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Sample records for aliquot regenerative dose

  1. The disappearance of the pfotzer-regener maximum in dose equivalent measurements in the stratosphere

    NASA Astrophysics Data System (ADS)

    Hands, A. D. P.; Ryden, K. A.; Mertens, C. J.

    2016-10-01

    The NASA Radiation Dosimetry Experiment (RaD-X) successfully deployed four radiation detectors on a high-altitude balloon for a period of approximately 20 h. One of these detectors was the RaySure in-flight monitor, which is a solid-state instrument designed to measure ionizing dose rates to aircrew and passengers. Data from RaySure on RaD-X show absorbed dose rates rising steadily as a function of altitude up to a peak at approximately 60,000 feet, known as the Pfotzer-Regener maximum. Above this altitude absorbed dose rates level off before showing a small decline as the RaD-X balloon approaches its maximum altitude of around 125,000 feet. The picture for biological dose equivalent, however, is very different. At high altitudes the fraction of dose from highly ionizing particles increases significantly. Dose from these particles causes a disproportionate amount of biological damage compared to dose from more lightly ionizing particles, and this is reflected in the quality factors used to calculate the dose equivalent quantity. By calculating dose equivalent from RaySure data, using coefficients derived from previous calibrations, we show that there is no peak in the dose equivalent rate at the Pfotzer-Regener maximum. Instead, the dose equivalent rate keeps increasing with altitude as the influence of dose from primary cosmic rays becomes increasingly important. This result has implications for high altitude aviation, space tourism and, due to its thinner atmosphere, the surface radiation environment on Mars.

  2. Dose-Dependent Onset of Regenerative Program in Neutron Irradiated Mouse Skin

    PubMed Central

    Artibani, Mara; Kobos, Katarzyna; Colautti, Paolo; Negri, Rodolfo; Amendola, Roberto

    2011-01-01

    Background Tissue response to irradiation is not easily recapitulated by cell culture studies. The objective of this investigation was to characterize, the transcriptional response and the onset of regenerative processes in mouse skin irradiated with different doses of fast neutrons. Methodology/Principal Findings To monitor general response to irradiation and individual animal to animal variation, we performed gene and protein expression analysis with both pooled and individual mouse samples. A high-throughput gene expression analysis, by DNA oligonucleotide microarray was done with three months old C57Bl/6 mice irradiated with 0.2 and 1 Gy of mono-energetic 14 MeV neutron compared to sham irradiated controls. The results on 440 irradiation modulated genes, partially validated by quantitative real time RT-PCR, showed a dose-dependent up-regulation of a sub-class of keratin and keratin associated proteins, and members of the S100 family of Ca2+-binding proteins. Immunohistochemistry confirmed mRNA expression data enabled mapping of protein expression. Interestingly, proteins up-regulated in thickening epidermis: keratin 6 and S100A8 showed the most significant up-regulation and the least mouse-to-mouse variation following 0.2 Gy irradiation, in a concerted effort toward skin tissue regeneration. Conversely, mice irradiated at 1 Gy showed most evidence of apoptosis (Caspase-3 and TUNEL staining) and most 8-oxo-G accumulation at 24 h post-irradiation. Moreover, no cell proliferation accompanied 1 Gy exposure as shown by Ki67 immunohistochemistry. Conclusions/Significance The dose-dependent differential gene expression at the tissue level following in vivo exposure to neutron radiation is reminiscent of the onset of re-epithelialization and wound healing and depends on the proportion of cells carrying multiple chromosomal lesions in the entire tissue. Thus, this study presents in vivo evidence of a skin regenerative program exerted independently from DNA repair

  3. Single-aliquot EPR dosimetry of wallboard (drywall).

    PubMed

    Mistry, R; Thompson, J W; Boreham, D R; Rink, W J

    2011-11-01

    Electron paramagnetic resonance spectra and dose-response curves are presented for a variety of wallboard samples obtained from different manufacturing facilities, as well as for source gypsum and anhydrite. The intensity of the CO(3)(-) paramagnetic centre (G2) is enhanced with gamma radiation. Isothermal decay curves are used to propose annealing methods for the removal of the radiosensitive CO(3)(-) radical without affecting the unirradiated baseline. Post-irradiation annealing of wallboard prevents recuperation of the radiosensitive CO(3)(-) radical with additional irradiation. A single-aliquot additive dose procedure is developed that successfully measures test doses as low as 0.76 Gy.

  4. Centrifugo-pneumatic multi-liquid aliquoting - parallel aliquoting and combination of multiple liquids in centrifugal microfluidics.

    PubMed

    Schwemmer, F; Hutzenlaub, T; Buselmeier, D; Paust, N; von Stetten, F; Mark, D; Zengerle, R; Kosse, D

    2015-08-07

    The generation of mixtures with precisely metered volumes is essential for reproducible automation of laboratory workflows. Splitting a given liquid into well-defined metered sub-volumes, the so-called aliquoting, has been frequently demonstrated on centrifugal microfluidics. However, so far no solution exists for assays that require simultaneous aliquoting of multiple, different liquids and the subsequent pairwise combination of aliquots with full fluidic separation before combination. Here, we introduce the centrifugo-pneumatic multi-liquid aliquoting designed for parallel aliquoting and pairwise combination of multiple liquids. All pumping and aliquoting steps are based on a combination of centrifugal forces and pneumatic forces. The pneumatic forces are thereby provided intrinsically by centrifugal transport of the assay liquids into dead end chambers to compress the enclosed air. As an example, we demonstrate simultaneous aliquoting of 1.) a common assay reagent into twenty 5 μl aliquots and 2.) five different sample liquids, each into four aliquots of 5 μl. Subsequently, the reagent and sample aliquots are simultaneously transported and combined into twenty collection chambers. All coefficients of variation for metered volumes were between 0.4%-1.0% for intra-run variations and 0.5%-1.2% for inter-run variations. The aliquoting structure is compatible to common assay reagents with a wide range of liquid and material properties, demonstrated here for contact angles between 20° and 60°, densities between 789 and 1855 kg m(-3) and viscosities between 0.89 and 4.1 mPa s. The centrifugo-pneumatic multi-liquid aliquoting is implemented as a passive fluidic structure into a single fluidic layer. Fabrication is compatible to scalable fabrication technologies such as injection molding or thermoforming and does not require any additional fabrication steps such as hydrophilic or hydrophobic coatings or integration of active valves.

  5. 20. BUILDING NO. 448, ORDNANCE FACILITY (HOWITZER AND ALIQUOT BAG ...

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

    20. BUILDING NO. 448, ORDNANCE FACILITY (HOWITZER AND ALIQUOT BAG LOADING), LOOKING WEST AT SOUTHEAST CORNER. BUILDING NO. 448-C, GENERAL STOREHOUSE (HIGH EXPLOSIVES MAGAZINE-WEIGHING & MIXING), IN BACKGROUND. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  6. Regenerative Aerobraking

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    2004-01-01

    NASA's exploration goals for Mars and Beyond will require new power systems and in situ resource utilization technologies. Regenerative aerobraking may offer a revolutionary approach for in situ power generation and oxygen harvesting during these exploration missions. In theory, power and oxygen can be collected during aerobraking and stored for later use in orbit or on the planet. This technology would capture energy and oxygen from the plasma field that occurs naturally during hypersonic entry using well understood principles of magnetohydrodynamics and oxygen filtration. This innovative approach generates resources upon arrival at the operational site, and thus greatly differs from the traditional approach of taking everything you need with you from Earth. Fundamental analysis, computational fluid dynamics, and some testing of experimental hardware have established the basic feasibility of generating power during a Mars entry. Oxygen filtration at conditions consistent with spacecraft entry parameters at Mars has been studied to a lesser extent. Other uses of the MHD power are presented. This paper illustrates how some features of regenerative aerobraking may be applied to support human and robotic missions at Mars.

  7. Regenerative Aerobraking

    NASA Astrophysics Data System (ADS)

    Moses, Robert W.

    2005-02-01

    NASA's exploration goals for Mars and Beyond will require new power systems and in situ resource utilization technologies. Regenerative aerobraking may offer a revolutionary approach for in situ power generation and oxygen harvesting during these exploration missions. In theory, power and oxygen can be collected during aerobraking and stored for later use in orbit or on the planet. This technology would capture energy and oxygen from the plasma field that occurs naturally during hypersonic entry using well understood principles of magnetohydrodynamics and oxygen filtration. This innovative approach generates resources upon arrival at the operational site, and thus greatly differs from the traditional approach of taking everything you need with you from Earth. Fundamental analysis, computational fluid dynamics, and some testing of experimental hardware have established the basic feasibility of generating power during a Mars entry. Oxygen filtration at conditions consistent with spacecraft entry parameters at Mars has been studied to a lesser extent. Other uses of the MHD power are presented. This paper illustrates how some features of regenerative aerobraking may be applied to support human and robotic missions at Mars.

  8. Fully relayed regenerative amplifier

    DOEpatents

    Glass, Alexander J.

    1981-01-01

    A regenerative laser apparatus and method using the optical relay concept to maintain high fill factors, to suppress diffraction effects, and to minimize phase distortions in a regenerative amplifier.

  9. [Regenerative approach for COPD].

    PubMed

    Kubo, Hiroshi

    2011-10-01

    No treatment to cure of chronic obstructive pulmonary disease (COPD) is available. Regenerative medicine is one of promising areas for this intractable disease. Several reagents and growth factors are known to promote lung regeneration in small animal models. However, regenerative medicines for human lungs are not achieved yet. Recent advances in stem cell biology and tissue engineering have expanded our understanding of lung endogenous stem cells, and this new knowledge provides us with new ideas for future regenerative therapy for lung diseases. Although lungs are the most challenging organ for regenerative medicine, our cumulative knowledge of lung regeneration and of endogenous progenitor cells makes clear the possibilities for regenerative approach to COPD.

  10. ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes

    DOE PAGES

    Dooraghi, Alex A.; Carroll, Lewis; Collins, Jeffrey; ...

    2016-03-09

    Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 (18F). The key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes. Results show the combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μLmore » or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average. In conclusion, the integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [18F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL-1) to the low values typical of batches of [18F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL-1).« less

  11. ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes

    SciTech Connect

    Dooraghi, Alex A.; Carroll, Lewis; Collins, Jeffrey; van Dam, R. Michael; Chatziioannou, Arion F.

    2016-03-09

    Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 (18F). The key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes. Results show the combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μL or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average. In conclusion, the integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [18F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL-1) to the low values typical of batches of [18F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL-1).

