-scale modeling, pathway assembling and genome engineering/editing, our ability to design and generate microbial cell factories with various phenotype becomes almost limitless. However, our lack of ability to measure and exert precise control over metabolite concentration related phenotypes becomes a bottleneck in metabolic engineering. Genetically encoded small molecule biosensors, which provide the means to couple metabolite concentration to measurable or actionable outputs, are highly promising solutions to the bottleneck. Here we review recent advances in the design, optimization and application of small molecule biosensor in metabolic engineering, with particular focus on optimization strategies for transcription factor (TF) based biosensors.

Biomaterials for Bone Regenerative Engineering.

PubMed

Yu, Xiaohua; Tang, Xiaoyan; Gohil, Shalini V; Laurencin, Cato T

2015-06-24

Strategies for bone tissue regeneration have been continuously evolving for the last 25 years since the introduction of the "tissue engineering" concept. The convergence of the life, physical, and engineering sciences has brought in several advanced technologies available to tissue engineers and scientists. This resulted in the creation of a new multidisciplinary field termed as "regenerative engineering". In this article, the role of biomaterials in bone regenerative engineering is systematically reviewed to elucidate the new design criteria for the next generation of biomaterials for bone regenerative engineering. The exemplary design of biomaterials harnessing various materials characteristics towards successful bone defect repair and regeneration is highlighted. Particular attention is given to the attempts of incorporating advanced materials science, stem cell technologies, and developmental biology into biomaterials design to engineer and develop the next generation bone grafts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design, Optimization and Application of Small Molecule Biosensor in Metabolic Engineering

PubMed Central

Liu, Yang; Liu, Ye; Wang, Meng

2017-01-01

The development of synthetic biology and metabolic engineering has painted a great future for the bio-based economy, including fuels, chemicals, and drugs produced from renewable feedstocks. With the rapid advance of genome-scale modeling, pathway assembling and genome engineering/editing, our ability to design and generate microbial cell factories with various phenotype becomes almost limitless. However, our lack of ability to measure and exert precise control over metabolite concentration related phenotypes becomes a bottleneck in metabolic engineering. Genetically encoded small molecule biosensors, which provide the means to couple metabolite concentration to measurable or actionable outputs, are highly promising solutions to the bottleneck. Here we review recent advances in the design, optimization and application of small molecule biosensor in metabolic engineering, with particular focus on optimization strategies for transcription factor (TF) based biosensors. PMID:29089935

Extracellular vesicles for personalized therapy decision support in advanced metastatic cancers and its potential impact for prostate cancer.

PubMed

Soekmadji, Carolina; Corcoran, Niall M; Oleinikova, Irina; Jovanovic, Lidija; Ramm, Grant A; Nelson, Colleen C; Jenster, Guido; Russell, Pamela J

2017-10-01

The use of circulating tumor cells (CTCs) and circulating extracellular vesicles (EVs), such as exosomes, as liquid biopsy-derived biomarkers for cancers have been investigated. CTC enumeration using the CellSearch based platform provides an accurate insight on overall survival where higher CTC counts indicate poor prognosis for patients with advanced metastatic cancer. EVs provide information based on their lipid, protein, and nucleic acid content and can be isolated from biofluids and analyzed from a relatively small volume, providing a routine and non-invasive modality to monitor disease progression. Our pilot experiment by assessing the level of two subpopulations of small EVs, the CD9 positive and CD63 positive EVs, showed that the CD9 positive EV level is higher in plasma from patients with advanced metastatic prostate cancer with detectable CTCs. These data show the potential utility of a particular EV subpopulation to serve as biomarkers for advanced metastatic prostate cancer. EVs can potentially be utilized as biomarkers to provide accurate genotypic and phenotypic information for advanced prostate cancer, where new strategies to design a more personalized therapy is currently the focus of considerable investigation. © 2017 Wiley Periodicals, Inc.

DNA nanotechnology: Bringing lipid bilayers into shape

NASA Astrophysics Data System (ADS)

Howorka, Stefan

2017-07-01

Lipid bilayers form the thin and floppy membranes that define the boundary of compartments such as cells. Now, a method to control the shape and size of bilayers using DNA nanoscaffolds has been developed. Such designer materials advance synthetic biology and could find use in membrane research.

Designing degradable hydrogels for orthogonal control of cell microenvironments

PubMed Central

Kharkar, Prathamesh M.

2013-01-01

Degradable and cell-compatible hydrogels can be designed to mimic the physical and biochemical characteristics of native extracellular matrices and provide tunability of degradation rates and related properties under physiological conditions. Hence, such hydrogels are finding widespread application in many bioengineering fields, including controlled bioactive molecule delivery, cell encapsulation for controlled three-dimensional culture, and tissue engineering. Cellular processes, such as adhesion, proliferation, spreading, migration, and differentiation, can be controlled within degradable, cell-compatible hydrogels with temporal tuning of biochemical or biophysical cues, such as growth factor presentation or hydrogel stiffness. However, thoughtful selection of hydrogel base materials, formation chemistries, and degradable moieties is necessary to achieve the appropriate level of property control and desired cellular response. In this review, hydrogel design considerations and materials for hydrogel preparation, ranging from natural polymers to synthetic polymers, are overviewed. Recent advances in chemical and physical methods to crosslink hydrogels are highlighted, as well as recent developments in controlling hydrogel degradation rates and modes of degradation. Special attention is given to spatial or temporal presentation of various biochemical and biophysical cues to modulate cell response in static (i.e., non-degradable) or dynamic (i.e., degradable) microenvironments. This review provides insight into the design of new cell-compatible, degradable hydrogels to understand and modulate cellular processes for various biomedical applications. PMID:23609001

Highly Reversible Zinc-ion Intercalation with Chevrel Phase Mo6S8 Nanocubes and Applications for Advanced Zinc-ion Batteries

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

Cheng, Yingwen; Luo, Langli; Zhong, Li

We demonstrate the application of the Chevrel phase Mo6S8 nanocubes as the anode material for rechargeable Zn-ion batteries. Mo6S8 can host Zn2+ ions reversibility both in aqueous and nonaqueous electrolytes with specific capacities around 90 mAh/g and exhibited remarkable intercalation kinetics as well as stability. Furthermore, we assembled full cells by integrating Mo6S8 anode with zinc-polyiodide (I-/I3-) based catholytes, and demonstrated that such fuel cells was also able to deliver outstanding rate performance and cyclic stability. This first demonstration of zinc intercalating anode could inspire the design of advanced Zn ion batteries.

Advanced on-site power plant development technology program

NASA Technical Reports Server (NTRS)

1984-01-01

A 30-cell, full area short stack containing advanced cell features was tested for 2900 hours. A stack acid addition approach was selected and will be evaluated on the stack at 5000 hours test time. A brassboard inverter was designed and fabrication was initiated. Evaluation of this brassboard inverter will take place in 1984. A Teflon coated commercial heat exchanger was selected as the preferred approach for the acid condenser. A reformer catalyst with significantly less pressure drop and equivalent performance relative to the 40-K baseline catalyst was selected for the development reformer. The early 40-kW field power plant history was reviewed and adjustments were made to the On-Site Technology Development Program to address critical component issues.

[Basic Studies on Locoregional Injection of a Newly Designed Chitin Sol].

PubMed

Chiba, Takehiro; Sugitachi, Akio; Kume, Kouhei; Segawa, Takenori; Nishinari, Yutaka; Ishida, Kaoru; Noda, Hironobu; Nishizuka, Satoshi; Kimura, Yusuke; Koeda, Keisuke; Sasaki, Akira

2015-11-01

Systemic chemotherapy in advanced cancer cases often provokes serious adverse events. We aimed to examine the fundamental properties and efficacy of a novel chitin sol, an anti-cancer agent with minor side effects designed to avoid the adverse effects of chemotherapy and enhance the QOL and ADL of patients. DAC-70 was used to create the novel agent termed DAC-70 sol. The anti-proliferative activity was assayed by the WST method using different types of cell lines. The anti-cancer efficacy of the novel agent was examined using cancer-bearing mice. DAC-70 sol was easily injectable through a 21-G needle. The sol suppressed proliferation of the cells in vitro. Intra-tumor injection of DAC-70 sol inhibited the rapid growth of solid tumors in the mice. CDDP-loaded DAC-70 sol, CDDP/DAC-70 sol, successfully controlled malignant ascites in the mice (p<0.05). Neither recurrence nor severe complications were encountered in these animals. These basic data strongly suggest that locoregional administration of our newly designed DAC-70 sol and CDDP/DAC-70 sol is clinically useful as novel cancer chemotherapy for advanced cases. This warrants further clinical studies in cancer chemotherapy.

Realization of compact, passively-cooled, high-flux photovoltaic prototypes

NASA Astrophysics Data System (ADS)

Feuermann, Daniel; Gordon, Jeffrey M.; Horne, Steve; Conley, Gary; Winston, Roland

2005-08-01

The materialization of a recent conceptual advance in high-flux photovoltaic concentrators into first-generation prototypes is reported. Our design strategy includes a tailored imaging dual-mirror (aplanatic) system, with a tapered glass rod that enhances concentration and accommodates larger optical errors. Designs were severely constrained by the need for ultra-compact (minimal aspect ratio) modules, simple passive heat rejection, liberal optical tolerances, incorporating off-the-shelf commercial solar cells, and pragmatic considerations of affordable fabrication technologies. Each unit has a geometric concentration of 625 and irradiates a single square 100 mm2 triple-junction high-efficiency solar cell at a net flux concentration of 500.

Use of Advanced Solar Cells for Commercial Communication Satellites

NASA Technical Reports Server (NTRS)

Bailey, Sheila G.; Landis, Geoffrey A.

1995-01-01

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

Use of advanced solar cells for commerical communication satellites

NASA Astrophysics Data System (ADS)

Landis, Geoffrey A.; Bailey, Sheila G.

1995-01-01

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

Use of advanced solar cells for commercial communication satellites

NASA Astrophysics Data System (ADS)

Bailey, Sheila G.; Landis, Geoffrey A.

1995-03-01

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

Nanostructured material-based biofuel cells: recent advances and future prospects.

PubMed

Zhao, Cui-E; Gai, Panpan; Song, Rongbin; Chen, Ying; Zhang, Jianrong; Zhu, Jun-Jie

2017-03-06

During the past decade, biofuel cells (BFCs) have emerged as an emerging technology on account of their ability to directly generate electricity from biologically renewable catalysts and fuels. Due to the boost in nanotechnology, significant advances have been accomplished in BFCs. Although it is still challenging to promote the performance of BFCs, adopting nanostructured materials for BFC construction has been extensively proposed as an effective and promising strategy to achieve high energy production. In this review, we presented the major novel nanostructured materials applied for BFCs and highlighted the breakthroughs in this field. Based on different natures of the bio-catalysts and electron transfer process at the bio-electrode surfaces, the fundamentals of BFC systems, including enzymatic biofuel cells (EBFCs) and microbial fuel cells (MFCs), have been elucidated. In particular, the principle of electrode materials design has been detailed in terms of enhancing electrical communications between biological catalysts and electrodes. Furthermore, we have provided the applications of BFCs and potential challenges of this technology.

Three-Dimensional Printing of Tissue/Organ Analogues Containing Living Cells.

PubMed

Park, Jeong Hun; Jang, Jinah; Lee, Jung-Seob; Cho, Dong-Woo

2017-01-01

The technical advances of three-dimensional (3D) printing in the field of tissue engineering have enabled the creation of 3D living tissue/organ analogues. Diverse 3D tissue/organ printing techniques with computer-aided systems have been developed and used to dispose living cells together with biomaterials and supporting biochemicals as pre-designed 3D tissue/organ models. Furthermore, recent advances in bio-inks, which are printable hydrogels with living cell encapsulation, have greatly enhanced the versatility of 3D tissue/organ printing. Here, we introduce 3D tissue/organ printing techniques and biomaterials that have been developed and widely used thus far. We also review a variety of applications in an attempt to repair or replace the damaged or defective tissue/organ, and develop the in vitro tissue/organ models. The potential challenges are finally discussed from the technical perspective of 3D tissue/organ printing.

Visible light induced electropolymerization of suspended hydrogel bioscaffolds in a microfluidic chip.

PubMed

Li, Pan; Yu, Haibo; Liu, Na; Wang, Feifei; Lee, Gwo-Bin; Wang, Yuechao; Liu, Lianqing; Li, Wen Jung

2018-05-23

The development of microengineered hydrogels co-cultured with cells in vitro could advance in vivo bio-systems in both structural complexity and functional hierarchy, which holds great promise for applications in regenerative tissues or organs, drug discovery and screening, and bio-sensors or bio-actuators. Traditional hydrogel microfabrication technologies such as ultraviolet (UV) laser or multiphoton laser stereolithography and three-dimensional (3D) printing systems have advanced the development of 3D hydrogel micro-structures but need either expensive and complex equipment, or harsh material selection with limited photoinitiators. Herein, we propose a simple and flexible hydrogel microfabrication method based on a ubiquitous visible-light projection system combined with a custom-designed photosensitive microfluidic chip, to rapidly (typically several to tens of seconds) fabricate various two-dimensional (2D) hydrogel patterns and 3D hydrogel constructs. A theoretical layer-by-layer model that involves continuous polymerizing-delaminating-polymerizing cycles is presented to explain the polymerization and structural formation mechanism of hydrogels. A large area of hydrogel patterns was efficiently fabricated without the usage of costly laser systems or photoinitiators, i.e., a stereoscopic mesh-like hydrogel network with intersecting hydrogel micro-belts was fabricated via a series of dynamic-changing digital light projections. The pores and gaps of the hydrogel network are tunable, which facilitates the supply of nutrients and discharge of waste in the construction of 3D thick bio-models. Cell co-culture experiments showed the effective regulation of cell spreading by hydrogel scaffolds fabricated by the new method presented here. This visible light enabled hydrogel microfabrication method may provide new prospects for designing cell-based units for advanced biomedical studies, e.g., for 3D bio-models or bio-actuators in the future.

Emerging science and therapies in non-small-cell lung cancer: targeting the MET pathway.

PubMed

Kris, Mark G; Arenberg, Douglas A; Herbst, Roy S; Riely, Gregory J

2014-11-01

During this enduring, learner-driven, interactive CME webseries, lung cancer specialists will address the science and targeted therapies for the MET pathway in non-small cell lung cancer. Over the past decade, research has evolved in the science of identifying targeted biological changes in DNA and individual cancer cells. Along with the advanced understanding of lung cancer mutations, has come the development of specific targeted therapies that improve patient outcomes. The first step in treating a patient with lung cancer is proper diagnosis and staging, applying to the principles of personalize medicine. Our current understanding of lung cancer is that of a collection of diseases individualized through specific mutations. This CME activity reviews the role of the pulmonologist and pathologist in proper tissue acquisition and analysis. This new era of personalized medicine and clinical research advances has changed the way clinicians evaluate and treat patients with lung cancer. The data on lung cancer cell mutations and newer targeted therapies have improved the progression free survival and quality of life of lung cancer patients. This CME activity is designed to present a practical overview of recent evidenced based data of MET targeted therapies for patients with lung cancer. As research continues to evolve, we continue to advance our understanding in the science of lung cancers involving the MET pathway. Evidenced based data supporting newer targeted therapeutics provides insight on applying treatment for optimal outcomes. This CME activity will focus on the individualized treatment strategies using practical decision making for patients with MET expression. This activity has been designed to meet the educational needs of medical oncologists, pathologists, radiation oncologists, surgeons, pulmonologists, internists, and other healthcare clinicians responsible for the care of patients with lung cancer. Online access:http://www.elseviercme.com/516/.

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.

Recent advances in acute myeloid leukemia stem cell biology.

PubMed

Horton, Sarah J; Huntly, Brian J P

2012-07-01

The existence of cancer stem cells has long been postulated, but was proven less than 20 years ago following the demonstration that only a small sub-fraction of leukemic cells from acute myeloid leukemia patients were able to propagate the disease in xenografts. These cells were termed leukemic stem cells since they exist at the apex of a loose hierarchy, possess extensive self-renewal and the ability to undergo limited differentiation into leukemic blasts. Acute myeloid leukemia is a heterogeneous condition at both the phenotypic and molecular level with a variety of distinct genetic alterations giving rise to the disease. Recent studies have highlighted that this heterogeneity extends to the leukemic stem cell, with this dynamic compartment evolving to overcome various selection pressures imposed upon it during disease progression. The result is a complex situation in which multiple pools of leukemic stem cells may exist within individual patients which differ both phenotypically and molecularly. Since leukemic stem cells are thought to be resistant to current chemotherapeutic regimens and mediate disease relapse, their study also has potentially profound clinical implications. Numerous studies have generated important recent advances in the field, including the identification of novel leukemic stem cell-specific cell surface antigens and gene expression signatures. These tools will no doubt prove invaluable for the rational design of targeted therapies in the future.

When stem cells grow old: phenotypes and mechanisms of stem cell aging.

PubMed

Schultz, Michael B; Sinclair, David A

2016-01-01

All multicellular organisms undergo a decline in tissue and organ function as they age. An attractive theory is that a loss in stem cell number and/or activity over time causes this decline. In accordance with this theory, aging phenotypes have been described for stem cells of multiple tissues, including those of the hematopoietic system, intestine, muscle, brain, skin and germline. Here, we discuss recent advances in our understanding of why adult stem cells age and how this aging impacts diseases and lifespan. With this increased understanding, it is feasible to design and test interventions that delay stem cell aging and improve both health and lifespan. © 2016. Published by The Company of Biologists Ltd.

When stem cells grow old: phenotypes and mechanisms of stem cell aging

PubMed Central

Schultz, Michael B.; Sinclair, David A.

2016-01-01

All multicellular organisms undergo a decline in tissue and organ function as they age. An attractive theory is that a loss in stem cell number and/or activity over time causes this decline. In accordance with this theory, aging phenotypes have been described for stem cells of multiple tissues, including those of the hematopoietic system, intestine, muscle, brain, skin and germline. Here, we discuss recent advances in our understanding of why adult stem cells age and how this aging impacts diseases and lifespan. With this increased understanding, it is feasible to design and test interventions that delay stem cell aging and improve both health and lifespan. PMID:26732838

New paradigms in internal architecture design and freeform fabrication of tissue engineering porous scaffolds.

PubMed

Yoo, Dongjin

2012-07-01

Advanced additive manufacture (AM) techniques are now being developed to fabricate scaffolds with controlled internal pore architectures in the field of tissue engineering. In general, these techniques use a hybrid method which combines computer-aided design (CAD) with computer-aided manufacturing (CAM) tools to design and fabricate complicated three-dimensional (3D) scaffold models. The mathematical descriptions of micro-architectures along with the macro-structures of the 3D scaffold models are limited by current CAD technologies as well as by the difficulty of transferring the designed digital models to standard formats for fabrication. To overcome these difficulties, we have developed an efficient internal pore architecture design system based on triply periodic minimal surface (TPMS) unit cell libraries and associated computational methods to assemble TPMS unit cells into an entire scaffold model. In addition, we have developed a process planning technique based on TPMS internal architecture pattern of unit cells to generate tool paths for freeform fabrication of tissue engineering porous scaffolds. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

CellLineNavigator: a workbench for cancer cell line analysis

PubMed Central

Krupp, Markus; Itzel, Timo; Maass, Thorsten; Hildebrandt, Andreas; Galle, Peter R.; Teufel, Andreas

2013-01-01

The CellLineNavigator database, freely available at http://www.medicalgenomics.org/celllinenavigator, is a web-based workbench for large scale comparisons of a large collection of diverse cell lines. It aims to support experimental design in the fields of genomics, systems biology and translational biomedical research. Currently, this compendium holds genome wide expression profiles of 317 different cancer cell lines, categorized into 57 different pathological states and 28 individual tissues. To enlarge the scope of CellLineNavigator, the database was furthermore closely linked to commonly used bioinformatics databases and knowledge repositories. To ensure easy data access and search ability, a simple data and an intuitive querying interface were implemented. It allows the user to explore and filter gene expression, focusing on pathological or physiological conditions. For a more complex search, the advanced query interface may be used to query for (i) differentially expressed genes; (ii) pathological or physiological conditions; or (iii) gene names or functional attributes, such as Kyoto Encyclopaedia of Genes and Genomes pathway maps. These queries may also be combined. Finally, CellLineNavigator allows additional advanced analysis of differentially regulated genes by a direct link to the Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources. PMID:23118487

Rational design and optimization of downstream processes of virus particles for biopharmaceutical applications: current advances.

PubMed

Vicente, Tiago; Mota, José P B; Peixoto, Cristina; Alves, Paula M; Carrondo, Manuel J T

2011-01-01

The advent of advanced therapies in the pharmaceutical industry has moved the spotlight into virus-like particles and viral vectors produced in cell culture holding great promise in a myriad of clinical targets, including cancer prophylaxis and treatment. Even though a couple of cases have reached the clinic, these products have yet to overcome a number of biological and technological challenges before broad utilization. Concerning the manufacturing processes, there is significant research focusing on the optimization of current cell culture systems and, more recently, on developing scalable downstream processes to generate material for pre-clinical and clinical trials. We review the current options for downstream processing of these complex biopharmaceuticals and underline current advances on knowledge-based toolboxes proposed for rational optimization of their processing. Rational tools developed to increase the yet scarce knowledge on the purification processes of complex biologicals are discussed as alternative to empirical, "black-boxed" based strategies classically used for process development. Innovative methodologies based on surface plasmon resonance, dynamic light scattering, scale-down high-throughput screening and mathematical modeling for supporting ion-exchange chromatography show great potential for a more efficient and cost-effective process design, optimization and equipment prototyping. Copyright © 2011 Elsevier Inc. All rights reserved.

Expanding the chemical palate of cells by combining systems biology and metabolic engineering.

PubMed

Curran, Kathleen A; Alper, Hal S

2012-07-01

The field of Metabolic Engineering has recently undergone a transformation that has led to a rapid expansion of the chemical palate of cells. Now, it is conceivable to produce nearly any organic molecule of interest using a cellular host. Significant advances have been made in the production of biofuels, biopolymers and precursors, pharmaceuticals and nutraceuticals, and commodity and specialty chemicals. Much of this rapid expansion in the field has been, in part, due to synergies and advances in the area of systems biology. Specifically, the availability of functional genomics, metabolomics and transcriptomics data has resulted in the potential to produce a wealth of new products, both natural and non-natural, in cellular factories. The sheer amount and diversity of this data however, means that uncovering and unlocking novel chemistries and insights is a non-obvious exercise. To address this issue, a number of computational tools and experimental approaches have been developed to help expedite the design process to create new cellular factories. This review will highlight many of the systems biology enabling technologies that have reduced the design cycle for engineered hosts, highlight major advances in the expanded diversity of products that can be synthesized, and conclude with future prospects in the field of metabolic engineering. Copyright © 2012 Elsevier Inc. All rights reserved.

Pivotal ERIVANCE basal cell carcinoma (BCC) study: 12-month update of efficacy and safety of vismodegib in advanced BCC.

PubMed

Sekulic, Aleksandar; Migden, Michael R; Lewis, Karl; Hainsworth, John D; Solomon, James A; Yoo, Simon; Arron, Sarah T; Friedlander, Philip A; Marmur, Ellen; Rudin, Charles M; Chang, Anne Lynn S; Dirix, Luc; Hou, Jeannie; Yue, Huibin; Hauschild, Axel

2015-06-01

Primary analysis from the pivotal ERIVANCE BCC study resulted in approval of vismodegib, a Hedgehog pathway inhibitor indicated for treatment of adults with metastatic or locally advanced basal cell carcinoma (BCC) that has recurred after surgery or for patients who are not candidates for surgery or radiation. An efficacy and safety analysis was conducted 12 months after primary analysis. This was a multinational, multicenter, nonrandomized, 2-cohort study in patients with measurable and histologically confirmed locally advanced or metastatic BCC taking oral vismodegib (150 mg/d). Primary outcome measure was objective response rate (complete and partial responses) assessed by independent review facility. After 12 months of additional follow-up, median duration of exposure to vismodegib was 12.9 months. Objective response rate increased from 30.3% to 33.3% in patients with metastatic disease, and from 42.9% to 47.6% in patients with the locally advanced form. Median duration of response in patients with locally advanced BCC increased from 7.6 to 9.5 months. No new safety signals emerged with extended treatment duration. Limitations include low prevalence of advanced BCC and challenges of designing a study with heterogenous manifestations. The 12-month update of the study confirms the efficacy and safety of vismodegib in management of advanced BCC. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Design of Polymeric Culture Substrates to Promote Proangiogenic Potential of Stem Cells.

PubMed

Kwon, Byeong-Ju; Wang, Xintong; Kang, Mi-Lan; You, Jin; Lee, Shin-Jeong; Kim, Won Shik; Yoon, Young-Sup; Park, Jong-Chul; Sung, Hak-Joon

2018-02-01

Stem cells are a promising cell source for regenerative medicine due to their differentiation and self-renewal capacities. In the field of regenerative medicine and tissue engineering, a variety of biomedical technologies have been tested to improve proangiogenic activities of stem cells. However, their therapeutic effect is found to be limited in the clinic because of cell loss, senescence, and insufficient therapeutic activities. To address this type of issue, advanced techniques for biomaterial synthesis and fabrication have been approached to mimic proangiogenic microenvironment and to direct proangiogenic activities. This review highlights the types of polymers and design strategies that have been studied to promote proangiogenic activities of stem cells. In particular, scaffolds, hydrogels, and surface topographies, as well as insight into their underlying mechanisms to improve proangiogenic activities are the focuses. The strategy to promote angiogenic activities of hMSCs by controlling substrate repellency is introduced, and the future direction is proposed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison and optimization of machine learning methods for automated classification of circulating tumor cells.

PubMed

Lannin, Timothy B; Thege, Fredrik I; Kirby, Brian J

2016-10-01

Advances in rare cell capture technology have made possible the interrogation of circulating tumor cells (CTCs) captured from whole patient blood. However, locating captured cells in the device by manual counting bottlenecks data processing by being tedious (hours per sample) and compromises the results by being inconsistent and prone to user bias. Some recent work has been done to automate the cell location and classification process to address these problems, employing image processing and machine learning (ML) algorithms to locate and classify cells in fluorescent microscope images. However, the type of machine learning method used is a part of the design space that has not been thoroughly explored. Thus, we have trained four ML algorithms on three different datasets. The trained ML algorithms locate and classify thousands of possible cells in a few minutes rather than a few hours, representing an order of magnitude increase in processing speed. Furthermore, some algorithms have a significantly (P < 0.05) higher area under the receiver operating characteristic curve than do other algorithms. Additionally, significant (P < 0.05) losses to performance occur when training on cell lines and testing on CTCs (and vice versa), indicating the need to train on a system that is representative of future unlabeled data. Optimal algorithm selection depends on the peculiarities of the individual dataset, indicating the need of a careful comparison and optimization of algorithms for individual image classification tasks. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

Action Biology. Advanced Placement for the Second Year. First Edition.

ERIC Educational Resources Information Center

Davis, Mary Pitt

This document provides biology experiments designed for students who have completed a first year biology course. This self contained laboratory booklet contains four sections. In section 1, "Instrumentation in the Study of Cells," discussion sections and suggestions for teacher demonstrations are provided. It also includes some basic materials…

Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

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

Fletcher, James H.; Cox, Philip; Harrington, William J

2013-09-03

ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focusedmore » on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel containment. PROJECT OVERVIEW The University of North Florida (UNF), with project partner the University of Florida, recently completed the Department of Energy (DOE) project entitled “Advanced Direct Methanol Fuel Cell for Mobile Computing”. The primary objective of the project was to advance portable fuel cell system technology towards the commercial targets as laid out in the DOE R&D roadmap by developing a 20-watt, direct methanol fuel cell (DMFC), portable power supply based on the UNF innovative “passive water recovery” MEA. Extensive component, sub-system, and system development and testing was undertaken to meet the rigorous demands of the consumer electronic application. Numerous brassboard (nonpackaged) systems were developed to optimize the integration process and facilitating control algorithm development. The culmination of the development effort was a fully-integrated, DMFC, power supply (referred to as DP4). The project goals were 40 W/kg for specific power, 55 W/l for power density, and 575 Whr/l for energy density. It should be noted that the specific power and power density were for the power section only, and did not include the hybrid battery. The energy density is based on three, 200 ml, fuel cartridges, and also did not include the hybrid battery. The results show that the DP4 system configured without the methanol concentration sensor exceeded all performance goals, achieving 41.5 W/kg for specific power, 55.3 W/l for power density, and 623 Whr/l for energy density. During the project, the DOE revised its technical targets, and the definition of many of these targets, for the portable power application. With this revision, specific power, power density, specific energy (Whr/kg), and energy density are based on the total system, including fuel tank, fuel, and hybridization battery. Fuel capacity is not defined, but the same value is required for all calculations. Test data showed that the DP4 exceeded all 2011 Technical Status values; for example, the DP4 energy density was 373 Whr/l versus the DOE 2011 status of 200 Whr/l. For the DOE 2013 Technical Goals, the operation time was increased from 10 hours to 14.3 hours. Under these conditions, the DP4 closely approached or surpassed the technical targets; for example, the DP4 achieved 468 Whr/l versus the goal of 500 Whr/l. Thus, UNF has successfully met the project goals. A fully-operational, 20-watt DMFC power supply was developed based on the UNF passive water recovery MEA. The power supply meets the project performance goals and advances portable power technology towards the commercialization targets set by the DOE.« less

Advances in ambient temperature secondary lithium cells

NASA Technical Reports Server (NTRS)

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

1989-01-01

The Jet Propulsion Laboratory is involved in a Research and Development program sponsored by NASA/OAST on the development of ambient temperature secondary lithium cells for future space applications. Some of the projected applications are planetary spacecraft, planetary rovers, and astronaut equipment. The main objective is to develop secondary lithium cells with greater than 100 Wh/kg specific energy while delivering 1000 cycles at 50 percent Depth of Discharge (DOD). To realize these ambitious goals, the work was initially focused on several important basic issues related to the cell chemistry, selection of cathode materials and electrolytes, and component development. The performance potential of Li-TiS2, Li-MoS3, Li-V6O13 and Li-NbSe3 electrochemical systems was examined. Among these four, the Li-TiS2 system was found to be the most promising system in terms of realizable specific energy and cycle life. Some of the major advancements made so far in the development of Li-TiS2 cells are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly. Methods were developed for the fabrication of large size high performance TiS2 cathodes. Among the various electrolytes examined, 1.5M LiAsF6/EC + 2-MeTHF mixed solvent electrolyte was found to be more stable towards lithium. Experimental cells activated with this electrolyte exhibited more than 300 cycles at 100 percent Depth of Discharge. Work is in progress in other areas such as selection of lithium alloys as candidate anode materials, optimization of cell design, and development of 5 Ah cells. The advances made at the Jet Propulsion Laboratory on the development of secondary lithium cells are summarized.

A phase I study of docetaxel as a radio-sensitizer for locally advanced squamous cell cervical cancer.

PubMed

Alvarez, Edwin A; Wolfson, Aaron H; Pearson, J Matt; Crisp, Meredith P; Mendez, Luis E; Lambrou, Nicholas C; Lucci, Joseph A

2009-05-01

This study was designed to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of weekly docetaxel with concurrent radiotherapy (RT) for the primary treatment of locally advanced squamous cell carcinoma of the cervix. Eligible patients included those with locally advanced squamous cell cervical cancer without para-aortic lymph node involvement. Docetaxel dose levels were 20 mg/m(2), 30 mg/m(2) and 40 mg/m(2) given intravenously weekly for 6 cycles. Three patients were to be treated at each dose level and 6 to receive the MTD. Fifteen patients completed 4-6 cycles of chemotherapy. One of three patients experienced 2 delayed grade 3 severe adverse events (SAE) at the 20 mg/m(2) dose level consisting of colonic and ureteral obstruction. At the 30 mg/m(2) dose level, 1/4 patients had a probable treatment-related celiotomy due to obstipation and a necrotic tumor. Of the 8 patients treated at the 40 mg/m(2) dose level, 1 experienced grade 3 pneumonitis, likely treatment related. Overall, 10/15 (67%) experienced grade 1 or 2 diarrhea, 6 had grade 2 hematologic toxicity, and 2 had grade 2 hypersensitivity. 10 of 16 patients (67%) had no evidence of disease with follow-up ranging from 10-33 months (average 23 months). The recommended phase II dose of docetaxel administered weekly with concurrent radiotherapy for locally advanced squamous cell carcinoma of the cervix is 40 mg/m(2).