  12. Regenerative (Regen) ECLSS Operations Water Balance

    NASA Technical Reports Server (NTRS)

    Tobias, Barry

    2010-01-01

    In November 2008, the Water Regenerative System racks were launched aboard Space Shuttle flight, STS-126 (ULF2) and installed and activated on the International Space Station (ISS). These racks, consisting of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA), completed the installation of the Regenerative (Regen) ECLSS systems which includes the Oxygen Generator Assembly (OGA) that was launched 2 years prior. With the onset of active water management on the US segment of the ISS, a new operational concept was required, that of "water balance." Even more recently, in 2010 the Sabatier system came online which converts H2 and CO2 into water and methane. The Regen ECLSS systems accept condensation from the atmosphere, urine from crew, and processes that fluid via various means into potable water which is used for crew drinking, building up skip-cycle water inventory, and water for electrolysis to produce oxygen. Specification rates of crew urine output, condensate output, O2 requirements, toilet flush water and drinking needs are well documented and used as a general plan when Regen ECLSS came online. Spec rates are useful in long term planning, however, daily or weekly rates are dependent on a number of variables. The constantly changing rates created a new challenge for the ECLSS flight controllers, who are responsible for operating the ECLSS systems onboard ISS. This paper will review the various inputs to rate changes and inputs to planning events, including but not limited to; crew personnel makeup, Regen ECLSS system operability, vehicle traffic, water containment availability, and Carbon Dioxide Removal Assembly (CDRA) capability. Along with the inputs that change the various rates, the paper will review the different systems, their constraints and finally the operational means by which flight controllers manage this new challenge of "water balance."

  13. Regenerative medicine blueprint.

    PubMed

    Terzic, Andre; Harper, C Michel; Gores, Gregory J; Pfenning, Michael A

    2013-12-01

    Regenerative medicine, a paragon of future healthcare, holds unprecedented potential in extending the reach of treatment modalities for individuals across diseases and lifespan. Emerging regenerative technologies, focused on structural repair and functional restoration, signal a radical transformation in medical and surgical practice. Regenerative medicine is poised to provide innovative solutions in addressing major unmet needs for patients, ranging from congenital disease and trauma to degenerative conditions. Realization of the regenerative model of care predicates a stringent interdisciplinary paradigm that will drive validated science into standardized clinical options. Designed as a catalyst in advancing rigorous new knowledge on disease causes and cures into informed delivery of quality care, the Mayo Clinic regenerative medicine blueprint offers a patient-centered, team-based strategy that optimizes the discovery-translation-application roadmap for the express purpose of science-supported practice advancement.

  14. Thermally assisted OSL application for equivalent dose estimation; comparison of multiple equivalent dose values as well as saturation levels determined by luminescence and ESR techniques for a sedimentary sample collected from a fault gouge

    NASA Astrophysics Data System (ADS)

    Şahiner, Eren; Meriç, Niyazi; Polymeris, George S.

    2017-02-01

    Equivalent dose estimation (De) constitutes the most important part of either trap-charge dating techniques or dosimetry applications. In the present work, multiple, independent equivalent dose estimation approaches were adopted, using both luminescence and ESR techniques; two different minerals were studied, namely quartz as well as feldspathic polymineral samples. The work is divided into three independent parts, depending on the type of signal employed. Firstly, different De estimation approaches were carried out on both polymineral and contaminated quartz, using single aliquot regenerative dose protocols employing conventional OSL and IRSL signals, acquired at different temperatures. Secondly, ESR equivalent dose estimations using the additive dose procedure both at room temperature and at 90 K were discussed. Lastly, for the first time in the literature, a single aliquot regenerative protocol employing a thermally assisted OSL signal originating from Very Deep Traps was applied for natural minerals. Rejection criteria such as recycling and recovery ratios are also presented. The SAR protocol, whenever applied, provided with compatible De estimations with great accuracy, independent on either the type of mineral or the stimulation temperature. Low temperature ESR signals resulting from Al and Ti centers indicate very large De values due to bleaching in-ability, associated with large uncertainty values. Additionally, dose saturation of different approaches was investigated. For the signal arising from Very Deep Traps in quartz saturation is extended almost by one order of magnitude. It is interesting that most of De values yielded using different luminescence signals agree with each other and ESR Ge center has very large D0 values. The results presented above highly support the argument that the stability and the initial ESR signal of the Ge center is highly sample-dependent, without any instability problems for the cases of quartz resulting from fault gouge.

  15. Regenerative Hydride Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  16. Therapeutic potential of nanoceria in regenerative medicine

    SciTech Connect

    Das, Soumen; Chigurupati, Srinivasulu; Dowding, Janet; Munusamy, Prabhakaran; Baer, Donald R.; McGinnis, James F.; Mattson, Mark P.; Self, William; Seal, Sudipta

    2014-11-01

    Tissue engineering and regenerative medicine aim to achieve functional restoration of tissue or cells damaged through disease, aging or trauma. Advancement of tissue engineering requires innovation in the field of 3D scaffolding, and functionalization with bioactive molecules. Nanotechnology offers advanced materials with patterned nano-morphologies for cell growth and different molecular substrates which can support cell survival and functions. Cerium oxide nanoparticles (nanoceria) can control intracellular as well as extracellular reactive oxygen and nitrogen species. Recent findings suggest that nanoceria can enhance long-term cell survival, enable cell migration and proliferation, and promote stem cell differentiation. Moreover, the self-regenerative property of nanoceria permits a small dose to remain catalytically active for extended time. This review summarizes the possibilities and applications of nanoceria in the field of tissue engineering and regenerative medicine.

  17. Regenerative Life Support Evaluation

    NASA Technical Reports Server (NTRS)

    Kleiner, G. N.; Thompson, C. D.

    1977-01-01

    This paper describes the development plan and design concept of the Regenerative Life Support Evaluation (RLSE) planned for flight testing in the European Space Agency Spacelab. The development plan encompasses the ongoing advanced life support subsystem and a systems integration effort to evolve concurrently subsystem concepts that perform their function and can be integrated with other subsystems in a flight demonstration of a regenerative life support system. The design concept for RLSE comprises water-electrolysis O2 generation, electrochemically depolarized CO2 removal, and Sabatier CO2 reduction for atmosphere regeneration, urine vapor-compression distillation, and wash-water hyperfiltration for waste-water recovery. The flight demonstration by RLSE is an important step in qualifying the regenerative concepts for life support in space stations.

  18. Regenerative similariton laser

    NASA Astrophysics Data System (ADS)

    North, Thibault; Brès, Camille-Sophie

    2016-05-01

    Self-pulsating lasers based on cascaded reshaping and reamplification (2R) are capable of initiating ultrashort pulses despite the accumulation of large amounts of nonlinearities in all-fiber resonators. The spectral properties of pulses in self-similar propagation are compatible with cascaded 2R regeneration by offset filtering, making parabolic pulses suitable for the design of a laser of this recently introduced class. A new type of regenerative laser giving birth to similaritons is numerically investigated and shows that this laser is the analog of regenerative sources based solely on self-phase modulation and offset filtering. The regenerative similariton laser does not suffer from instabilities due to excessive nonlinearities and enables ultrashort pulse generation in a simple cavity configuration.

  19. Device and method for automated separation of a sample of whole blood into aliquots

    DOEpatents

    Burtis, Carl A.; Johnson, Wayne F.

    1989-01-01

    A device and a method for automated processing and separation of an unmeasured sample of whole blood into multiple aliquots of plasma. Capillaries are radially oriented on a rotor, with the rotor defining a sample chamber, transfer channels, overflow chamber, overflow channel, vent channel, cell chambers, and processing chambers. A sample of whole blood is placed in the sample chamber, and when the rotor is rotated, the blood moves outward through the transfer channels to the processing chambers where the blood is centrifugally separated into a solid cellular component and a liquid plasma component. When the rotor speed is decreased, the plasma component backfills the capillaries resulting in uniform aliquots of plasma which may be used for subsequent analytical procedures.

  20. Microscale Regenerative Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2006-01-01

    The device described herein is designed primarily for use as a regenerative heat exchanger in a miniature Stirling engine or Stirling-cycle heat pump. A regenerative heat exchanger (sometimes called, simply, a "regenerator" in the Stirling-engine art) is basically a thermal capacitor: Its role in the Stirling cycle is to alternately accept heat from, then deliver heat to, an oscillating flow of a working fluid between compression and expansion volumes, without introducing an excessive pressure drop. These volumes are at different temperatures, and conduction of heat between these volumes is undesirable because it reduces the energy-conversion efficiency of the Stirling cycle.

  1. Heterogeneity in small aliquots of Apolllo 15 olivine-normative basalt: Implications for breccia clast studies

    NASA Technical Reports Server (NTRS)

    Lindstrom, Marilyn M.; Shervais, John W.; Vetter, Scott K.

    1993-01-01

    Most of the recent advances in lunar petrology are the direct result of breccia pull-apart studies, which have identified a wide array of new highland and mare basalt rock types that occur only as clasts within the breccias. These rocks show that the lunar crust is far more complex than suspected previously, and that processes such as magma mixing and wall-rock assimilation were important in its petrogenesis. These studies are based on the implicit assumption that the breccia clasts, which range in size from a few mm to several cm across, are representative of the parent rock from which they were derived. In many cases, the aliquot allocated for analysis may be only a few grain diameters across. While this problem is most acute for coarse-grained highland rocks, it can also cause considerable uncertainty in the analysis of mare basalt clasts. Similar problems arise with small aliquots of individual hand samples. Our study of sample heterogeneity in 9 samples of Apollo 15 olivine normative basalt (ONB) which exhibit a range in average grain size from coarse to fine are reported. Seven of these samples have not been analyzed previously, one has been analyzed by INAA only, and one has been analyzed by XRF+INAA. Our goal is to assess the effects of small aliquot size on the bulk chemistry of large mare basalt samples, and to extend this assessment to analyses of small breccia clasts.

  2. Regenerative periodontal therapy.

    PubMed

    Hägi, Tobias T; Laugisch, Oliver; Ivanovic, Aleksandar; Sculean, Anton

    2014-03-01

    The goal of regenerative periodontal therapy is to completely restore the tooth's supporting apparatus that has been lost due to inflammatory periodontal disease or injury. It is characterized by formation of new cementum with inserting collagen fibers, new periodontal ligament, and new alveolar bone. Indeed conventional, nonsurgical, and surgical periodontal therapy usually result in clinical improvements evidenced by probing depth reduction and clinical attachment gain, but the healing occurs predominantly through formation of a long junctional epithelium and no or only unpredictable periodontal regeneration. Therefore, there is an ongoing search for new materials and improved surgical techniques, with the aim of predictably promoting periodontal wound healing/regeneration and improving the clinical outcome. This article attempts to provide the clinician with an overview of the most important biologic events involved in periodontal wound healing/ regeneration and on the criteria on how to select the appropriate regenerative material and surgical technique in order to optimize the clinical outcomes.

  3. Regenerative photonic therapy: Review

    NASA Astrophysics Data System (ADS)

    Salansky, Natasha; Salansky, Norman

    2012-09-01

    After four decades of research of photobiomodulation phenomena in mammals in vitro and in vivo, a solid foundation is created for the use of photobiomodulation in regenerative medicine. Significant accomplishments are achieved in animal models that demonstrate opportunities for photo-regeneration of injured or pathological tissues: skin, muscles and nerves. However, the use of photobiomodulation in clinical studies leads to controversial results while negative or marginal clinical efficacy is reported along with positive findings. A thor ough analysis of requirements to the optical parameters (dosimetry) for high efficacy in photobimodulation led us to the conclusion that there are several misconceptions in the clinical applications of low level laser therapy (LLLT). We present a novel appr oach of regenerative photonic therapy (RPT) for tissue healing and regeneration that overcomes major drawbacks of LLLT. Encouraging clinical results on RPT efficacy are presented. Requirements for RPT approach and vision for its future development for tissue regeneration is discussed.

  4. MASS MEASUREMENT UNCERTAINTY FOR PLUTONIUM ALIQUOTS ASSAYED BY CONTROLLED-POTENTIAL COULOMETRY

    SciTech Connect

    Holland, M.; Cordaro, J.

    2009-03-18

    Minimizing plutonium measurement uncertainty is essential to nuclear material control and international safeguards. In 2005, the International Organization for Standardization (ISO) published ISO 12183 'Controlled-potential coulometric assay of plutonium', 2nd edition. ISO 12183:2005 recommends a target of {+-}0.01% for the mass of original sample in the aliquot because it is a critical assay variable. Mass measurements in radiological containment were evaluated and uncertainties estimated. The uncertainty estimate for the mass measurement also includes uncertainty in correcting for buoyancy effects from air acting as a fluid and from decreased pressure of heated air from the specific heat of the plutonium isotopes.

  5. Regenerative fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry L.; Kackley, Nancy D.; Laconti, Anthony B.

    1992-01-01

    A development status evaluation is presented for moderate-temperature, single-unit, regenerative fuel cells using either alkaline or solid polymer proton-exchange membrane (PEM) electrolytes. Attention is given to the results thus far obtained for Pt, Ir, Rh, and Na(x)Pt3O4 catalysts. Alkaline electrolyte tests have been performed on a half-cell basis with a floating-electrode cell; PEM testing has been with complete fuel cells, using Nafion 117.

  6. Regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Swette, Larry L.; Kackley, Nancy D.; Laconti, Anthony B.

    A development status evaluation is presented for moderate-temperature, single-unit, regenerative fuel cells using either alkaline or solid polymer proton-exchange membrane (PEM) electrolytes. Attention is given to the results thus far obtained for Pt, Ir, Rh, and Na(x)Pt3O4 catalysts. Alkaline electrolyte tests have been performed on a half-cell basis with a floating-electrode cell; PEM testing has been with complete fuel cells, using Nafion 117.

  7. Regenerative feedback resonant circuit

    DOEpatents

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  8. Cytomics in regenerative medicine

    NASA Astrophysics Data System (ADS)

    Tárnok, Attila; Pierzchalski, Arkadiusz

    2008-02-01

    Cytomics is the high-content analysis of cell-systems [6, 78]. The area of Cytomics and Systems Biology received great attention during the last years as it harbours the promise to substantially impact on various fields of biomedicine, drug discovery, predictive medicine [6] and may have major potential for regenerative medicine. In regenerative medicine Cytomics includes process control of cell preparation and culturing using non-invasive detection techniques, quality control and standardization for GMP and GLP conformity and even prediction of cell fate based on sophisticated data analysis. Cytomics requires quantitative and stoichiometric single cell analysis. In some areas the leading cytometric techniques represent the cutting edge today. Many different applications/variations of multicolour staining were developed for flow- or slide-based cytometry (SBC) analysis of suspensions and sections to whole animal analysis [78]. SBC has become an important analytical technology in drug discovery, diagnosis and research and is an emerging technology for systems analysis [78]. It enables high-content high-throughput measurement of cell suspensions, cell cultures and tissues. In the last years various commercial SBC instruments were launched principally enabling to perform similar tasks. Standardisation as well as comparability of different instruments is a major challenge. Hyperspectral optical imaging may be implemented in SBC analysis for label free cell detection based on cellular autofluorescence [3]. All of these developments push the systemic approach of the analysis of biological specimens to enhance the outcome of regenerative medicine.

  9. Time effect and aliquot concentration in Streptococcus mutans elimination by plasma needle

    NASA Astrophysics Data System (ADS)

    García-Alcantara, E.; López-Callejas, R.; Peña-Eguiluz, R.; Lagunas-Bernabé, S.; Valencia-Alvarado, R.; Mercado-Cabrera, A.; Barocio, S. R.; Muñoz-Castro, A. E.; Rodríguez-Méndez, B. G.; de la Piedad-Beneitez, A.

    2012-06-01

    Atmospheric plasma needle systems are being intensively studied with a view to potential applications in medicine. The aim of this in vitro study is the improved elimination of Streptococcus Mutants (S. mutans) bacteria. A 5 ml volume of Luria-Bertani culture medium has been inoculated with a test bacterial population and incubated during 24 hours, followed by ten dilutions producing aliquots at 20, 50 and 100 micro l per dilution. Each aliquot is deposited on a paper filter and then exposed to a 2 W RF room pressure helium plasma needle discharge at a 1.5 l.p.m. rate for 1, 3, 5 or 7 minutes. Each sample paper is placed in a test tube, again containing Luria-Bertani fluid, in order to develop a new bacterium colony after a 24h incubation period. The plasma needle lethality has been evaluated from absorbance studies by means of a 6305 Jeway spectrophotometer at a 600 nm wavelength, indicating a clear correlation with exposure time. These studies validate the high disinfection efficacy of the plasma needle.

  10. REGENERATIVE TRANSISTOR AMPLIFIER

    DOEpatents

    Kabell, L.J.

    1958-11-25

    Electrical circults for use in computers and the like are described. particularly a regenerative bistable transistor amplifler which is iurned on by a clock signal when an information signal permits and is turned off by the clock signal. The amplifier porforms the above function with reduced power requirements for the clock signal and circuit operation. The power requirements are reduced in one way by employing transformer coupling which increases the collector circuit efficiency by eliminating the loss of power in the collector load resistor.

  11. Regenerative adsorbent heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  12. Regenerative Sorption Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Wen, Liang-Chi; Bard, Steven

    1991-01-01

    Two-stage sorption refrigerator achieves increased efficiency via regenerative-heating concept in which waste heat from praseodymium/cerium oxide (PCO) chemisorption compressor runs charcoal/krypton (C/Kr) sorption compressor. Waste heat from each PCO sorption compressor used to power surrounding C/Kr sorption compressor. Flows of heat in two compressor modules controlled by gas-gap thermal switches. Has no wearing moving parts other than extremely long life, room-temperature check valves operating about twice per hour. Virtually no measurable vibration, and has potential operating life of at least ten years.

  13. Regenerative air heater

    DOEpatents

    Hasselquist, P.B.; Baldner, R.

    1980-11-26

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  14. Regenerative air heater

    DOEpatents

    Hasselquist, Paul B.; Baldner, Richard

    1982-01-01

    A gas-cooled steel skirt is used to support a refractory cored brick matrix and dome structure in a high temperature regenerative air heater useful in magnetohydrodynamic power generation. The steel skirt thermally expands to accommodate the thermal expansion of the dome structure despite substantial temperature differential thereby reducing relative movement between the dome bricks. Gas cooling of the steel skirt allows the structure to operate above its normal temperature during clean-out cycles and also allows for the control of the thermal expansion of the steel skirt.

  15. Regenerative Medicine Build-Out

    PubMed Central

    Pfenning, Michael A.; Gores, Gregory J.; Harper, C. Michel

    2015-01-01

    Summary Regenerative technologies strive to boost innate repair processes and restitute normative impact. Deployment of regenerative principles into practice is poised to usher in a new era in health care, driving radical innovation in patient management to address the needs of an aging population challenged by escalating chronic diseases. There is urgency to design, execute, and validate viable paradigms for translating and implementing the science of regenerative medicine into tangible health benefits that provide value to stakeholders. A regenerative medicine model of care would entail scalable production and standardized application of clinical grade biotherapies supported by comprehensive supply chain capabilities that integrate sourcing and manufacturing with care delivery. Mayo Clinic has rolled out a blueprint for discovery, translation, and application of regenerative medicine therapies for accelerated adoption into the standard of care. To establish regenerative medical and surgical service lines, the Mayo Clinic model incorporates patient access, enabling platforms and delivery. Access is coordinated through a designated portal, the Regenerative Medicine Consult Service, serving to facilitate patient/provider education, procurement of biomaterials, referral to specialty services, and/or regenerative interventions, often in clinical trials. Platforms include the Regenerative Medicine Biotrust and Good Manufacturing Practice facilities for manufacture of clinical grade products for cell-based, acellular, and/or biomaterial applications. Care delivery leverages dedicated interventional suites for provision of regenerative services. Performance is tracked using a scorecard system to inform decision making. The Mayo Clinic roadmap exemplifies an integrated organization in the discovery, development, and delivery of regenerative medicine within a growing community of practice at the core of modern health care. Significance Regenerative medicine is at the

  16. Will Regenerative Medicine Replace Transplantation?

    PubMed Central

    Orlando, Giuseppe; Soker, Shay; Stratta, Robert J.; Atala, Anthony

    2013-01-01

    Recent groundbreaking advances in organ bioengineering and regeneration have provided evidence that regenerative medicine holds promise to dramatically improve the approach to organ transplantation. The two fields, however, share a common heritage. Alexis Carrel can be considered the father of both regenerative medicine and organ transplantation, and it is now clear that his legacy is equally applicable for the present and future generations of transplant and regenerative medicine investigators. In this review, we will briefly illustrate the interplay that should be established between these two complementary disciplines of health sciences. Although regenerative medicine has shown to the transplant field its potential, transplantation is destined to align with regenerative medicine and foster further progress probably more than either discipline alone. Organ bioengineering and regeneration technologies hold the promise to meet at the same time the two most urgent needs in organ transplantation, namely, the identification of a new, potentially inexhaustible source of organs and immunosuppression-free transplantation of tissues and organs. PMID:23906883

  17. Active Magnetic Regenerative Liquefier

    SciTech Connect

    Barclay, John A.; Oseen-Send, Kathryn; Ferguson, Luke; Pouresfandiary, Jamshid; Cousins, Anand; Ralph, Heather; Hampto, Tom

    2016-01-12

    This final report for the DOE Project entitled Active Magnetic Regenerative Liquefier (AMRL) funded under Grant DE-FG36-08GO18064 to Heracles Energy Corporation d.b.a. Prometheus Energy (Heracles/Prometheus) describes an active magnetic regenerative refrigerator (AMRR) prototype designed and built during the period from July 2008 through May 2011. The primary goal of this project was to make significant technical advances toward highly efficient liquefaction of hydrogen. Conventional hydrogen liquefiers at any scale have a maximum FOM of ~0.35 due primarily to the intrinsic difficulty of rapid, efficient compression of either hydrogen or helium working gases. Numerical simulation modeling of high performance AMRL designs indicates certain designs have promise to increase thermodynamic efficiency from a FOM of ~0.35 toward ~0.5 to ~0.6. The technical approach was the use of solid magnetic working refrigerants cycled in and out of high magnetic fields to build an efficient active regenerative magnetic refrigeration module providing cooling power for AMRL. A single-stage reciprocating AMRR with a design temperature span from ~290 K to ~120 K was built and tested with dual magnetic regenerators moving in and out of the conductively-cooled superconducting magnet subsystem. The heat transfer fluid (helium) was coupled to the process stream (refrigeration/liquefaction load) via high performance heat exchangers. In order to maximize AMRR efficiency a helium bypass loop with adjustable flow was incorporated in the design because the thermal mass of magnetic refrigerants is higher in low magnetic field than in high magnetic field. Heracles/Prometheus designed experiments to measure AMRR performance under a variety of different operational parameters such as cycle frequency, magnetic field strength, heat transfer fluid flow rate, amount of bypass flow of the heat transfer fluid while measuring work input, temperature span, cooling capability as a function of cold temperature

  18. Regenerative periodontal therapy.

    PubMed

    Kao, Daniel W K; Fiorellini, Joseph P

    2012-01-01

    Traditional treatment for loss of bone and attachment due to periodontal disease has focused around repairing the damage induced. However, over the past few decades, clinicians have begun to utilize regenerative techniques to rebuild bone, cementum and the periodontal ligament. Conventional procedures most often involve the use of barrier membranes with bone grafts that foster selective cell repopulation and regrowth of osseous structures. Since the predictability of these techniques may be limited to certain case types, pharmacologically based efforts are underway to investigate the possibility of harnessing osseous regrowth potential. Clinical research has found that proteins are potent biological mediators that promote many of the events in wound healing, and have been shown to promote bone formation in human clinical studies.