Single Cell Gene Expression Profiling of Skeletal Muscle-Derived Cells.

PubMed

Gatto, Sole; Puri, Pier Lorenzo; Malecova, Barbora

2017-01-01

Single cell gene expression profiling is a fundamental tool for studying the heterogeneity of a cell population by addressing the phenotypic and functional characteristics of each cell. Technological advances that have coupled microfluidic technologies with high-throughput quantitative RT-PCR analyses have enabled detailed analyses of single cells in various biological contexts. In this chapter, we describe the procedure for isolating the skeletal muscle interstitial cells termed Fibro-Adipogenic Progenitors (FAPs ) and their gene expression profiling at the single cell level. Moreover, we accompany our bench protocol with bioinformatics analysis designed to process raw data as well as to visualize single cell gene expression data. Single cell gene expression profiling is therefore a useful tool in the investigation of FAPs heterogeneity and their contribution to muscle homeostasis.

Advances in Understanding Stimulus Responsive Phase Behavior of Intrinsically Disordered Protein Polymers.

PubMed

Ruff, Kiersten M; Roberts, Stefan; Chilkoti, Ashutosh; Pappu, Rohit V

2018-06-24

Proteins and synthetic polymers can undergo phase transitions in response to changes to intensive solution parameters such as temperature, proton chemical potentials (pH), and hydrostatic pressure. For proteins and protein-based polymers, the information required for stimulus responsive phase transitions is encoded in their amino acid sequence. Here, we review some of the key physical principles that govern the phase transitions of archetypal intrinsically disordered protein polymers (IDPPs). These are disordered proteins with highly repetitive amino acid sequences. Advances in recombinant technologies have enabled the design and synthesis of protein sequences of a variety of sequence complexities and lengths. We summarize insights that have been gleaned from the design and characterization of IDPPs that undergo thermo-responsive phase transitions and build on these insights to present a general framework for IDPPs with pH and pressure responsive phase behavior. In doing so, we connect the stimulus responsive phase behavior of IDPPs with repetitive sequences to the coil-to-globule transitions that these sequences undergo at the single chain level in response to changes in stimuli. The proposed framework and ongoing studies of stimulus responsive phase behavior of designed IDPPs have direct implications in bioengineering, where designing sequences with bespoke material properties broadens the spectrum of applications, and in biology and medicine for understanding the sequence-specific driving forces for the formation of protein-based membraneless organelles as well as biological matrices that act as scaffolds for cells and mediators of cell-to-cell communication. Copyright © 2018. Published by Elsevier Ltd.

Poly(ester-urethane) scaffolds: effect of structure on properties and osteogenic activity of stem cells.

PubMed

Kiziltay, Aysel; Marcos-Fernandez, Angel; San Roman, Julio; Sousa, Rui A; Reis, Rui L; Hasirci, Vasif; Hasirci, Nesrin

2015-08-01

The present study aimed to investigate the effect of structure (design and porosity) on the matrix stiffness and osteogenic activity of stem cells cultured on poly(ester-urethane) (PEU) scaffolds. Different three-dimensional (3D) forms of scaffold were prepared from lysine-based PEU using traditional salt-leaching and advanced bioplotting techniques. The resulting scaffolds were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mercury porosimetry and mechanical testing. The scaffolds had various pore sizes with different designs, and all were thermally stable up to 300 °C. In vitro tests, carried out using rat bone marrow stem cells (BMSCs) for bone tissue engineering, demonstrated better viability and higher cell proliferation on bioplotted scaffolds compared to salt-leached ones, most probably due to their larger and interconnected pores and stiffer nature, as shown by higher compressive moduli, which were measured by compression testing. Similarly, SEM, von Kossa staining and EDX analyses indicated higher amounts of calcium deposition on bioplotted scaffolds during cell culture. It was concluded that the design with larger interconnected porosity and stiffness has an effect on the osteogenic activity of the stem cells. Copyright © 2013 John Wiley & Sons, Ltd.

Full space device optimization for solar cells.

PubMed

Baloch, Ahmer A B; Aly, Shahzada P; Hossain, Mohammad I; El-Mellouhi, Fedwa; Tabet, Nouar; Alharbi, Fahhad H

2017-09-20

Advances in computational materials have paved a way to design efficient solar cells by identifying the optimal properties of the device layers. Conventionally, the device optimization has been governed by single or double descriptors for an individual layer; mostly the absorbing layer. However, the performance of the device depends collectively on all the properties of the material and the geometry of each layer in the cell. To address this issue of multi-property optimization and to avoid the paradigm of reoccurring materials in the solar cell field, a full space material-independent optimization approach is developed and presented in this paper. The method is employed to obtain an optimized material data set for maximum efficiency and for targeted functionality for each layer. To ensure the robustness of the method, two cases are studied; namely perovskite solar cells device optimization and cadmium-free CIGS solar cell. The implementation determines the desirable optoelectronic properties of transport mediums and contacts that can maximize the efficiency for both cases. The resulted data sets of material properties can be matched with those in materials databases or by further microscopic material design. Moreover, the presented multi-property optimization framework can be extended to design any solid-state device.

Advanced overlay analysis through design based metrology

NASA Astrophysics Data System (ADS)

Ji, Sunkeun; Yoo, Gyun; Jo, Gyoyeon; Kang, Hyunwoo; Park, Minwoo; Kim, Jungchan; Park, Chanha; Yang, Hyunjo; Yim, Donggyu; Maruyama, Kotaro; Park, Byungjun; Yamamoto, Masahiro

2015-03-01

As design rule shrink, overlay has been critical factor for semiconductor manufacturing. However, the overlay error which is determined by a conventional measurement with an overlay mark based on IBO and DBO often does not represent the physical placement error in the cell area. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion caused by etching or CMP also can be a source of the mismatch. In 2014, we have demonstrated that method of overlay measurement in the cell area by using DBM (Design Based Metrology) tool has more accurate overlay value than conventional method by using an overlay mark. We have verified the reproducibility by measuring repeatable patterns in the cell area, and also demonstrated the reliability by comparing with CD-SEM data. We have focused overlay mismatching between overlay mark and cell area until now, further more we have concerned with the cell area having different pattern density and etch loading. There appears a phenomenon which has different overlay values on the cells with diverse patterning environment. In this paper, the overlay error was investigated from cell edge to center. For this experiment, we have verified several critical layers in DRAM by using improved(Better resolution and speed) DBM tool, NGR3520.

Innovative Tools and Technology for Analysis of Single Cells and Cell-Cell Interaction.

PubMed

Konry, Tania; Sarkar, Saheli; Sabhachandani, Pooja; Cohen, Noa

2016-07-11

Heterogeneity in single-cell responses and intercellular interactions results from complex regulation of cell-intrinsic and environmental factors. Single-cell analysis allows not only detection of individual cellular characteristics but also correlation of genetic content with phenotypic traits in the same cell. Technological advances in micro- and nanofabrication have benefited single-cell analysis by allowing precise control of the localized microenvironment, cell manipulation, and sensitive detection capabilities. Additionally, microscale techniques permit rapid, high-throughput, multiparametric screening that has become essential for -omics research. This review highlights innovative applications of microscale platforms in genetic, proteomic, and metabolic detection in single cells; cell sorting strategies; and heterotypic cell-cell interaction. We discuss key design aspects of single-cell localization and isolation in microfluidic systems, dynamic and endpoint analyses, and approaches that integrate highly multiplexed detection of various intracellular species.

In vitro anticancer effects of a RAGE inhibitor discovered using a structure-based drug design system

PubMed Central

El-Far, Ali Hafez Ali Mohammed; Munesue, Seiichi; Harashima, Ai; Sato, Akira; Shindo, Mika; Nakajima, Shingo; Inada, Mana; Tanaka, Mariko; Takeuchi, Akihiko; Tsuchiya, Hiroyuki; Yamamoto, Hiroshi; Shaheen, Hazem M.E.; El-Sayed, Yasser S.; Kawano, Shuhei; Tanuma, Sei-Ichi; Yamamoto, Yasuhiko

2018-01-01

Receptor for advanced glycation end-products (RAGE) is a pattern recognition receptor implicated in the pathogenesis of certain types of cancer. In the present study, papaverine was identified as a RAGE inhibitor using the conversion to small molecules through optimized-peptide strategy drug design system. Papaverine significantly inhibited RAGE-dependent nuclear factor κ-B activation driven by high mobility group box-1, a RAGE ligand. Using RAGE- or dominant-negative RAGE-expressing HT1080 human fibrosarcoma cells, the present study revealed that papaverine suppressed RAGE-dependent cell proliferation and migration dose-dependently. Furthermore, papaverine significantly inhibited cell invasion. The results of the present study suggested that papaverine could inhibit RAGE, and provided novel insights into the field of RAGE biology, particularly anticancer therapies. PMID:29541234

Vismodegib in patients with advanced basal cell carcinoma (STEVIE): a pre-planned interim analysis of an international, open-label trial.

PubMed

Basset-Seguin, Nicole; Hauschild, Axel; Grob, Jean-Jacques; Kunstfeld, Rainer; Dréno, Brigitte; Mortier, Laurent; Ascierto, Paolo A; Licitra, Lisa; Dutriaux, Caroline; Thomas, Luc; Jouary, Thomas; Meyer, Nicolas; Guillot, Bernard; Dummer, Reinhard; Fife, Kate; Ernst, D Scott; Williams, Sarah; Fittipaldo, Alberto; Xynos, Ioannis; Hansson, Johan

2015-06-01

The Hedgehog pathway inhibitor vismodegib has shown clinical benefit in patients with advanced basal cell carcinoma and is approved for treatment of patients with advanced basal cell carcinoma for whom surgery is inappropriate. STEVIE was designed to assess the safety of vismodegib in a situation similar to routine practice, with a long follow-up. In this multicentre, open-label trial, adult patients with histologically confirmed locally advanced basal cell carcinoma or metastatic basal cell carcinoma were recruited from regional referral centres or specialist clinics. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and adequate organ function. Patients with locally advanced basal cell carcinoma had to have been deemed ineligible for surgery. All patients received 150 mg oral vismodegib capsules once a day on a continuous basis in 28-day cycles. The primary objective was safety (incidence of adverse events until disease progression or unacceptable toxic effects), with assessments on day 1 of each treatment cycle (28 days) by principal investigator and coinvestigators at the site. Efficacy variables were assessed as secondary endpoints. The safety evaluable population included all patients who received at least one dose of study drug. Patients with histologically confirmed basal cell carcinoma who received at least one dose of study drug were included in the efficacy analysis. An interim analysis was pre-planned after 500 patients achieved 1 year of follow-up. This trial is registered with ClinicalTrials.gov, number NCT01367665. The study is still ongoing. Between June 30, 2011, and Nov 6, 2014, we enrolled 1227 patients. At clinical cutoff (Nov 6, 2013), 499 patients (468 with locally advanced basal cell carcinoma and 31 with metastatic basal cell carcinoma) had received study drug and had the potential to be followed up for 12 months or longer. Treatment was discontinued in 400 (80%) patients; 180 (36%) had adverse events, 70 (14%) had progressive disease, and 51 (10%) requested to stop treatment. Median duration of vismodegib exposure was 36·4 weeks (IQR 17·7-62·0). Adverse events happened in 491 (98%) patients; the most common were muscle spasms (317 [64%]), alopecia (307 [62%]), dysgeusia (269 [54%]), weight loss (162 [33%]), asthenia (141 [28%]), decreased appetite (126 [25%]), ageusia (112 [22%]), diarrhoea (83 [17%]), nausea (80 [16%]), and fatigue (80 [16%]). Most adverse events were grade 1 or 2. We recorded serious adverse events in 108 (22%) of 499 patients. Of the 31 patients who died, 21 were the result of adverse events. As assessed by investigators, 302 (66·7%, 62·1-71·0) of 453 patients with locally advanced basal cell carcinoma had an overall response (153 complete responses and 149 partial responses); 11 (37·9%; 20·7-57·7) of 29 patients with metastatic basal cell carcinoma had an overall response (two complete responses, nine partial responses). This study assessed the use of vismodegib in a setting representative of routine clinical practice for patients with advanced basal cell carcinoma. Our results show that treatment with vismodegib adds a novel therapeutic modality from which patients with advanced basal cell carcinoma can benefit substantially. F Hoffmann-La Roche. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coupled thermal, electrical, and fluid flow analyses of AMTEC converters, with illustrative application to OSC`s cell design

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

Schock, A.; Noravian, H.; Or, C.

1997-12-31

This paper presents the background and introduction to the OSC AMTEC (Alkali Metal Thermal-to-Electrical Conversion) studies, which were conducted for the Department of energy (DOE) and NASA`s jet Propulsion Laboratory (JPL). After describing the basic principle of AMTEC, the paper describes and explains the operation of multi-tube vapor/vapor cells, which have been under development by AMPS (Advance Modular Power Systems, Inc.) for the Air Force Phillips Laboratory (AFPL) and JPL for possible application to the Europa Orbiter, Pluto Express, and other space missions. It then describes a novel OSC-generated methodology for analyzing the performance of such cells. This methodology consistsmore » of an iterative procedure for the coupled solution of the interdependent thermal, electrical, and fluid flow differential and integral equations governing the performance of AMTEC cells and generators, taking proper account of the non-linear axial variations of temperature, pressure, open-circuit voltage, inter-electrode voltages, current density, axial current, sodium mass flow rate, and power density. The paper illustrates that analytical procedure by applying it to OSC`s latest cell design and by presenting detailed analytical results for that design. The OSC-developed analytic methodology constitutes a unique and powerful tool for accurate parametric analyses and design optimizations of the multi-tube AMTEC cells and of radioisotope power systems. This is illustrated in two companion papers in these proceedings. The first of those papers applies the OSC-derived program to determine the effect of various design parameters on the performance of single AMTEC cells with adiabatic side walls, culminating in an OSC-recommended revised cell design. And the second describes a number of OSC-generated AMTEC generator designs consisting of 2 and 3 GPHS heat source modules, 16 multi-tube converter cells, and a hybrid insulation design, and presents the results of applying the above analysis program to determine the applicability of those generators to possible future missions under consideration by NASA.« less

Prostate Cancer Stem-Like Cells | Center for Cancer Research

Cancer.gov

Prostate cancer is the third leading cause of cancer-related death among men, killing an estimated 27,000 men each year in the United States. Men with advanced prostate cancer often become resistant to conventional therapies. Many researchers speculate that the emergence of resistance is due to the presence of cancer stem cells, which are believed to be a small subpopulation of tumor cells that can self-renew and give rise to more differentiated tumor cells. It is thought that these stem cells survive initial therapies (such as chemotherapy and hormone therapy) and then generate new tumor cells that are resistant to these standard treatments. If prostate cancer stem cells could be identified and characterized, it might be possible to design treatments that prevent resistance.

Development of an encapsulated stem cell-based therapy for diabetes.

PubMed

Tomei, Alice Anna; Villa, Chiara; Ricordi, Camillo

2015-01-01

Islet transplantation can treat the most severe cases of type 1 diabetes but it currently requires deceased donor pancreata as an islet source and chronic immunosuppression to prevent rejection and recurrence of autoimmunity. Stem cell-derived insulin-producing cells may address the shortage of organ donors, whereas cell encapsulation may reduce or eliminate the requirement for immunosuppression, minimizing the risks associated with the islet transplantation procedure, and potentially prolonging graft survival. This review focuses on the design principles for immunoisolation devices and on stem cell differentiation into insulin-producing cell products. The reader will gain understanding of the different types of immunoisolation devices and the key parameters that affect the outcome of the encapsulated graft. Progresses in stem cell differentiation towards mature endocrine islet cells, including the most recent clinical trials and the challenges associated with the application of immunoisolation devices designed for primary islets to stem-cell products, are also discussed. Recent advancements in the field of stem cell-derived islet cell products and immunoisolation strategies hold great promise for type 1 diabetes. However, a combination product including both cells and an immunoisolation strategy still needs to be optimized and tested for safety and efficacy.

NASA advanced design program: Analysis, design, and construction of a solar powered aircraft. B.S. Thesis

NASA Technical Reports Server (NTRS)

Chan, Agnes; Conley, Kristin; Javorski, Christian T.; Cheung, Kwok-Hung; Crivelli, Paul M.; Torrey, Nancy P.; Traver, Michael L.

1992-01-01

Increase in energy demands coupled with rapid depletion of natural energy resources have deemed solar energy as the most logical alternative source of power. The major objective of this project was to build a solar powered remotely controlled aircraft to demonstrate the feasibility of solar energy as an effective, alternate source of power. The final design was optimized for minimum weight and maximum strength of the structure. These design constraints necessitated a carbon fiber composite structure. Surya is a lightweight, durable aircraft capable of achieving level flight powered entirely by solar cells.

Aerospace Nickel-cadmium Cell Verification

NASA Technical Reports Server (NTRS)

Manzo, Michelle A.; Strawn, D. Michael; Hall, Stephen W.

2001-01-01

During the early years of satellites, NASA successfully flew "NASA-Standard" nickel-cadmium (Ni-Cd) cells manufactured by GE/Gates/SAFF on a variety of spacecraft. In 1992 a NASA Battery Review Board determined that the strategy of a NASA Standard Cell and Battery Specification and the accompanying NASA control of a standard manufacturing control document (MCD) for Ni-Cd cells and batteries was unwarranted. As a result of that determination, standards were abandoned and the use of cells other than the NASA Standard was required. In order to gain insight into the performance and characteristics of the various aerospace Ni-Cd products available, tasks were initiated within the NASA Aerospace Flight Battery Systems Program that involved the procurement and testing of representative aerospace Ni-Cd cell designs. A standard set of test conditions was established in order to provide similar information about the products from various vendors. The objective of this testing was to provide independent verification of representative commercial flight cells available in the marketplace today. This paper will provide a summary of the verification tests run on cells from various manufacturers: Sanyo 35 Ampere-hour (Ali) standard and 35 Ali advanced Ni-Cd cells, SAFr 50 Ah Ni-Cd cells and Eagle-Picher 21 Ali Magnum and 21 Ali Super Ni-CdTM cells from Eagle-Picher were put through a full evaluation. A limited number of 18 and 55 Ali cells from Acme Electric were also tested to provide an initial evaluation of the Acme aerospace cell designs. Additionally, 35 Ali aerospace design Ni-MH cells from Sanyo were evaluated under the standard conditions established for this program. Ile test program is essentially complete. The cell design parameters, the verification test plan and the details of the test result will be discussed.

Engineering synthetic vaccines using cues from natural immunity

PubMed Central

Irvine, Darrell J.; Swartz, Melody A.; Szeto, Gregory L.

2014-01-01

Vaccines aim to protect against or treat diseases through manipulation of the immune response, promoting either immunity or tolerance. The former generate antibodies and T-cells poised to protect against future pathogen encounter or attack diseased cells such as tumors; the latter, which are far less developed, block pathogenic autoreactive T-cells and autoantibodies that target self tissue. Enormous challenges remain, however, as a consequence of our incomplete understanding of human immunity. A rapidly growing field of research is the design of synthetic materials in vaccines to 1) target organs, tissues, cells, or intracellular compartments; 2) co-deliver immunomodulatory signals that control the quality of the immune response; or 3) directly act as immune regulators, and there exists great potential for well-defined materials to further our understanding of immunity. Here we describe recent advances in the design of synthetic materials to direct immune responses, highlighting successes and challenges in prophylactic, therapeutic, and tolerance-inducing vaccines. PMID:24150416

Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

NASA Technical Reports Server (NTRS)

Mittelsteadt, Cortney K.; Braff, William

2009-01-01

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

Advanced Lithium Ion Systems for Military Vehicle Applications

DTIC Science & Technology

2007-06-11

High Power and Very High Power Cell technology will be shown, in addition to recent applications of LiFePO4 materials into Saft’s High Power cell...upon, temperature, SOC, and prior usage conditions. Iron Phosphate and Saft’s VL-V Power Technology The LiFePO4 chemistry is interesting for...certain applications, as the improved thermal stability of the LiFePO4 design allows for even more tolerance to extreme abuse conditions. Recent

Whole-cell based hybrid materials for green energy production, environmental remediation and smart cell-therapy.

PubMed

Léonard, Alexandre; Dandoy, Philippe; Danloy, Emeric; Leroux, Grégory; Meunier, Christophe F; Rooke, Joanna C; Su, Bao-Lian

2011-02-01

This critical review highlights the advances that have been made over recent years in the domain of whole-cell immobilisation and encapsulation for applications relating to the environment and human health, particularly focusing on examples of photosynthetic plant cells, bacteria and algae as well as animal cells. Evidence that encapsulated photosynthetic cells remain active in terms of CO(2) sequestration and biotransformation (solar driven conversion of CO(2) into biofuels, drugs, fine chemicals etc.), coupled with the most recent advances made in the field of cell therapy, reveals the need to develop novel devices based on the preservation of living cells within abiotic porous frameworks. This review shall corroborate this statement by selecting precise examples that unambiguously demonstrate the necessity and the benefits of such smart materials. As will be described, the handling and exploitation of photosynthetic cells are enhanced by entrapment or encapsulation since the cells are physically separated from the liquid medium, thereby facilitating the recovery of the metabolites produced. In the case of animal cells, their encapsulation within a matrix is essential in order to create a physical barrier that can protect the cells auto-immune defenders upon implantation into a living body. For these two research axes, the key parameters that have to be kept in mind when designing hybrid materials will be identified, concentrating on essential aspects such as biocompatibility, mechanical strength and controlled porosity (264 references).

Materials Science of Electrodes and Interfaces for High-Performance Organic Photovoltaics

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

Marks, Tobin

The science of organic photovoltaic (OPV) cells has made dramatic advances over the past three years with power conversion efficiencies (PCEs) now reaching ~12%. The upper PCE limit of light-to-electrical power conversion for single-junction OPVs as predicted by theory is ~23%. With further basic research, the vision of such devices, composed of non-toxic, earth-abundant, readily easily processed materials replacing/supplementing current-generation inorganic solar cells may become a reality. Organic cells offer potentially low-cost, roll-to-roll manufacturable, and durable solar power for diverse in-door and out-door applications. Importantly, further gains in efficiency and durability, to that competitive with inorganic PVs, will require fundamental,more » understanding-based advances in transparent electrode and interfacial materials science and engineering. This team-science research effort brought together an experienced and highly collaborative interdisciplinary group with expertise in hard and soft matter materials chemistry, materials electronic structure theory, solar cell fabrication and characterization, microstructure characterization, and low temperature materials processing. We addressed in unconventional ways critical electrode-interfacial issues underlying OPV performance -- controlling band offsets between transparent electrodes and organic active-materials, addressing current loss/leakage phenomena at interfaces, and new techniques in cost-effective low temperature and large area cell fabrication. The research foci were: 1) Theory-guided design and synthesis of advanced crystalline and amorphous transparent conducting oxide (TCO) layers which test our basic understanding of TCO structure-transport property relationships, and have high conductivity, transparency, and tunable work functions but without (or minimizing) the dependence on indium. 2) Development of theory-based understanding of optimum configurations for the interfaces between oxide electrodes/interfacial layers and OPV active layer organic molecules/polymers. 3) Exploration and perfection of new processing strategies and cell architectures for the next-generation, large-area flexible OPVs. The goal has been to develop for the solar energy community the fundamental scientific understanding needed to design, fabricate, prototype, and ultimately test high-efficiency cells incorporating these new concepts. We achieved success in all of these directions.« less

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.

Concise Review: Organ Engineering: Design, Technology, and Integration.

PubMed

Kaushik, Gaurav; Leijten, Jeroen; Khademhosseini, Ali

2017-01-01

Engineering complex tissues and whole organs has the potential to dramatically impact translational medicine in several avenues. Organ engineering is a discipline that integrates biological knowledge of embryological development, anatomy, physiology, and cellular interactions with enabling technologies including biocompatible biomaterials and biofabrication platforms such as three-dimensional bioprinting. When engineering complex tissues and organs, core design principles must be taken into account, such as the structure-function relationship, biochemical signaling, mechanics, gradients, and spatial constraints. Technological advances in biomaterials, biofabrication, and biomedical imaging allow for in vitro control of these factors to recreate in vivo phenomena. Finally, organ engineering emerges as an integration of biological design and technical rigor. An overall workflow for organ engineering and guiding technology to advance biology as well as a perspective on necessary future iterations in the field is discussed. Stem Cells 2017;35:51-60. © 2016 AlphaMed Press.

Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants

NASA Astrophysics Data System (ADS)

Ulery, Bret D.; Petersen, Latrisha K.; Phanse, Yashdeep; Kong, Chang Sun; Broderick, Scott R.; Kumar, Devender; Ramer-Tait, Amanda E.; Carrillo-Conde, Brenda; Rajan, Krishna; Wannemuehler, Michael J.; Bellaire, Bryan H.; Metzger, Dennis W.; Narasimhan, Balaji

2011-12-01

An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens.

de novo computational enzyme design.

PubMed

Zanghellini, Alexandre

2014-10-01

Recent advances in systems and synthetic biology as well as metabolic engineering are poised to transform industrial biotechnology by allowing us to design cell factories for the sustainable production of valuable fuels and chemicals. To deliver on their promises, such cell factories, as much as their brick-and-mortar counterparts, will require appropriate catalysts, especially for classes of reactions that are not known to be catalyzed by enzymes in natural organisms. A recently developed methodology, de novo computational enzyme design can be used to create enzymes catalyzing novel reactions. Here we review the different classes of chemical reactions for which active protein catalysts have been designed as well as the results of detailed biochemical and structural characterization studies. We also discuss how combining de novo computational enzyme design with more traditional protein engineering techniques can alleviate the shortcomings of state-of-the-art computational design techniques and create novel enzymes with catalytic proficiencies on par with natural enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Developmental engineering: a new paradigm for the design and manufacturing of cell-based products. Part II: from genes to networks: tissue engineering from the viewpoint of systems biology and network science.

PubMed

Lenas, Petros; Moos, Malcolm; Luyten, Frank P

2009-12-01

The field of tissue engineering is moving toward a new concept of "in vitro biomimetics of in vivo tissue development." In Part I of this series, we proposed a theoretical framework integrating the concepts of developmental biology with those of process design to provide the rules for the design of biomimetic processes. We named this methodology "developmental engineering" to emphasize that it is not the tissue but the process of in vitro tissue development that has to be engineered. To formulate the process design rules in a rigorous way that will allow a computational design, we should refer to mathematical methods to model the biological process taking place in vitro. Tissue functions cannot be attributed to individual molecules but rather to complex interactions between the numerous components of a cell and interactions between cells in a tissue that form a network. For tissue engineering to advance to the level of a technologically driven discipline amenable to well-established principles of process engineering, a scientifically rigorous formulation is needed of the general design rules so that the behavior of networks of genes, proteins, or cells that govern the unfolding of developmental processes could be related to the design parameters. Now that sufficient experimental data exist to construct plausible mathematical models of many biological control circuits, explicit hypotheses can be evaluated using computational approaches to facilitate process design. Recent progress in systems biology has shown that the empirical concepts of developmental biology that we used in Part I to extract the rules of biomimetic process design can be expressed in rigorous mathematical terms. This allows the accurate characterization of manufacturing processes in tissue engineering as well as the properties of the artificial tissues themselves. In addition, network science has recently shown that the behavior of biological networks strongly depends on their topology and has developed the necessary concepts and methods to describe it, allowing therefore a deeper understanding of the behavior of networks during biomimetic processes. These advances thus open the door to a transition for tissue engineering from a substantially empirical endeavor to a technology-based discipline comparable to other branches of engineering.

NASA Handbook for Nickel-Hydrogen Batteries

NASA Technical Reports Server (NTRS)

Dunlop, James D.; Gopalakrishna, M. Rao; Yi, Thomas Y.

1993-01-01

Nickel-hydrogen (NiH2) batteries are finding more applications in the aerospace energy storage. Since 1983, NiH2 batteries have become the primary energy storage system used for Geosynchronous-Orbit (GEO) Satellites. The first NASA application for NiH2 batteries was the Low Earth Orbit (LEO) Hubble Space Telescope Satellite launched in 1990. The handbook was prepared as a reference book to aid in the application of this technology. That is, to aid in the cell and battery design, procurement, testing, and handling of NiH2 batteries. The design of individual pressure vessel NiH2 cells is covered in Chapter l. LEO and GEO applications and their requirements are discussed in Chapter 2. The design of NiH2 batteries for both GEO and LEO applications is discussed in Chapter 3. Advanced design concepts such as the common pressure vessel and bipolar NiH2 batteries are described in Chapter 4. Performance data are presented in Chapter 5. Storage and handling of the NiH2 cells and batteries are discussed in Chapter 6. Standard test procedures are presented in Chapter 7. Cell and battery procurements are discussed in Chapter 8. Finally, safety procedures are discussed in Chapter 9.

Stem cell-biomaterial interactions for regenerative medicine.

PubMed

Martino, Sabata; D'Angelo, Francesco; Armentano, Ilaria; Kenny, Josè Maria; Orlacchio, Aldo

2012-01-01

The synergism of stem cell biology and biomaterial technology promises to have a profound impact on stem-cell-based clinical applications for tissue regeneration. Biomaterials development is rapidly advancing to display properties that, in a precise and physiological fashion, could drive stem-cell fate both in vitro and in vivo. Thus, the design of novel materials is trying to recapitulate the molecular events involved in the production, clearance and interaction of molecules within tissue in pathologic conditions and regeneration of tissue/organs. In this review we will report on the challenges behind translating stem cell biology and biomaterial innovations into novel clinical therapeutic applications for tissue and organ replacements (graphical abstract). Copyright © 2011 Elsevier Inc. All rights reserved.

The power of combining adoptive cell therapy (ACT) and pathogen-boosted vaccination to treat solid tumors.

PubMed

Zander, Ryan; Cui, Weiguo

2017-10-03

Recent advancements in adoptive cell therapy (ACT) are opening up new frontiers for cancer immunotherapy. CAR T cells targeting CD19 have emerged as a remarkable T cell-based therapy for the successful treatment of certain types of leukemia and lymphomas. Despite these clinical successes, as well as significant breakthroughs in T cell engineering, the treatment of solid tumors with ACT remains a relentless challenge. Thus, the current consensus of the field is that an urgent need exists for the design of innovative approaches that can improve the efficacy of ACT in treating solid cancers while maintaining a high degree of reliability and safety.

Alkaline regenerative fuel cell energy storage system for manned orbital satellites

NASA Technical Reports Server (NTRS)

Martin, R. E.; Gitlow, B.; Sheibley, D. W.

1982-01-01

It is pointed out that the alkaline regenerative fuel cell system represents a highly efficient, lightweight, reliable approach for providing energy storage in an orbiting satellite. In addition to its energy storage function, the system can supply hydrogen and oxygen for attitude control of the satellite and for life support. A summary is presented of the results to date obtained in connection with the NASA-sponsored fuel cell technology advancement program, giving particular attention to the requirements of the alkaline regenerative fuel cell and the low-earth mission. Attention is given to system design guidelines, weight considerations, gold-platinum cathode cell performance, matrix development, the electrolyte reservoir plate, and the cyclical load profile tests.

Micro- and nanoengineering for stem cell biology: the promise with a caution.

PubMed

Kshitiz; Kim, Deok-Ho; Beebe, David J; Levchenko, Andre

2011-08-01

Current techniques used in stem cell research only crudely mimic the physiological complexity of the stem cell niches. Recent advances in the field of micro- and nanoengineering have brought an array of in vitro cell culture models that have enabled development of novel, highly precise and standardized tools that capture physiological details in a single platform, with greater control, consistency, and throughput. In this review, we describe the micro- and nanotechnology-driven modern toolkit for stem cell biologists to design novel experiments in more physiological microenvironments with increased precision and standardization, and caution them against potential challenges that the modern technologies might present. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Advanced interface modelling of n-Si/HNO3 doped graphene solar cells to identify pathways to high efficiency

NASA Astrophysics Data System (ADS)

Zhao, Jing; Ma, Fa-Jun; Ding, Ke; Zhang, Hao; Jie, Jiansheng; Ho-Baillie, Anita; Bremner, Stephen P.

2018-03-01

In graphene/silicon solar cells, it is crucial to understand the transport mechanism of the graphene/silicon interface to further improve power conversion efficiency. Until now, the transport mechanism has been predominantly simplified as an ideal Schottky junction. However, such an ideal Schottky contact is never realised experimentally. According to literature, doped graphene shows the properties of a semiconductor, therefore, it is physically more accurate to model graphene/silicon junction as a Heterojunction. In this work, HNO3-doped graphene/silicon solar cells were fabricated with the power conversion efficiency of 9.45%. Extensive characterization and first-principles calculations were carried out to establish an advanced technology computer-aided design (TCAD) model, where p-doped graphene forms a straddling heterojunction with the n-type silicon. In comparison with the simple Schottky junction models, our TCAD model paves the way for thorough investigation on the sensitivity of solar cell performance to graphene properties like electron affinity. According to the TCAD heterojunction model, the cell performance can be improved up to 22.5% after optimizations of the antireflection coatings and the rear structure, highlighting the great potentials for fabricating high efficiency graphene/silicon solar cells and other optoelectronic devices.

Nanostructured materials for advanced energy conversion and storage devices

NASA Astrophysics Data System (ADS)

Aricò, Antonino Salvatore; Bruce, Peter; Scrosati, Bruno; Tarascon, Jean-Marie; van Schalkwijk, Walter

2005-05-01

New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.

The Automated Array Assembly Task of the Low-cost Silicon Solar Array Project, Phase 2

NASA Technical Reports Server (NTRS)

Coleman, M. G.; Grenon, L.; Pastirik, E. M.; Pryor, R. A.; Sparks, T. G.

1978-01-01

An advanced process sequence for manufacturing high efficiency solar cells and modules in a cost-effective manner is discussed. Emphasis is on process simplicity and minimizing consumed materials. The process sequence incorporates texture etching, plasma processes for damage removal and patterning, ion implantation, low pressure silicon nitride deposition, and plated metal. A reliable module design is presented. Specific process step developments are given. A detailed cost analysis was performed to indicate future areas of fruitful cost reduction effort. Recommendations for advanced investigations are included.

Advances in bioluminescence imaging: new probes from old recipes.

PubMed

Yao, Zi; Zhang, Brendan S; Prescher, Jennifer A

2018-06-04

Bioluminescent probes are powerful tools for visualizing biology in live tissues and whole animals. Recent years have seen a surge in the number of new luciferases, luciferins, and related tools available for bioluminescence imaging. Many were crafted using classic methods of optical probe design and engineering. Here we highlight recent advances in bioluminescent tool discovery and development, along with applications of the probes in cells, tissues, and organisms. Collectively, these tools are improving in vivo imaging capabilities and bolstering new research directions. Copyright © 2018 Elsevier Ltd. All rights reserved.

The `advanced DIR-MCFC development' project, an overview

NASA Astrophysics Data System (ADS)

Kortbeek, P. J.; Ottervanger, R.

An overview is given of the approach and mid-term status of the joint European `Advanced DIR-MCFC Development' project, in which BCN, BG plc, GDF, ECN, Stork, Schelde and Sydkraft co-operate. Hospitals are identified as an attractive initial market for cogeneration direct internal reforming-molten carbonate fuel cell (DIR-MCFC) systems in the size of 400 kWe. Innovative system and stack design concepts are being developed for this application. The `SMARTER' system, based on DIR stacks, combines high electric efficiency and a wide operational window with optimal system simplicity and low cost.

Engineering hybrid exosomes by membrane fusion with liposomes.

PubMed

Sato, Yuko T; Umezaki, Kaori; Sawada, Shinichi; Mukai, Sada-atsu; Sasaki, Yoshihiro; Harada, Naozumi; Shiku, Hiroshi; Akiyoshi, Kazunari

2016-02-25

Exosomes are a valuable biomaterial for the development of novel nanocarriers as functionally advanced drug delivery systems. To control and modify the performance of exosomal nanocarriers, we developed hybrid exosomes by fusing their membranes with liposomes using the freeze-thaw method. Exosomes embedded with a specific membrane protein isolated from genetically modified cells were fused with various liposomes, confirming that membrane engineering methods can be combined with genetic modification techniques. Cellular uptake studies performed using the hybrid exosomes revealed that the interactions between the developed exosomes and cells could be modified by changing the lipid composition or the properties of the exogenous lipids. These results suggest that the membrane-engineering approach reported here offers a new strategy for developing rationally designed exosomes as hybrid nanocarriers for use in advanced drug delivery systems.

Nanostructured Ion-Exchange Membranes for Fuel Cells: Recent Advances and Perspectives.

PubMed

He, Guangwei; Li, Zhen; Zhao, Jing; Wang, Shaofei; Wu, Hong; Guiver, Michael D; Jiang, Zhongyi

2015-09-23

Polymer-based materials with tunable nanoscale structures and associated microenvironments hold great promise as next-generation ion-exchange membranes (IEMs) for acid or alkaline fuel cells. Understanding the relationships between nanostructure, physical and chemical microenvironment, and ion-transport properties are critical to the rational design and development of IEMs. These matters are addressed here by discussing representative and important advances since 2011, with particular emphasis on aromatic-polymer-based nanostructured IEMs, which are broadly divided into nanostructured polymer membranes and nanostructured polymer-filler composite membranes. For each category of membrane, the core factors that influence the physical and chemical microenvironments of the ion nanochannels are summarized. In addition, a brief perspective on the possible future directions of nanostructured IEMs is presented. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microfluidic systems for stem cell-based neural tissue engineering.

PubMed

Karimi, Mahdi; Bahrami, Sajad; Mirshekari, Hamed; Basri, Seyed Masoud Moosavi; Nik, Amirala Bakhshian; Aref, Amir R; Akbari, Mohsen; Hamblin, Michael R

2016-07-05

Neural tissue engineering aims at developing novel approaches for the treatment of diseases of the nervous system, by providing a permissive environment for the growth and differentiation of neural cells. Three-dimensional (3D) cell culture systems provide a closer biomimetic environment, and promote better cell differentiation and improved cell function, than could be achieved by conventional two-dimensional (2D) culture systems. With the recent advances in the discovery and introduction of different types of stem cells for tissue engineering, microfluidic platforms have provided an improved microenvironment for the 3D-culture of stem cells. Microfluidic systems can provide more precise control over the spatiotemporal distribution of chemical and physical cues at the cellular level compared to traditional systems. Various microsystems have been designed and fabricated for the purpose of neural tissue engineering. Enhanced neural migration and differentiation, and monitoring of these processes, as well as understanding the behavior of stem cells and their microenvironment have been obtained through application of different microfluidic-based stem cell culture and tissue engineering techniques. As the technology advances it may be possible to construct a "brain-on-a-chip". In this review, we describe the basics of stem cells and tissue engineering as well as microfluidics-based tissue engineering approaches. We review recent testing of various microfluidic approaches for stem cell-based neural tissue engineering.

CD8+ T cells induce complete regression of advanced ovarian cancers by an interleukin (IL)-2/IL-15 dependent mechanism.

PubMed

Yang, Taimei; Wall, Erika M; Milne, Katy; Theiss, Patty; Watson, Peter; Nelson, Brad H

2007-12-01

In vitro studies suggest that ovarian cancer evades immune rejection by fostering an immunosuppressive environment within the peritoneum; however, the functional responses of ovarian cancer-specific T cells have not been directly investigated in vivo. Therefore, we developed a new murine model to enable tracking of tumor-specific CD8(+) T-cell responses to advanced ovarian tumors. The ovarian tumor cell line ID8 was transfected to stably express an epitope-tagged version of HER-2/neu (designated Neu(OT-I/OT-II)). After i.p. injection into C57BL/6 mice, ID8 cells expressing Neu(OT-I/OT-II) gave rise to disseminated serous adenocarcinomas with extensive ascites. CD8(+) T cells expressing a transgenic T-cell receptor specific for the OT-I epitope of Neu(OT-I/OT-II) were adoptively transferred into tumor-bearing mice, and functional responses were monitored. Cytokine signaling requirements were evaluated by comparing the responses of wild-type donor T cells with those with genetic deletion of the interleukin (IL)-2/IL-15 receptor beta subunit (CD122) or the IL-2 receptor alpha subunit (CD25). On adoptive transfer into tumor-bearing hosts, wild-type OT-I T cells underwent a striking proliferative response, reaching peak densities of approximately 40% and approximately 90% of CD8(+) T cells in peripheral blood and ascites, respectively. OT-I cells infiltrated and destroyed tumor tissue, and ascites completely resolved within 10 days. By contrast, CD122(-/-) OT-I cells and CD25(-/-) OT-I cells proliferated in blood but failed to accumulate in ascites or tumor tissue or induce tumor regression. Contrary to expectation, advanced ovarian cancers can support extraordinary CD8(+) T-cell proliferation and antitumor activity through an IL-2/IL-15-dependent mechanism.

Control of stem cell fate by engineering their micro and nanoenvironment

PubMed Central

Griffin, Michelle F; Butler, Peter E; Seifalian, Alexander M; Kalaskar, Deepak M

2015-01-01

Stem cells are capable of long-term self-renewal and differentiation into specialised cell types, making them an ideal candidate for a cell source for regenerative medicine. The control of stem cell fate has become a major area of interest in the field of regenerative medicine and therapeutic intervention. Conventional methods of chemically inducing stem cells into specific lineages is being challenged by the advances in biomaterial technology, with evidence highlighting that material properties are capable of driving stem cell fate. Materials are being designed to mimic the clues stem cells receive in their in vivo stem cell niche including topographical and chemical instructions. Nanotopographical clues that mimic the extracellular matrix (ECM) in vivo have shown to regulate stem cell differentiation. The delivery of ECM components on biomaterials in the form of short peptides sequences has also proved successful in directing stem cell lineage. Growth factors responsible for controlling stem cell fate in vivo have also been delivered via biomaterials to provide clues to determine stem cell differentiation. An alternative approach to guide stem cells fate is to provide genetic clues including delivering DNA plasmids and small interfering RNAs via scaffolds. This review, aims to provide an overview of the topographical, chemical and molecular clues that biomaterials can provide to guide stem cell fate. The promising features and challenges of such approaches will be highlighted, to provide directions for future advancements in this exciting area of stem cell translation for regenerative medicine. PMID:25621104

Thermophotovoltaic Energy Conversion for Space Applications

NASA Astrophysics Data System (ADS)

Teofilo, V. L.; Choong, P.; Chen, W.; Chang, J.; Tseng, Y.-L.

2006-01-01

Thermophotovoltaic (TPV) energy conversion cells have made steady and over the years considerable progress since first evaluated by Lockheed Martin for direct conversion using nuclear power sources in the mid 1980s. The design trades and evaluations for application to the early defensive missile satellites of the Strategic Defense Initiative found the cell technology to be immature with unacceptably low cell efficiencies comparable to thermoelectric of <10%. Rapid advances in the epitaxial growth technology for ternary compound semiconductors, novel double hetero-structure junctions, innovative monolithic integrated cell architecture, and bandpass tandem filter have, in concert, significantly improved cell efficiencies to 25% with the promise of 35% using solar cell like multi-junction approach in the near future. Recent NASA sponsored design and feasibility testing programs have demonstrated the potential for 19% system efficiency for 100 We radioisotopic power sources at an integrated specific power of ~14 We/kg. Current state of TPV cell technology however limits the operating temperature of the converter cells to < 400K due to radiator mass consideration. This limitation imposes no system mass penalty for the low power application for use with radioisotopes power sources because of the high specific power of the TPV cell converters. However, the application of TPV energy conversion for high power sources has been perceived as having a major impediment above 1 kWe due to the relative low waste heat rejection temperature. We explore this limitation and compare the integrated specific power of TPV converters with current and projected TPV cells with other advanced space power conversion technologies. We find that when the redundancy needed required for extended space exploration missions is considered, the TPV converters have a much higher range of applicability then previously understood. Furthermore, we believe that with a relatively modest modifications of the current epitaxial growth in MOCVD, an optimal cell architecture for elevated TPV operation can be found to out-perform the state-of-the-art TPV at an elevated temperature.

Phase I Study of a Poxviral TRICOM-Based Vaccine Directed Against the Transcription Factor Brachyury.

PubMed

Heery, Christopher R; Palena, Claudia; McMahon, Sheri; Donahue, Renee N; Lepone, Lauren M; Grenga, Italia; Dirmeier, Ulrike; Cordes, Lisa; Marté, Jenn; Dahut, William; Singh, Harpreet; Madan, Ravi A; Fernando, Romaine I; Hamilton, Duane H; Schlom, Jeffrey; Gulley, James L

2017-11-15

Purpose: The transcription factor brachyury has been shown in preclinical studies to be a driver of the epithelial-to-mesenchymal transition (EMT) and resistance to therapy of human tumor cells. This study describes the characterization of a Modified Vaccinia Ankara (MVA) vector-based vaccine expressing the transgenes for brachyury and three human costimulatory molecules (B7.1, ICAM-1, and LFA-3, designated TRICOM) and a phase I study with this vaccine. Experimental Design: Human dendritic cells (DC) were infected with MVA-brachyury-TRICOM to define their ability to activate brachyury-specific T cells. A dose-escalation phase I study (NCT02179515) was conducted in advanced cancer patients ( n = 38) to define safety and to identify brachyury-specific T-cell responses. Results: MVA-brachyury-TRICOM-infected human DCs activated CD8 + and CD4 + T cells specific against the self-antigen brachyury in vitro No dose-limiting toxicities were observed due to vaccine in cancer patients at any of the three dose levels. One transient grade 3 adverse event (AE) possibly related to vaccine (diarrhea) resolved without intervention and did not recur with subsequent vaccine. All other AEs related to vaccine were transient and ≤grade 2. Brachyury-specific T-cell responses were observed at all dose levels and in most patients. Conclusions: The MVA-brachyury-TRICOM vaccine directed against a transcription factor known to mediate EMT can be administered safely in patients with advanced cancer and can activate brachyury-specific T cells in vitro and in patients. Further studies of this vaccine in combination therapies are warranted and planned. Clin Cancer Res; 23(22); 6833-45. ©2017 AACR . ©2017 American Association for Cancer Research.

Advanced Combustor in the Four Burner Area

NASA Image and Video Library

1966-03-21

Engineer Frank Kutina and a National Aeronautics and Space Administration (NASA) mechanic examine the setup of an advanced combustor rig inside one of the test cells at the Lewis Research Center’s Four Burner Area in the Engine Research Building. Kutina, of the Research Operations Branch, served as go-between for the researchers and the mechanics. He helped develop the test configurations and get the hardware installed. At the time of this photograph, Lewis Center Director Abe Silverstein had just established the Airbreathing Engine Division to address the new propulsion of the 1960s. After nearly a decade of focusing almost exclusively on space, NASA Lewis began tackling issues relating to the new turbofan engine, noise reduction, energy efficiency, supersonic transport, and the never-ending quest for higher performance levels with smaller and more lightweight engines. The Airbreathing Engine Division’s Combustion Branch was dedicated to the study and mitigation of the high temperatures and pressures found in advanced combustor designs. These high temperatures and pressures could destroy engine components. The Lewis investigation included film cooling, diffuser flow, and jet mixing. Components were tested in smaller test cells, but a full-scale augmenting burner rig, seen here, was tested extensively in the Four Burner Area test cell.

Proteomics Insights into Autophagy.

PubMed

Cudjoe, Emmanuel K; Saleh, Tareq; Hawkridge, Adam M; Gewirtz, David A

2017-10-01

Autophagy, a conserved cellular process by which cells recycle their contents either to maintain basal homeostasis or in response to external stimuli, has for the past two decades become one of the most studied physiological processes in cell biology. The 2016 Nobel Prize in Medicine and Biology awarded to Dr. Ohsumi Yoshinori, one of the first scientists to characterize this cellular mechanism, attests to its importance. The induction and consequent completion of the process of autophagy results in wide ranging changes to the cellular proteome as well as the secretome. MS-based proteomics affords the ability to measure, in an unbiased manner, the ubiquitous changes that occur when autophagy is initiated and progresses in the cell. The continuous improvements and advances in mass spectrometers, especially relating to ionization sources and detectors, coupled with advances in proteomics experimental design, has made it possible to study autophagy, among other process, in great detail. Innovative labeling strategies and protein separation techniques as well as complementary methods including immuno-capture/blotting/staining have been used in proteomics studies to provide more specific protein identification. In this review, we will discuss recent advances in proteomics studies focused on autophagy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Antagonistic control of a dual-input mammalian gene switch by food additives.

PubMed

Xie, Mingqi; Ye, Haifeng; Hamri, Ghislaine Charpin-El; Fussenegger, Martin

2014-08-01

Synthetic biology has significantly advanced the design of mammalian trigger-inducible transgene-control devices that are able to programme complex cellular behaviour. Fruit-based benzoate derivatives licensed as food additives, such as flavours (e.g. vanillate) and preservatives (e.g. benzoate), are a particularly attractive class of trigger compounds for orthogonal mammalian transgene control devices because of their innocuousness, physiological compatibility and simple oral administration. Capitalizing on the genetic componentry of the soil bacterium Comamonas testosteroni, which has evolved to catabolize a variety of aromatic compounds, we have designed different mammalian gene expression systems that could be induced and repressed by the food additives benzoate and vanillate. When implanting designer cells engineered for gene switch-driven expression of the human placental secreted alkaline phosphatase (SEAP) into mice, blood SEAP levels of treated animals directly correlated with a benzoate-enriched drinking programme. Additionally, the benzoate-/vanillate-responsive device was compatible with other transgene control systems and could be assembled into higher-order control networks providing expression dynamics reminiscent of a lap-timing stopwatch. Designer gene switches using licensed food additives as trigger compounds to achieve antagonistic dual-input expression profiles and provide novel control topologies and regulation dynamics may advance future gene- and cell-based therapies. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Reaction-based small-molecule fluorescent probes for dynamic detection of ROS and transient redox changes in living cells and small animals.

PubMed

Lü, Rui

2017-09-01

Dynamic detection of transient redox changes in living cells and animals has broad implications for human health and disease diagnosis, because intracellular redox homeostasis regulated by reactive oxygen species (ROS) plays important role in cell functions, normal physiological functions and some serious human diseases (e.g., cancer, Alzheimer's disease, diabetes, etc.) usually have close relationship with the intracellular redox status. Small-molecule ROS-responsive fluorescent probes can act as powerful tools for dynamic detection of ROS and redox changes in living cells and animals through fluorescence imaging techniques; and great advances have been achieved recently in the design and synthesis of small-molecule ROS-responsive fluorescent probes. This article highlights up-to-date achievements in designing and using the reaction-based small-molecule fluorescent probes (with high sensitivity and selectivity to ROS and redox cycles) in the dynamic detection of ROS and transient redox changes in living cells and animals through fluorescence imaging. Copyright © 2017. Published by Elsevier Ltd.

The food additive vanillic acid controls transgene expression in mammalian cells and mice.

PubMed

Gitzinger, Marc; Kemmer, Christian; Fluri, David A; El-Baba, Marie Daoud; Weber, Wilfried; Fussenegger, Martin

2012-03-01

Trigger-inducible transcription-control devices that reversibly fine-tune transgene expression in response to molecular cues have significantly advanced the rational reprogramming of mammalian cells. When designed for use in future gene- and cell-based therapies the trigger molecules have to be carefully chosen in order to provide maximum specificity, minimal side-effects and optimal pharmacokinetics in a mammalian organism. Capitalizing on control components that enable Caulobacter crescentus to metabolize vanillic acid originating from lignin degradation that occurs in its oligotrophic freshwater habitat, we have designed synthetic devices that specifically adjust transgene expression in mammalian cells when exposed to vanillic acid. Even in mice transgene expression was robust, precise and tunable in response to vanillic acid. As a licensed food additive that is regularly consumed by humans via flavoured convenience food and specific fresh vegetable and fruits, vanillic acid can be considered as a safe trigger molecule that could be used for diet-controlled transgene expression in future gene- and cell-based therapies.

CREATE: Cross-tumoral Phase 2 With Crizotinib

ClinicalTrials.gov

2018-01-18

Locally Advanced and/or Metastatic Anaplastic Large Cell Lymphoma; Locally Advanced and/or Metastatic Inflammatory Myofibroblastic Tumor; Locally Advanced and/or Metastatic Papillary Renal Cell Carcinoma Type 1; Locally Advanced and/or Metastatic Alveolar Soft Part Sarcoma; Locally Advanced and/or Metastatic Clear Cell Sarcoma; Locally Advanced and/or Metastatic Alveolar Rhabdomyosarcoma

Chimeric antigen receptors: driving immunology towards synthetic biology

PubMed Central

Sadelain, Michel

2017-01-01

The advent of second generation CARs and the CD19 paradigm have ushered a new therapeutic modality in oncology. In contrast to earlier forms of adoptive cell therapy, which were based on the isolation and expansion of naturally occurring T cells, CAR therapy is based on the design and manufacture of engineered T cells with optimized properties. A new armamentarium, comprising not only CARs but also chimeric costimulatory receptors, chimeric cytokine receptors, inhibitory receptors and synthetic Notch receptors, expressed in naïve, central memory or stem cell-like memory T cells, is being developed for clinical use in a wide range of cancers. Immunological principles are thus finding a new purpose thanks to advances in genetic engineering, synthetic biology and cell manufacturing sciences. PMID:27372731

Scalable human ES culture for therapeutic use: propagation, differentiation, genetic modification and regulatory issues.

PubMed

Rao, M

2008-01-01

Embryonic stem cells unlike most adult stem cell populations can replicate indefinitely while preserving genetic, epigenetic, mitochondrial and functional profiles. ESCs are therefore an excellent candidate cell type for providing a bank of cells for allogenic therapy and for introducing targeted genetic modifications for therapeutic intervention. This ability of prolonged self-renewal of stem cells and the unique advantages that this offers for gene therapy, discovery efforts, cell replacement, personalized medicine and other more direct applications requires the resolution of several important manufacturing, gene targeting and regulatory issues. In this review, we assess some of the advance made in developing scalable culture systems, improvement in vector design and gene insertion technology and the changing regulatory landscape.

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.

High altitude solar power platform. [aircraft design analysis

NASA Technical Reports Server (NTRS)

Bailey, M. D.; Bower, M. V.

1992-01-01

Solar power is a preeminent alternative to conventional aircraft propulsion. With the continued advances in solar cells, fuel cells, and composite materials technology, the solar powered airplane is no longer a simple curiosity constrained to flights of several feet in altitude or minutes of duration. A high altitude solar powered platform (HASPP) has several potential missions, including communications and agriculture. In remote areas, a HASPP could be used as a communication link. In large farming areas, a HASPP could perform remote sensing of crops. The impact of HASPP in continuous flight for one year on agricultural monitoring mission is presented. This mission provides farmers with near real-time data twice daily from an altitude which allows excellant resolution on water conditions, crop diseases, and insect infestation. Accurate, timely data will enable farmers to increase their yield and efficiency. A design for HASPP for the foregoing mission is presented. In the design power derived from solar cells covering the wings is used for propulsion, avionics, and sensors. Excess power produced midday will be stored in fuel cells for use at night to maintain altitude and course.

Design, engineering, and construction of photosynthetic microbial cell factories for renewable solar fuel production.

PubMed

Lindblad, Peter; Lindberg, Pia; Oliveira, Paulo; Stensjö, Karin; Heidorn, Thorsten

2012-01-01

There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H(2) production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted.

The prognostic implication of the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in primary locally advanced oral squamous cell carcinoma cases: a tissue microarray study.

PubMed

Solomon, Monica Charlotte; Vidyasagar, M S; Fernandes, Donald; Guddattu, Vasudev; Mathew, Mary; Shergill, Ankur Kaur; Carnelio, Sunitha; Chandrashekar, Chetana

2016-12-01

Oral squamous cell carcinomas comprise a heterogeneous tumor cell population with varied molecular characteristics, which makes prognostication of these tumors a complex and challenging issue. Thus, molecular profiling of these tumors is advantageous for an accurate prognostication and treatment planning. This is a retrospective study on a cohort of primary locally advanced oral squamous cell carcinomas (n = 178) of an Indian rural population. The expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of primary locally advanced oral squamous cell carcinomas was evaluated. A potential biomarker that can predict the tumor response to treatment was identified. Formalin-fixed paraffin-embedded tumor blocks of (n = 178) of histopathologically diagnosed cases of locally advanced oral squamous cell carcinomas were selected. Tissue microarray blocks were constructed with 2 cores of 2 mm diameter from each tumor block. Four-micron-thick sections were cut from these tissue microarray blocks. These tissue microarray sections were immunohistochemically stained for EGFR, p53, Bcl-2, cyclin D1 and p16. In this cohort, EGFR was the most frequently expressed 150/178 (84%) biomarker of the cases. Kaplan-Meier analysis showed a significant association (p = 0.038) between expression of p53 and a poor prognosis. A Poisson regression analysis showed that tumors that expressed p53 had a two times greater chance of recurrence (unadjusted IRR-95% CI 2.08 (1.03, 4.5), adjusted IRR-2.29 (1.08, 4.8) compared with the tumors that did not express this biomarker. Molecular profiling of oral squamous cell carcinomas will enable us to categorize our patients into more realistic risk groups. With biologically guided tumor characterization, personalized treatment protocols can be designed for individual patients, which will improve the quality of life of these patients.

Performance of High-Efficiency Advanced Triple-Junction Solar Panels for the LILT Mission Dawn

NASA Technical Reports Server (NTRS)

Fatemi, Navid S.; Sharma, Surya; Buitrago, Oscar; Sharps, Paul R.; Blok, Ron; Kroon, Martin; Jalink, Cees; Harris, Robin; Stella, Paul; Distefano, Sal

2005-01-01

NASA's Discovery Mission Dawn is designed to (LILT) conditions. operate within the solar system's Asteroid belt, where the large distance from the sun creates a low-intensity, low-temperature (LILT) condition. To meet the mission power requirements under LlLT conditions, very high-efficiency multi-junction solar cells were selected to power the spacecraft to be built by Orbital Sciences Corporation (OSC) under contract with JPL. Emcore's InGaP/InGaAs/Ge advanced triple-junction (ATJ) solar cells, exhibiting an average air mass zero (AMO) efficiency of greater than 27.6% (one-sun, 28 C), were used to populate the solar panels [1]. The two solar array wings, to be built by Dutch Space, with 5 large- area panels each (total area of 36.4 sq. meters) are projected to produce between 10.3 kWe and 1.3 kWe of end-of life (EOL) power in the 1.0 to 3.0 AU range, respectively. The details of the solar panel design, testing and power analysis are presented.

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

NASA Technical Reports Server (NTRS)

Mandelkorn, J.; Lamneck, J. H.

1975-01-01

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

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results: Fifth Report

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

Eudy, Leslie; Post, Matthew; Jeffers, 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 13 advanced-design fuel cell buses and two hydrogen fueling stations. The ZEBA partners are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. NREL has published four previous reports describing operation of these buses. This report presents new and updated results covering data from January 2015 through December 2015.

Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration Results: Sixth Report

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

Eudy, Leslie; Post, Matthew B.; Jeffers, Matthew A.

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 13 advanced-design fuel cell buses and two hydrogen fueling stations. The ZEBA partners are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service. NREL has published five previous reports describing operation of these buses. This report presents new and updated results covering data from January 2016 through December 2016.

Ratiometric activatable cell-penetrating peptides provide rapid in vivo readout of thrombin activation.

PubMed

Whitney, Michael; Savariar, Elamprakash N; Friedman, Beth; Levin, Rachel A; Crisp, Jessica L; Glasgow, Heather L; Lefkowitz, Roy; Adams, Stephen R; Steinbach, Paul; Nashi, Nadia; Nguyen, Quyen T; Tsien, Roger Y

2013-01-02

In real time: thrombin activation in vivo can be imaged in real time with ratiometric activatable cell penetrating peptides (RACPPs). RACPPs are designed to combine 1) dual-emission ratioing, 2) far red to infrared wavelengths for in vivo mammalian imaging, and 3) cleavage-dependent spatial localization. The most advanced RACPP uses norleucine (Nle)-TPRSFL as a linker that increases sensitivity to thrombin by about 90-fold. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Programmable single-cell mammalian biocomputers.

PubMed

Ausländer, Simon; Ausländer, David; Müller, Marius; Wieland, Markus; Fussenegger, Martin

2012-07-05

Synthetic biology has advanced the design of standardized control devices that program cellular functions and metabolic activities in living organisms. Rational interconnection of these synthetic switches resulted in increasingly complex designer networks that execute input-triggered genetic instructions with precision, robustness and computational logic reminiscent of electronic circuits. Using trigger-controlled transcription factors, which independently control gene expression, and RNA-binding proteins that inhibit the translation of transcripts harbouring specific RNA target motifs, we have designed a set of synthetic transcription–translation control devices that could be rewired in a plug-and-play manner. Here we show that these combinatorial circuits integrated a two-molecule input and performed digital computations with NOT, AND, NAND and N-IMPLY expression logic in single mammalian cells. Functional interconnection of two N-IMPLY variants resulted in bitwise intracellular XOR operations, and a combinatorial arrangement of three logic gates enabled independent cells to perform programmable half-subtractor and half-adder calculations. Individual mammalian cells capable of executing basic molecular arithmetic functions isolated or coordinated to metabolic activities in a predictable, precise and robust manner may provide new treatment strategies and bio-electronic interfaces in future gene-based and cell-based therapies.

The Direct FuelCell™ stack engineering

NASA Astrophysics Data System (ADS)

Doyon, J.; Farooque, M.; Maru, H.

FuelCell Energy (FCE) has developed power plants in the size range of 300 kW to 3 MW for distributed power generation. Field-testing of the sub-megawatt plants is underway. The FCE power plants are based on its Direct FuelCell™ (DFC) technology. This is so named because of its ability to generate electricity directly from a hydrocarbon fuel, such as natural gas, by reforming it inside the fuel cell stack itself. All FCE products use identical 8000 cm 2 cell design, approximately 350-400 cells per stack, external gas manifolds, and similar stack compression systems. The difference lies in the packaging of the stacks inside the stack module. The sub-megawatt system stack module contains a single horizontal stack whereas the MW-class stack module houses four identical vertical stacks. The commonality of the design, internal reforming features, and atmospheric operation simplify the system design, reduce cost, improve efficiency, increase reliability and maintainability. The product building-block stack design has been advanced through three full-size stack operations at company's headquarters in Danbury, CT. The initial proof-of-concept of the full-size stack design was verified in 1999, followed by a 1.5 year of endurance verification in 2000-2001, and currently a value-engineered stack version is in operation. This paper discusses the design features, important engineering solutions implemented, and test results of FCE's full-size DFC stacks.

Meta-analysis Exploring the Effectiveness of S-1-Based Chemotherapy for Advanced Non-Small Cell Lung Cancer.