  19. Regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1982-01-12

    Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

  20. Hydrogels in Regenerative Medicine

    PubMed Central

    Slaughter, Brandon V.; Khurshid, Shahana S.; Fisher, Omar Z.; Khademhosseini, Ali

    2015-01-01

    Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures, and serve as adhesives or barriers between tissue and material surfaces. In this work, the properties of hydrogels that are important for tissue engineering applications and the inherent material design constraints and challenges are discussed. Recent research involving several different hydrogels polymerized from a variety of synthetic and natural monomers using typical and novel synthetic methods are highlighted. Finally, special attention is given to the microfabrication techniques that are currently resulting in important advances in the field. PMID:20882499

  1. PEM regenerative fuel cells

    NASA Technical Reports Server (NTRS)

    Swette, Larry L.; Laconti, Anthony B.; Mccatty, Stephen A.

    1993-01-01

    This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane (PEM) regenerative fuel cells. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes). The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C. In fuel cell mode, humidified hydrogen and oxygen were supplied at 207 kPa (30 psi); in electrolysis mode, water was pumped over the positive electrode and the gases were evolved at ambient pressure. Cycling data will be presented for Pt-Ir catalysts and limited bifunctional data will be presented for Pt, Ir, Ru, Rh, and Na(x)Pt3O4 catalysts as well as for electrode structure variations.

  2. Regenerative combustion device

    DOEpatents

    West, Phillip B.

    2004-03-16

    A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

  3. The pharmacology of regenerative medicine.

    PubMed

    Christ, George J; Saul, Justin M; Furth, Mark E; Andersson, Karl-Erik

    2013-07-01

    Regenerative medicine is a rapidly evolving multidisciplinary, translational research enterprise whose explicit purpose is to advance technologies for the repair and replacement of damaged cells, tissues, and organs. Scientific progress in the field has been steady and expectations for its robust clinical application continue to rise. The major thesis of this review is that the pharmacological sciences will contribute critically to the accelerated translational progress and clinical utility of regenerative medicine technologies. In 2007, we coined the phrase "regenerative pharmacology" to describe the enormous possibilities that could occur at the interface between pharmacology, regenerative medicine, and tissue engineering. The operational definition of regenerative pharmacology is "the application of pharmacological sciences to accelerate, optimize, and characterize (either in vitro or in vivo) the development, maturation, and function of bioengineered and regenerating tissues." As such, regenerative pharmacology seeks to cure disease through restoration of tissue/organ function. This strategy is distinct from standard pharmacotherapy, which is often limited to the amelioration of symptoms. Our goal here is to get pharmacologists more involved in this field of research by exposing them to the tools, opportunities, challenges, and interdisciplinary expertise that will be required to ensure awareness and galvanize involvement. To this end, we illustrate ways in which the pharmacological sciences can drive future innovations in regenerative medicine and tissue engineering and thus help to revolutionize the discovery of curative therapeutics. Hopefully, the broad foundational knowledge provided herein will spark sustained conversations among experts in diverse fields of scientific research to the benefit of all.

  4. Decellularized scaffolds in regenerative medicine

    PubMed Central

    Yu, Yaling; Alkhawaji, Ali; Ding, Yuqiang; Mei, Jin

    2016-01-01

    Allogeneic organ transplantation remains the ultimate solution for end-stage organ failure. Yet, the clinical application is limited by the shortage of donor organs and the need for lifelong immunosuppression, highlighting the importance of developing effective therapeutic strategies. In the field of regenerative medicine, various regenerative technologies have lately been developed using various biomaterials to address these limitations. Decellularized scaffolds, derived mainly from various non-autologous organs, have been proved a regenerative capability in vivo and in vitro and become an emerging treatment approach. However, this regenerative capability varies between scaffolds as a result of the diversity of anatomical structure and cellular composition of organs used for decellularization. Herein, recent advances in scaffolds based on organ regeneration in vivo and in vitro are highlighted along with aspects where further investigations and analyses are needed. PMID:27486772

  5. Regenerative switching CMOS system

    DOEpatents

    Welch, James D.

    1998-01-01

    Complementary Metal Oxide Semiconductor (CMOS) Schottky barrier Field Effect Transistor systems, which are a seriesed combination of N and P-Channel MOSFETS, in which Source Schottky barrier junctions of the N and P-Channel Schottky barrier MOSFETS are electically interconnected, (rather than the Drains as in conventional diffused junction CMOS), which Schottky barrier MOSFET system demonstrates Regenerative Inverting Switching Characteristics in use are disclosed. Both the N and P-Channel Schottky barrier MOSFET devices are unique in that they provide operational Drain Current vs. Drain to Source voltage as a function of Gate voltage only where the polarities of the Drain voltage and Gate voltage are opposite, referenced to the Source as a common terminal, and where the polarity of the voltage applied to the Gate is appropriate to cause Channel inversion. Experimentally derived results which demonstrate and verify the operation of N and P-Channel Schottky barrier MOSFETS actually fabricated on P and N-type Silicon respectively, by a common procedure using vacuum deposited Chromium as a Schottky barrier forming metal, are also provided.

  6. Regenerative switching CMOS system

    DOEpatents

    Welch, J.D.

    1998-06-02

    Complementary Metal Oxide Semiconductor (CMOS) Schottky barrier Field Effect Transistor systems, which are a series combination of N and P-Channel MOSFETS, in which Source Schottky barrier junctions of the N and P-Channel Schottky barrier MOSFETS are electrically interconnected, (rather than the Drains as in conventional diffused junction CMOS), which Schottky barrier MOSFET system demonstrates Regenerative Inverting Switching Characteristics in use are disclosed. Both the N and P-Channel Schottky barrier MOSFET devices are unique in that they provide operational Drain Current vs. Drain to Source voltage as a function of Gate voltage only where the polarities of the Drain voltage and Gate voltage are opposite, referenced to the Source as a common terminal, and where the polarity of the voltage applied to the Gate is appropriate to cause Channel inversion. Experimentally derived results which demonstrate and verify the operation of N and P-Channel Schottky barrier MOSFETS actually fabricated on P and N-type Silicon respectively, by a common procedure using vacuum deposited Chromium as a Schottky barrier forming metal, are also provided. 14 figs.

  7. Personalized Regenerative Medicine.

    PubMed

    Arjmand, Babak; Goodarzi, Parisa; Mohamadi-Jahani, Fereshteh; Falahzadeh, Khadijeh; Larijani, Bagher

    2017-03-01

    Personalized medicine as a novel field of medicine refers to the prescription of specific therapeutics procedure for an individual. This approach has established based on pharmacogenetic and pharmacogenomic information and data. The terms precision and personalized medicines are sometimes applied interchangeably. However, there has been a shift from "personalized medicine" towards "precision medicine". Although personalized medicine emerged from pharmacogenetics, nowadays it covers many fields of healthcare. Accordingly, regenerative medicine and cellular therapy as the new fields of medicine use cell-based products in order to develop personalized treatments. Different sources of stem cells including mesenchymal stem cells, embryonic stem cells and induced pluripotent stem cells (iPSCs) have been considered in targeted therapies which could give many advantages. iPSCs as the novel and individual pluripotent stem cells have been introduced as the appropriate candidates for personalized cell therapies. Cellular therapies can provide a personalized approach. Because of person-to-person and population differences in the result of stem cell therapy, individualized cellular therapy must be adjusted according to the patient specific profile, in order to achieve best therapeutic results and outcomes. Several factors should be considered to achieve personalized stem cells therapy such as, recipient factors, donor factors, and the overall body environment in which the stem cells could be active and functional. In addition to these factors, the source of stem cells must be carefully chosen based on functional and physical criteria that lead to optimal outcomes.

  8. Thermally regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Ludwig, F. A.; Kindler, A.; McHardy, J.

    1991-10-01

    The three phase project was undertaken to investigate solventless ionic liquids as possible working fluids for a new type of thermally regenerative fuel cell (TRFC). The heart of the new device, invented at Hughes Aircraft Company in 1983, is an electrochemical concentration cell where acid and base streams react to produce electrical energy. Thermal energy is then used to decompose the resulting salts and regenerate the cell reactants. In principle, a TRFC can be matched to any source of thermal energy simply by selecting working fluids with the appropriate regeneration temperature. However, aqueous working fluids (the focus of previous studies) impose limitations on both the operating temperatures and the achievable energy densities. It was the need to overcome these limitations that prompted the present investigation. Specific aims were to identify possible working fluids for TRFC systems with both low and high regeneration temperatures. A major advantage of our aqueous-fluid TRFC systems has been the ability to use hydrogen electrodes. The low activation and mass transfer losses of these electrodes contribute substantially to overall system efficiency.

  9. The Pharmacology of Regenerative Medicine

    PubMed Central

    Saul, Justin M.; Furth, Mark E.; Andersson, Karl-Erik

    2013-01-01

    Regenerative medicine is a rapidly evolving multidisciplinary, translational research enterprise whose explicit purpose is to advance technologies for the repair and replacement of damaged cells, tissues, and organs. Scientific progress in the field has been steady and expectations for its robust clinical application continue to rise. The major thesis of this review is that the pharmacological sciences will contribute critically to the accelerated translational progress and clinical utility of regenerative medicine technologies. In 2007, we coined the phrase “regenerative pharmacology” to describe the enormous possibilities that could occur at the interface between pharmacology, regenerative medicine, and tissue engineering. The operational definition of regenerative pharmacology is “the application of pharmacological sciences to accelerate, optimize, and characterize (either in vitro or in vivo) the development, maturation, and function of bioengineered and regenerating tissues.” As such, regenerative pharmacology seeks to cure disease through restoration of tissue/organ function. This strategy is distinct from standard pharmacotherapy, which is often limited to the amelioration of symptoms. Our goal here is to get pharmacologists more involved in this field of research by exposing them to the tools, opportunities, challenges, and interdisciplinary expertise that will be required to ensure awareness and galvanize involvement. To this end, we illustrate ways in which the pharmacological sciences can drive future innovations in regenerative medicine and tissue engineering and thus help to revolutionize the discovery of curative therapeutics. Hopefully, the broad foundational knowledge provided herein will spark sustained conversations among experts in diverse fields of scientific research to the benefit of all. PMID:23818131

  10. 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.