PubMed

Sun, Xin; Sun, Li; Zhang, Shu-Ling; Xiong, Zhi-Cheng; Ma, Jie-Tao; Han, Cheng-Bo

2017-01-01

S-1 is a new oral fluoropyrimidine formulation that comprises tegafur, 5-chloro-2,4-dihydroxypyridine, and potassium oxonate. S-1 is designed to enhance antitumor activity and to reduce gastrointestinal toxicity. Several studies have demonstrated that both S-1 monotherapy and S-1 combination regimens showed encouraging efficacies and mild toxicities in the treatment of lung squamous cell carcinoma and adenocarcinoma. However, it is unclear whether S-1 can be used as standard care in advanced non-small cell lung cancer (NSCLC). The purpose of this meta-analysis was to assess the efficacy and safety of S-1-based chemotherapy, compared with standard chemotherapy, in patients with locally advanced or metastatic NSCLC. Thirteen randomized controlled trials (RCTs) involving 2,134 patients with a similar ratio of different pathological types were included. In first-line or second-line chemotherapy, compared with standard chemotherapy, S-1-based chemotherapy showed similar efficacy in terms of median overall survival (mOS), median progression free survival (mPFS), and objective response rate (ORR) (all P > 0.1), and significantly reduced the incidence of grade ≥ 3 hematological toxicities. In patients with locally advanced NSCLC receiving concurrent chemoradiotherapy, compared with standard chemoradiotherapy, significantly improved survival in the S-1-based chemotherapy was noted in terms of mOS and mPFS (risk radio [RR] = 1.289, P = 0.009; RR = 1.289, P = 0.000, respectively) with lower incidence of grade ≥ 3 neutropenia (RR = 0.453, P = 0.000). The present meta-analysis demonstrates that S-1-based chemotherapy shows similar benefits in advanced NSCLC and improves survival in locally advanced NSCLC, compared with standard treatment.

Microbial fuel cells as an alternative energy source: current status.

PubMed

Javed, Muhammad Mohsin; Nisar, Muhammad Azhar; Ahmad, Muhammad Usman; Yasmeen, Nighat; Zahoor, Sana

2018-06-22

Microbial fuel cell (MFC) technology is an emerging area for alternative renewable energy generation and it offers additional opportunities for environmental bioremediation. Recent scientific studies have focused on MFC reactor design as well as reactor operations to increase energy output. The advancement in alternative MFC models and their performance in recent years reflect the interests of scientific community to exploit this technology for wider practical applications and environmental benefit. This is reflected in the diversity of the substrates available for use in MFCs at an economically viable level. This review provides an overview of the commonly used MFC designs and materials along with the basic operating parameters that have been developed in recent years. Still, many limitations and challenges exist for MFC development that needs to be further addressed to make them economically feasible for general use. These include continued improvements in fuel cell design and efficiency as well scale-up with economically practical applications tailored to local needs.

Biomimetic Layer-by-Layer Self-Assembly of Nanofilms, Nanocoatings, and 3D Scaffolds for Tissue Engineering.

PubMed

Zhang, Shichao; Xing, Malcolm; Li, Bingyun

2018-06-01

Achieving surface design and control of biomaterial scaffolds with nanometer- or micrometer-scaled functional films is critical to mimic the unique features of native extracellular matrices, which has significant technological implications for tissue engineering including cell-seeded scaffolds, microbioreactors, cell assembly, tissue regeneration, etc. Compared with other techniques available for surface design, layer-by-layer (LbL) self-assembly technology has attracted extensive attention because of its integrated features of simplicity, versatility, and nanoscale control. Here we present a brief overview of current state-of-the-art research related to the LbL self-assembly technique and its assembled biomaterials as scaffolds for tissue engineering. An overview of the LbL self-assembly technique, with a focus on issues associated with distinct routes and driving forces of self-assembly, is described briefly. Then, we highlight the controllable fabrication, properties, and applications of LbL self-assembly biomaterials in the forms of multilayer nanofilms, scaffold nanocoatings, and three-dimensional scaffolds to systematically demonstrate advances in LbL self-assembly in the field of tissue engineering. LbL self-assembly not only provides advances for molecular deposition but also opens avenues for the design and development of innovative biomaterials for tissue engineering.

Applications technology satellites advanced mission study

NASA Technical Reports Server (NTRS)

Gould, L. M.

1972-01-01

Three spacecraft configurations were designed for operation as a high powered synchronous communications satellite. Each spacecraft includes a 1 kw TWT and a 2 kw Klystron power amplifier feeding an antenna with multiple shaped beams. One of the spacecraft is designed to be boosted by a Thor-Delta launch vehicle and raised to synchronous orbit with electric propulsion. The other two are inserted into a elliptical transfer orbit with an Atlas Centaur and injected into final orbit with an apogee kick motor. Advanced technologies employed in the several configurations include tubes with multiple stage collectors radiating directly to space, multiple-contoured beam antennas, high voltage rollout solar cell arrays with integral power conditioning, electric propulsion for orbit raising and on-station attitude control and station-keeping, and liquid metal slip rings.

Recent advances in the design of tailored nanomaterials for efficient oxygen reduction reaction

DOE PAGES

Lv, Haifeng; Li, Dongguo; Strmcnik, Dusan; ...

2016-04-11

In the past decade, polymer electrolyte membrane fuels (PEMFCs) have been evaluated for both automotive and stationary applications. One of the main obstacles for large scale commercialization of this technology is related to the sluggish oxygen reduction reaction that takes place on the cathode side of fuel cell. Consequently, ongoing research efforts are focused on the design of cathode materials that could improve the kinetics and durability. Majority of these efforts rely on novel synthetic approaches that provide control over the structure, size, shape and composition of catalytically active materials. This article highlights the most recent advances that have beenmore » made to tailor critical parameters of the nanoscale materials in order to achieve more efficient performance of the oxygen reduction reaction (ORR).« less

Functional Impairment of Myeloid Dendritic Cells during Advanced Stage of HIV-1 Infection: Role of Factors Regulating Cytokine Signaling.

PubMed

Sachdeva, Meenakshi; Sharma, Aman; Arora, Sunil K

2015-01-01

Severely immunocompromised state during advanced stage of HIV-1 infection has been linked to functionally defective antigen presentation by dendritic cells (DCs). The molecular mechanisms behind DC impairment are still obscure. We investigated changes in DC function and association of key regulators of cytokine signaling during different stages of HIV-1 infection and following antiretroviral therapy (ART). Phenotypic and functional characteristics of circulating myeloid DCs (mDCs) in 56 ART-naive patients (23 in early and 33 in advanced stage of disease), 36 on ART and 24 healthy controls were evaluated. Sixteen patients were studied longitudinally prior-to and 6 months after the start of ART. For functional studies, monocyte-derived DCs (Mo-DCs) were evaluated for endocytosis, allo-stimulation and cytokine secretion. The expression of suppressor of cytokine signaling (SOCS)-1 and other regulators of cytokine signaling was evaluated by real-time RT-PCR. The ability to respond to an antigenic stimulation was severely impaired in patients in advanced HIV-1 disease which showed partial recovery in the treated group. Mo-DCs from patients with advanced HIV-disease remained immature with low allo-stimulation and reduced cytokine secretion even after TLR-4 mediated stimulation ex-vivo. The cells had an increased expression of negative regulatory factors like SOCS-1, SOCS-3, SH2-containing phosphatase (SHP)-1 and a reduced expression of positive regulators like Janus kinase (JAK)2 and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)1. A functional recovery after siRNA mediated silencing of SOCS-1 in these mo-DCs confirms the role of negative regulatory factors in functional impairment of these cells. Functionally defective DCs in advanced stage of HIV-1 infection seems to be due to imbalanced state of negative and positive regulatory gene expression. Whether this is a cause or effect of increased viral replication at this stage of disease, needs further investigation. The information may be useful in design of novel therapeutic targets for better management of disease.

Home administration of maintenance pemetrexed for patients with advanced non-squamous non-small cell lung cancer: rationale, practicalities and phase II feasibility study design.

PubMed

Lal, Rohit; Bourayou, Nawel; Hillerdal, Gunnar; Nicolson, Marianne; Vikstrom, Anders; Lorenzo, Maria; D'yachkova, Yulia; Barriga, Susana; Visseren-Grul, Carla

2013-10-03

Home-based care in oncology is mainly reserved for patients at the end of life. Regulations regarding home delivery of cytotoxics differ across Europe, with a notable lack of practice guidelines in most countries. This has led to a lack of data addressing the feasibility of home-based administration of cytotoxic chemotherapy. In advanced non-squamous non-small cell lung cancer, pemetrexed is approved as maintenance therapy after first-line chemotherapy. In this setting, patients have the potential to be treated long-term with maintenance therapy, which, in the absence of unacceptable toxicity, is continued until disease progression. The favourable safety profile of pemetrexed and the ease of its administration by 10-minute intravenous infusion every 3 weeks make this drug a suitable candidate for administration in a home setting. Literature and regulations relevant to the home-based delivery of cytotoxic therapy were reviewed, and a phase II feasibility study of home administration of pemetrexed maintenance therapy was designed. At least 50 patients with advanced non-squamous non-small cell lung cancer, Eastern Cooperative Oncology Group performance status 0-1 and no progressive disease after four cycles of platinum-based first-line therapy are required to allow investigation of the feasibility of home-based administration of pemetrexed maintenance therapy (500 mg/m(2) every 3 weeks until progressive disease or unacceptable toxicity). Feasibility is being assessed as adherence to the home-based administration process (primary endpoint), patient safety, impact on patients' quality of life, patient and physician satisfaction with home care, and healthcare resource use and costs. Enrolment of patients from the UK and Sweden, where home-based care is relatively well developed, commenced in December 2011. This feasibility study addresses an important aspect of maintenance therapy, that is, patient comfort during protracted home-based chemotherapy. The study design requires unusual methodology and specific logistics to address outcomes relevant to the home-delivery approach. This article presents a study design that offers a novel and reproducible model for home-based chemotherapy, and provides an up-to-date overview of the literature regarding this type of treatment. ClinicalTrials.gov: NCT01473563.

In silico designing of power conversion efficient organic lead dyes for solar cells using todays innovative approaches to assure renewable energy for future

NASA Astrophysics Data System (ADS)

Kar, Supratik; Roy, Juganta K.; Leszczynski, Jerzy

2017-06-01

Advances in solar cell technology require designing of new organic dye sensitizers for dye-sensitized solar cells with high power conversion efficiency to circumvent the disadvantages of silicon-based solar cells. In silico studies including quantitative structure-property relationship analysis combined with quantum chemical analysis were employed to understand the primary electron transfer mechanism and photo-physical properties of 273 arylamine organic dyes from 11 diverse chemical families explicit to iodine electrolyte. The direct quantitative structure-property relationship models enable identification of the essential electronic and structural attributes necessary for quantifying the molecular prerequisites of 11 classes of arylamine organic dyes, responsible for high power conversion efficiency of dye-sensitized solar cells. Tetrahydroquinoline, N,N'-dialkylaniline and indoline have been least explored classes under arylamine organic dyes for dye-sensitized solar cells. Therefore, the identified properties from the corresponding quantitative structure-property relationship models of the mentioned classes were employed in designing of "lead dyes". Followed by, a series of electrochemical and photo-physical parameters were computed for designed dyes to check the required variables for electron flow of dye-sensitized solar cells. The combined computational techniques yielded seven promising lead dyes each for all three chemical classes considered. Significant (130, 183, and 46%) increment in predicted %power conversion efficiency was observed comparing with the existing dye with highest experimental %power conversion efficiency value for tetrahydroquinoline, N,N'-dialkylaniline and indoline, respectively maintaining required electrochemical parameters.

Using DNA nanotechnology to produce a drug delivery system

NASA Astrophysics Data System (ADS)

Huyen La, Thi; Thu Thuy Nguyen, Thi; Phuc Pham, Van; Huyen Nguyen, Thi Minh; Huan Le, Quang

2013-03-01

Drug delivery to cancer cells in chemotherapy is one of the most advanced research topics. The effectiveness of the current cancer treatment drugs is limited because they are not capable of distinguishing between cancer cells and normal cells so that they kill not only cancer cells but also normal ones. To overcome this disadvantage by profiting from the differences in physical and chemical properties between cancer and normal cells, nanoparticles (NPs) delivering a drug are designed in a specific manner such that they can distinguish the cancer cells from the normal ones and are targeted only to the cancer cells. Currently, there are various drug delivery systems with many advantages, but sharing some common disadvantages such as difficulty with controlling the size, low encapsulation capacity and low stability. With the development and success of DNA nanotechnology, DNA strands are used to create effective drug delivery NPs with precisely controlled size and structure, safety and high stability. This article presents our study on drug encapsulation in DNA nanostructure which loaded docetaxel and curcumin in a desire to create a new and effective drug delivery system with high biological compatibility. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology, 30 October-2 November, 2012, Ha Long, Vietnam.

Automated analysis of individual sperm cells using stain-free interferometric phase microscopy and machine learning.

PubMed

Mirsky, Simcha K; Barnea, Itay; Levi, Mattan; Greenspan, Hayit; Shaked, Natan T

2017-09-01

Currently, the delicate process of selecting sperm cells to be used for in vitro fertilization (IVF) is still based on the subjective, qualitative analysis of experienced clinicians using non-quantitative optical microscopy techniques. In this work, a method was developed for the automated analysis of sperm cells based on the quantitative phase maps acquired through use of interferometric phase microscopy (IPM). Over 1,400 human sperm cells from 8 donors were imaged using IPM, and an algorithm was designed to digitally isolate sperm cell heads from the quantitative phase maps while taking into consideration both the cell 3D morphology and contents, as well as acquire features describing sperm head morphology. A subset of these features was used to train a support vector machine (SVM) classifier to automatically classify sperm of good and bad morphology. The SVM achieves an area under the receiver operating characteristic curve of 88.59% and an area under the precision-recall curve of 88.67%, as well as precisions of 90% or higher. We believe that our automatic analysis can become the basis for objective and automatic sperm cell selection in IVF. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

Future of cell and gene therapies for Parkinson's disease.

PubMed

Isacson, Ole; Kordower, Jeffrey H

2008-12-01

The experimental field of restorative neurology continues to advance with implantation of cells or transfer of genes to treat patients with neurological disease. Both strategies have generated a consensus that demonstrates their capacity for structural and molecular brain modification in the adult brain. However, both approaches have yet to successfully address the complexities to make such novel therapeutic modalities work in the clinic. Prior experimental cell transplantation to patients with PD utilized dissected pieces of fetal midbrain tissue, containing mixtures of cells and neuronal types, as donor cells. Stem cell and progenitor cell biology provide new opportunities for selection and development of large batches of specific therapeutic cells. This may allow for cell composition analysis and dosing to optimize the benefit to an individual patient. The biotechnology used for cell and gene therapy for treatment of neurological disease may eventually be as advanced as today's pharmaceutical drug-related design processes. Current gene therapy phase 1 safety trials for PD include the delivery of a growth factor (neurturin via the glial cell line-derived neurotrophic factor receptor) and a transmitter enzyme (glutamic acid decarboxylase and aromatic acid decarboxylase). Many new insights from cell biological and molecular studies provide opportunities to selectively express or suppress factors relevant to neuroprotection and improved function of neurons involved in PD. Future gene and cell therapies are likely to coexist with classic pharmacological therapies because their use can be tailored to individual patients' underlying disease process and need for neuroprotective or restorative interventions.

Additive Manufacturing of Biomedical Constructs with Biomimetic Structural Organizations.

PubMed

Li, Xiao; He, Jiankang; Zhang, Weijie; Jiang, Nan; Li, Dichen

2016-11-09

Additive manufacturing (AM), sometimes called three-dimensional (3D) printing, has attracted a lot of research interest and is presenting unprecedented opportunities in biomedical fields, because this technology enables the fabrication of biomedical constructs with great freedom and in high precision. An important strategy in AM of biomedical constructs is to mimic the structural organizations of natural biological organisms. This can be done by directly depositing cells and biomaterials, depositing biomaterial structures before seeding cells, or fabricating molds before casting biomaterials and cells. This review organizes the research advances of AM-based biomimetic biomedical constructs into three major directions: 3D constructs that mimic tubular and branched networks of vasculatures; 3D constructs that contains gradient interfaces between different tissues; and 3D constructs that have different cells positioned to create multicellular systems. Other recent advances are also highlighted, regarding the applications of AM for organs-on-chips, AM-based micro/nanostructures, and functional nanomaterials. Under this theme, multiple aspects of AM including imaging/characterization, material selection, design, and printing techniques are discussed. The outlook at the end of this review points out several possible research directions for the future.

Effects of the architecture of tissue engineering scaffolds on cell seeding and culturing.

PubMed

Melchels, Ferry P W; Barradas, Ana M C; van Blitterswijk, Clemens A; de Boer, Jan; Feijen, Jan; Grijpma, Dirk W

2010-11-01

The advance of rapid prototyping techniques has significantly improved control over the pore network architecture of tissue engineering scaffolds. In this work, we have assessed the influence of scaffold pore architecture on cell seeding and static culturing, by comparing a computer designed gyroid architecture fabricated by stereolithography with a random pore architecture resulting from salt leaching. The scaffold types showed comparable porosity and pore size values, but the gyroid type showed a more than 10-fold higher permeability due to the absence of size-limiting pore interconnections. The higher permeability significantly improved the wetting properties of the hydrophobic scaffolds and increased the settling speed of cells upon static seeding of immortalised mesenchymal stem cells. After dynamic seeding followed by 5 days of static culture gyroid scaffolds showed large cell populations in the centre of the scaffold, while salt-leached scaffolds were covered with a cell sheet on the outside and no cells were found in the scaffold centre. It was shown that interconnectivity of the pores and permeability of the scaffold prolonged the time of static culture before overgrowth of cells at the scaffold periphery occurred. Furthermore, novel scaffold designs are proposed to further improve the transport of oxygen and nutrients throughout the scaffolds and to create tissue engineering grafts with a designed, pre-fabricated vasculature. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Modeling of flow-induced shear stress applied on 3D cellular scaffolds: Implications for vascular tissue engineering.

PubMed

Lesman, Ayelet; Blinder, Yaron; Levenberg, Shulamit

2010-02-15

Novel tissue-culture bioreactors employ flow-induced shear stress as a means of mechanical stimulation of cells. We developed a computational fluid dynamics model of the complex three-dimensional (3D) microstructure of a porous scaffold incubated in a direct perfusion bioreactor. Our model was designed to predict high shear-stress values within the physiological range of those naturally sensed by vascular cells (1-10 dyne/cm(2)), and will thereby provide suitable conditions for vascular tissue-engineering experiments. The model also accounts for cellular growth, which was designed as an added cell layer grown on all scaffold walls. Five model variants were designed, with geometric differences corresponding to cell-layer thicknesses of 0, 50, 75, 100, and 125 microm. Four inlet velocities (0.5, 1, 1.5, and 2 cm/s) were applied to each model. Wall shear-stress distribution and overall pressure drop calculations were then used to characterize the relation between flow rate, shear stress, cell-layer thickness, and pressure drop. The simulations showed that cellular growth within 3D scaffolds exposes cells to elevated shear stress, with considerably increasing average values in correlation to cell growth and inflow velocity. Our results provide in-depth analysis of the microdynamic environment of cells cultured within 3D environments, and thus provide advanced control over tissue development in vitro. 2009 Wiley Periodicals, Inc.

A Pressure Test to Make 10 Molecules in 90 Days: External Evaluation of Methods to Engineer Biology.

PubMed

Casini, Arturo; Chang, Fang-Yuan; Eluere, Raissa; King, Andrew M; Young, Eric M; Dudley, Quentin M; Karim, Ashty; Pratt, Katelin; Bristol, Cassandra; Forget, Anthony; Ghodasara, Amar; Warden-Rothman, Robert; Gan, Rui; Cristofaro, Alexander; Borujeni, Amin Espah; Ryu, Min-Hyung; Li, Jian; Kwon, Yong-Chan; Wang, He; Tatsis, Evangelos; Rodriguez-Lopez, Carlos; O'Connor, Sarah; Medema, Marnix H; Fischbach, Michael A; Jewett, Michael C; Voigt, Christopher; Gordon, D Benjamin

2018-03-28

Centralized facilities for genetic engineering, or "biofoundries", offer the potential to design organisms to address emerging needs in medicine, agriculture, industry, and defense. The field has seen rapid advances in technology, but it is difficult to gauge current capabilities or identify gaps across projects. To this end, our foundry was assessed via a timed "pressure test", in which 3 months were given to build organisms to produce 10 molecules unknown to us in advance. By applying a diversity of new approaches, we produced the desired molecule or a closely related one for six out of 10 targets during the performance period and made advances toward production of the others as well. Specifically, we increased the titers of 1-hexadecanol, pyrrolnitrin, and pacidamycin D, found novel routes to the enediyne warhead underlying powerful antimicrobials, established a cell-free system for monoterpene production, produced an intermediate toward vincristine biosynthesis, and encoded 7802 individually retrievable pathways to 540 bisindoles in a DNA pool. Pathways to tetrahydrofuran and barbamide were designed and constructed, but toxicity or analytical tools inhibited further progress. In sum, we constructed 1.2 Mb DNA, built 215 strains spanning five species ( Saccharomyces cerevisiae, Escherichia coli, Streptomyces albidoflavus, Streptomyces coelicolor, and Streptomyces albovinaceus), established two cell-free systems, and performed 690 assays developed in-house for the molecules.

Use of near-infrared spectroscopy (NIRs) in the biopharmaceutical industry for real-time determination of critical process parameters and integration of advanced feedback control strategies using MIDUS control.

PubMed

Vann, Lucas; Sheppard, John

2017-12-01

Control of biopharmaceutical processes is critical to achieve consistent product quality. The most challenging unit operation to control is cell growth in bioreactors due to the exquisitely sensitive and complex nature of the cells that are converting raw materials into new cells and products. Current monitoring capabilities are increasing, however, the main challenge is now becoming the ability to use the data generated in an effective manner. There are a number of contributors to this challenge including integration of different monitoring systems as well as the functionality to perform data analytics in real-time to generate process knowledge and understanding. In addition, there is a lack of ability to easily generate strategies and close the loop to feedback into the process for advanced process control (APC). The current research aims to demonstrate the use of advanced monitoring tools along with data analytics to generate process understanding in an Escherichia coli fermentation process. NIR spectroscopy was used to measure glucose and critical amino acids in real-time to help in determining the root cause of failures associated with different lots of yeast extract. First, scale-down of the process was required to execute a simple design of experiment, followed by scale-up to build NIR models as well as soft sensors for advanced process control. In addition, the research demonstrates the potential for a novel platform technology that enables manufacturers to consistently achieve "goldenbatch" performance through monitoring, integration, data analytics, understanding, strategy design and control (MIDUS control). MIDUS control was employed to increase batch-to-batch consistency in final product titers, decrease the coefficient of variability from 8.49 to 1.16%, predict possible exhaust filter failures and close the loop to prevent their occurrence and avoid lost batches.

Proton-Exchange-Membrane Fuel Cell Powerplants Developed and Tested for Exploration Missions

NASA Technical Reports Server (NTRS)

Hoberecht, Mark A.; Pham, Nang T.

2005-01-01

Proton-exchange-membrane fuel cell (PEMFC) technology has received major attention for terrestrial applications, such as the automotive and residential markets, for the past 20 years. This attention has significantly advanced the maturity of the technology, resulting in ever more compact, efficient, reliable, and inexpensive PEMFC designs. In comparison to the terrestrial operating environment, the space operating environment is much more demanding. Microgravity to high-gravity loads and the need to use pure oxygen (rather than air) as the fuel cell oxidizer place more stringent demands on PEMFC technology. NASA and its partners from industry are leveraging terrestrial PEMFC advancements by conducting parallel space technology development for future exploration missions. A team from the NASA Glenn Research Center, NASA Johnson Space Center, and NASA Kennedy Space Center recently completed the first phase of a PEMFC powerplant development effort for exploration missions. The industry partners for this phase of the development effort were ElectroChem, Inc., and Teledyne Energy Systems, Inc. Under contract to Glenn, both of these industry partners successfully designed, fabricated, and tested a breadboard PEMFC powerplant in the 1- to 5-kW power range. These powerplants were based on existing company-proprietary fuel cell stack designs, combined with off-the-shelf components, which formed the balance of the powerplant design. Subsequent to the contractor development efforts, both powerplants were independently tested at Johnson to verify operational and performance characteristics, and to determine suitability for further technology development in the second phase of the NASA-led effort. Following the independent NASA testing, Teledyne Energy Systems, Inc., was selected to develop an engineering model PEMFC powerplant. This effort was initiated by the 2nd Generation Reusable Launch Vehicle (RLV) Program Office in 2001; it transitioned to the Next Generation Launch Technologies (NGLT) Program Office in 2003. The effort is now being funded by the Exploration Program Office. We plan to summarize the results from the ongoing engineering model PEMFC powerplant development in a future Research & Technology article.

Proton-Exchange-Membrane Fuel Cell Powerplants Developed and Tested for Exploration Missions

NASA Astrophysics Data System (ADS)

Hoberecht, Mark A.; Pham, Nang T.

2005-06-01

Proton-exchange-membrane fuel cell (PEMFC) technology has received major attention for terrestrial applications, such as the automotive and residential markets, for the past 20 years. This attention has significantly advanced the maturity of the technology, resulting in ever more compact, efficient, reliable, and inexpensive PEMFC designs. In comparison to the terrestrial operating environment, the space operating environment is much more demanding. Microgravity to high-gravity loads and the need to use pure oxygen (rather than air) as the fuel cell oxidizer place more stringent demands on PEMFC technology. NASA and its partners from industry are leveraging terrestrial PEMFC advancements by conducting parallel space technology development for future exploration missions. A team from the NASA Glenn Research Center, NASA Johnson Space Center, and NASA Kennedy Space Center recently completed the first phase of a PEMFC powerplant development effort for exploration missions. The industry partners for this phase of the development effort were ElectroChem, Inc., and Teledyne Energy Systems, Inc. Under contract to Glenn, both of these industry partners successfully designed, fabricated, and tested a breadboard PEMFC powerplant in the 1- to 5-kW power range. These powerplants were based on existing company-proprietary fuel cell stack designs, combined with off-the-shelf components, which formed the balance of the powerplant design. Subsequent to the contractor development efforts, both powerplants were independently tested at Johnson to verify operational and performance characteristics, and to determine suitability for further technology development in the second phase of the NASA-led effort. Following the independent NASA testing, Teledyne Energy Systems, Inc., was selected to develop an engineering model PEMFC powerplant. This effort was initiated by the 2nd Generation Reusable Launch Vehicle (RLV) Program Office in 2001; it transitioned to the Next Generation Launch Technologies (NGLT) Program Office in 2003. The effort is now being funded by the Exploration Program Office. We plan to summarize the results from the ongoing engineering model PEMFC powerplant development in a future Research & Technology article.

Advanced nickel-hydrogen cell configuration study

NASA Technical Reports Server (NTRS)

Adler, E.; Perez, F.

1984-01-01

Three nickel hydrogen battery designs, individual pressure vessel (IPV), common pressure vessel (CPV), and a bipolar battery module were studied. Weight, system complexity and cost were compared for a satellite operating in a 6 hour, 5600 nautical mile orbit. The required energy storage is 52 kWh. A 25% improvement in specific energy is observed by employing a bipolar battery versus a battery comprised of hundreds of IPV's. Further weight benefits are realized by the development of light weight technologies in the bipolar design.

Design of clinical trials for therapeutic cancer vaccines development.

PubMed

Mackiewicz, Jacek; Mackiewicz, Andrzej

2009-12-25

Advances in molecular and cellular biology as well as biotechnology led to definition of a group of drugs referred to as medicinal products of advanced technologies. It includes gene therapy products, somatic cell therapeutics and tissue engineering. Therapeutic cancer vaccines including whole cell tumor cells vaccines or gene modified whole cells belong to somatic therapeutics and/or gene therapy products category. The drug development is a multistep complex process. It comprises of two phases: preclinical and clinical. Guidelines on preclinical testing of cell based immunotherapy medicinal products have been defined by regulatory agencies and are available. However, clinical testing of therapeutic cancer vaccines is still under debate. It presents a serious problem since recently clinical efficacy of the number of cancer vaccines has been demonstrated that focused a lot of public attention. In general clinical testing in the current form is very expensive, time consuming and poorly designed what may lead to overlooking of products clinically beneficial for patients. Accordingly regulatory authorities and researches including Cancer Vaccine Clinical Trial Working Group proposed three regulatory solutions to facilitate clinical development of cancer vaccines: cost-recovery program, conditional marketing authorization, and a new development paradigm. Paradigm includes a model in which cancer vaccines are investigated in two types of clinical trials: proof-of-principle and efficacy. The proof-of-principle trial objectives are: safety; dose selection and schedule of vaccination; and demonstration of proof-of-principle. Efficacy trials are randomized clinical trials with objectives of demonstrating clinical benefit either directly or through a surrogate. The clinical end points are still under debate.

High-performance batteries for stationary energy storage and electric-vehicle propulsion. Progress report, October--December 1976. [Li--Al/LiCl--KCl/FeS or FeS/sub 2/, operate at 400 to 450 C

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

Nelson, P.A.; Yao, N.P.; Steunenberg, R.K.

1977-04-01

These batteries are being developed for electric vehicle propulsion and for stationary energy storage applications. The present battery cells, which operate at 400 to 450/sup 0/C, are of a vertically oriented, prismatic design with a central positive electrode of FeS or FeS/sub 2/, two facing negative electrodes of lithium--aluminum alloy, and an electrolyte of molten LiCl--KCl. Testing and evaluation of industrially fabricated cells is continuing. During this period, Li--Al/FeS and Li--Al/FeS/sub 2/ cells from Eagle-Picher Industries were tested, and tests of Li--Al/FeS cells from Gould Inc. were initiated. The cells are tested individually and in parallel and series battery configurations.more » These tests provide information on the effects of cell design modifications and alternative materials. Improved electrode and cell designs are being developed and tested at ANL, and the more promising designs are incorporated in the industrially fabricated cells. Among the concepts receiving major attention are carbon-bonded positive electrodes, scaled-up stationary energy storage cell designs, additives to extend electrode lifetime, and alternative electrode separators. The materials development efforts include the development of a new lightweight electrical feedthrough; investigations of new separator materials (e.g.,Y/sub 2/O/sub 3/ powder, Y/sub 2/O/sub 3/ felt, and porous, rigid ceramics); corrosion tests of materials for cell components; and postoperative examinations of cells. The cell chemistry studies were directed to discharge mechanisms of FeS electrodes, emf measurements of the LiAl/FeS/sub 2/ couple at various states of discharge, and studies of other transition-metal sulfides as positive-electrode materials. The advanced battery effort mainly concerned the use of calcium alloys for negative electrode and transition metal sulfides or oxides for the positive electrode. 13 figures, 18 tables.« less

Radiation-hardened microwave communications system

NASA Astrophysics Data System (ADS)

Smith, S. F.; Bible, D. W.; Crutcher, R. I.; Hannah, J. H.; Moore, J. A.; Nowlin, C. H.; Vandermolen, R. I.; Chagnot, D.; Leroy, A.

1993-03-01

To develop a wireless communication system to meet the stringent requirements for a nuclear hot cell and similar environments, including control of advanced servomanipulators, a microwave signal transmission system development program was established to produce a demonstration prototype for the Consolidated Fuel Reprocessing Program at Oak Ridge National Laboratory (ORNL). Proof-of-principle tests in a partially metal lined enclosure at ORNL successfully demonstrated the feasibility of directed microwave signal transmission techniques for remote systems applications. The potential for much more severe radio-frequency (RF) multipath propagation conditions in fully metal lined cells led to a programmatic decision to conduct additional testing in more typical hot-cell environments at other sites. Again, the test results were excellent. Based on the designs of the earlier systems, an advanced microwave signal transmission system configuration was subsequently developed that, in highly reflective environments, will support both high-performance video channels and high baud-rate digital data links at total gamma dose tolerance levels exceeding 10(exp 7) rads and at elevated ambient temperatures.

Progress and Challenges in Macroencapsulation Approaches for Type 1 Diabetes (T1D) Treatment: Cells, Biomaterials, and Devices

PubMed Central

Song, Shang; Roy, Shuvo

2018-01-01

Macroencapsulation technology has been an attractive topic in the field of treatment for Type 1 diabetes due to mechanical stability, versatility, and retrievability of the macrocapsule design. Macro-capsules can be categorized into extravascular and intravascular devices, in which solute transport relies either on diffusion or convection, respectively. Failure of macroencapsulation strategies can be due to limited regenerative capacity of the encased insulin-producing cells, sub-optimal performance of encapsulation biomaterials, insufficient immunoisolation, excessive blood thrombosis for vascular perfusion devices, and inadequate modes of mass transfer to support cell viability and function. However, significant technical advancements have been achieved in macroencapsulation technology, namely reducing diffusion distance for oxygen and nutrients, using pro-angiogenic factors to increase vascularization for islet engraftment, and optimizing membrane permeability and selectivity to prevent immune attacks from host’s body. This review presents an overview of existing macroencapsulation devices and discusses the advances based on tissue-engineering approaches that will stimulate future research and development of macroencapsulation technology. PMID:26615050

Advanced Cell Classifier: User-Friendly Machine-Learning-Based Software for Discovering Phenotypes in High-Content Imaging Data.

PubMed

Piccinini, Filippo; Balassa, Tamas; Szkalisity, Abel; Molnar, Csaba; Paavolainen, Lassi; Kujala, Kaisa; Buzas, Krisztina; Sarazova, Marie; Pietiainen, Vilja; Kutay, Ulrike; Smith, Kevin; Horvath, Peter

2017-06-28

High-content, imaging-based screens now routinely generate data on a scale that precludes manual verification and interrogation. Software applying machine learning has become an essential tool to automate analysis, but these methods require annotated examples to learn from. Efficiently exploring large datasets to find relevant examples remains a challenging bottleneck. Here, we present Advanced Cell Classifier (ACC), a graphical software package for phenotypic analysis that addresses these difficulties. ACC applies machine-learning and image-analysis methods to high-content data generated by large-scale, cell-based experiments. It features methods to mine microscopic image data, discover new phenotypes, and improve recognition performance. We demonstrate that these features substantially expedite the training process, successfully uncover rare phenotypes, and improve the accuracy of the analysis. ACC is extensively documented, designed to be user-friendly for researchers without machine-learning expertise, and distributed as a free open-source tool at www.cellclassifier.org. Copyright © 2017 Elsevier Inc. All rights reserved.

Magnetic manipulation device for the optimization of cell processing conditions.

PubMed

Ito, Hiroshi; Kato, Ryuji; Ino, Kosuke; Honda, Hiroyuki

2010-02-01

Variability in human cell phenotypes make it's advancements in optimized cell processing necessary for personalized cell therapy. Here we propose a strategy of palm-top sized device to assist physically manipulating cells for optimizing cell preparations. For the design of such a device, we combined two conventional approaches: multi-well plate formatting and magnetic cell handling using magnetite cationic liposomes (MCLs). From our previous works, we showed the labeling applications of MCL on adhesive cells for various tissue engineering approaches. To feasibly transfer cells in multi-well plate, we here evaluated the magnetic response of MCL-labeled suspension type cells. The cell handling performance of Jurkat cells proved to be faster and more robust compared to MACS (Magnetic Cell Sorting) bead methods. To further confirm our strategy, prototype palm-top sized device "magnetic manipulation device (MMD)" was designed. In the device, the actual cell transportation efficacy of Jurkat cells was satisfying. Moreover, as a model of the most distributed clinical cell processing, primary peripheral blood mononuclear cells (PBMCs) from different volunteers were evaluated. By MMD, individual PBMCs indicated to have optimum Interleukin-2 (IL-2) concentrations for the expansion. Such huge differences of individual cells indicated that MMD, our proposing efficient and self-contained support tool, could assist the feasible and cost-effective optimization of cell processing in clinical facilities. Copyright (c) 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Advanced continuous cultivation methods for systems microbiology.

PubMed

Adamberg, Kaarel; Valgepea, Kaspar; Vilu, Raivo

2015-09-01

Increasing the throughput of systems biology-based experimental characterization of in silico-designed strains has great potential for accelerating the development of cell factories. For this, analysis of metabolism in the steady state is essential as only this enables the unequivocal definition of the physiological state of cells, which is needed for the complete description and in silico reconstruction of their phenotypes. In this review, we show that for a systems microbiology approach, high-resolution characterization of metabolism in the steady state--growth space analysis (GSA)--can be achieved by using advanced continuous cultivation methods termed changestats. In changestats, an environmental parameter is continuously changed at a constant rate within one experiment whilst maintaining cells in the physiological steady state similar to chemostats. This increases the resolution and throughput of GSA compared with chemostats, and, moreover, enables following of the dynamics of metabolism and detection of metabolic switch-points and optimal growth conditions. We also describe the concept, challenge and necessary criteria of the systematic analysis of steady-state metabolism. Finally, we propose that such systematic characterization of the steady-state growth space of cells using changestats has value not only for fundamental studies of metabolism, but also for systems biology-based metabolic engineering of cell factories.

Apoptosis: a four-week laboratory investigation for advanced molecular and cellular biology students.

PubMed

DiBartolomeis, Susan M; Moné, James P

2003-01-01

Over the past decade, apoptosis has emerged as an important field of study central to ongoing research in many diverse fields, from developmental biology to cancer research. Apoptosis proceeds by a highly coordinated series of events that includes enzyme activation, DNA fragmentation, and alterations in plasma membrane permeability. The detection of each of these phenotypic changes is accessible to advanced undergraduate cell and molecular biology students. We describe a 4-week laboratory sequence that integrates cell culture, fluorescence microscopy, DNA isolation and analysis, and western blotting (immunoblotting) to follow apoptosis in cultured human cells. Students working in teams chemically induce apoptosis, and harvest, process, and analyze cells, using their data to determine the order of events during apoptosis. We, as instructors, expose the students to an environment closely simulating what they would encounter in an active cell or molecular biology research laboratory by having students coordinate and perform multiple tasks simultaneously and by having them experience experimental design using current literature, data interpretation, and analysis to answer a single question. Students are assessed by examination of laboratory notebooks for completeness of experimental protocols and analysis of results and for completion of an assignment that includes questions pertaining to data interpretation and apoptosis.

Fuel cell technology program

NASA Technical Reports Server (NTRS)

1973-01-01

A fuel cell technology program was established to advance the state-of-the-art of hydrogen-oxygen fuel cells using low temperature, potassium hydroxide electrolyte technology as the base. Program tasks are described consisting of baseline cell design and stack testing, hydrogen pump design and testing, and DM-2 powerplant testing and technology extension efforts. A baseline cell configuration capable of a minimum of 2000 hours of life was defined. A 6-cell prototype stack, incorporating most of the scheme cell features, was tested for a total of 10,497 hours. A 6-cell stack incorporating all of the design features was tested. The DM-2 powerplant with a 34 cell stack, an accessory section packaged in the basic configuration anticipated for the space shuttle powerplant and a powerplant control unit, was defined, assembled, and tested. Cells were used in the stack and a drag-type hydrogen pump was installed in the accessory section. A test program was established, in conjunction with NASA/JSC, based on space shuttle orbiter mission. A 2000-hour minimum endurance test and a 5000-hour goal were set and the test started on August 8, 1972. The 2000-hour milestone was completed on November 3, 1972. On 13 March 1973, at the end of the thirty-first simulated seven-day mission and 5072 load hours, the test was concluded, all goals having been met. At this time, the DM-2 was in excellent condition and capable of additional endurance.

Hematopoietic stem cell engineering at a crossroads.

PubMed

Rivière, Isabelle; Dunbar, Cynthia E; Sadelain, Michel

2012-02-02

The genetic engineering of hematopoietic stem cells is the basis for potentially treating a large array of hereditary and acquired diseases, and stands as the paradigm for stem cell engineering in general. Recent clinical reports support the formidable promise of this approach but also highlight the limitations of the technologies used to date, which have on occasion resulted in clonal expansion, myelodysplasia, or leukemogenesis. New research directions, predicated on improved vector designs, targeted gene delivery or the therapeutic use of pluripotent stem cells, herald the advent of safer and more effective hematopoietic stem cell therapies that may transform medical practice. In this review, we place these recent advances in perspective, emphasizing the solutions emerging from a wave of new technologies and highlighting the challenges that lie ahead.

Recent progress in stem cell differentiation directed by material and mechanical cues.

PubMed

Lin, Xunxun; Shi, Yuan; Cao, Yilin; Liu, Wei

2016-02-02

Stem cells play essential roles in tissue regeneration in vivo via specific lineage differentiation induced by environmental factors. In the past, biochemical signals were the focus of induced stem cell differentiation. As reported by Engler et al (2006 Cell 126 677-89), biophysical signal mediated stem cell differentiation could also serve as an important inducer. With the advancement of material science, it becomes a possible strategy to generate active biophysical signals for directing stem cell fate through specially designed material microstructures. In the past five years, significant progress has been made in this field, and these designed biophysical signals include material elasticity/rigidity, micropatterned structure, extracellular matrix (ECM) coated materials, material transmitted extracellular mechanical force etc. A large number of investigations involved material directed differentiation of mesenchymal stem cells, neural stem/progenitor cells, adipose derived stem cells, hematopoietic stem/progenitor cells, embryonic stem cells and other cells. Hydrogel based materials were commonly used to create varied mechanical properties via modifying the ratio of different components, crosslinking levels, matrix concentration and conjugation with other components. Among them, polyacrylamide (PAM) and polydimethylsiloxane (PDMS) hydrogels remained the major types of material. Specially designed micropatterning was not only able to create a unique topographical surface to control cell shape, alignment, cell-cell and cell-matrix contact for basic stem cell biology study, but also could be integrated with 3D bioprinting to generate micropattered 3D structure and thus to induce stem cell based tissue regeneration. ECM coating on a specific topographical structure was capable of inducing even more specific and potent stem cell differentiation along with soluble factors and mechanical force. The article overviews the progress of the past five years in this particular field.

Inorganic separator technology program

NASA Technical Reports Server (NTRS)

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

1973-01-01

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

Bacterial growth laws and their applications

PubMed Central

SCOTT, Matthew; HWA, Terence

2011-01-01

Quantitative empirical relationships between cell composition and growth rate played an important role in the early days of microbiology. Gradually, the focus of the field began to shift from growth physiology to the ever more elaborate molecular mechanisms of regulation employed by the organisms. Advances in systems biology and biotechnology have renewed interest in the physiology of the cell as a whole. Furthermore, gene expression is known to be intimately coupled to the growth state of the cell. Here, we review recent efforts in characterizing such couplings, particularly the quantitative phenomenological approaches exploiting bacterial `growth laws.' These approaches point toward underlying design principles that can guide the predictive manipulation of cell behavior in the absence of molecular details. PMID:21592775

Spatial transcriptomics: paving the way for tissue-level systems biology.

PubMed

Moor, Andreas E; Itzkovitz, Shalev

2017-08-01

The tissues in our bodies are complex systems composed of diverse cell types that often interact in highly structured repeating anatomical units. External gradients of morphogens, directional blood flow, as well as the secretion and absorption of materials by cells generate distinct microenvironments at different tissue coordinates. Such spatial heterogeneity enables optimized function through division of labor among cells. Unraveling the design principles that govern this spatial division of labor requires techniques to quantify the entire transcriptomes of cells while accounting for their spatial coordinates. In this review we describe how recent advances in spatial transcriptomics open the way for tissue-level systems biology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ligand design for riboswitches, an emerging target class for novel antibiotics.

PubMed

Rekand, Illimar Hugo; Brenk, Ruth

2017-09-01

Riboswitches are cis-acting gene regulatory elements and constitute potential targets for new antibiotics. Recent studies in this field have started to explore these targets for drug discovery. New ligands found by fragment screening, design of analogs of the natural ligands or serendipitously by phenotypic screening have shown antibacterial effects in cell assays against a range of bacteria strains and in animal models. In this review, we highlight the most advanced drug design work of riboswitch ligands and discuss the challenges in the field with respect to the development of antibiotics with a new mechanism of action.

Advances toward LSD1 inhibitors for cancer therapy.

PubMed

Fu, Xiaoli; Zhang, Peng; Yu, Bin

2017-07-01

LSD1 has become an important biologically validated epigenetic target for cancer therapy since its identification in 2004. LSD1 mediates many cellular signaling pathways and is involved in the initiation and development of cancers. Aberrant overexpression of LSD1 has been observed in different types of cancers, and inactivation by small molecules suppresses cancer cell differentiation, proliferation, invasion and migration. To date, a large number of LSD1 inhibitors have been reported, RG6016, GSK-2879552, INCB059872, IMG-7289 and CC-90011 are currently undergoing clinical assessment for the treatment of acute myeloid leukemia, small-cell lung cancer, etc. In this review, we briefly highlight recent advances of LSD1 inhibitors mainly covering the literatures from 2015 to 2017 and tentatively propose our perspectives on the design of new LSD1 inhibitors for cancer therapy.

Sunitinib Proves Beneficial in Metastatic Kidney Cancer | Center for Cancer Research

Cancer.gov

Many researchers and clinicians consider targeted therapies, such as tyrosine kinase inhibitors and antibody-based drugs, to be a great advance in the treatment of patients with cancer. Unlike older chemotherapy drugs, targeted therapies are designed to direct drugs specifically to cancer cells or to interfere with pathways essential to tumor growth with less toxicity to

Competence-Based, Research-Related Lab Courses for Materials Modeling: The Case of Organic Photovoltaics

ERIC Educational Resources Information Center

Schellhammer, Karl Sebastian; Cuniberti, Gianaurelio

2017-01-01

We are hereby presenting a didactic concept for an advanced lab course that focuses on the design of donor materials for organic solar cells. Its research-related and competence-based approach qualifies the students to independently and creatively apply computational methods and to profoundly and critically discuss the results obtained. The high…

Cost as a technology driver. [in aerospace R and D

NASA Technical Reports Server (NTRS)

Fitzgerald, P. E., Jr.; Savage, M.

1976-01-01

Cost managment as a guiding factor in optimum development of technology, and proper timing of cost-saving programs in the development of a system or technology with payoffs in development and operational advances are discussed and illustrated. Advances enhancing the performance of hardware or software advances raising productivity or reducing cost, are outlined, with examples drawn from: thermochemical thrust maximization, development of cryogenic storage tanks, improvements in fuel cells for Space Shuttle, design of a spacecraft pyrotechnic initiator, cost cutting by reduction in the number of parts to be joined, and cost cutting by dramatic reductions in circuit component number with small-scale double-diffused integrated circuitry. Program-focused supporting research and technology models are devised to aid judicious timing of cost-conscious research programs.

Targeting cancer with hyaluronic acid-based nanocarriers: recent advances and translational perspectives.

PubMed

Cadete, Ana; Alonso, María José

2016-09-01

Hyaluronic acid is a natural polysaccharide that has been widely explored for the development of anticancer therapies due to its ability to target cancer cells. Moreover, advances made in the last decade have revealed the versatility of this biomaterial in the design of multifunctional carriers, intended for the delivery of a variety of bioactive molecules, including polynucleotides, immunomodulatory drugs and imaging agents. In this review, we aim to provide an overview of the major recent achievements in this field, highlighting the application of the newly developed nanostructures in combination therapies, immunomodulation and theranostics. Finally, we will discuss the main challenges and technological advances that will allow these carriers to be considered as candidates for clinical development.

Designing Citizen Science Projects in the Era of Mega-Information and Connected Activism

NASA Astrophysics Data System (ADS)

Pompea, S. M.

2010-12-01

The design of citizen science projects must take many factors into account in order to be successful. Currently, there are a wide variety of citizen science projects with different aims, audiences, reporting methods, and degrees of scientific rigor and usefulness. Projects function on local, national, and worldwide scales and range in time from limited campaigns to around the clock projects. For current and future projects, advanced cell phones and mobile computing allow an unprecedented degree of connectivity and data transfer. These advances will greatly influence the design of citizen science projects. An unprecedented amount of data is available for data mining by interested citizen scientists; how can projects take advantage of this? Finally, a variety of citizen scientist projects have social activism and change as part of their mission and goals. How can this be harnessed in a constructive and efficient way? The design of projects must also select the proper role for experts and novices, provide quality control, and must motivate users to encourage long-term involvement. Effective educational and instructional materials design can be used to design responsive and effective projects in a more highly connected age with access to very large amounts of information.

Continuous-flow multi-pulse electroporation at low DC voltages by microfluidic flipping of the voltage space topology

NASA Astrophysics Data System (ADS)

Bhattacharjee, N.; Horowitz, L. F.; Folch, A.

2016-10-01

Concerns over biosafety, cost, and carrying capacity of viral vectors have accelerated research into physical techniques for gene delivery such as electroporation and mechanoporation. Advances in microfabrication have made it possible to create high electric fields over microscales, resulting in more efficient DNA delivery and higher cell viability. Continuous-flow microfluidic methods are typically more suitable for cellular therapies where a large number of cells need to be transfected under sterile conditions. However, the existing continuous-flow designs used to generate multiple pulses either require expensive peripherals such as high-voltage (>400 V) sources or function generators, or result in reduced cell viability due to the proximity of the cells to the electrodes. In this paper, we report a continuous-flow microfluidic device whose channel geometry reduces instrumentation demands and minimizes cellular toxicity. Our design can generate multiple pulses of high DC electric field strength using significantly lower voltages (15-60 V) than previous designs. The cells flow along a serpentine channel that repeatedly flips the cells between a cathode and an anode at high throughput. The cells must flow through a constriction each time they pass from an anode to a cathode, exposing them to high electric field strength for short durations of time (the "pulse-width"). A conductive biocompatible poly-aniline hydrogel network formed in situ is used to apply the DC voltage without bringing the metal electrodes close to the cells, further sheltering cells from the already low voltage electrodes. The device was used to electroporate multiple cell lines using electric field strengths between 700 and 800 V/cm with transfection efficiencies superior than previous flow-through designs.

Continuous-flow multi-pulse electroporation at low DC voltages by microfluidic flipping of the voltage space topology.

PubMed

Bhattacharjee, N; Horowitz, L F; Folch, A

2016-10-17

Concerns over biosafety, cost, and carrying capacity of viral vectors have accelerated research into physical techniques for gene delivery such as electroporation and mechanoporation. Advances in microfabrication have made it possible to create high electric fields over microscales, resulting in more efficient DNA delivery and higher cell viability. Continuous-flow microfluidic methods are typically more suitable for cellular therapies where a large number of cells need to be transfected under sterile conditions. However, the existing continuous-flow designs used to generate multiple pulses either require expensive peripherals such as high-voltage (>400 V) sources or function generators, or result in reduced cell viability due to the proximity of the cells to the electrodes. In this paper, we report a continuous-flow microfluidic device whose channel geometry reduces instrumentation demands and minimizes cellular toxicity. Our design can generate multiple pulses of high DC electric field strength using significantly lower voltages (15-60 V) than previous designs. The cells flow along a serpentine channel that repeatedly flips the cells between a cathode and an anode at high throughput. The cells must flow through a constriction each time they pass from an anode to a cathode, exposing them to high electric field strength for short durations of time (the "pulse-width"). A conductive biocompatible poly-aniline hydrogel network formed in situ is used to apply the DC voltage without bringing the metal electrodes close to the cells, further sheltering cells from the already low voltage electrodes. The device was used to electroporate multiple cell lines using electric field strengths between 700 and 800 V/cm with transfection efficiencies superior than previous flow-through designs.

Feasibility of controlling CD38-CAR T cell activity with a Tet-on inducible CAR design

PubMed Central

Poels, Renée; Mulders, Manon J.; van de Donk, Niels W. C. J.; Themeli, Maria; Lokhorst, Henk M.; Mutis, Tuna

2018-01-01

Recent clinical advances with chimeric antigen receptor (CAR) T cells have led to the accelerated clinical approval of CD19-CARs to treat acute lymphoblastic leukemia. The CAR T cell therapy is nevertheless associated with toxicities, especially if the CARs are not entirely tumor-specific. Therefore, strategies for controlling the CAR T cell activity are required to improve their safety profile. Here, by using the multiple myeloma (MM)-associated CD38 molecule as target molecule, we tested the feasibility and utility of a doxycycline (DOX) inducible Tet-on CD38-CAR design to control the off-target toxicities of CAR T cells. Using CARs with high affinity to CD38, we demonstrate that this strategy allows the proper induction of CD38-CARs and CAR-mediated T cell cytotoxicity in a DOX-dose dependent manner. Especially when the DOX dose was limited to 10ng/ml, its removal resulted in a relatively rapid decay of CAR- related off-tumor effects within 24 hours, indicating the active controllability of undesired CAR activity. This Tet-on CAR design also allowed us to induce the maximal anti-MM cytotoxic activity of affinity-optimized CD38-CAR T cells, which already display a low toxicity profile, hereby adding a second level of safety to these cells. Collectively, these results indicate the possibility to utilize this DOX inducible CAR-design to actively regulate the CAR-mediated activities of therapeutic T cells. We therefore conclude that the Tet-on system may be more advantageous above suicide-genes to control the potential toxicities of CAR T cells without the need to destroy them permanently. PMID:29847570

1990 fuel cell seminar: Program and abstracts

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

Not Available

1990-12-31

This volume contains author prepared short resumes of the presentations at the 1990 Fuel Cell Seminar held November 25-28, 1990 in Phoenix, Arizona. Contained herein are 134 short descriptions organized into topic areas entitled An Environmental Overview, Transportation Applications, Technology Advancements for Molten Carbonate Fuel Cells, Technology Advancements for Solid Fuel Cells, Component Technologies and Systems Analysis, Stationary Power Applications, Marine and Space Applications, Technology Advancements for Acid Type Fuel Cells, and Technology Advancement for Solid Oxide Fuel Cells.

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

Space radioisotope power source requirements update and technology status

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

Mondt, J.F.

1998-07-01

The requirements for a space advanced radioisotope power source are based on potential deep space missions being investigated for the NASA Advanced Space Systems Development Program. Since deep space missions have not been approved, updating requirements is a continuos parallel process of designing the spacecraft and the science instruments to accomplish the potential missions and developing the power source technology to meet changing requirements. There are at least two potential missions, Pluto/Kuiper Express and Europa Orbiter, which may require space advanced radioisotope power sources. The Europa Orbiter has been selected as the preferred first potential mission. However the final decisionmore » will depend on the technology readiness of all the subsystems and the project must be able to switch to Pluto Kuiper Express as the first mission as late as the beginning of fiscal year 2000. Therefore the requirements for the power source will cover both potential missions. As the deep space spacecraft design evolves to meet the science requirements and the Alkali Metal Thermal to Electric (AMTEC) technology matures the advanced radioisotope power source design requirements are updated The AMTEC technology developed to date uses stainless steel for the sodium containment material. The higher efficiency required for the space power system dictates that the AMTEC technology must operate at a higher temperature than possible with stainless steel. Therefore refractory materials have been selected as the baseline material for the AMTEC cell. These refractory materials are Nb1Zr for the hot side and Nb1Zr or Nb10Hf1Ti for the cold side. These materials were selected so the AMTEC cell can operate at 1150K to 1350K hot side temperature and 600K to 700K cold side temperature and meet the present power and mass requirements using four to six general purpose heat source modules as the heat source. The new containment materials and brazes will be evaluated as to lifetime, compatibility and performance with the AMTEC beta prime Alumina, the TiN electrodes, the sodium and the molybdenum current collectors. AMTEC cell components and cells will be built with the baseline containment materials and brazes and tested to determine the performance as a function of temperature. These containment materials will be also be tested with all the other AMTEC components to determine acceleration factors needed to predict AMTEC performance degradation and failure as a function of operating time at temperature.« less

From neural-based object recognition toward microelectronic eyes

NASA Technical Reports Server (NTRS)

Sheu, Bing J.; Bang, Sa Hyun

1994-01-01

Engineering neural network systems are best known for their abilities to adapt to the changing characteristics of the surrounding environment by adjusting system parameter values during the learning process. Rapid advances in analog current-mode design techniques have made possible the implementation of major neural network functions in custom VLSI chips. An electrically programmable analog synapse cell with large dynamic range can be realized in a compact silicon area. New designs of the synapse cells, neurons, and analog processor are presented. A synapse cell based on Gilbert multiplier structure can perform the linear multiplication for back-propagation networks. A double differential-pair synapse cell can perform the Gaussian function for radial-basis network. The synapse cells can be biased in the strong inversion region for high-speed operation or biased in the subthreshold region for low-power operation. The voltage gain of the sigmoid-function neurons is externally adjustable which greatly facilitates the search of optimal solutions in certain networks. Various building blocks can be intelligently connected to form useful industrial applications. Efficient data communication is a key system-level design issue for large-scale networks. We also present analog neural processors based on perceptron architecture and Hopfield network for communication applications. Biologically inspired neural networks have played an important role towards the creation of powerful intelligent machines. Accuracy, limitations, and prospects of analog current-mode design of the biologically inspired vision processing chips and cellular neural network chips are key design issues.

Fostering synergy between cell biology and systems biology.

PubMed

Eddy, James A; Funk, Cory C; Price, Nathan D

2015-08-01

In the shared pursuit of elucidating detailed mechanisms of cell function, systems biology presents a natural complement to ongoing efforts in cell biology. Systems biology aims to characterize biological systems through integrated and quantitative modeling of cellular information. The process of model building and analysis provides value through synthesizing and cataloging information about cells and molecules, predicting mechanisms and identifying generalizable themes, generating hypotheses and guiding experimental design, and highlighting knowledge gaps and refining understanding. In turn, incorporating domain expertise and experimental data is crucial for building towards whole cell models. An iterative cycle of interaction between cell and systems biologists advances the goals of both fields and establishes a framework for mechanistic understanding of the genome-to-phenome relationship. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Engineering Therapeutic T Cells: From Synthetic Biology to Clinical Trials.

PubMed

Esensten, Jonathan H; Bluestone, Jeffrey A; Lim, Wendell A

2017-01-24

Engineered T cells are currently in clinical trials to treat patients with cancer, solid organ transplants, and autoimmune diseases. However, the field is still in its infancy. The design, and manufacturing, of T cell therapies is not standardized and is performed mostly in academic settings by competing groups. Reliable methods to define dose and pharmacokinetics of T cell therapies need to be developed. As of mid-2016, there are no US Food and Drug Administration (FDA)-approved T cell therapeutics on the market, and FDA regulations are only slowly adapting to the new technologies. Further development of engineered T cell therapies requires advances in immunology, synthetic biology, manufacturing processes, and government regulation. In this review, we outline some of these challenges and discuss the contributions that pathologists can make to this emerging field.

High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results

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

J.E. O'Brien; X. Zhang; K. DeWall

2012-09-01

This report provides results of long-term stack testing completed in the new high-temperature steam electrolysis multi-kW test facility recently developed at INL. The report includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This facility has provided a demonstration of high-temperature steam electrolysis operation at the 4 kW scale with advanced cell and stack technology. This successful large-scale demonstration of high-temperature steam electrolysis will help to advance the technology toward near-term commercialization.

Synthetic biology: tools to design microbes for the production of chemicals and fuels.

PubMed

Seo, Sang Woo; Yang, Jina; Min, Byung Eun; Jang, Sungho; Lim, Jae Hyung; Lim, Hyun Gyu; Kim, Seong Cheol; Kim, Se Yeon; Jeong, Jun Hong; Jung, Gyoo Yeol

2013-11-01

The engineering of biological systems to achieve specific purposes requires design tools that function in a predictable and quantitative manner. Recent advances in the field of synthetic biology, particularly in the programmable control of gene expression at multiple levels of regulation, have increased our ability to efficiently design and optimize biological systems to perform designed tasks. Furthermore, implementation of these designs in biological systems highlights the potential of using these tools to build microbial cell factories for the production of chemicals and fuels. In this paper, we review current developments in the design of tools for controlling gene expression at transcriptional, post-transcriptional and post-translational levels, and consider potential applications of these tools. Copyright © 2013 Elsevier Inc. All rights reserved.

Advances in Automated Plankton Imaging: Enhanced Throughput, Automated Staining, and Extended Deployment Modes for Imaging FlowCytobot

NASA Astrophysics Data System (ADS)

Sosik, H. M.; Olson, R. J.; Brownlee, E.; Brosnahan, M.; Crockford, E. T.; Peacock, E.; Shalapyonok, A.

2016-12-01

Imaging FlowCytobot (IFCB) was developed to fill a need for automated identification and monitoring of nano- and microplankton, especially phytoplankton in the size range 10 200 micrometer, which are important in coastal blooms (including harmful algal blooms). IFCB uses a combination of flow cytometric and video technology to capture high resolution (1 micrometer) images of suspended particles. This proven, now commercially available, submersible instrument technology has been deployed in fixed time series locations for extended periods (months to years) and in shipboard laboratories where underway water is automatically analyzed during surveys. Building from these successes, we have now constructed and evaluated three new prototype IFCB designs that extend measurement and deployment capabilities. To improve cell counting statistics without degrading image quality, a high throughput version (IFCB-HT) incorporates in-flow acoustic focusing to non-disruptively pre-concentrate cells before the measurement area of the flow cell. To extend imaging to all heterotrophic cells (even those that do not exhibit chlorophyll fluorescence), Staining IFCB (IFCB-S) incorporates automated addition of a live-cell fluorescent stain (fluorescein diacetate) to samples before analysis. A horizontally-oriented IFCB-AV design addresses the need for spatial surveying from surface autonomous vehicles, including design features that reliably eliminate air bubbles and mitigate wave motion impacts. Laboratory evaluation and test deployments in waters near Woods Hole show the efficacy of each of these enhanced IFCB designs.

Solar power satellite system definition study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1979-01-01

Configuration concepts, option sizes, and systems definitions study design evolutions are reviewed. The main features of the present reference design silicon solar cell solar power satellite are described, as well as the provisions for space construction and support systems. The principal study accomplishments and conclusions are summarized according to the following tasks: (1) baseline critique; (2) construction and maintenance; (3) industrial complex needs, cost estimates, and production capacity; (4) launch complex requirements at KSC or at an offshore facility; (5) integration of the SPS/ground power network; (6) technology advancement and development; (7) costs and schedules; and (8) exploratory technology: laser annealing of solar cells degraded by proton irradiation, and a fiber-optic phase distribution link at 980 MHz.

Coating Processes Boost Performance of Solar Cells

NASA Technical Reports Server (NTRS)

2012-01-01

NASA currently has spacecraft orbiting Mercury (MESSENGER), imaging the asteroid Vesta (Dawn), roaming the red plains of Mars (the Opportunity rover), and providing a laboratory for humans to advance scientific research in space (the International Space Station, or ISS). The heart of the technology that powers those missions and many others can be held in the palm of your hand - the solar cell. Solar, or photovoltaic (PV), cells are what make up the panels and arrays that draw on the Sun s light to generate electricity for everything from the Hubble Space Telescope s imaging equipment to the life support systems for the ISS. To enable NASA spacecraft to utilize the Sun s energy for exploring destinations as distant as Jupiter, the Agency has invested significant research into improving solar cell design and efficiency. Glenn Research Center has been a national leader in advancing PV technology. The Center s Photovoltaic and Power Technologies Branch has conducted numerous experiments aimed at developing lighter, more efficient solar cells that are less expensive to manufacture. Initiatives like the Forward Technology Solar Cell Experiments I and II in which PV cells developed by NASA and private industry were mounted outside the ISS have tested how various solar technologies perform in the harsh conditions of space. While NASA seeks to improve solar cells for space applications, the results are returning to Earth to benefit the solar energy industry.