  11. Bio-regenerative life support

    NASA Technical Reports Server (NTRS)

    Macelroy, Robert D.; Wydeven, Theodore, Jr.

    1989-01-01

    The basis for and the potential uses of bio-regenerative life support are examined. Bio-regenerative life support systems are an alternative to physical-chemical regeneration techniques for use when resupply of a crew in space is expensive, or when the logistics of resupply are difficult. Many of the scientific studies required for bio-regenerative life support systems have been completed and preliminary development of some components will begin within the next 12 to 18 months. The focus of the work that lies ahead will be efficient power and mass use, long-term system stability, component function, systems integration, and extensive testing in the space environment. Because of the advantages of bio-regeneration, it is anticipated that human life support for long-term space missions will evolve to include increasingly large amounts of biologically-based regeneration.

  12. Thermoacoustic simulator for regenerative machines

    NASA Astrophysics Data System (ADS)

    Luo, E.; Wu, J.; Yang, J.; Xiao, J.

    2002-05-01

    Linear thermoacoustic theory is a powerful tool to understand the working mechanism of many regenerative machines. Based on the theory, the authors have developed a computer code "Thermoacoustic Simulator" for analyzing and designing different regenerative cryocoolers including String refrigerators, Stirling and G-M types of pulse tube refrigerators and G-M cryocoolers. Also, standing-wave and traveling-wave thermoacoustic machines can be simulated, too. This paper will present the philosophy of the "Thermoacoustic Simulator" and some demonstrations of simulation for different types of cryocoolers and thermoacoustic engines.

  13. Regenerative Endodontics by Cell Homing.

    PubMed

    He, Ling; Zhong, Juan; Gong, Qimei; Cheng, Bin; Kim, Sahng G; Ling, Junqi; Mao, Jeremy J

    2017-01-01

    Apical revascularization (AR) and platelet-rich plasma have been used to restore dental pulp vitality in infected immature permanent teeth. Two regenerative therapies are cell transplantation and cell homing. This article updates and benchmarks these therapies with cell homing. A case report concluded that AR increased root length; however, quantitative and statistical assessments disproved this. Regenerative endodontic therapies require prospective clinical trials demonstrating safety and efficacy. These therapies are intrinsically susceptible to procedural and patient variations. Cell homing uses novel molecules that drive therapeutic efficacy, and may be less sensitive to procedural and patient variations.

  14. Regeneratively Cooled Porous Media Jacket

    NASA Technical Reports Server (NTRS)

    Mungas, Greg (Inventor); Fisher, David J. (Inventor); London, Adam Pollok (Inventor); Fryer, Jack Merrill (Inventor)

    2013-01-01

    The fluid and heat transfer theory for regenerative cooling of a rocket combustion chamber with a porous media coolant jacket is presented. This model is used to design a regeneratively cooled rocket or other high temperature engine cooling jacket. Cooling jackets comprising impermeable inner and outer walls, and porous media channels are disclosed. Also disclosed are porous media coolant jackets with additional structures designed to transfer heat directly from the inner wall to the outer wall, and structures designed to direct movement of the coolant fluid from the inner wall to the outer wall. Methods of making such jackets are also disclosed.

  15. Laser system using regenerative amplifier

    DOEpatents

    Emmett, J.L.

    1980-03-04

    High energy laser system is disclosed using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output. 10 figs.

  16. [Regenerative nodular hyperplasia in HIV].

    PubMed

    González, Ramiro Javier Romo; Chaves, Emiliano; Mullen, Eduardo; Copello, Hercilia

    2011-12-01

    Nodular regenerative hyperplasia of the liver is a rare condition. We describe here the case of a patient with HIV who presented with a clinical syndrome of portal hypertension. After multiple evaluations the diagnosis was recognized by the histology. The findings were attributed to the prolonged use of didanosine.

  17. Nondestructive test of regenerative chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Stauffis, R.; Wood, R.

    1972-01-01

    Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

  18. Regenerative Strategies for Craniofacial Disorders

    PubMed Central

    Garland, Catharine B.; Pomerantz, Jason H.

    2012-01-01

    Craniofacial disorders present markedly complicated problems in reconstruction because of the complex interactions of the multiple, simultaneously affected tissues. Regenerative medicine holds promise for new strategies to improve treatment of these disorders. This review addresses current areas of unmet need in craniofacial reconstruction and emphasizes how craniofacial tissues differ from their analogs elsewhere in the body. We present a problem-based approach to illustrate current treatment strategies for various craniofacial disorders, to highlight areas of need, and to suggest regenerative strategies for craniofacial bone, fat, muscle, nerve, and skin. For some tissues, current approaches offer excellent reconstructive solutions using autologous tissue or prosthetic materials. Thus, new “regenerative” approaches would need to offer major advantages in order to be adopted. In other tissues, the unmet need is great, and we suggest the greatest regenerative need is for muscle, skin, and nerve. The advent of composite facial tissue transplantation and the development of regenerative medicine are each likely to add important new paradigms to our treatment of craniofacial disorders. PMID:23248598

  19. Biomimetic microenvironments for regenerative endodontics.

    PubMed

    Kaushik, Sagar N; Kim, Bogeun; Walma, Alexander M Cruz; Choi, Sung Chul; Wu, Hui; Mao, Jeremy J; Jun, Ho-Wook; Cheon, Kyounga

    2016-01-01

    Regenerative endodontics has been proposed to replace damaged and underdeveloped tooth structures with normal pulp-dentin tissue by providing a natural extracellular matrix (ECM) mimicking environment; stem cells, signaling molecules, and scaffolds. In addition, clinical success of the regenerative endodontic treatments can be evidenced by absence of signs and symptoms; no bony pathology, a disinfected pulp, and the maturation of root dentin in length and thickness. In spite of the various approaches of regenerative endodontics, there are several major challenges that remain to be improved: a) the endodontic root canal is a strong harbor of the endodontic bacterial biofilm and the fundamental etiologic factors of recurrent endodontic diseases, (b) tooth discolorations are caused by antibiotics and filling materials, (c) cervical root fractures are caused by endodontic medicaments, (d) pulp tissue is not vascularized nor innervated, and (e) the dentin matrix is not developed with adequate root thickness and length. Generally, current clinical protocols and recent studies have shown a limited success of the pulp-dentin tissue regeneration. Throughout the various approaches, the construction of biomimetic microenvironments of pulp-dentin tissue is a key concept of the tissue engineering based regenerative endodontics. The biomimetic microenvironments are composed of a synthetic nano-scaled polymeric fiber structure that mimics native pulp ECM and functions as a scaffold of the pulp-dentin tissue complex. They will provide a framework of the pulp ECM, can deliver selective bioactive molecules, and may recruit pluripotent stem cells from the vicinity of the pulp apex. The polymeric nanofibers are produced by methods of self-assembly, electrospinning, and phase separation. In order to be applied to biomedical use, the polymeric nanofibers require biocompatibility, stability, and biodegradability. Therefore, this review focuses on the development and application of the

  20. Nanotechnology Biomimetic Cartilage Regenerative Scaffolds

    PubMed Central

    Sardinha, Jose Paulo; Myers, Simon

    2014-01-01

    Cartilage has a limited regenerative capacity. Faced with the clinical challenge of reconstruction of cartilage defects, the field of cartilage engineering has evolved. This article reviews current concepts and strategies in cartilage engineering with an emphasis on the application of nanotechnology in the production of biomimetic cartilage regenerative scaffolds. The structural architecture and composition of the cartilage extracellular matrix and the evolution of tissue engineering concepts and scaffold technology over the last two decades are outlined. Current advances in biomimetic techniques to produce nanoscaled fibrous scaffolds, together with innovative methods to improve scaffold biofunctionality with bioactive cues are highlighted. To date, the majority of research into cartilage regeneration has been focused on articular cartilage due to the high prevalence of large joint osteoarthritis in an increasingly aging population. Nevertheless, the principles and advances are applicable to cartilage engineering for plastic and reconstructive surgery. PMID:24883273

  1. Electrospun Nanofibers for Regenerative Medicine**

    PubMed Central

    Liu, Wenying; Thomopoulos, Stavros

    2013-01-01

    This article reviews recent progress in applying electrospun nanofibers to the emerging field of regenerative medicine. We begin with a brief introduction to electrospinning and nanofibers, with a focus on issues related to the selection of materials, incorporation of bioactive molecules, degradation characteristics, control of mechanical properties, and facilitation of cell infiltration. We then discuss a number of approaches to fabrication of scaffolds from electrospun nanofibers, including techniques for controlling the alignment of nanofibers and for producing scaffolds with complex architectures. We also highlight applications of the nanofiber-based scaffolds in four areas of regenerative medicine that involve nerves, dural tissues, tendons, and the tendon-to-bone insertion site. We conclude this review with perspectives on challenges and future directions for design, fabrication, and utilization of scaffolds based on electrospun nanofibers. PMID:23184683

  2. The unitized regenerative fuel cell

    SciTech Connect

    1997-05-01

    Fuel cells can operate on hydrogen fuel and oxygen from air. If the fuel cell is designed to also operate in reverse as an electrolyzer, then electricity can be used to convert the water back into hydrogen and oxygen. This dual function system is known as a reversible or unitized regenerative fuel cell. This is an excellent energy source in situations where weight is a concern.

  3. Evaluation of environmental dose at JCO using luminescence from quartz stimulated by blue light.

    PubMed

    Hong, D G; Galloway, R B; Takano, M; Hashimoto, T

    2001-01-01

    The environmental dose due to the recent nuclear accident at JCO, Japan, was estimated using luminescence optically stimulated from unheated quartz. Two methods originally developed for dating analysis, the single aliquot additive dose method and the single aliquot regeneration added dose method, were employed to confirm the dose rate. Consistent results were obtained from both methods and from thermoluminescence measurements. Although the dose rate values had lower precision than can be obtained from heated materials, it is suggested that luminescence from sedimentary quartz can usefully be employed in retrosepective dosimetry.

  4. Regenerative endodontics: regeneration or repair?

    PubMed

    Simon, Stéphane R J; Tomson, Phillip L; Berdal, Ariane

    2014-04-01

    Recent advances in biotechnology and translational research have made it possible to provide treatment modalities that protect the vital pulp, allow manipulation of reactionary and reparative dentinogenesis, and, more recently, permit revascularization of an infected root canal space. These approaches are referred to as regenerative procedures. The method currently used to determine the origin of the tissue secreted during the repair/regeneration process is largely based on the identification of cellular markers (usually proteins) left by cells that were responsible for this tissue production. The presence of these proteins in conjunction with other indicators of cellular behavior (especially biomineralization) and analysis of the structure of the newly generated tissue allow conclusions to be made of how it was formed. Thus far, it has not been possible to truly establish the biological mechanism controlling tertiary dentinogenesis. This article considers current therapeutic techniques to treat the dentin-pulp complex and contextualize them in terms of reparative and regenerative processes. Although it may be considered a semantic argument rather than a biological one, the definitions of regeneration and repair are explored to clarify our position in this era of regenerative endodontics.