Gemcitabine or gemcitabine plus oxaliplatin in the first-line treatment of patients with advanced transitional cell carcinoma of the urothelium unfit for cisplatin-based chemotherapy: a randomized phase 2 study of the French Genitourinary Tumor Group (GETUG V01).

PubMed

Culine, Stéphane; Fléchon, Aude; Guillot, Aline; Le Moulec, Sylvestre; Pouessel, Damien; Rolland, Frédéric; Ravaud, Alain; Houédé, Nadine; Mignot, Laurent; Joly, Florence; Oudard, Stéphane; Gourgou, Sophie

2011-12-01

The optimal chemotherapy for patients with advanced transitional cell carcinoma of the urothelium who are not eligible for cisplatin remains to be defined. To assess the activity of gemcitabine alone (GEM) or in combination with oxaliplatin (GEMOX) in a randomized phase 2 trial. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors criteria. The sample size was based on a two-stage Fleming design with p0=35% and p1=55%. At the end of the first stage designed to register 20 patients on each treatment arm, the observation of seven or more objective responses would have led to the inclusion of 30 more patients in each arm. From July 2004 to March 2009, 44 patients in 10 centers were randomly assigned into the GEM or the GEMOX arm, 22 on each treatment arm. The median age was 76 yr. Seven patients were included for a performance status (PS) of 2 only. The remaining 37 patients had an impaired renal function, 11 of whom also had a PS of 2. The median creatinine clearance was 45 ml/min (range: 30-80 ml/min). The trial was closed after the first part because the GEMOX arm did not reach the targeted objective response rate to proceed further. Oxaliplatin does not add any significant activity (in terms of response rates) compared with gemcitabine alone in patients with advanced transitional cell carcinoma of the urothelium who are ineligible for cisplatin. Copyright © 2011 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Thermal Characterization Study of Lithium-Ion Cells

NASA Technical Reports Server (NTRS)

Britton, Doris L.; Miller, Thomas B.; Bennett, William R.

2007-01-01

The primary challenge in designing a full scale lithium-ion (Li-ion) battery system is safety under both normal operating as well as abusive conditions. The normal conditions involve expected charge/discharge cycles and it is known that heat evolves in batteries during those cycles. This is a major concern in the design for high power applications and careful thermal management is necessary to alleviate this concern. An emerging thermal measurement technology, such as the electrochemical calorimetric of batteries, will aid in the development of advanced, safe battery system. To support this technology, several "commercial-off-the-shelf" (COTS) Li-ion cells with different chemistries and designs are being evaluated for different cycling regimes at a given operating temperature. The Accelerated Rate Calorimeter (ARC)-Arbin cycler setup is used to measure the temperature, voltage, and current of the cells at different charge/discharge rates. Initial results demonstrated good cell cyclability. During the cycle testing, the cell exhibited an endothermic cooling in the initial part of the charge cycle. The discharge portion of the cycle is exothermic during the entire discharge period. The presence of an endothermic reaction indicates a significant entropy effect during the beginning of charge cycle. Further studies will be performed to understand the thermal characteristics of the Li-ion cells at the different operating conditions. The effects on the thermal response on cell aging and states-of-charge will also be identified.

Single-cell computational analysis of light harvesting in a flat-panel photo-bioreactor.

PubMed

Loomba, Varun; Huber, Gregor; von Lieres, Eric

2018-01-01

Flat-panel photo-bioreactors (PBRs) are customarily applied for investigating growth of microalgae. Optimal design and operation of such reactors is still a challenge due to complex non-linear combinations of various impact factors, particularly hydrodynamics, light irradiation, and cell metabolism. A detailed analysis of single-cell light reception can lead to novel insights into the complex interactions of light exposure and algae movement in the reactor. The combined impacts of hydrodynamics and light irradiation on algae cultivation in a flat-panel PBR were studied by tracing the light exposure of individual cells over time. Hydrodynamics and turbulent mixing in this air-sparged bioreactor were simulated using the Eulerian approach for the liquid phase and a slip model for the gas phase velocity profiles. The liquid velocity was then used for tracing single cells and their light exposure, using light intensity profiles obtained from solving the radiative transfer equation at different wavelengths. The residence times of algae cells in defined dark and light zones of the PBR were statistically analyzed for different algal concentrations and sparging rates. The results indicate poor mixing caused by the reactor design which can be only partially improved by increased sparging rates. The results provide important information for optimizing algal biomass productivity by improving bioreactor design and operation and can further be utilized for an in-depth analysis of algal growth by using advanced models of cell metabolism.

Regenerative fuel cell study for satellites in GEO orbit

NASA Technical Reports Server (NTRS)

Levy, Alexander; Vandine, Leslie L.; Stedman, James K.

1987-01-01

Summarized are the results of a 12-month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application. Emphasis was placed on concepts with the potential for high energy density (W-hr/lb) and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. The first, the integrated design, utilized a configuration in which the fuel cell and electrolysis cells are alternately stacked inside a pressure vessel. Product water is transferred by diffusion during electrolysis and waste heat is conducted through the pressure wall, thus using completely passive means for transfer and control. The second alkaline system, the dedicated design, uses a separate fuel cell and electrolysis stack so that each unit can be optimized in size and weight based on its orbital operating period. The third design was a dual function stack configuration, in which each cell can operate in both fuel cell and electrolysis mode, thus eliminating the need for two separate stacks and associated equipment. Results indicate that using near term technology energy densities between 46 and 52 W-hr/lb can be achieved at efficiencies of 55 percent. System densities of 115 W-hr/lb are contemplated.

Targeting Notch, Hedgehog, and Wnt pathways in cancer stem cells: clinical update

PubMed Central

Miele, Lucio; Harris, Pamela Jo; Jeong, Woondong; Bando, Hideaki; Kahn, Michael; Yang, Sherry X.

2015-01-01

During the past decade, cancer stem cells (CSCs) have been increasingly identified in many malignancies. Although the origin and plasticity of these cells remain controversial, tumour heterogeneity and the presence of small populations of cells with stem-like characteristics is established in most malignancies. CSCs display many features of embryonic or tissue stem cells, and typically demonstrate persistent activation of one or more highly conserved signal transduction pathways involved in development and tissue homeostasis, including the Notch, Hedgehog (HH), and Wnt pathways. CSCs generally have slow growth rates and are resistant to chemotherapy and/or radiotherapy. Thus, new treatment strategies targeting these pathways to control stem-cell replication, survival and differentiation are under development. Herein, we provide an update on the latest advances in the clinical development of such approaches, and discuss strategies for overcoming CSC-associated primary or acquired resistance to cancer treatment. Given the crosstalk between the different embryonic developmental signalling pathways, as well as other pathways, designing clinical trials that target CSCs with rational combinations of agents to inhibit possible compensatory escape mechanisms could be of particular importance. We also share our views on the future directions for targeting CSCs to advance the clinical development of these classes of agents. PMID:25850553

Recent Advances in Biosensing With Photonic Crystal Surfaces: A Review

PubMed Central

Cunningham, B.T.; Zhang, M.; Zhuo, Y.; Kwon, L.; Race, C.

2016-01-01

Photonic crystal surfaces that are designed to function as wavelength-selective optical resonators have become a widely adopted platform for label-free biosensing, and for enhancement of the output of photon-emitting tags used throughout life science research and in vitro diagnostics. While some applications, such as analysis of drug-protein interactions, require extremely high resolution and the ability to accurately correct for measurement artifacts, others require sensitivity that is high enough for detection of disease biomarkers in serum with concentrations less than 1 pg/ml. As the analysis of cells becomes increasingly important for studying the behavior of stem cells, cancer cells, and biofilms under a variety of conditions, approaches that enable high resolution imaging of live cells without cytotoxic stains or photobleachable fluorescent dyes are providing new tools to biologists who seek to observe individual cells over extended time periods. This paper will review several recent advances in photonic crystal biosensor detection instrumentation and device structures that are being applied towards direct detection of small molecules in the context of high throughput drug screening, photonic crystal fluorescence enhancement as utilized for high sensitivity multiplexed cancer biomarker detection, and label-free high resolution imaging of cells and individual nanoparticles as a new tool for life science research and single-molecule diagnostics. PMID:27642265

Precision targeting with a tracking adaptive optics scanning laser ophthalmoscope

NASA Astrophysics Data System (ADS)

Hammer, Daniel X.; Ferguson, R. Daniel; Bigelow, Chad E.; Iftimia, Nicusor V.; Ustun, Teoman E.; Noojin, Gary D.; Stolarski, David J.; Hodnett, Harvey M.; Imholte, Michelle L.; Kumru, Semih S.; McCall, Michelle N.; Toth, Cynthia A.; Rockwell, Benjamin A.

2006-02-01

Precise targeting of retinal structures including retinal pigment epithelial cells, feeder vessels, ganglion cells, photoreceptors, and other cells important for light transduction may enable earlier disease intervention with laser therapies and advanced methods for vision studies. A novel imaging system based upon scanning laser ophthalmoscopy (SLO) with adaptive optics (AO) and active image stabilization was designed, developed, and tested in humans and animals. An additional port allows delivery of aberration-corrected therapeutic/stimulus laser sources. The system design includes simultaneous presentation of non-AO, wide-field (~40 deg) and AO, high-magnification (1-2 deg) retinal scans easily positioned anywhere on the retina in a drag-and-drop manner. The AO optical design achieves an error of <0.45 waves (at 800 nm) over +/-6 deg on the retina. A MEMS-based deformable mirror (Boston Micromachines Inc.) is used for wave-front correction. The third generation retinal tracking system achieves a bandwidth of greater than 1 kHz allowing acquisition of stabilized AO images with an accuracy of ~10 μm. Normal adult human volunteers and animals with previously-placed lesions (cynomolgus monkeys) were tested to optimize the tracking instrumentation and to characterize AO imaging performance. Ultrafast laser pulses were delivered to monkeys to characterize the ability to precisely place lesions and stimulus beams. Other advanced features such as real-time image averaging, automatic highresolution mosaic generation, and automatic blink detection and tracking re-lock were also tested. The system has the potential to become an important tool to clinicians and researchers for early detection and treatment of retinal diseases.

Engineering synthetic vaccines using cues from natural immunity.

PubMed

Irvine, Darrell J; Swartz, Melody A; Szeto, Gregory L

2013-11-01

Vaccines aim to protect against or treat diseases through manipulation of the immune response, promoting either immunity or tolerance. In the former case, vaccines generate antibodies and T cells poised to protect against future pathogen encounter or attack diseased cells such as tumours; in the latter case, which is far less developed, vaccines block pathogenic autoreactive T cells and autoantibodies that target self tissue. Enormous challenges remain, however, as a consequence of our incomplete understanding of human immunity. A rapidly growing field of research is the design of vaccines based on synthetic materials to target organs, tissues, cells or intracellular compartments; to co-deliver immunomodulatory signals that control the quality of the immune response; or to act directly as immune regulators. There exists great potential for well-defined materials to further our understanding of immunity. Here we describe recent advances in the design of synthetic materials to direct immune responses, highlighting successes and challenges in prophylactic, therapeutic and tolerance-inducing vaccines.

Engineering synthetic vaccines using cues from natural immunity

NASA Astrophysics Data System (ADS)

Irvine, Darrell J.; Swartz, Melody A.; Szeto, Gregory L.

2013-11-01

Vaccines aim to protect against or treat diseases through manipulation of the immune response, promoting either immunity or tolerance. In the former case, vaccines generate antibodies and T cells poised to protect against future pathogen encounter or attack diseased cells such as tumours; in the latter case, which is far less developed, vaccines block pathogenic autoreactive T cells and autoantibodies that target self tissue. Enormous challenges remain, however, as a consequence of our incomplete understanding of human immunity. A rapidly growing field of research is the design of vaccines based on synthetic materials to target organs, tissues, cells or intracellular compartments; to co-deliver immunomodulatory signals that control the quality of the immune response; or to act directly as immune regulators. There exists great potential for well-defined materials to further our understanding of immunity. Here we describe recent advances in the design of synthetic materials to direct immune responses, highlighting successes and challenges in prophylactic, therapeutic and tolerance-inducing vaccines.

Design of programmable intelligent cell phone jammer

NASA Astrophysics Data System (ADS)

Elangovan, Divya; Ravi, Aswin

2011-12-01

The usage of cell phones has increased enormously; at present silence and security is the need of the hour in many places. This can be done by using cell phone jammer, which blocks all the signals. This paper describes the design of an enhanced technique for jamming the cell phone signals. Our main objective is to concentrate on a specific band of frequency, which makes communication possible, by jamming this frequency we block out the specific signal that are responsible for making the call. This method enables the jammer to be more precise and effective, so precise that it can focus on specific area and allowing the programmer to define the area. The major advancement will be that emergency services can be availed which is very crucial in case of any calamity, they are intelligent devices as they act only after they receive signals and also it has a lesser power consumption than existing models. This technique has infinite potentials and sure can this be modified to match all our imaginations.

A hydrothermal atomic force microscope for imaging in aqueous solution up to 150 °C

NASA Astrophysics Data System (ADS)

Higgins, Steven R.; Eggleston, Carrick M.; Knauss, Kevin G.; Boro, Carl O.

1998-08-01

We present the design of a contact atomic force microscope (AFM) that can be used to image solid surfaces in aqueous solution up to 150 °C and 6 atm. The main features of this unique AFM are: (1) an inert gas pressurized microscope base containing stepper motor for coarse advance and the piezoelectric tube scanner; (2) a chemically inert membrane separating these parts from the fluid cell; (3) a titanium fluid cell with fluid inlet-outlet ports, a thermocouple port, and a sapphire optical window; (4) a resistively heated ceramic booster heater for the fluid cell to maintain the temperature of solutions sourced from a hydrothermal bomb; and (5) mass flow control. The design overcomes current limitations on the temperature and pressure range accessible to AFM imaging in aqueous solutions. Images taken at temperature and pressure are presented, demonstrating the unit-cell scale (<1 nm) vertical resolution of the AFM under hydrothermal conditions.

Three-dimensional nano-biointerface as a new platform for guiding cell fate.

PubMed

Liu, Xueli; Wang, Shutao

2014-04-21

Three-dimensional nano-biointerface has been emerging as an important topic for chemistry, nanotechnology, and life sciences in recent years. Understanding the exchanges of materials, signals, and energy at biological interfaces has inspired and helped the serial design of three-dimensional nano-biointerfaces. The intimate interactions between cells and nanostructures bring many novel properties, making three-dimensional nano-biointerfaces a powerful platform to guide cell fate in a controllable and accurate way. These advantages and capabilities endow three-dimensional nano-biointerfaces with an indispensable role in developing advanced biological science and technology. This tutorial review is mainly focused on the recent progress of three-dimensional nano-biointerfaces and highlights the new explorations and unique phenomena of three-dimensional nano-biointerfaces for cell-related fundamental studies and biomedical applications. Some basic bio-inspired principles for the design and creation of three-dimensional nano-biointerfaces are also delivered in this review. Current and further challenges of three-dimensional nano-biointerfaces are finally addressed and proposed.

Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells

PubMed Central

Liu, Yuhang; Zhao, Jingbo; Li, Zhengke; Mu, Cheng; Hu, Huawei; Jiang, Kui; Lin, Haoran; Ade, Harald; Yan, He

2014-01-01

Although the field of polymer solar cell has seen much progress in device performance in the past few years, several limitations are holding back its further development. For instance, current high-efficiency (>9.0%) cells are restricted to material combinations that are based on limited donor polymers and only one specific fullerene acceptor. Here we report the achievement of high-performance (efficiencies up to 10.8%, fill factors up to 77%) thick-film polymer solar cells for multiple polymer:fullerene combinations via the formation of a near-ideal polymer:fullerene morphology that contains highly crystalline yet reasonably small polymer domains. This morphology is controlled by the temperature-dependent aggregation behaviour of the donor polymers and is insensitive to the choice of fullerenes. The uncovered aggregation and design rules yield three high-efficiency (>10%) donor polymers and will allow further synthetic advances and matching of both the polymer and fullerene materials, potentially leading to significantly improved performance and increased design flexibility. PMID:25382026

Hot Cell Installation and Demonstration of the Severe Accident Test Station

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

Linton, Kory D.; Burns, Zachary M.; Terrani, Kurt A.

A Severe Accident Test Station (SATS) capable of examining the oxidation kinetics and accident response of irradiated fuel and cladding materials for design basis accident (DBA) and beyond design basis accident (BDBA) scenarios has been successfully installed and demonstrated in the Irradiated Fuels Examination Laboratory (IFEL), a hot cell facility at Oak Ridge National Laboratory. The two test station modules provide various temperature profiles, steam, and the thermal shock conditions necessary for integral loss of coolant accident (LOCA) testing, defueled oxidation quench testing and high temperature BDBA testing. The installation of the SATS system restores the domestic capability to examinemore » postulated and extended LOCA conditions on spent fuel and cladding and provides a platform for evaluation of advanced fuel and accident tolerant fuel (ATF) cladding concepts. This document reports on the successful in-cell demonstration testing of unirradiated Zircaloy-4. It also contains descriptions of the integral test facility capabilities, installation activities, and out-of-cell benchmark testing to calibrate and optimize the system.« less

Designing ternary blend bulk heterojunction solar cells with reduced carrier recombination and a fill factor of 77%

NASA Astrophysics Data System (ADS)

Gasparini, Nicola; Jiao, Xuechen; Heumueller, Thomas; Baran, Derya; Matt, Gebhard J.; Fladischer, Stefanie; Spiecker, Erdmann; Ade, Harald; Brabec, Christoph J.; Ameri, Tayebeh

2016-09-01

In recent years the concept of ternary blend bulk heterojunction (BHJ) solar cells based on organic semiconductors has been widely used to achieve a better match to the solar irradiance spectrum, and power conversion efficiencies beyond 10% have been reported. However, the fill factor of organic solar cells is still limited by the competition between recombination and extraction of free charges. Here, we design advanced material composites leading to a high fill factor of 77% in ternary blends, thus demonstrating how the recombination thresholds can be overcome. Extending beyond the typical sensitization concept, we add a highly ordered polymer that, in addition to enhanced absorption, overcomes limits predicted by classical recombination models. An effective charge transfer from the disordered host system onto the highly ordered sensitizer effectively avoids traps of the host matrix and features an almost ideal recombination behaviour.

Graphene Oxide-Gallic Acid Nanodelivery System for Cancer Therapy

NASA Astrophysics Data System (ADS)

Dorniani, Dena; Saifullah, Bullo; Barahuie, Farahnaz; Arulselvan, Palanisamy; Hussein, Mohd Zobir Bin; Fakurazi, Sharida; Twyman, Lance J.

2016-11-01

Despite the technological advancement in the biomedical science, cancer remains a life-threatening disease. In this study, we designed an anticancer nanodelivery system using graphene oxide (GO) as nanocarrier for an active anticancer agent gallic acid (GA). The successful formation nanocomposite (GOGA) was characterized using XRD, FTIR, HRTEM, Raman, and UV/Vis spectroscopy. The release study shows that the release of GA from the designed anticancer nanocomposite (GOGA) occurs in a sustained manner in phosphate-buffered saline (PBS) solution at pH 7.4. In in vitro biological studies, normal fibroblast (3T3) and liver cancer cells (HepG2) were treated with different concentrations of GO, GOGA, and GA for 72 h. The GOGA nanocomposite showed the inhibitory effect to cancer cell growth without affecting normal cell growth. The results of this research are highly encouraging to go further for in vivo studies.

Exploiting virus-like particles as innovative vaccines against emerging viral infections.

PubMed

Jeong, Hotcherl; Seong, Baik Lin

2017-03-01

Emerging viruses pose a major threat to humans and livestock with global public health and economic burdens. Vaccination remains an effective tool to reduce this threat, and yet, the conventional cell culture often fails to produce sufficient vaccine dose. As an alternative to cell-culture based vaccine, virus-like particles (VLPs) are considered as a highpriority vaccine strategy against emerging viruses. VLPs represent highly ordered repetitive structures via macromolecular assemblies of viral proteins. The particulate nature allows efficient uptake into antigen presenting cells stimulating both innate and adaptive immune responses towards enhanced vaccine efficacy. Increasing research activity and translation opportunity necessitate the advances in the design of VLPs and new bioprocessing modalities for efficient and cost-effective production. Herein, we describe major achievements and challenges in this endeavor, with respect to designing strategies to harnessing the immunogenic potential, production platforms, downstream processes, and some exemplary cases in developing VLP-based vaccines.

WE-H-BRA-04: Biological Geometries for the Monte Carlo Simulation Toolkit TOPASNBio

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

McNamara, A; Held, K; Paganetti, H

2016-06-15

Purpose: New advances in radiation therapy are most likely to come from the complex interface of physics, chemistry and biology. Computational simulations offer a powerful tool for quantitatively investigating radiation interactions with biological tissue and can thus help bridge the gap between physics and biology. The aim of TOPAS-nBio is to provide a comprehensive tool to generate advanced radiobiology simulations. Methods: TOPAS wraps and extends the Geant4 Monte Carlo (MC) simulation toolkit. TOPAS-nBio is an extension to TOPAS which utilizes the physics processes in Geant4-DNA to model biological damage from very low energy secondary electrons. Specialized cell, organelle and molecularmore » geometries were designed for the toolkit. Results: TOPAS-nBio gives the user the capability of simulating biological geometries, ranging from the micron-scale (e.g. cells and organelles) to complex nano-scale geometries (e.g. DNA and proteins). The user interacts with TOPAS-nBio through easy-to-use input parameter files. For example, in a simple cell simulation the user can specify the cell type and size as well as the type, number and size of included organelles. For more detailed nuclear simulations, the user can specify chromosome territories containing chromatin fiber loops, the later comprised of nucleosomes on a double helix. The chromatin fibers can be arranged in simple rigid geometries or within factual globules, mimicking realistic chromosome territories. TOPAS-nBio also provides users with the capability of reading protein data bank 3D structural files to simulate radiation damage to proteins or nucleic acids e.g. histones or RNA. TOPAS-nBio has been validated by comparing results to other track structure simulation software and published experimental measurements. Conclusion: TOPAS-nBio provides users with a comprehensive MC simulation tool for radiobiological simulations, giving users without advanced programming skills the ability to design and run complex simulations.« less

Remote control of therapeutic T cells through a small molecule-gated chimeric receptor.

PubMed

Wu, Chia-Yung; Roybal, Kole T; Puchner, Elias M; Onuffer, James; Lim, Wendell A

2015-10-16

There is growing interest in using engineered cells as therapeutic agents. For example, synthetic chimeric antigen receptors (CARs) can redirect T cells to recognize and eliminate tumor cells expressing specific antigens. Despite promising clinical results, these engineered T cells can exhibit excessive activity that is difficult to control and can cause severe toxicity. We designed "ON-switch" CARs that enable small-molecule control over T cell therapeutic functions while still retaining antigen specificity. In these split receptors, antigen-binding and intracellular signaling components assemble only in the presence of a heterodimerizing small molecule. This titratable pharmacologic regulation could allow physicians to precisely control the timing, location, and dosage of T cell activity, thereby mitigating toxicity. This work illustrates the potential of combining cellular engineering with orthogonal chemical tools to yield safer therapeutic cells that tightly integrate cell-autonomous recognition and user control. Copyright © 2015, American Association for the Advancement of Science.

Progress with the use of monoclonal antibodies for the treatment of systemic lupus erythematosus.

PubMed

Jordan, Natasha; Lutalo, Pamela Mk; D'Cruz, David P

2015-01-01

In recent years, significant progress has been made in the use of monoclonal antibodies in the treatment of systemic lupus erythematosus (SLE). Advances in our understanding of the complexity of SLE immunopathogenesis have led to the testing of several biologic agents in clinical trials. Monoclonal therapies currently emerging or under development include B-cell depletion therapies, agents targeting B-cell survival factors, blockade of T-cell co-stimulation and anticytokine therapies. Issues remain, however, regarding clinical trial design and outcome measures in SLE which need to be addressed to optimize translation of these promising therapies into clinical practice.

In vitro models of the metastatic cascade: from local invasion to extravasation

PubMed Central

Bersini, S.; Jeon, J.S.; Moretti, Matteo; Kamm, R.D.

2014-01-01

A crucial event in the metastatic cascade is the extravasation of circulating cancer cells from blood capillaries to the surrounding tissues. The past 5 years have been characterized by a significant evolution in the development of in vitro extravasation models, which moved from traditional transmigration chambers to more sophisticated microfluidic devices, enabling the study of complex cell–cell and cell–matrix interactions in multicellular, controlled environments. These advanced assays could be applied to screen easily and rapidly a broad spectrum of molecules inhibiting cancer cell endothelial adhesion and extravasation, thus contributing to the design of more focused in vivo tests. PMID:24361339

Aptamer-siRNA Chimeras: Discovery, Progress, and Future Prospects

PubMed Central

Kruspe, Sven; Giangrande, Paloma H.

2017-01-01

Synthetic nucleic acid ligands (aptamers) have emerged as effective delivery tools for many therapeutic oligonucleotide-based drugs, including small interfering RNAs (siRNAs). In this review, we summarize recent progress in the aptamer selection technology that has made possible the identification of cell-specific, cell-internalizing aptamers for the cell-targeted delivery of therapeutic oligonucleotides. In addition, we review the original, proof-of-concept aptamer-siRNA delivery studies and discuss recent advances in aptamer-siRNA conjugate designs for applications ranging from cancer therapy to the development of targeted antivirals. Challenges and prospects of aptamer-targeted siRNA drugs for clinical development are further highlighted. PMID:28792479

Stem cell therapy: MRI guidance and monitoring.

PubMed

Kraitchman, Dara L; Gilson, Wesley D; Lorenz, Christine H

2008-02-01

With the recent advances in magnetic resonance (MR) labeling of cellular therapeutics, it is natural that interventional MRI techniques for targeting would be developed. This review provides an overview of the current methods of stem cell labeling and the challenges that are created with respect to interventional MRI administration. In particular, stem cell therapies will require specialized, MR-compatible devices as well as integration of graphical user interfaces with pulse sequences designed for interactive, real-time delivery in many organs. Specific applications that are being developed will be reviewed as well as strategies for future translation to the clinical realm. (Copyright) 2008 Wiley-Liss, Inc.

Seeing and believing: recent advances in imaging cell-cell interactions

PubMed Central

Yap, Alpha S.; Michael, Magdalene; Parton, Robert G.

2015-01-01

Advances in cell and developmental biology have often been closely linked to advances in our ability to visualize structure and function at many length and time scales. In this review, we discuss how new imaging technologies and new reagents have provided novel insights into the biology of cadherin-based cell-cell junctions. We focus on three developments: the application of super-resolution optical technologies to characterize the nanoscale organization of cadherins at cell-cell contacts, new approaches to interrogate the mechanical forces that act upon junctions, and advances in electron microscopy which have the potential to transform our understanding of cell-cell junctions. PMID:26543555

Seeing and believing: recent advances in imaging cell-cell interactions.

PubMed

Yap, Alpha S; Michael, Magdalene; Parton, Robert G

2015-01-01

Advances in cell and developmental biology have often been closely linked to advances in our ability to visualize structure and function at many length and time scales. In this review, we discuss how new imaging technologies and new reagents have provided novel insights into the biology of cadherin-based cell-cell junctions. We focus on three developments: the application of super-resolution optical technologies to characterize the nanoscale organization of cadherins at cell-cell contacts, new approaches to interrogate the mechanical forces that act upon junctions, and advances in electron microscopy which have the potential to transform our understanding of cell-cell junctions.

Fishing on chips: up-and-coming technological advances in analysis of zebrafish and Xenopus embryos.

PubMed

Zhu, Feng; Skommer, Joanna; Huang, Yushi; Akagi, Jin; Adams, Dany; Levin, Michael; Hall, Chris J; Crosier, Philip S; Wlodkowic, Donald

2014-11-01

Biotests performed on small vertebrate model organisms provide significant investigative advantages as compared with bioassays that employ cell lines, isolated primary cells, or tissue samples. The main advantage offered by whole-organism approaches is that the effects under study occur in the context of intact physiological milieu, with all its intercellular and multisystem interactions. The gap between the high-throughput cell-based in vitro assays and low-throughput, disproportionally expensive and ethically controversial mammal in vivo tests can be closed by small model organisms such as zebrafish or Xenopus. The optical transparency of their tissues, the ease of genetic manipulation and straightforward husbandry, explain the growing popularity of these model organisms. Nevertheless, despite the potential for miniaturization, automation and subsequent increase in throughput of experimental setups, the manipulation, dispensing and analysis of living fish and frog embryos remain labor-intensive. Recently, a new generation of miniaturized chip-based devices have been developed for zebrafish and Xenopus embryo on-chip culture and experimentation. In this work, we review the critical developments in the field of Lab-on-a-Chip devices designed to alleviate the limits of traditional platforms for studies on zebrafish and clawed frog embryo and larvae. © 2014 International Society for Advancement of Cytometry. © 2014 International Society for Advancement of Cytometry.

Anode Design Based on Microscale Porous Scaffolds for Advanced Lithium Ion Batteries

NASA Astrophysics Data System (ADS)

Park, Hyeji; Choi, Hyelim; Nam, Kyungju; Lee, Sukyung; Um, Ji Hyun; Kim, Kyungbae; Kim, Jae-Hun; Yoon, Won-Sub; Choe, Heeman

2017-06-01

Considering the increasing demands for advanced power sources, present-day lithium-ion batteries (LIBs) must provide a higher energy and power density and better cycling stability than conventional LIBs. This study suggests a promising electrode design solution to this problem using Cu, Co, and Ti scaffolds with a microscale porous structure synthesized via freeze-casting. Co3O4 and TiO2 layers are uniformly formed on the Co and Ti scaffolds, respectively, through a simple thermal heat-treatment process, and a SnO2 layer is formed on the Cu scaffold through electroless plating and thermal oxidation. This paper characterizes and evaluates the physical and electrochemical properties of the proposed electrodes using scanning electron microscopy, four-point probe and coin-cell tests to confirm the feasibility of their potential use in LIBs.

Polymeric Biomaterials: Diverse Functions Enabled by Advances in Macromolecular Chemistry

PubMed Central

Liang, Yingkai; Li, Linqing; Scott, Rebecca A.; Kiick, Kristi L.

2017-01-01

Biomaterials have been extensively used to leverage beneficial outcomes in various therapeutic applications, such as providing spatial and temporal control over the release of therapeutic agents in drug delivery as well as engineering functional tissues and promoting the healing process in tissue engineering and regenerative medicine. This perspective presents important milestones in the development of polymeric biomaterials with defined structures and properties. Contemporary studies of biomaterial design have been reviewed with focus on constructing materials with controlled structure, dynamic functionality, and biological complexity. Examples of these polymeric biomaterials enabled by advanced synthetic methodologies, dynamic chemistry/assembly strategies, and modulated cell-material interactions have been highlighted. As the field of polymeric biomaterials continues to evolve with increased sophistication, current challenges and future directions for the design and translation of these materials are also summarized. PMID:29151616

Space Electrochemical Research and Technology Conference, 2nd, Cleveland, OH, Apr. 11-13, 1989, Proceedings

NASA Technical Reports Server (NTRS)

O'Donnell, Patricia M. (Editor)

1990-01-01

Attention is given to topics of advanced concepts, hydrogen-oxygen fuel cells and electrolyzers, nickel electrodes, and advanced rechargeable batteries. Papers are presented on human exploration mission studies, advanced rechargeable sodium batteries with novel cathodes, advanced double-layer capacitors, recent advances in solid-polymer electrolyte fuel cell technology with low platinum loading electrodes, electrocatalysts for oxygen electrodes in fuel cells and water electrolyzers for space applications, and the corrosion testing of candidates for the alkaline fuel cell cathode. Other papers are on a structural comparison of nickel electodes and precursor phases, the application of electrochemical impedance spectroscopy for characterizing the degradation of Ni(OH)2/NiOOH electrodes, advances in lightweight nickel electrode technology, multimission nickel-hydrogen battery cell for the 1990s, a sodium-sulfur battery flight experiment definition study, and advances in ambient-temperature secondary lithium cells.

Spinoff 2011

NASA Technical Reports Server (NTRS)

2012-01-01

Topics include: Bioreactors Drive Advances in Tissue Engineering; Tooling Techniques Enhance Medical Imaging; Ventilator Technologies Sustain Critically Injured Patients; Protein Innovations Advance Drug Treatments, Skin Care; Mass Analyzers Facilitate Research on Addiction; Frameworks Coordinate Scientific Data Management; Cameras Improve Navigation for Pilots, Drivers; Integrated Design Tools Reduce Risk, Cost; Advisory Systems Save Time, Fuel for Airlines; Modeling Programs Increase Aircraft Design Safety; Fly-by-Wire Systems Enable Safer, More Efficient Flight; Modified Fittings Enhance Industrial Safety; Simulation Tools Model Icing for Aircraft Design; Information Systems Coordinate Emergency Management; Imaging Systems Provide Maps for U.S. Soldiers; High-Pressure Systems Suppress Fires in Seconds; Alloy-Enhanced Fans Maintain Fresh Air in Tunnels; Control Algorithms Charge Batteries Faster; Software Programs Derive Measurements from Photographs; Retrofits Convert Gas Vehicles into Hybrids; NASA Missions Inspire Online Video Games; Monitors Track Vital Signs for Fitness and Safety; Thermal Components Boost Performance of HVAC Systems; World Wind Tools Reveal Environmental Change; Analyzers Measure Greenhouse Gasses, Airborne Pollutants; Remediation Technologies Eliminate Contaminants; Receivers Gather Data for Climate, Weather Prediction; Coating Processes Boost Performance of Solar Cells; Analyzers Provide Water Security in Space and on Earth; Catalyst Substrates Remove Contaminants, Produce Fuel; Rocket Engine Innovations Advance Clean Energy; Technologies Render Views of Earth for Virtual Navigation; Content Platforms Meet Data Storage, Retrieval Needs; Tools Ensure Reliability of Critical Software; Electronic Handbooks Simplify Process Management; Software Innovations Speed Scientific Computing; Controller Chips Preserve Microprocessor Function; Nanotube Production Devices Expand Research Capabilities; Custom Machines Advance Composite Manufacturing; Polyimide Foams Offer Superior Insulation; Beam Steering Devices Reduce Payload Weight; Models Support Energy-Saving Microwave Technologies; Materials Advance Chemical Propulsion Technology; and High-Temperature Coatings Offer Energy Savings.

Using Polymeric Materials to Control Stem Cell Behavior for Tissue Regeneration

PubMed Central

Zhang, Nianli; Kohn, David H.

2017-01-01

Patients with organ failure often suffer from increased morbidity and decreased quality of life. Current strategies of treating organ failure have limitations, including shortage of donor organs, low efficiency of grafts, and immunological problems. Tissue engineering emerged about two decades ago as a strategy to restore organ function with a living, functional engineered substitute. However, the ability to engineer a functional organ substitute is limited by a limited understanding of the interactions between materials and cells that are required to yield functional tissue equivalents. Polymeric materials are one of the most promising classes of materials for use in tissue engineering due to their biodegradability, flexibility in processing and property design, and the potential to use polymer properties to control cell function. Stem cells offer potential in tissue engineering because of their unique capacity to self renew and differentiate into neurogenic, osteogenic, chondrogenic, myogenic lineages under appropriate stimuli from extracellular components. This review examines recent advances in stem cell-polymer interactions for tissue regeneration, specifically highlighting control of polymer properties to direct adhesion, proliferation, and differentiation of stem cells, and how biomaterials can be designed to provide some of the stimuli to cells that the natural extracellular matrix does. PMID:22457178

Stable Gene Targeting in Human Cells Using Single-Strand Oligonucleotides with Modified Bases

PubMed Central

Rios, Xavier; Briggs, Adrian W.; Christodoulou, Danos; Gorham, Josh M.; Seidman, Jonathan G.; Church, George M.

2012-01-01

Recent advances allow multiplexed genome engineering in E. coli, employing easily designed oligonucleotides to edit multiple loci simultaneously. A similar technology in human cells would greatly expedite functional genomics, both by enhancing our ability to test how individual variants such as single nucleotide polymorphisms (SNPs) are related to specific phenotypes, and potentially allowing simultaneous mutation of multiple loci. However, oligo-mediated targeting of human cells is currently limited by low targeting efficiencies and low survival of modified cells. Using a HeLa-based EGFP-rescue reporter system we show that use of modified base analogs can increase targeting efficiency, in part by avoiding the mismatch repair machinery. We investigate the effects of oligonucleotide toxicity and find a strong correlation between the number of phosphorothioate bonds and toxicity. Stably EGFP-corrected cells were generated at a frequency of ~0.05% with an optimized oligonucleotide design combining modified bases and reduced number of phosphorothioate bonds. We provide evidence from comparative RNA-seq analysis suggesting cellular immunity induced by the oligonucleotides might contribute to the low viability of oligo-corrected cells. Further optimization of this method should allow rapid and scalable genome engineering in human cells. PMID:22615794

Design and Application of Sensors for Chemical Cytometry.

PubMed

Vickerman, Brianna M; Anttila, Matthew M; Petersen, Brae V; Allbritton, Nancy L; Lawrence, David S

2018-02-08

The bulk cell population response to a stimulus, be it a growth factor or a cytotoxic agent, neglects the cell-to-cell variability that can serve as a friend or as a foe in human biology. Biochemical variations among closely related cells furnish the basis for the adaptability of the immune system but also act as the root cause of resistance to chemotherapy by tumors. Consequently, the ability to probe for the presence of key biochemical variables at the single-cell level is now recognized to be of significant biological and biomedical impact. Chemical cytometry has emerged as an ultrasensitive single-cell platform with the flexibility to measure an array of cellular components, ranging from metabolite concentrations to enzyme activities. We briefly review the various chemical cytometry strategies, including recent advances in reporter design, probe and metabolite separation, and detection instrumentation. We also describe strategies for improving intracellular delivery, biochemical specificity, metabolic stability, and detection sensitivity of probes. Recent applications of these strategies to small molecules, lipids, proteins, and other analytes are discussed. Finally, we assess the current scope and limitations of chemical cytometry and discuss areas for future development to meet the needs of single-cell research.

Treating patients with ALK-positive non-small cell lung cancer: latest evidence and management strategy

PubMed Central

Liao, Bin-Chi; Shih, Jin-Yuan; Yang, James Chih-Hsin

2015-01-01

Rearrangements in anaplastic lymphoma kinase (ALK) gene and echinoderm microtubule-associated protein-like 4 (EML4) gene were first described in a small portion of patients with non-small cell lung cancer (NSCLC) in 2007. Fluorescence in situ hybridization is used as the diagnostic test for detecting an EML4–ALK rearrangement. Crizotinib, an ALK inhibitor, is effective in treating advanced ALK-positive NSCLC, and the US Food and Drug Administration approved it for treating ALK-positive NSCLC in 2011. Several mechanisms of acquired resistance to crizotinib have recently been reported. Second-generation ALK inhibitors were designed to overcome these resistance mechanisms. Two of them, ceritinib and alectinib, were approved in 2014 for advanced ALK-positive NSCLC in the US and Japan, respectively. Heat shock protein 90 (Hsp90) inhibitors also showed activity against ALK-positive NSCLC. Here we review the recent development of crizotinib, ceritinib, alectinib and other second-generation ALK inhibitors as well as Hsp90 inhibitors. We also discuss management strategies for advanced ALK-positive NSCLC. PMID:26327925

Systems and operations - Living with complexity and growth

NASA Astrophysics Data System (ADS)

Hook, W. R.

1983-03-01

Since the space station concept currently being developed by NASA calls for system updates and additions over a period of at least ten years following launch, attention must be given to the interfaces between station elements. Efforts have begun to develop generic fault detection, isolation, and correction techniques that could simplify on-orbit operations, maintenance and repair. An integrated hydrogen-oxygen system has been identified as the feature promising the greatest reduction in resupply costs. Scavenging excess fuel from the Space Shuttle's internal and external tanks, and using leftover Shuttle payload for fluid tankage, could supply hydrogen and oxygen for consumption in the form of propellants, fuel cell electricity, and life support gases. Advancements in cryogenic fluid management and storage technology are the keys to the design of this integrated system. Attention is given to the Interactive Design and Evaluation of Advanced Spacecraft computer-aided design and analysis system, which allows system engineers to study the integration problems presented by 40 technical modules.

Cell-tower deployment of counter-sniper sensors

NASA Astrophysics Data System (ADS)

Storch, Michael T.

2004-09-01

Cellular telephone antenna towers are evaluated as sites for rapid, effective & efficient deployment of counter-sniper sensors, especially in urban environments. They are expected to offer a suitable density, excellent LOS, and a generally limited variety of known or readily-characterized mechanical interfaces. Their precise locations are easily mapped in advance of deployment, are easily accessible by ground and air, and are easily spotted by deployment teams in real-time. We survey issues of EMI & RFI, susceptibility to denial & ambush in military scenarios, and the impact of trends in cell tower design & construction.

Rational design of competitive electrocatalysts for the oxygen reduction reaction in hydrogen fuel cells

NASA Astrophysics Data System (ADS)

Stolbov, Sergey; Alcántara Ortigoza, Marisol

2012-02-01

The large-scale application of one of the most promising clean and renewable sources of energy, hydrogen fuel cells, still awaits efficient and cost-effective electrocatalysts for the oxygen reduction reaction (ORR) occurring on the cathode. We demonstrate that truly rational design renders electrocatalysts possessing both qualities. By unifying the knowledge on surface morphology, composition, electronic structure and reactivity, we solve that sandwich-like structures are an excellent choice for optimization. Their constituting species couple synergistically yielding reaction-environment stability, cost-effectiveness and tunable reactivity. This cooperative-action concept enabled us to predict two advantageous ORR electrocatalysts. Density functional theory calculations of the reaction free-energy diagrams confirm that these materials are more active toward ORR than the so far best Pt-based catalysts. Our designing concept advances also a general approach for engineering materials in heterogeneous catalysis.

PEMFC MEA and System Design Considerations

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

Knights, Shanna; Bashyam, Rajesh; He, Ping

2011-07-01

Proton exchange membrane fuel cells (PEMFCs) are being developed and sold commercially for multiple near term markets. Ballard Power Systems is focused on the near term markets of backup power, distributed generation, materials handling, and buses. Significant advances have been made in cost and durability of fuel cell products. Improved tolerance to a wide range of system operation and environmental noises will enable increased viability across a broad range of applications. In order to apply the most effective membrane electrode assembly (MEA) design for each market, the system requirements and associated MEA failures must be well understood. The failure modesmore » associated with the electrodes and membrane degradation are discussed with respect to associated system operation and mitigating approaches. A few key system considerations that influence MEA design include expected fuel quality, balance-of-plant materials, time under idle or open circuit operation, and start-up and shut-down conditions.« less

Cell-based tissue engineering strategies used in the clinical repair of articular cartilage

PubMed Central

Huang, Brian J.; Hu, Jerry C.; Athanasiou, Kyriacos A.

2016-01-01

One of the most important issues facing cartilage tissue engineering is the inability to move technologies into the clinic. Despite the multitude of review articles on the paradigm of biomaterials, signals, and cells, it is reported that 90% of new drugs that advance past animal studies fail clinical trials (1). The intent of this review is to provide readers with an understanding of the scientific details of tissue engineered cartilage products that have demonstrated a certain level of efficacy in humans, so that newer technologies may be developed upon this foundation. Compared to existing treatments, such as microfracture or autologous chondrocyte implantation, a tissue engineered product can potentially provide more consistent clinical results in forming hyaline repair tissue and in filling the entirety of the defect. The various tissue engineering strategies (e.g., cell expansion, scaffold material, media formulations, biomimetic stimuli, etc.) used in forming these products, as collected from published literature, company websites, and relevant patents, are critically discussed. The authors note that many details about these products remain proprietary, not all information is made public, and that advancements to the products are continuously made. Nevertheless, by fully understanding the design and production processes of these emerging technologies, one can gain tremendous insight into how to best use them and also how to design the next generation of tissue engineered cartilage products. PMID:27177218

Dopant-Free and Carrier-Selective Heterocontacts for Silicon Solar Cells: Recent Advances and Perspectives.

PubMed

Gao, Pingqi; Yang, Zhenhai; He, Jian; Yu, Jing; Liu, Peipei; Zhu, Juye; Ge, Ziyi; Ye, Jichun

2018-03-01

By combining the most successful heterojunctions (HJ) with interdigitated back contacts, crystalline silicon (c-Si) solar cells (SCs) have recently demonstrated a record efficiency of 26.6%. However, such SCs still introduce optical/electrical losses and technological issues due to parasitic absorption/Auger recombination inherent to the doped films and the complex process of integrating discrete p + - and n + -HJ contacts. These issues have motivated the search for alternative new functional materials and simplified deposition technologies, whereby carrier-selective contacts (CSCs) can be formed directly with c-Si substrates, and thereafter form IBC cells, via a dopant-free method. Screening and modifying CSC materials in a wider context is beneficial for building dopant-free HJ contacts with better performance, shedding new light on the relatively mature Si photovoltaic field. In this review, a significant number of achievements in two representative dopant-free hole-selective CSCs, i.e . , poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/Si and transition metal oxides/Si, have been systemically presented and surveyed. The focus herein is on the latest advances in hole-selective materials modification, interfacial passivation, contact resistivity, light-trapping structure and device architecture design, etc. By analyzing the structure-property relationships of hole-selective materials and assessing their electrical transport properties, promising functional materials as well as important design concepts for such CSCs toward high-performance SCs have been highlighted.

Dopant‐Free and Carrier‐Selective Heterocontacts for Silicon Solar Cells: Recent Advances and Perspectives

PubMed Central

Yang, Zhenhai; He, Jian; Yu, Jing; Liu, Peipei; Zhu, Juye; Ge, Ziyi; Ye, Jichun

2017-01-01

Abstract By combining the most successful heterojunctions (HJ) with interdigitated back contacts, crystalline silicon (c‐Si) solar cells (SCs) have recently demonstrated a record efficiency of 26.6%. However, such SCs still introduce optical/electrical losses and technological issues due to parasitic absorption/Auger recombination inherent to the doped films and the complex process of integrating discrete p+‐ and n+‐HJ contacts. These issues have motivated the search for alternative new functional materials and simplified deposition technologies, whereby carrier‐selective contacts (CSCs) can be formed directly with c‐Si substrates, and thereafter form IBC cells, via a dopant‐free method. Screening and modifying CSC materials in a wider context is beneficial for building dopant‐free HJ contacts with better performance, shedding new light on the relatively mature Si photovoltaic field. In this review, a significant number of achievements in two representative dopant‐free hole‐selective CSCs, i.e., poly(3,4‐ethylene dioxythiophene):poly(styrenesulfonate)/Si and transition metal oxides/Si, have been systemically presented and surveyed. The focus herein is on the latest advances in hole‐selective materials modification, interfacial passivation, contact resistivity, light‐trapping structure and device architecture design, etc. By analyzing the structure–property relationships of hole‐selective materials and assessing their electrical transport properties, promising functional materials as well as important design concepts for such CSCs toward high‐performance SCs have been highlighted. PMID:29593956

Use of Aromatase Inhibitors in Large Cell Calcifying Sertoli Cell Tumors: Effects on Gynecomastia, Growth Velocity, and Bone Age

PubMed Central

Crocker, Melissa K.; Gourgari, Evgenia; Stratakis, Constantine A.

2014-01-01

Context: Large cell calcifying Sertoli cell tumors (LCCSCT) present in isolation or, especially in children, in association with Carney Complex (CNC) or Peutz-Jeghers Syndrome (PJS). These tumors overexpress aromatase (CYP19A1), which leads to increased conversion of delta-4-androstenedione to estrone and testosterone to estradiol. Prepubertal boys may present with growth acceleration, advanced bone age, and gynecomastia. Objective: To investigate the outcomes of aromatase inhibitor therapy (AIT) in prepubertal boys with LCCSCTs. Design: Case series of a very rare tumor and chart review of cases treated at other institutions. Setting: Tertiary care and referral center. Patients: Six boys, five with PJS and one with CNC, were referred to the National Institutes of Health for treatment of LCCSCT. All patients had gynecomastia, testicular enlargement, and advanced bone ages, and were being treated by their referring physicians with AIT. Interventions: Patients were treated for a total of 6–60 months on AIT. Main Outcome Measures: Height, breast tissue mass, and testicular size were all followed; physical examination, scrotal ultrasounds, and bone ages were obtained, and hormonal concentrations and tumor markers were measured. Results: Tumor markers were negative. All patients had decreases in breast tissue while on therapy. Height percentiles declined, and predicted adult height moved closer to midparental height as bone age advancement slowed. Testicular enlargement stabilized until entry into central puberty. Only one patient required unilateral orchiectomy. Conclusions: Patients with LCCSCT benefit from AIT with reduction and/or elimination of gynecomastia and slowing of linear growth and bone age advancement. Further study of long-term outcomes and safety monitoring are needed but these preliminary data suggest that mammoplasty and/or orchiectomy may be foregone in light of the availability of medical therapy. PMID:25226294

Translating Stem Cell Research to Cardiac Disease Therapies: Pitfalls and Prospects for Improvement

PubMed Central

Rosen, Michael R.; Myerburg, Robert J.; Francis, Darrel P.; Cole, Graham D.; Marbán, Eduardo

2014-01-01

Over the past 2 decades, there have been numerous stem cell studies focused on cardiac diseases, ranging from proof-of-concept to phase 2 trials. This series of articles focuses on the legacy of these studies and the outlook for future treatment of cardiac diseases with stem cell therapies. The first section by Rosen and Myerburg is an independent review that analyzes the basic science and translational strategies supporting the rapid advance of stem cell technology to the clinic, the philosophies behind them, trial designs, and means for going forward that may impact favorably on progress. The second and third sections were collected in response to the initial section of this review. The commentary by Francis and Cole discusses the Rosen and Myerburg review and details how trial outcomes can be affected by noise, poor trial design (particularly the absence of blinding), and normal human tendencies toward optimism and denial. The final, independent article by Marbán takes a different perspective concerning the potential for positive impact of stem cell research applied to heart disease and future prospects for its clinical application. PMID:25169179

Stem cells for amyotrophic lateral sclerosis modeling and therapy: myth or fact?

PubMed

Coatti, G C; Beccari, M S; Olávio, T R; Mitne-Neto, M; Okamoto, O K; Zatz, M

2015-03-01

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease whose pathophysiology is poorly understood. Aiming to better understand the cause of motor neuron death, the use of experimental cell-based models increased significantly over the past years. In this scenario, much knowledge has been generated from the study of motor neurons derived from embryonic stem cells and induced pluripotent stem cells. These methods, however, have advantages and disadvantages, which must be balanced on experimental design. Preclinical studies provide valuable information, making it possible to combine diverse methods to build an expanded knowledge of ALS pathophysiology. In addition to using stem cells as experimental models for understanding disease mechanism, these cells had been quoted for therapy in ALS. Despite ethical issues involved in its use, cell therapy with neural stem cells stands out. A phase I clinical trial was recently completed and a phase II is on its way, attesting the method's safety. In another approach, mesenchymal stromal cells capable of releasing neuroregulatory and anti-inflammatory factors have also been listed as candidates for cell therapy for ALS, and have been admitted as safe in a phase I trial. Despite recent advances, application of stem cells as an actual therapy for ALS patients is still in debate. Here, we discuss how stem cells have been useful in modeling ALS and address critical topics concerning their therapeutic use, such as administration protocols, injection site, cell type to be administered, type of transplantation (autologous vs. allogeneic) among other issues with particular implications for ALS therapy. © 2015 International Society for Advancement of Cytometry.

Computational materials design of crystalline solids.

PubMed

Butler, Keith T; Frost, Jarvist M; Skelton, Jonathan M; Svane, Katrine L; Walsh, Aron

2016-11-07

The modelling of materials properties and processes from first principles is becoming sufficiently accurate as to facilitate the design and testing of new systems in silico. Computational materials science is both valuable and increasingly necessary for developing novel functional materials and composites that meet the requirements of next-generation technology. A range of simulation techniques are being developed and applied to problems related to materials for energy generation, storage and conversion including solar cells, nuclear reactors, batteries, fuel cells, and catalytic systems. Such techniques may combine crystal-structure prediction (global optimisation), data mining (materials informatics) and high-throughput screening with elements of machine learning. We explore the development process associated with computational materials design, from setting the requirements and descriptors to the development and testing of new materials. As a case study, we critically review progress in the fields of thermoelectrics and photovoltaics, including the simulation of lattice thermal conductivity and the search for Pb-free hybrid halide perovskites. Finally, a number of universal chemical-design principles are advanced.

Atomic force microscopy – looking at mechanosensors on the cell surface

PubMed Central

Heinisch, Jürgen J.; Lipke, Peter N.; Beaussart, Audrey; El Kirat Chatel, Sofiane; Dupres, Vincent; Alsteens, David; Dufrêne, Yves F.

2012-01-01

Summary Living cells use cell surface proteins, such as mechanosensors, to constantly sense and respond to their environment. However, the way in which these proteins respond to mechanical stimuli and assemble into large complexes remains poorly understood at the molecular level. In the past years, atomic force microscopy (AFM) has revolutionized the way in which biologists analyze cell surface proteins to molecular resolution. In this Commentary, we discuss how the powerful set of advanced AFM techniques (e.g. live-cell imaging and single-molecule manipulation) can be integrated with the modern tools of molecular genetics (i.e. protein design) to study the localization and molecular elasticity of individual mechanosensors on the surface of living cells. Although we emphasize recent studies on cell surface proteins from yeasts, the techniques described are applicable to surface proteins from virtually all organisms, from bacteria to human cells. PMID:23077172

Microfluidic fuel cell systems

NASA Astrophysics Data System (ADS)

Ho, Bernard; Kjeang, Erik

2011-06-01

A microfluidic fuel cell is a microfabricated device that produces electrical power through electrochemical reactions involving a fuel and an oxidant. Microfluidic fuel cell systems exploit co-laminar flow on the microscale to separate the fuel and oxidant species, in contrast to conventional fuel cells employing an ion exchange membrane for this function. Since 2002 when the first microfluidic fuel cell was invented, many different fuels, oxidants, and architectures have been investigated conceptually and experimentally. In this mini-review article, recent advancements in the field of microfluidic fuel cell systems are documented, with particular emphasis on design, operation, and performance. The present microfluidic fuel cell systems are categorized by the fluidic phases of the fuel and oxidant streams, featuring gaseous/gaseous, liquid/gaseous, and liquid/liquid systems. The typical cell configurations and recent contributions in each category are analyzed. Key research challenges and opportunities are highlighted and recommendations for further work are provided.

Gene and cell therapy for children — New medicines, new challenges?☆

PubMed Central

Buckland, Karen F.; Bobby Gaspar, H.

2014-01-01

The range of possible gene and cell therapy applications is expanding at an extremely rapid rate and advanced therapy medicinal products (ATMPs) are currently the hottest topic in novel medicines, particularly for inherited diseases. Paediatric patients stand to gain enormously from these novel therapies as it now seems plausible to develop a gene or cell therapy for a vast number of inherited diseases. There are a wide variety of potential gene and cell therapies in various stages of development. Patients who received first gene therapy treatments for primary immune deficiencies (PIDs) are reaching 10 and 15 years post-treatment, with robust and sustained immune recovery. Cell therapy clinical trials are underway for a variety of tissues including corneal, retinal and muscle repair and islet cell transplantation. Various cell therapy approaches are also being trialled to enhance the safety of bone marrow transplants, which should improve survival rates in childhood cancers and PIDs. Progress in genetic engineering of lymphocyte populations to target and kill cancerous cells is also described. If successful these ATMPs may enhance or replace the existing chemo-ablative therapy for several paediatric cancers. Emerging applications of gene therapy now include skin and neurological disorders such as epidermolysis bullosa, epilepsy and leukodystrophy. Gene therapy trials for haemophilia, muscular dystrophy and a range of metabolic disorders are underway. There is a vast array of potential advanced therapy medicinal products (ATMPs), and these are likely to be more cost effective than existing medicines. However, the first clinical trials have not been without setbacks and some of the key adverse events are discussed. Furthermore, the arrival of this novel class of therapies brings many new challenges for the healthcare industry. We present a summary of the key non-clinical factors required for successful delivery of these potential treatments. Technological advances are needed in vector design, raw material manufacture, cell culture and transduction methodology, and particularly in making all these technologies readily scalable. PMID:24583376

Using the ribosome to synthesize peptidomimetics

PubMed Central

2009-01-01

Peptidomimetic research is an approach to identify peptide-based drugs designed to mimic structural, conformational, and biological properties of peptides while overcoming their limitations, such as protease instability and poor cell penetration. With recent advances in ribosomal synthesis of peptides containing unnatural amino acids, this technology appears suitable for preparing large structurally diverse libraries of peptidomimetics for drug discovery screening. PMID:20948631

Engineering liposomal nanoparticles for targeted gene therapy.

PubMed

Zylberberg, C; Gaskill, K; Pasley, S; Matosevic, S

2017-08-01

Recent mechanistic studies have attempted to deepen our understanding of the process by which liposome-mediated delivery of genetic material occurs. Understanding the interactions between lipid nanoparticles and cells is still largely elusive. Liposome-mediated delivery of genetic material faces systemic obstacles alongside entry into the cell, endosomal escape, lysosomal degradation and nuclear uptake. Rational design approaches for targeted delivery have been developed to reduce off-target effects and enhance transfection. These strategies, which have included the modification of lipid nanoparticles with target-specific ligands to enhance intracellular uptake, have shown significant promise at the proof-of-concept stage. Control of physical and chemical specifications of liposome composition, which includes lipid-to-DNA charge, size, presence of ester bonds, chain length and nature of ligand complexation, is integral to the performance of targeted liposomes as genetic delivery agents. Clinical advances are expected to rely on such systems in the therapeutic application of liposome nanoparticle-based gene therapy. Here, we discuss the latest breakthroughs in the development of targeted liposome-based agents for the delivery of genetic material, paying particular attention to new ligand and cationic lipid design as well as recent in vivo advances.

Advanced driver assistance systems: Using multimodal redundant warnings to enhance road safety.

PubMed

Biondi, Francesco; Strayer, David L; Rossi, Riccardo; Gastaldi, Massimiliano; Mulatti, Claudio

2017-01-01

This study investigated whether multimodal redundant warnings presented by advanced assistance systems reduce brake response times. Warnings presented by assistance systems are designed to assist drivers by informing them that evasive driving maneuvers are needed in order to avoid a potential accident. If these warnings are poorly designed, they may distract drivers, slow their responses, and reduce road safety. In two experiments, participants drove a simulated vehicle equipped with a forward collision avoidance system. Auditory, vibrotactile, and multimodal warnings were presented when the time to collision was shorter than five seconds. The effects of these warnings were investigated with participants performing a concurrent cell phone conversation (Exp. 1) or driving in high-density traffic (Exp. 2). Braking times and subjective workload were measured. Multimodal redundant warnings elicited faster braking reaction times. These warnings were found to be effective even when talking on a cell phone (Exp. 1) or driving in dense traffic (Exp. 2). Multimodal warnings produced higher ratings of urgency, but ratings of frustration did not increase compared to other warnings. Findings obtained in these two experiments are important given that faster braking responses may reduce the potential for a collision. Copyright © 2016 Elsevier Ltd. All rights reserved.

Phase 2 study of ABT-510 in patients with previously untreated advanced renal cell carcinoma.

PubMed

Ebbinghaus, Scot; Hussain, Maha; Tannir, Nizar; Gordon, Michael; Desai, Apurva A; Knight, Raymond A; Humerickhouse, Rod A; Qian, Jiang; Gordon, Gary B; Figlin, Robert

2007-11-15

Angiogenesis is a characteristic of renal cell carcinoma. ABT-510 is an angiogenesis inhibitor that mimics the antiangiogenic properties of thrombospondin-1. This study was designed to assess the safety and efficacy of ABT-510 in patients with advanced renal cell carcinoma. Patients with previously untreated metastatic or unresectable renal cell carcinoma were randomized to treatment with one of two doses of ABT-510, self-administered s.c. twice daily in 28-day treatment periods without intervening rest periods. End points were progression-free survival (PFS), objective response rate, overall survival, and toxicity. The objective response rate was 4% in the 10 mg twice daily group, and there were two unconfirmed PRs in the 100 mg twice daily group. Respective median PFS was 4.2 and 3.3 months, with a 6-month PFS of 39% and 32%. Median overall survival was 27.8 months (10 mg twice daily) and 26.1 months (100 mg twice daily). The most frequent adverse events were injection site reactions (84%), fatigue (50%), headache (20%), and nausea (19%). The incidence of treatment-related, grade 3/4 adverse events was low and included three bleeding episodes (gastrointestinal hemorrhage, intracranial hemorrhage, and hemoptysis) and one thrombotic event (deep vein thrombosis). No deaths were attributed to ABT-510. There was little evidence of clinical activity for ABT-510, and further evaluation as a single agent for treating advanced renal cell carcinoma is not warranted. The evidence of a favorable safety profile may justify further evaluation in combination therapy.

Contribution of high-resolution correlative imaging techniques in the study of the liver sieve in three-dimensions.

PubMed

Braet, Filip; Wisse, Eddie; Bomans, Paul; Frederik, Peter; Geerts, Willie; Koster, Abraham; Soon, Lilian; Ringer, Simon

2007-03-01

Correlative microscopy has become increasingly important for the analysis of the structure, function, and dynamics of cells. This is largely due to the result of recent advances in light-, probe-, laser- and various electron microscopy techniques that facilitate three-dimensional studies. Furthermore, the improved understanding in the past decade of imaging cell compartments in the third dimension has resulted largely from the availability of powerful computers, fast high-resolution CCD cameras, specifically developed imaging analysis software, and various probes designed for labeling living and or fixed cells. In this paper, we review different correlative high-resolution imaging methodologies and how these microscopy techniques facilitated the accumulation of new insights in the morpho-functional and structural organization of the hepatic sieve. Various aspects of hepatic endothelial fenestrae regarding their structure, origin, dynamics, and formation will be explored throughout this paper by comparing the results of confocal laser scanning-, correlative fluorescence and scanning electron-, atomic force-, and whole-mount electron microscopy. Furthermore, the recent advances of vitrifying cells with the vitrobot in combination with the glove box for the preparation of cells for cryo-electron microscopic investigation will be discussed. Finally, the first transmission electron tomography data of the liver sieve in three-dimensions are presented. The obtained data unambiguously show the involvement of special domains in the de novo formation and disappearance of hepatic fenestrae, and focuses future research into the (supra)molecular structure of the fenestrae-forming center, defenestration center and fenestrae-, and sieve plate cytoskeleton ring by using advanced cryo-electron tomography. (c) 2007 Wiley-Liss, Inc.

Hematopoietic stem cell engineering at a crossroads

PubMed Central

Rivière, Isabelle; Dunbar, Cynthia E.

2012-01-01

The genetic engineering of hematopoietic stem cells is the basis for potentially treating a large array of hereditary and acquired diseases, and stands as the paradigm for stem cell engineering in general. Recent clinical reports support the formidable promise of this approach but also highlight the limitations of the technologies used to date, which have on occasion resulted in clonal expansion, myelodysplasia, or leukemogenesis. New research directions, predicated on improved vector designs, targeted gene delivery or the therapeutic use of pluripotent stem cells, herald the advent of safer and more effective hematopoietic stem cell therapies that may transform medical practice. In this review, we place these recent advances in perspective, emphasizing the solutions emerging from a wave of new technologies and highlighting the challenges that lie ahead. PMID:22096239

Noncovalent interaction-assisted drug delivery system with highly efficient uptake and release of paclitaxel for anticancer therapy.