  5. Current research on regenerative systems.

    PubMed

    Shapira, J; Mandel, A D; Quattrone, P D; Bell, N L

    1969-01-01

    Multiple studies directed toward the development of a regenerative life support system have shown that easily synthesized organic compounds and microbiological materials are potentially capable of being used as foods for long-duration space missions. Animal feeding studies have supported these views. The organic compounds presently believed to offer the greatest potential are glycerol, simple glycerol derivatives such as triacetin, and formose sugars. Laboratory studies indicate that glycerol can be synthesized from formaldehyde which in turn is obtained by the direct catalytic oxidation of methane, a by-product of the Sabatier reaction used in spacecraft atmosphere control system. Formose sugars are derived from the self-condensation of formaldehyde. Mixtures of glycerol and triacetin have been shown to be suitable as a major component of diets fed to weanling rats for prolonged periods. These compounds do not exist as stereoisomers and therefore offer advantages over the formose sugars. Hydrogenomonas eutropha is the microbiological system under investigation. An automated system for the continuous autotrophic production of Hydrogenomonas bacteria is in operation, and the nutritional requirements for growth in the system using urea as a nitrogen source are being studied. Nutritional evaluation of Hydrogenomonas bacteria has shown they are capable of supplying the total protein requirement of growing rats for prolonged periods. The potential and problems of these regenerative systems and the prospects for the accomplishment of a totally regenerative food system will be discussed.

  6. A review on endogenous regenerative technology in periodontal regenerative medicine.

    PubMed

    Chen, Fa-Ming; Zhang, Jing; Zhang, Min; An, Ying; Chen, Fang; Wu, Zhi-Fen

    2010-11-01

    Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key

  7. Regenerative Engineering and Bionic Limbs

    PubMed Central

    James, Roshan; Laurencin, Cato T.

    2015-01-01

    Amputations of the upper extremity are severely debilitating, current treatments support very basic limb movement, and patients undergo extensive physiotherapy and psychological counselling. There is no prosthesis that allows the amputees near-normal function. With increasing number of amputees due to injuries sustained in accidents, natural calamities and international conflicts, there is a growing requirement for novel strategies and new discoveries. Advances have been made in technological, material and in prosthesis integration where researchers are now exploring artificial prosthesis that integrate with the residual tissues and function based on signal impulses received from the residual nerves. Efforts are focused on challenging experts in different disciplines to integrate ideas and technologies to allow for the regeneration of injured tissues, recording on tissue signals and feed-back to facilitate responsive movements and gradations of muscle force. A fully functional replacement and regenerative or integrated prosthesis will rely on interface of biological process with robotic systems to allow individual control of movement such as at the elbow, forearm, digits and thumb in the upper extremity. Regenerative engineering focused on the regeneration of complex tissue and organ systems will be realized by the cross-fertilization of advances over the past thirty years in the fields of tissue engineering, nanotechnology, stem cell science, and developmental biology. The convergence of toolboxes crated within each discipline will allow interdisciplinary teams from engineering, science, and medicine to realize new strategies, mergers of disparate technologies, such as biophysics, smart bionics, and the healing power of the mind. Tackling the clinical challenges, interfacing the biological process with bionic technologies, engineering biological control of the electronic systems, and feed-back will be the important goals in regenerative engineering over the next

  8. Advanced regenerative absorption refrigeration cycles

    DOEpatents

    Dao, Kim

    1990-01-01

    Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

  9. Regenerative superheated steam turbine cycles

    NASA Technical Reports Server (NTRS)

    Fuller, L. C.; Stovall, T. K.

    1980-01-01

    PRESTO computer program was developed to analyze performance of wide range of steam turbine cycles with special attention given to regenerative superheated steam turbine cycles. It can be used to model standard turbine cycles, including such features as process steam extraction, induction and feedwater heating by external sources, peaking, and high back pressure. Expansion line efficiencies, exhaust loss, leakages, mechanical losses, and generator losses are used to calculate cycle heat rate and generator output. Program provides power engineer with flexible aid for design and analysis of steam turbine systems.

  10. Wavelength tunable alexandrite regenerative amplifier

    SciTech Connect

    Harter, D.J.; Bado, P.

    1988-11-01

    We describe a wavelength tunable alexandrite regenerative amplifier which is used to amplify nanosecond slices from a single-frequency cw dye laser or 50-ps pulses emitted by a diode laser to energies in the 10-mJ range. The amplified 5-ns slices generated by the cw-pumped line narrowed dye laser are Fourier transform limited. The 50-ps pulses emitted by a gain-switched diode laser are amplified by more than 10 orders of magnitude in a single stage.

  11. Method and apparatus for automated processing and aliquoting of whole blood samples for analysis in a centrifugal fast analyzer

    DOEpatents

    Burtis, Carl A.; Johnson, Wayne F.; Walker, William A.

    1988-01-01

    A rotor and disc assembly for use in a centrifugal fast analyzer. The assembly is designed to process multiple samples of whole blood followed by aliquoting of the resultant serum into precisely measured samples for subsequent chemical analysis. The assembly requires minimal operator involvement with no mechanical pipetting. The system comprises (1) a whole blood sample disc, (2) a serum sample disc, (3) a sample preparation rotor, and (4) an analytical rotor. The blood sample disc and serum sample disc are designed with a plurality of precision bore capillary tubes arranged in a spoked array. Samples of blood are loaded into the blood sample disc in capillary tubes filled by capillary action and centrifugally discharged into cavities of the sample preparation rotor where separation of serum and solids is accomplished. The serum is loaded into the capillaries of the serum sample disc by capillary action and subsequently centrifugally expelled into cuvettes of the analytical rotor for analysis by conventional methods.

  12. Method and apparatus for automated processing and aliquoting of whole blood samples for analysis in a centrifugal fast analyzer

    DOEpatents

    Burtis, C.A.; Johnson, W.F.; Walker, W.A.

    1985-08-05

    A rotor and disc assembly for use in a centrifugal fast analyzer. The assembly is designed to process multiple samples of whole blood followed by aliquoting of the resultant serum into precisely measured samples for subsequent chemical analysis. The assembly requires minimal operator involvement with no mechanical pipetting. The system comprises: (1) a whole blood sample disc; (2) a serum sample disc; (3) a sample preparation rotor; and (4) an analytical rotor. The blood sample disc and serum sample disc are designed with a plurality of precision bore capillary tubes arranged in a spoked array. Samples of blood are loaded into the blood sample disc by capillary action and centrifugally discharged into cavities of the sample preparation rotor where separation of serum and solids is accomplished. The serum is loaded into the capillaries of the serum sample disc by capillary action and subsequently centrifugally expelled into cuvettes of the analyticaly rotor for conventional methods. 5 figs.

  13. Optimal performance of regenerative cryocoolers

    NASA Astrophysics Data System (ADS)

    de Boer, P. C. T.

    2011-02-01

    The key component of a regenerative cryocooler is its regenerative heat exchanger. This device is subject to losses due to imperfect heat transfer between the regenerator material and the gas, as well as due to viscous dissipation. The relative magnitudes of these losses can be characterized by the ratio of the Stanton number St to the Fanning friction factor f. Using available data for the ratio St/ f, results are developed for the optimal cooling rate and Carnot efficiency. The variations of pressure and temperature are taken to be sinusoidal in time, and to have small amplitudes. The results are applied to the case of the Stirling cryocooler, with flow being generated by pistons at both sides of the regenerator. The performance is found to be close to optimal at large ratio of the warm space volume to the regenerator void volume. The results are also applied to the Orifice Pulse Tube Refrigerator. In this case, optimal performance additionally requires a large ratio of the regenerator void volume to the cold space volume.

  14. Lessons from developmental biology for regenerative medicine.

    PubMed

    Turner, Neill J; Keane, Timothy J; Badylak, Stephen F

    2013-09-01

    The ultimate goal of regenerative medicine is the functional restoration of lost or damaged tissues and organs. Since most tissues in man lack true regenerative properties and instead respond to injury with an inflammatory response and scar tissue formation, regenerative medicine strategies that include combinations of cells, scaffolds, and bioactive molecules to replace injured or missing tissues have been developed. The physical, chemical, and electrical cues that define the microenvironmental niche and the effect of these influences upon cell behavior during development are of interest to developmental biologists, with obvious overlap to the interest of the regenerative medicine field. This manuscript provides an overview of current approaches for tissue restoration being investigated in the field of regenerative medicine and attempts to identify areas of mutual beneficial interest with the field of developmental biology.

  15. Unitized regenerative fuel cell systems

    SciTech Connect

    Mitlitsky, F; Molter, T M; Myers, B; Weisberg, A H

    1998-09-10

    Energy storage systems with extremely high specific energy (>400 Wh/kg) have been designed that use lightweight pressure vessels to contain the gases generated by reversible (unitized) regenerative fuel cells (URFCs).[1] URFC systems are being designed and developed for a variety of applications, including high altitude long endurance (HALE) solar rechargeable aircraft (SRA), zero emission vehicles (ZEVs), hybrid energy storage/propulsion systems for spacecraft, energy storage for remote (off-grid) power sources, and peak shaving for on-grid applications.[1-10] Energy storage for HALE SRA was the original application for this set of innovations, and a prototype solar powered aircraft (Pathfinder-Plus) recently set another altitude record for all propeller-driven aircraft on August 6, 1998, when it flew to 80,285 feet (24.47 km).[11

  16. Unitized regenerative fuel cell system

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A. (Inventor)

    2008-01-01

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

  17. [Regenerative medicine: history and perspectives].

    PubMed

    Okabayashi, Koji; Asashima, Makoto

    2008-05-01

    Regenerative medicine using stem cells is one of the most important topics today. Embryonic stem cells (ES cells) are useful in the studies of the differentiation of various cells or tissues for transplantation therapy, because of their pluripotency to differentiate into almost all types of cells in the body. However, it is controversial to use human ES cells, because it is necessary to sacrifice the life of human embryos for the establishment of these cells. Induced pluripotent stem cells (iPS cells) generated from somatic cells of patients are one of the alternative sources of human pluripotent stem cells while avoiding ethical problems. Epigenetic studies using iPS cells may be valuable to find the way to control cell differentiation more effectively.

  18. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O.

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  19. Regenerative Electroless Etching of Silicon.

    PubMed

    Kolasinski, Kurt W; Gimbar, Nathan J; Yu, Haibo; Aindow, Mark; Mäkilä, Ermei; Salonen, Jarno

    2017-01-09

    Regenerative electroless etching (ReEtching), described herein for the first time, is a method of producing nanostructured semiconductors in which an oxidant (Ox1 ) is used as a catalytic agent to facilitate the reaction between a semiconductor and a second oxidant (Ox2 ) that would be unreactive in the primary reaction. Ox2 is used to regenerate Ox1 , which is capable of initiating etching by injecting holes into the semiconductor valence band. Therefore, the extent of reaction is controlled by the amount of Ox2 added, and the rate of reaction is controlled by the injection rate of Ox2 . This general strategy is demonstrated specifically for the production of highly luminescent, nanocrystalline porous Si from the reaction of V2 O5 in HF(aq) as Ox1 and H2 O2 (aq) as Ox2 with Si powder and wafers.

  20. Rapid analysis of pharmaceuticals and personal care products in fish plasma micro-aliquots using liquid chromatography tandem mass spectrometry.