PubMed

Wei, Yuping; Ma, Liang; Zhang, Liang; Xu, Xia

2017-01-01

An effective drug delivery system requires efficient drug uptake and release inside cancer cells. Here, we report a novel drug delivery system, in which paclitaxel (PTX) interacts with a novel cell penetrating peptide (CPP) through noncovalent interaction designed based on molecular simulations. This CPP/PTX complex confers high efficiency in delivering PTX into cancer cells not by endocytosis but by an energy-independent pathway. Once inside cells, the noncovalent interaction between PTX and the CPP may allow fast release of PTX within cells due to the direct translocation of CPP/PTX. This drug delivery system exhibits strong capacity for inhibition of tumor growth and offers a new avenue for the development of advanced drug delivery systems for anticancer therapy.

Microfluidic cell chips for high-throughput drug screening

PubMed Central

Chi, Chun-Wei; Ahmed, AH Rezwanuddin; Dereli-Korkut, Zeynep; Wang, Sihong

2016-01-01

The current state of screening methods for drug discovery is still riddled with several inefficiencies. Although some widely used high-throughput screening platforms may enhance the drug screening process, their cost and oversimplification of cell–drug interactions pose a translational difficulty. Microfluidic cell-chips resolve many issues found in conventional HTS technology, providing benefits such as reduced sample quantity and integration of 3D cell culture physically more representative of the physiological/pathological microenvironment. In this review, we introduce the advantages of microfluidic devices in drug screening, and outline the critical factors which influence device design, highlighting recent innovations and advances in the field including a summary of commercialization efforts on microfluidic cell chips. Future perspectives of microfluidic cell devices are also provided based on considerations of present technological limitations and translational barriers. PMID:27071838

Technology advancement of the electrochemical CO2 concentrating process

NASA Technical Reports Server (NTRS)

Schubert, F. H.; Woods, R. R.; Hallick, T. M.; Heppner, D. B.

1978-01-01

The overall objectives of the present program are to: (1) improve the performance of the electrochemical CO2 removal technique by increasing CO2 removal efficiencies at pCO2 levels below 400 Pa, increasing cell power output and broadening the tolerance of electrochemical cells for operation over wide ranges of cabin relative humidity; (2) design, fabricate, and assemble development hardware to continue the evolution of the electrochemical concentrating technique from the existing level to an advanced level able to efficiently meet the CO2 removal needs of a spacecraft air revitalization system (ARS); (3) develop and incorporate into the EDC the components and concepts that allow for the efficient integration of the electrochemical technique with other subsystems to form a spacecraft ARS; (4) combine ARS functions to enable the elimination of subsystem components and interfaces; and (5) demonstrate the integration concepts through actual operation of a functionally integrated ARS.

Biological soft X-ray tomography on beamline 2.1 at the Advanced Light Source.

PubMed

Le Gros, Mark A; McDermott, Gerry; Cinquin, Bertrand P; Smith, Elizabeth A; Do, Myan; Chao, Weilun L; Naulleau, Patrick P; Larabell, Carolyn A

2014-11-01

Beamline 2.1 (XM-2) is a transmission soft X-ray microscope in sector 2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. XM-2 was designed, built and is now operated by the National Center for X-ray Tomography as a National Institutes of Health Biomedical Technology Research Resource. XM-2 is equipped with a cryogenic rotation stage to enable tomographic data collection from cryo-preserved cells, including large mammalian cells. During data collection the specimen is illuminated with `water window' X-rays (284-543 eV). Illuminating photons are attenuated an order of magnitude more strongly by biomolecules than by water. Consequently, differences in molecular composition generate quantitative contrast in images of the specimen. Soft X-ray tomography is an information-rich three-dimensional imaging method that can be applied either as a standalone technique or as a component modality in correlative imaging studies.

Expanding the B Cell Centric View of Systemic Lupus Erythematosus

PubMed Central

Morawski, Peter A.; Bolland, Silvia

2017-01-01

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by a breakdown of self-tolerance in B cells and production of antibodies against nuclear self-antigens. Increasing evidence supports the notion that additional cellular contributors beyond B cells are important for lupus pathogenesis. In this Review, we consider recent advances regarding both pathogenic and regulatory roles of lymphocytes in SLE, beyond the production of IgG autoantibodies. We also discuss various inflammatory effector cell types involved in cytokine production, removal of self-antigens, and responses to autoreactive IgE antibodies. We aim to integrate these ideas to expand the current understanding of the cellular components that contribute to disease progression and ultimately help in the design of novel targeted therapeutics. PMID:28274696

Bacterial growth laws and their applications.

PubMed

Scott, Matthew; Hwa, Terence

2011-08-01

Quantitative empirical relationships between cell composition and growth rate played an important role in the early days of microbiology. Gradually, the focus of the field began to shift from growth physiology to the ever more elaborate molecular mechanisms of regulation employed by the organisms. Advances in systems biology and biotechnology have renewed interest in the physiology of the cell as a whole. Furthermore, gene expression is known to be intimately coupled to the growth state of the cell. Here, we review recent efforts in characterizing such couplings, particularly the quantitative phenomenological approaches exploiting bacterial 'growth laws.' These approaches point toward underlying design principles that can guide the predictive manipulation of cell behavior in the absence of molecular details. Copyright © 2011 Elsevier Ltd. All rights reserved.

Three-Dimensional Cell Culture Models for Infectious Disease and Drug Development

NASA Technical Reports Server (NTRS)

Nickerson, Cheryl A.; Honer zu Bentrup, Kerstin; Ott, C. Mark

2005-01-01

Three-dimensional (3-D) cell cultures hold enormous potential to advance our understanding of infectious disease and to effectively translate basic cellular research into clinical applications. Using novel NASA bioreactor technology, the rotating wall vessel (RWV), we have engineered physiologically relevant 3-D human tissue culture models for infectious disease studies. The design of the RWV is based on the understanding that organs and tissues function in a 3-D environment, and that this 3-D architecture is critical for the differentiated form and function of tissues in vivo. The RWV provides large numbers of cells which are amenable to a wide variety of experimental manipulations and provides an easy, reproducible, and cost-effective approach to enhance differentiated features of cell culture models.

Cell Patterning for Liver Tissue Engineering via Dielectrophoretic Mechanisms

PubMed Central

Yahya, Wan Nurlina Wan; Kadri, Nahrizul Adib; Ibrahim, Fatimah

2014-01-01

Liver transplantation is the most common treatment for patients with end-stage liver failure. However, liver transplantation is greatly limited by a shortage of donors. Liver tissue engineering may offer an alternative by providing an implantable engineered liver. Currently, diverse types of engineering approaches for in vitro liver cell culture are available, including scaffold-based methods, microfluidic platforms, and micropatterning techniques. Active cell patterning via dielectrophoretic (DEP) force showed some advantages over other methods, including high speed, ease of handling, high precision and being label-free. This article summarizes liver function and regenerative mechanisms for better understanding in developing engineered liver. We then review recent advances in liver tissue engineering techniques and focus on DEP-based cell patterning, including microelectrode design and patterning configuration. PMID:24991941

Treatment Rationale and Design for J-SONIC: A Randomized Study of Carboplatin Plus Nab-paclitaxel With or Without Nintedanib for Advanced Non-Small-cell Lung Cancer With Idiopathic Pulmonary Fibrosis.

PubMed

Otsubo, Kohei; Kishimoto, Junji; Kenmotsu, Hirotsugu; Minegishi, Yuji; Ichihara, Eiki; Shiraki, Akira; Kato, Terufumi; Atagi, Shinji; Horinouchi, Hidehito; Ando, Masahiko; Kondoh, Yasuhiro; Kusumoto, Masahiko; Ichikado, Kazuya; Yamamoto, Nobuyuki; Nakanishi, Yoichi; Okamoto, Isamu

2018-01-01

We describe the treatment rationale and procedure for a randomized study (J-SONIC; University Hospital Medical Information Network Clinical Trials Registry identification no., UMIN000026799) of carboplatin plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel) with or without nintedanib for patients with advanced non-small cell lung cancer (NSCLC) and idiopathic pulmonary fibrosis (IPF). The study was designed to examine the efficacy and safety of nintedanib administered with carboplatin plus nab-paclitaxel versus carboplatin plus nab-paclitaxel alone in chemotherapy-naive patients with advanced NSCLC associated with IPF. Eligible patients (enrollment target, n = 170) will be randomized at a 1:1 ratio to receive 4 cycles of carboplatin (area under the curve, 6 on day 1) plus nab-paclitaxel (100 mg/m 2 on days 1, 8, and 15) administered every 3 weeks either without (arm A) or with (arm B) nintedanib (150 mg twice daily), to be followed in arm B by single-agent administration of nintedanib (150 mg twice daily). The present trial is the first randomized controlled study for the treatment of NSCLC associated with IPF. The goal of the study is to demonstrate that nintedanib combined with carboplatin plus nab-paclitaxel prolongs the interval to acute exacerbation of IPF compared with carboplatin plus nab-paclitaxel alone. Copyright © 2017 Elsevier Inc. All rights reserved.

Responses of advanced directives by Jehovah’s Witnesses on a gynecologic oncology service

PubMed Central

Nagarsheth, Nimesh P; Gupta, Nikhil; Gupta, Arpeta; Moshier, Erin; Gretz, Herbert; Shander, Aryeh

2015-01-01

Objectives To review the responses of advance directives signed by Jehovah’s Witness patients prior to undergoing surgery at a gynecologic oncology service. Study design A retrospective chart review of gynecologic oncology patients undergoing surgery at a bloodless surgery center from 1998–2007 was conducted. Demographic, pathologic, and clinical data were recorded. The proportion of patients who accepted and refused various blood-derived products was determined and was compared to previously published results from a similar study of labor and delivery unit patients. Results No gynecologic oncology patients agreed to accept transfusions of whole blood, red cells, white cells, platelets, or plasma under any circumstance, whereas 9.8% of pregnant patients accepted transfusion (P=0.0385). However, 98% of gynecologic oncology patients agreed to accept some blood products, including fractions such as albumin, immunoglobulins, and clotting factors, while only 39% of pregnant patients agreed (P<0.0001). In addition, all gynecologic oncology patients (100%) accepted intraoperative hemodilution, compared to 55% of pregnant patients (P<0.0001). Conclusion Our results confirm the commonly held belief that the majority of Jehovah’s Witness patients refuse to accept major blood components. However, Jehovah’s Witness patients at a gynecologic oncology service will accept a variety of blood-derived products (minor fractions) and interventions designed to optimize outcomes when undergoing transfusion-free surgery. Patients presenting to a gynecologic oncology service respond differently to advanced directives related to bloodless surgery, as compared to patients from an obstetrical service. PMID:25565911

Coupled thermal, electrical, and fluid flow analyses of AMTEC multitube cell with adiabatic side wall

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

Schock, A.; Or, C.; Noravian, H.

1997-01-01

The paper describes a novel OSC-generated methodology for analyzing the performance of multitube AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells, which are under development by AMPS (Advanced Modular Power Systems, Inc.) for the Air Force Phillips Laboratory (AFPL) and NASA{close_quote}s Jet Propulsion Laboratory (JPL), for possible application to the Pluto Express and other space missions. The OSC study was supported by the Department of Energy (DOE), and was strongly encouraged by JPL, AFPL, and AMPS. It resulted in an iterative procedure for the coupled solution of the interdependent thermal, electrical, and fluid flow differential and integral equations governing the performance ofmore » AMTEC cells and generators. The paper clarifies the OSC procedure by presenting detailed results of its application to an illustrative example of a converter cell with an adiabatic side wall, including the non-linear axial variation of temperature, pressure, open-circuit voltage, interelectrode voltage, current density, axial current, sodium mass flow, and power density. The next paper in these proceedings describes parametric results obtained by applying the same procedure to variations of the baseline adiabatic converter design, culminating in an OSC-recommended revised cell design. A subsequent paper in these proceedings extends the procedure to analyze a variety of OSC-designed radioisotope-heated generators employing non-adiabatic multitube AMTEC cells. {copyright} {ital 1997 American Institute of Physics.}« less

Genetic biomarkers for neoplastic colorectal cancer in peripheral lymphocytes.

PubMed

Ionescu, Mirela; Ciocirlan, Mihai; Ionescu, Cristina; Becheanu, Gabriel; Gologan, Serban; Teiusanu, Adriana; Arbanas, Tudor; Mircea, Diculescu

2011-04-01

Loss of genomic stability appears as a key step in colorectal carcinogenesis. Micronucleus (MN) designates a chromosome fragment or an entire chromosme which lags behind mitosis. MN may be noticed as an additional nucleus within the cytoplasm cell during the intermediate mitosis phases. We tested the hypothesis that MN and its related anomalies may be associated with the presence of neoplastic colorectal lesions. Peripheral blood lymphocytes were cultured and microscopically examined. The frequency of micronuclei (FMN) and the presence of nucleoplasmic bridges (NPB) in binucleated cells were compared in patients with of without colorectal neoplastic lesions. We included 45 patients undergoing colonoscopy, 23 males and 22 females, with a median age of 59. 17 patients had polyps, 11 colorectal cancer (CRC) and 17 had a normal colonoscopy. The FMN was significantly higher in women than in men (8.14 vs 4.17, p=0.008); NPB were significantly less frequent in patients with advanced adenomas (>10mm or vilous) or CRC (p=0.044) when compared with patients with normal colonoscopy, hiperplastic polyps or non-advanced adenomas. Micronuclei are more frequent in women, but its frequency was not significantly different in patients with advanced adenomas or CRC. Null or low frequency values for nucleoplasmic bridges presence in peripheral lymphocyte may be predictive for advanced adenomas and colorectal cancer.

Pin routability and pin access analysis on standard cells for layout optimization

NASA Astrophysics Data System (ADS)

Chen, Jian; Wang, Jun; Zhu, ChengYu; Xu, Wei; Li, Shuai; Lin, Eason; Ou, Odie; Lai, Ya-Chieh; Qu, Shengrui

2018-03-01

At advanced process nodes, especially at sub-28nm technology, pin accessibility and routability of standard cells has become one of the most challenging design issues due to the limited router tracks and the increased pin density. If this issue can't be found and resolved during the cell design stage, the pin access problem will be very difficult to be fixed in implementation stage and will make the low efficiency for routing. In this paper, we will introduce a holistic approach for the pin accessibility scoring and routability analysis. For accessibility, the systematic calculator which assigns score for each pin will search the available access points, consider the surrounded router layers, basic design rule and allowed via geometry. Based on the score, the "bad" pins can be found and modified. On pin routability analysis, critical pin points (placing via on this point would lead to failed via insertion) will be searched out for either layout optimization guide or set as OBS for via insertion blocking. By using this pin routability and pin access analysis flow, we are able to improve the library quality and performance.

Non-Volatile Memory Technology Symposium 2000: Proceedings

NASA Technical Reports Server (NTRS)

Aranki, Nazeeh (Editor)

2000-01-01

This publication contains the proceedings for the Non-Volatile Memory Technology Symposium 2000 that was held on November 15-16, 2000 in Arlington, Virginia. The proceedings contains a wide range of papers that cover the presentations of myriad advances in the nonvolatile memory technology during the recent past including memory cell design, simulations, radiation environment, and emerging memory technologies. The papers presented in the proceedings address the design challenges and applications and deals with newer, emerging memory technologies as well as related issues of radiation environment and die packaging.

Basal cell nevus syndrome (Gorlin syndrome): genetic insights, diagnostic challenges, and unmet milestones.

PubMed

Akbari, Maryam; Chen, Harold; Guo, Grace; Legan, Zachary; Ghali, Ghali

2018-01-31

In this article, we present three clinical case reports on Basal Cell Nevus Syndrome (Gorlin Syndrome). Gorlin syndrome is an inherited medical condition with challenges that manifest in multiple body systems and complicate early diagnosis. We examine the epidemiology of the disease and benefits of genetic testing, molecular pathophysiology, and advancement in the molecular-based therapy of Basal Cell Nevus syndrome. The goal of this paper is to shed light on both unmet challenges and advancements in the management of Gorlin syndrome and to provide a new clinical perspective and guidance for future research. Furthermore, the FDA approved Hedgehog pathway inhibitors Vismodegib and Sonidegib designed for advanced basal cell carcinoma have opened a new door for treatment that may ultimately decrease the number of surgeries for a patient with Gorlin syndrome. The role of these agents in syndromic odontogenic keratocyst has not been studied extensively, but one study found that hedgehog pathway inhibitors decrease the size of syndromic odontogenic keratocyst. Ideal surgical treatment that balances low recurrence rates with low impact on one's quality of life for syndromic odontogenic keratocyst is another unanswered question for oral and maxillofacial surgeons. Per survey studies, treatment options practiced for syndromic odontogenic keratocyst range from marsupialization to segmental osteotomy. Future studies performed should take a comprehensive long-term approach with at least three years of follow-up in order to determine the most appropriate treatment. Copyright © 2018 Elsevier B.V. All rights reserved.

Wideband spectrum analysis of ultra-high frequency radio-wave signals due to advanced one-phonon non-collinear anomalous light scattering.

PubMed

Shcherbakov, Alexandre S; Arellanes, Adan Omar

2017-04-20

We present a principally new acousto-optical cell providing an advanced wideband spectrum analysis of ultra-high frequency radio-wave signals. For the first time, we apply a recently developed approach with the tilt angle to a one-phonon non-collinear anomalous light scattering. In contrast to earlier cases, now one can exploit a regime with the fixed optical wavelength for processing a great number of acoustic frequencies simultaneously in the linear regime. The chosen rutile-crystal combines a moderate acoustic velocity with low acoustic attenuation and allows us wide-band data processing within GHz-frequency acoustic waves. We have created and experimentally tested a 6-cm aperture rutile-made acousto-optical cell providing the central frequency 2.0 GHz, frequency bandwidth ∼0.52  GHz with the frequency resolution about 68.3 kHz, and ∼7620 resolvable spots. A similar cell permits designing an advanced ultra-high-frequency arm within a recently developed multi-band radio-wave acousto-optical spectrometer for astrophysical studies. This spectrometer is intended to operate with a few parallel optical arms for processing the multi-frequency data flows within astrophysical observations. Keeping all the instrument's advantages of the previous schematic arrangement, now one can create the highest-frequency arm using the developed rutile-based acousto-optical cell. It permits optimizing the performances inherent in that arm via regulation of both the central frequency and the frequency bandwidth for spectrum analysis.

Additive Manufacturing of Biomedical Constructs with Biomimetic Structural Organizations

PubMed Central

Li, Xiao; He, Jiankang; Zhang, Weijie; Jiang, Nan; Li, Dichen

2016-01-01

Additive manufacturing (AM), sometimes called three-dimensional (3D) printing, has attracted a lot of research interest and is presenting unprecedented opportunities in biomedical fields, because this technology enables the fabrication of biomedical constructs with great freedom and in high precision. An important strategy in AM of biomedical constructs is to mimic the structural organizations of natural biological organisms. This can be done by directly depositing cells and biomaterials, depositing biomaterial structures before seeding cells, or fabricating molds before casting biomaterials and cells. This review organizes the research advances of AM-based biomimetic biomedical constructs into three major directions: 3D constructs that mimic tubular and branched networks of vasculatures; 3D constructs that contains gradient interfaces between different tissues; and 3D constructs that have different cells positioned to create multicellular systems. Other recent advances are also highlighted, regarding the applications of AM for organs-on-chips, AM-based micro/nanostructures, and functional nanomaterials. Under this theme, multiple aspects of AM including imaging/characterization, material selection, design, and printing techniques are discussed. The outlook at the end of this review points out several possible research directions for the future. PMID:28774030

Advances in understanding tumour evolution through single-cell sequencing.

PubMed

Kuipers, Jack; Jahn, Katharina; Beerenwinkel, Niko

2017-04-01

The mutational heterogeneity observed within tumours poses additional challenges to the development of effective cancer treatments. A thorough understanding of a tumour's subclonal composition and its mutational history is essential to open up the design of treatments tailored to individual patients. Comparative studies on a large number of tumours permit the identification of mutational patterns which may refine forecasts of cancer progression, response to treatment and metastatic potential. The composition of tumours is shaped by evolutionary processes. Recent advances in next-generation sequencing offer the possibility to analyse the evolutionary history and accompanying heterogeneity of tumours at an unprecedented resolution, by sequencing single cells. New computational challenges arise when moving from bulk to single-cell sequencing data, leading to the development of novel modelling frameworks. In this review, we present the state of the art methods for understanding the phylogeny encoded in bulk or single-cell sequencing data, and highlight future directions for developing more comprehensive and informative pictures of tumour evolution. This article is part of a Special Issue entitled: Evolutionary principles - heterogeneity in cancer?, edited by Dr. Robert A. Gatenby. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Characterizing the Role of Nanoparticle Design on Tumor Transport and Stability in the Extracellular Environment

NASA Astrophysics Data System (ADS)

Albanese, Alexandre

Nanotechnology has emerged as an exciting strategy for the delivery of diagnostic and therapeutic agents into established tumors. Advancements in nanomaterial synthesis have generated an extensive number of nanoparticle designs made from different materials. Unfortunately, it remains impossible to predict a design's effectiveness for in vivo tumor accumulation. Little is known about how a nanoparticle's morphology and surface chemistry affect its interactions with cells and proteins inside the tumor tissue. This thesis focuses on the development of in vitro experimental tools to evaluate how nanoparticle design affects transport in a three-dimensional tumor tissue and stability in the tumor microenvironment. Nanoparticle transport was evaluated using a novel 'tumor-on-a-chip' system where multicellular tumor spheroids were immobilized in a microfluidic channel. This setup created a three-dimensional tumor environment displaying physiological cell density, extracellular matrix organization, and interstitial flow rates. The tumor-on-a-chip demonstrated that accumulation of nanoparticles was limited to diameters below 110 nm and was improved by receptor targeting. Nanoparticle stability in the tumor microenvironment was evaluated using media isolated from different tumor cell lines. Nanoparticle diameter and surface chemistry were important determinants of stability in cancer cell-conditioned media. Small nanoparticles with unstable surface chemistries adsorbed cellular proteins on their surface and were prone to aggregation. Nanoparticle aggregation altered cellular interactions leading to changes in cell uptake. Using a novel technique to generate different aggregate sizes possessing a uniform surface composition, it was determined that aggregation can change receptor affinity, cell internalization mechanisms and sub-cellular sequestration patterns. Data from this thesis characterize the behavior of nanoparticles within modeled tumor environments and provide some preliminary design guidelines for maximizing nanoparticle tumor accumulation. This work highlights the importance of characterizing nano-bio interactions for engineering successful nanomaterial-based delivery systems.

Development & experimental validation of a SINDA/FLUINT thermal/fluid/electrical model of a multi-tube AMTEC cell

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

Hendricks, T.J.; Borkowski, C.A.; Huang, C.

1998-01-01

AMTEC (Alkali Metal Thermal-to-Electric Conversion) cell development has received increased attention and funding in the space power community because of several desirable performance characteristics compared to current radioisotope thermoelectric generation and solar photovoltaic (PV) power generation. AMTEC cell development is critically dependent upon the ability to predict thermal, fluid dynamic and electrical performance of an AMTEC cell which has many complex thermal, fluid dynamic and electrical processes and interactions occurring simultaneously. Development of predictive capability is critical to understanding the complex processes and interactions within the AMTEC cell, and thereby creating the ability to design high-performance, cost-effective AMTEC cells. Amore » flexible, sophisticated thermal/fluid/electrical model of an operating AMTEC cell has been developed using the SINDA/FLUINT analysis software. This model can accurately simulate AMTEC cell performance at any hot side and cold side temperature combination desired, for any voltage and current conditions, and for a broad range of cell design parameters involving the cell dimensions, current collector and electrode design, electrode performance parameters, and cell wall and thermal shield emissivity. The model simulates the thermal radiation network within the AMTEC cell using RadCAD thermal radiation analysis; hot side, cold side and cell wall conductive and radiative coupling; BASE (Beta Alumina Solid Electrode) tube electrochemistry, including electrode over-potentials; the fluid dynamics of the low-pressure sodium vapor flow to the condenser and liquid sodium flow in the wick; sodium condensation at the condenser; and high-temperature sodium evaporation in the wick. The model predicts the temperature profiles within the AMTEC cell walls, the BASE tube temperature profiles, the sodium temperature profile in the artery return, temperature profiles in the evaporator, thermal energy flows throughout the AMTEC cell, all sodium pressure drops from hot BASE tubes to the condenser, the current, voltage, and power output from the cell, and the cell efficiency. This AMTEC cell model is so powerful and flexible that it is used in radioisotope AMTEC power system design, solar AMTEC power system design, and combustion-driven power system design on several projects at Advanced Modular Power Systems, Inc. (AMPS). The model has been successfully validated against actual cell experimental data and its performance predictions agree very well with experimental data on PX-5B cells and other test cells at AMPS. {copyright} {ital 1998 American Institute of Physics.}« less

Robust Design of Biological Circuits: Evolutionary Systems Biology Approach

PubMed Central

Chen, Bor-Sen; Hsu, Chih-Yuan; Liou, Jing-Jia

2011-01-01

Artificial gene circuits have been proposed to be embedded into microbial cells that function as switches, timers, oscillators, and the Boolean logic gates. Building more complex systems from these basic gene circuit components is one key advance for biologic circuit design and synthetic biology. However, the behavior of bioengineered gene circuits remains unstable and uncertain. In this study, a nonlinear stochastic system is proposed to model the biological systems with intrinsic parameter fluctuations and environmental molecular noise from the cellular context in the host cell. Based on evolutionary systems biology algorithm, the design parameters of target gene circuits can evolve to specific values in order to robustly track a desired biologic function in spite of intrinsic and environmental noise. The fitness function is selected to be inversely proportional to the tracking error so that the evolutionary biological circuit can achieve the optimal tracking mimicking the evolutionary process of a gene circuit. Finally, several design examples are given in silico with the Monte Carlo simulation to illustrate the design procedure and to confirm the robust performance of the proposed design method. The result shows that the designed gene circuits can robustly track desired behaviors with minimal errors even with nontrivial intrinsic and external noise. PMID:22187523

AMTEC radioisotope power system design and analysis for Pluto Express Fly-By

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

Hendricks, T.J.; Huang, C.; Sievers, R.K.

1997-12-31

The Pluto Express Fly-By program requires a Radioisotope Power System (RPS) to supply spacecraft power for various internal functions and mission instruments and experiments. AMTEC (Alkali-Metal Thermal-Electric Conversion) power conversion is the DOE-selected technology for an advanced, high-efficiency RPS to power the Pluto Express Fly-By spacecraft. An AMTEC-based RPS using the General Purpose Heat Source (GPHS) has been conceptually designed to satisfy the Pluto Express power requirements. Integrated AMTEC cell and system thermal/electrical design analyses, structural design analyses, and mass analyses were performed to define an optimum system design. Using fresh radioisotope fuel at beginning of mission, the RPS producesmore » 102 watts of power, has a mass of 8.35 kg (specific power density = 12.2 watts/kg), with a system conversion efficiency of 20.3%. Mass/power scale-up estimates have also been generated, indicating that a 150-watt version of this RPS would weigh approximately 11.3 kg. This paper presents and discusses the key features of this RPS design, the design and analysis methodology, and the numerous system and AMTEC cell tradeoff studies establishing the optimum AMTEC-based RPS.« less

Robust design of biological circuits: evolutionary systems biology approach.

PubMed

Chen, Bor-Sen; Hsu, Chih-Yuan; Liou, Jing-Jia

2011-01-01

Artificial gene circuits have been proposed to be embedded into microbial cells that function as switches, timers, oscillators, and the Boolean logic gates. Building more complex systems from these basic gene circuit components is one key advance for biologic circuit design and synthetic biology. However, the behavior of bioengineered gene circuits remains unstable and uncertain. In this study, a nonlinear stochastic system is proposed to model the biological systems with intrinsic parameter fluctuations and environmental molecular noise from the cellular context in the host cell. Based on evolutionary systems biology algorithm, the design parameters of target gene circuits can evolve to specific values in order to robustly track a desired biologic function in spite of intrinsic and environmental noise. The fitness function is selected to be inversely proportional to the tracking error so that the evolutionary biological circuit can achieve the optimal tracking mimicking the evolutionary process of a gene circuit. Finally, several design examples are given in silico with the Monte Carlo simulation to illustrate the design procedure and to confirm the robust performance of the proposed design method. The result shows that the designed gene circuits can robustly track desired behaviors with minimal errors even with nontrivial intrinsic and external noise.

Modulation of human multipotent and pluripotent stem cells using surface nanotopographies and surface-immobilised bioactive signals: A review.

PubMed

Wang, Peng-Yuan; Thissen, Helmut; Kingshott, Peter

2016-11-01

The ability to control the interactions of stem cells with synthetic surfaces is proving to be effective and essential for the quality of passaged stem cells and ultimately the success of regenerative medicine. The stem cell niche is crucial for stem cell self-renewal and differentiation. Thus, mimicking the stem cell niche, and here in particular the extracellular matrix (ECM), in vitro is an important goal for the expansion of stem cells and their applications. Here, surface nanotopographies and surface-immobilised biosignals have been identified as major factors that control stem cell responses. The development of tailored surfaces having an optimum nanotopography and displaying suitable biosignals is proposed to be essential for future stem cell culture, cell therapy and regenerative medicine applications. While early research in the field has been restricted by the limited availability of micro- and nanofabrication techniques, new approaches involving the use of advanced fabrication and surface immobilisation methods are starting to emerge. In addition, new cell types such as induced pluripotent stem cells (iPSCs) have become available in the last decade, but have not been fully understood. This review summarises significant advances in the area and focuses on the approaches that are aimed at controlling the behavior of human stem cells including maintenance of their self-renewal ability and improvement of their lineage commitment using nanotopographies and biosignals. More specifically, we discuss developments in biointerface science that are an important driving force for new biomedical materials and advances in bioengineering aiming at improving stem cell culture protocols and 3D scaffolds for clinical applications. Cellular responses revolve around the interplay between the surface properties of the cell culture substrate and the biomolecular composition of the cell culture medium. Determination of the precise role played by each factor, as well as the synergistic effects amongst the factors, all of which influence stem cell responses is essential for future developments. This review provides an overview of the current state-of-the-art in the design of complex material surfaces aimed at being the next generation of tools tailored for applications in cell culture and regenerative medicine. This review focuses on the effect of surface nanotopographies and surface-bound biosignals on human stem cells. Recently, stem cell research attracts much attention especially the induced pluripotent stem cells (iPSCs) and direct lineage reprogramming. The fast advance of stem cell research benefits disease treatment and cell therapy. On the other hand, surface property of cell adhered materials has been demonstrated very important for in vitro cell culture and regenerative medicine. Modulation of cell behavior using surfaces is costeffective and more defined. Thus, we summarise the recent progress of modulation of human stem cells using surface science. We believe that this review will capture a broad audience interested in topographical and chemical patterning aimed at understanding complex cellular responses to biomaterials. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Regulation of endogenous human gene expression by ligand-inducible TALE transcription factors.

PubMed

Mercer, Andrew C; Gaj, Thomas; Sirk, Shannon J; Lamb, Brian M; Barbas, Carlos F

2014-10-17

The construction of increasingly sophisticated synthetic biological circuits is dependent on the development of extensible tools capable of providing specific control of gene expression in eukaryotic cells. Here, we describe a new class of synthetic transcription factors that activate gene expression in response to extracellular chemical stimuli. These inducible activators consist of customizable transcription activator-like effector (TALE) proteins combined with steroid hormone receptor ligand-binding domains. We demonstrate that these ligand-responsive TALE transcription factors allow for tunable and conditional control of gene activation and can be used to regulate the expression of endogenous genes in human cells. Since TALEs can be designed to recognize any contiguous DNA sequence, the conditional gene regulatory system described herein will enable the design of advanced synthetic gene networks.