    PubMed

    Chen, Fangfang; Gong, Zhiyuan; Kelly, Barry C

    2015-02-27

    A sensitive analytical method based on liquid-liquid extraction (LLE) and liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for rapid analysis of 11 pharmaceuticals and personal care products (PPCPs) in fish plasma micro-aliquots (∼20μL). Target PPCPs included, bisphenol A, carbamazepine, diclofenac, fluoxetine, gemfibrozil, ibuprofen, naproxen, risperidone, sertraline, simvastatin and triclosan. A relatively quicker and cheaper LLE procedure exhibited comparable analyte recoveries with solid-phase extraction. Rapid separation and analysis of target compounds in fish plasma extracts was achieved by employing a high efficiency C-18 HPLC column (Agilent Poroshell 120 SB-C18, 2.1mm×50mm, 2.7μm) and fast polarity switching, enabling effective monitoring of positive and negative ions in a single 9min run. With the exception of bisphenol A, which exhibited relatively high background contamination, method detection limits of individual PPCPs ranged between 0.15 and 0.69pg/μL, while method quantification limits were between 0.05 and 2.3pg/μL. Mean matrix effect (ME) values ranged between 65 and 156% for the various target analytes. Isotope dilution quantification using isotopically labelled internal surrogates was utilized to correct for signal suppression or enhancement and analyte losses during sample preparation. The method was evaluated by analysis of 20μL plasma micro-aliquots collected from zebrafish (Danio rerio) from a laboratory bioaccumulation study, which included control group fish (no exposure), as well as fish exposed to environmentally relevant concentrations of PPCPs. Using the developed LC-MS/MS based method, concentrations of the studied PPCPs were consistently detected in the low pg/μL (ppb) range. The method may be useful for investigations requiring fast, reliable concentration measurements of PPCPs in fish plasma. In particular, the method may be applicable for in situ contaminant biomonitoring, as well as

  1. Modeling regenerative braking and storage for vehicles

    SciTech Connect

    Wicks, F.; Donnelly, K.

    1997-12-31

    The fuel savings benefits of regenerative braking and storage for vehicles are often described but not quantified. For example, the federal government and automobile manufacturers are sponsoring a Program for a New Generation of Vehicles (PGNV) with a goal of obtaining a performance of 80 mpg in a family size car. It is typically suggested that such a vehicle will be a hybrid engine and electric drive with regenerative braking. The authors note that while regenerative braking has the potential of saving fuel, it may also do more harm than good as a result of additional weight, less than ideal charge/discharge efficiency on the batteries or storage flywheels and the limited portion of the entire driving cycle when regenerative braking can be utilized. The authors also noted that if regenerative braking can have a net benefit, it would be on a heavy vehicle such as a municipal bus because of the frequent stop and go requirements for both traffic light and passengers. Thus the authors initiated a study of regenerative braking on such a vehicle. The resulting analysis presented in this paper includes data following municipal buses to define the driving cycle, modeling the bus power requirements from weight, aerodynamics and rolling resistance, and then calculating the fuel saving that could result from an ideal regenerative braking system.

  2. Comparison of different methods to calculate total runoff and sediment yield based on aliquot sampling from rainfall simulations

    NASA Astrophysics Data System (ADS)

    Tresch, Simon; Fister, Wolfgang; Marzen, Miriam; Kuhn, Nikolaus J.

    2015-04-01

    The quality of data obtained by rainfall experiments depends mainly on the quality of the rainfall simulation itself. However, the best rainfall simulation cannot deliver valuable data, if runoff and sediment discharge from the plot are not sampled at a proper interval or if poor interpolation methods are being used. The safest way to get good results would be to collect all runoff and sediment amounts that come off the plot in the shortest possible intervals. Unfortunately, high rainfall amounts often coincide with limited transport and analysis capacities. Therefore, it is in most cases necessary to find a good compromise between sampling frequency, interpolation method, and available analysis capacities. The aim of this study was to compare different methods to calculate total sediment yield based on aliquot sampling intervals. The methods tested were (1) simple extrapolation of one sample until next sample was collected; (2) averaging between two successive samples; (3) extrapolation of the sediment concentration; (4) extrapolation using a regression function. The results indicate that all methods could, theoretically, be used to calculate total sediment yields, but errors between 10-25% would have to be taken into account for interpretation of the gained data. Highest deviations were always found for the first measurement interval, which shows that it is very important to capture the initial flush of sediment from the plot to be able to calculate reliable total values.

  3. Stem cell research and regenerative medicine in 2014: first year of regenerative medicine in Japan.

    PubMed

    Okano, Hideyuki

    2014-09-15

    It is my great pleasure to announce that we were able to publish the Japan Issue in Stem Cells and Development, especially in this year 2014. This year, 2014, is said to be the First Year of Regenerative Medicine in Japan. This movement is likely to be based on the establishment of a new law system regarding regenerative medicine (an Act for Ensuring the Safety of Regenerative Medicine or the so-called Regenerative Medicine Law) and the partial revision of the Pharmaceutical Affairs Law (PAL). Both laws will come into effect in 2014 in this country. These new law systems are expected to have a great impact on the facilitation of R&D related to regenerative medicine and stem cell biology. In the present Japan Issue, some excellent stem cell research in this country will be introduced to celebrate the First Year of Regenerative Medicine in Japan.

  4. Regenerative medicine: a primer for paediatricians.

    PubMed

    Polak, Dame Julia M

    2009-11-01

    Regenerative medicine is a multidisciplinary field concerned with the replacement, repair or restoration of injured tissues. Cell therapy and tissue engineering are part of the broader remit of regenerative medicine. The ultimate aim is to provide safe and efficient therapies for a large number of clinical conditions. Novel regenerative therapies are already in use in initial clinical trials. The main components of regenerative medicine are cells and specially designed materials. A vast variety of cells types are currently used including: adult and stem cells. Equally a large number of natural and man-made materials have been investigated. Despite of considerable advances many challenges lie ahead. These are summarised in this review article. The field is slowly maturing and the initial unhelpful hype has been replaced by a more measured, mature and realistic outlook.

  5. Regenerative medicine applications in combat casualty care.

    PubMed

    Fleming, Mark E; Bharmal, Husain; Valerio, Ian

    2014-03-01

    The purpose of this report is to describe regenerative medicine applications in the management of complex injuries sustained by service members injured in support of the wars in Afghanistan and Iraq. Improvements in body armor, resuscitative techniques and faster transport have translated into increased patient survivability and more complex wounds. Combat-related blast injuries have resulted in multiple extremity injuries, significant tissue loss and amputations. Due to the limited availability and morbidity associated with autologous tissue donor sites, the introduction of regenerative medicine has been critical in managing war extremity injuries with composite massive tissue loss. Through case reports and clinical images, this report reviews the application of regenerative medicine modalities employed to manage combat-related injuries. It illustrates that the novel use of hybrid reconstructions combining traditional and regenerative medicine approaches are an effective tool in managing wounds. Lessons learned can be adapted to civilian care.

  6. Regenerative rotary displacer Stirling engine

    SciTech Connect

    Isshiki, Naotsugu; Watanabe, Hiroichi; Raggi, L.; Isshiki, Seita; Hirata, Koichi

    1996-12-31

    A few rotary displacer Stirling engines in which the displacer has one gas pocket space at one side and rotates in a main enclosed cylinder, which is heated from one side and cooled from opposite side without any regenerator, have been studied for some time by the authors. The authors tried to improve this engine by equipping it with a regenerator, because without a regenerator, pressure oscillation and efficiency are too small. Here, several types of regenerative rotary displacer piston Stirling engines are proposed. One is the contra-rotating tandem two disc type displacer engine using axial heat conduction through side walls or by heat pipes and another is a single disc type with circulating fluid regenerator or heat pipes. Stirling engines of this new rotary displacer type are thought to attain high speed. Here, experimental results of the original rotary displacer Stirling engine without a regenerator, and one contra-rotating tandem displacer engine with side wall regenerator by axial heat conduction are reported accompanied with a discussion of the results.

  7. A regenerative elastocaloric heat pump

    NASA Astrophysics Data System (ADS)

    Tušek, Jaka; Engelbrecht, Kurt; Eriksen, Dan; Dall'Olio, Stefano; Tušek, Janez; Pryds, Nini

    2016-10-01

    A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years; however, caloric-based technologies (those using the magnetocaloric, electrocaloric, barocaloric or elastocaloric effect) have recently shown a significant potential as alternatives to replace this technology due to high efficiency and the use of green solid-state refrigerants. Here, we report a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg-1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications.

  8. High power regenerative laser amplifier

    DOEpatents

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  9. High power regenerative laser amplifier

    DOEpatents

    Miller, John L.; Hackel, Lloyd A.; Dane, Clifford B.; Zapata, Luis E.

    1994-01-01

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

  10. Staged regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

    A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

  11. Clinical imaging in regenerative medicine

    PubMed Central

    Naumova, Anna V; Modo, Michel; Moore, Anna; Murry, Charles E; Frank, Joseph A

    2014-01-01

    In regenerative medicine, clinical imaging is indispensable for characterizing damaged tissue and for measuring the safety and efficacy of therapy. However, the ability to track the fate and function of transplanted cells with current technologies is limited. Exogenous contrast labels such as nanoparticles give a strong signal in the short term but are unreliable long term. Genetically encoded labels are good both short- and long-term in animals, but in the human setting they raise regulatory issues related to the safety of genomic integration and potential immunogenicity of reporter proteins. Imaging studies in brain, heart and islets share a common set of challenges, including developing novel labeling approaches to improve detection thresholds and early delineation of toxicity and function. Key areas for future research include addressing safety concerns associated with genetic labels and developing methods to follow cell survival, differentiation and integration with host tissue. Imaging may bridge the gap between cell therapies and health outcomes by elucidating mechanisms of action through longitudinal monitoring. PMID:25093889

  12. Regenerative fuel cell engineering - FY99

    SciTech Connect

    Michael A. Inbody; Rodney L. Borup; James C. Hedstrom; Jose Tafoya; Byron Morton; Lois Zook; Nicholas E. Vanderborgh

    2000-01-01

    The authors report the work conducted by the ESA-EPE Fuel Cell Engineering Team at Los Alamos National Laboratory during FY99 on regenerative fuel cell system engineering. The work was focused on the evaluation of regenerative fuel cell system components obtained through the RAFCO program. These components included a 5 kW PEM electrolyzer, a two-cell regenerative fuel cell stack, and samples of the electrolyzer membrane, anode, and cathode. The samples of the electrolyzer membrane, anode, and cathode were analyzed to determine their structure and operating characteristics. Tests were conducted on the two-cell regenerative fuel cell stack to characterize its operation as an electrolyzer and as a fuel cell. The 5 kW PEM electrolyzer was tested in the Regenerative Fuel Cell System Test Facility. These tests served to characterize the operation of the electrolyzer and, also, to verify the operation of the newly completed test facility. Future directions for this work in regenerative fuel cell systems are discussed.

  13. Current overview on challenges in regenerative endodontics

    PubMed Central

    Bansal, Ramta; Jain, Aditya; Mittal, Sunandan

    2015-01-01

    Introduction: Regenerative endodontics provides hope of converting the non-vital tooth into vital once again. It focuses on substituting traumatized and pathological pulp with functional pulp tissue. Current regenerative procedures successfully produce root development but still fail to re-establish real pulp tissue and give unpredictable results. There are several drawbacks that need to be addressed to improve the quality and efficiency of the treatment. Aim: The aim of this review article is to discuss major priorities that ought to be dealt before applications of regenerative endodontics flourish the clinical practice. Materials and Methods: A web-based research on MEDLINE was done using filter terms Review, published in the last 10 years and Dental journals. Keywords used for research were “regenerative endodontics,” “dental stem cells,” “growth factor regeneration,” “scaffolds,” and “challenges in regeneration.” This review article screened about 150 articles and then the relevant information was compiled. Results: Inspite of the impressive growth in regenerative endodontic field, there are certain loopholes in the existing treatment protocols that might sometimes result in undesired and unpredictable outcomes. Conclusion: Considerable research and development efforts are required to improve and update existing regenerative endodontic strategies to make it an effective, safe, and biological mode to save teeth. PMID:25657518

  14. The Problem of using Quartz as a radiation dosimeter: fundamentals of dose dependence

    NASA Astrophysics Data System (ADS)

    King, G. E.; Finch, A. A.; Robinson, R. A. J.; Hole, D. E.

    2009-04-01

    Quartz is widely used as a radiation dosimeter in Quaternary geomorphological and archaeological dating applications through Optically Stimulated Luminescence (over 1,200 journal publications since 2000). However, obtaining an accurate equivalent radiation dose (DE) can be challenging, especially where the luminescence intensity of the quartz is dim. The causes of variation in luminescence intensity between quartz grains of different provenances, transport and thermal histories is unknown, however it has been suggested that it relates to either the dosimetric history of the grain, or mechanical processes which occur in transit. Investigation of the fundamental properties of the luminescence of quartz, enables investigation of dose dependent changes in luminescence intensity. A series of dose dependence experiments were conducted using spectroscopic ionoluminescence, which comprises the excitation of quartz with protons accelerated at 0.95 MeV. The energy delivered to the sample throughout ion implantation is similar to that received during gamma irradiation, and thus approximates sample radiation dosing. A natural macro-crystal of α-quartz was investigated parallel and perpendicular to c, to observe any orientation dependent effects, as well as a calibration quartz from the Risø National Laboratory, Denmark, and a Scottish geomorphological sample, prepared using standard laboratory procedures. The calibration quartz sample has excellent luminescence intensity and is suited to analysis using the single-aliquot regenerative dose (SAR) standard OSL protocol, the Scottish sample alternatively has very dim luminescence and exhibits variable behaviour when analysed with SAR. Despite the differences between the luminescence behaviour of the samples, all three responded to the dose dependence experiments in a similar manner. The UV/blue emission was observed to deplete with increasing dose, whereas the red emission, not normally analysed within OSL, exhibited increased

  15. Regenerative medicine: Current therapies and future directions

    PubMed Central

    Mao, Angelo S.; Mooney, David J.

    2015-01-01

    Organ and tissue loss through disease and injury motivate the development of therapies that can regenerate tissues and decrease reliance on transplantations. Regenerative medicine, an interdisciplinary field that applies engineering and life science principles to promote regeneration, can potentially restore diseased and injured tissues and whole organs. Since the inception of the field several decades ago, a number of regenerative medicine therapies, including those designed for wound healing and orthopedics applications, have received Food and Drug Administration (FDA) approval and are now commercially available. These therapies and other regenerative medicine approaches currently being studied in preclinical and clinical settings will be covered in this review. Specifically, developments in fabricating sophisticated grafts and tissue mimics and technologies for integrating grafts with host vasculature will be discussed. Enhancing the intrinsic regenerative capacity of the host by altering its environment, whether with cell injections or immune modulation, will be addressed, as well as methods for exploiting recently developed cell sources. Finally, we propose directions for current and future regenerative medicine therapies. PMID:26598661

  16. Functional imaging for regenerative medicine.

    PubMed

    Leahy, Martin; Thompson, Kerry; Zafar, Haroon; Alexandrov, Sergey; Foley, Mark; O'Flatharta, Cathal; Dockery, Peter

    2016-04-19

    In vivo imaging is a platform technology with the power to put function in its natural structural context. With the drive to translate stem cell therapies into pre-clinical and clinical trials, early selection of the right imaging techniques is paramount to success. There are many instances in regenerative medicine where the biological, biochemical, and biomechanical mechanisms behind the proposed function of stem cell therapies can be elucidated by appropriate imaging. Imaging techniques can be divided according to whether labels are used and as to whether the imaging can be done in vivo. In vivo human imaging places additional restrictions on the imaging tools that can be used. Microscopies and nanoscopies, especially those requiring fluorescent markers, have made an extraordinary impact on discovery at the molecular and cellular level, but due to their very limited ability to focus in the scattering tissues encountered for in vivo applications they are largely confined to superficial imaging applications in research laboratories. Nanoscopy, which has tremendous benefits in resolution, is limited to the near-field (e.g. near-field scanning optical microscope (NSNOM)) or to very high light intensity (e.g. stimulated emission depletion (STED)) or to slow stochastic events (photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM)). In all cases, nanoscopy is limited to very superficial applications. Imaging depth may be increased using multiphoton or coherence gating tricks. Scattering dominates the limitation on imaging depth in most tissues and this can be mitigated by the application of optical clearing techniques that can impose mild (e.g. topical application of glycerol) or severe (e.g. CLARITY) changes to the tissue to be imaged. Progression of therapies through to clinical trials requires some thought as to the imaging and sensing modalities that should be used. Smoother progression is facilitated by the use of

  17. Cardiovascular Regenerative Technologies: Update and Future Outlook

    PubMed Central

    Mallone, Anna; Weber, Benedikt; Hoerstrup, Simon P.

    2016-01-01

    In the effort of improving treatment for cardiovascular disease (CVD), scientists struggle with the lack of the regenerative capacities of finally differentiated cardiovascular tissues. In this context, the advancements in regenerative medicine contributed to the development of cell-based therapies as well as macro- and micro-scale tissue-engineering technologies. The current experimental approaches focus on different regenerative strategies including a broad spectrum of techniques such as paracrine-based stimulation of autologous cardiac stem cells, mesenchymal cell injections, 3D microtissue culture techniques and vascular tissue-engineering methods. These potential next-generation strategies are leading the way to a revolution in addressing CVD, and numerous studies are now undertaken to assess their therapeutic value. With this review, we provide an update on the current research directions, on their major challenges, limitations, and achievements. PMID:27721705

  18. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  19. Combined hydraulic and regenerative braking system

    SciTech Connect

    Venkataperumal, Rama R.; Mericle, Gerald E.

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  20. Regenerative therapy: a periodontal-endodontic perspective.

    PubMed

    Kinaia, Bassam Michael; Chogle, Sami M A; Kinaia, Atheel M; Goodis, Harold E

    2012-07-01

    Periodontal and endodontic diseases are inflammatory responses leading to periodontal and pulpal tissue loss. Regenerative therapies aim to restore the lost structures to vitality and function. Various materials and treatments methods have been used such as bone grafts, guided tissue regeneration, enamel matrix derivatives, growth and differentiation factors, and stem cells. Although the current materials and methods demonstrated adequate clinical results, true and complete biological tissue regeneration is not yet attainable. The current article reviews chronologically the materials and methods used in periodontal and endodontic regeneration highlighting their clinical success and shortcomings, and discussing future directions in regenerative therapy.

  1. Improved Regenerative Sorbent-Compressor Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Conceptual regenerative sorbent-compressor refrigerator attains regeneration efficiency and, therefore, overall power efficiency and performance greater than conventional refrigerators. Includes two fluid loops. In one, CH2FCF3 (R134a) ciculates by physical adsorption and desorption in four activated-charcoal sorption compressors. In other, liquid or gas coolant circulated by pump. Wave of regenerative heating and cooling propagates cyclically like peristatic wave among sorption compressors and associated heat exchangers. Powered by electricity, oil, gas, solar heat, or waste heat. Used as air conditioners, refrigerators, and heat pumps in industrial, home, and automotive applications.

  2. WIDE BAND REGENERATIVE FREQUENCY DIVIDER AND MULTIPLIER

    DOEpatents

    Laine, E.F.

    1959-11-17

    A regenerative frequency divider and multiplier having wide band input characteristics is presented. The circuit produces output oscillations having frequencies related by a fixed ratio to input oscillations over a wide band of frequencies. In accomplishing this end, the divider-multiplier includes a wide band input circuit coupled by mixer means to a wide band output circuit having a pass band related by a fixed ratio to that of the input circuit. A regenerative feedback circuit derives a fixed frequency ratio feedback signal from the output circuit and applies same to the mixer means in proper phase relation to sustain fixed frequency ratio oscillations in the output circuit.

  3. Regenerative medicine: does Erythropoietin have a role?

    PubMed

    Buemi, Michele; Lacquaniti, Antonio; Maricchiolo, Giulia; Bolignano, Davide; Campo, Susanna; Cernaro, Valeria; Sturiale, Alessio; Grasso, Giovanni; Buemi, Antoine; Allegra, Alessandro; Donato, Valentina; Genovese, Lucrezia

    2009-01-01

    Regenerative Medicine, a recent new medical domain, aims to develop new therapies through the stimulation of natural regenerative processes also in human beings. In this field, Erythropoietin (EPO) represents a significant subject of research. Several studies allow the assertion that EPO, in different concentrations, has protective effects mainly on the central nervous system, cardiovascular system and renal tissue. This action is carried out through one of few regenerative activities of human beings: angiogenesis. This mechanism, which involves endothelial stem cells and VEGF (Vascular Endothelial Growth Factor), has been experimentally demonstrated with Recombinant human erythropoietin (rHuEPO) and Darbepoetin, a long-acting EPO derivate. Furthermore, the demonstration of a cardiac production of EPO in Fugu rubripes and in Zebrafish has led cardiologists to "discover" Erythropoietin, postulating a hypothetical role in treatment of cardiovascular disease for this hormone. This is some of the experimental evidence which demonstrates that EPO can be in reason considered an important element of research of Regenerative Medicine and put in the network of drugs able to regenerate tissues and organs.

  4. Simulations of the LANL regenerative amplifier FEL

    SciTech Connect

    Kesselring, M.; Colson, W.B.; Wong, R.K.; Sheffield, R.L.

    1997-08-01

    The LANL regenerative amplifier FEL is designed to produce an average output power of 1 kW. Simulations study the transverse effects due to guiding by the intense electron beam and feedback. These simulations coupled with experimental measurements can be used to improve future high-power FEL designs.

  5. Regenerative fuel cells for space applications

    NASA Technical Reports Server (NTRS)

    Appleby, A. John

    1987-01-01

    After several years of development of the regenerative fuel cell (RFC) as the electrochemical storage system to be carried by the future space station, the official stance has now been adopted that nickel hydrogen batteries would be a better system choice. RFCs are compared with nickel hydrogen and other battery systems for space platform applications.

  6. Regenerative Studies: College Community and Community College.

    ERIC Educational Resources Information Center

    Woltz, Mary G.

    This case study applies principles derived from the Center for Regenerative Studies (CRS) to a community college in North Carolina. CRS, on the campus of California State Polytechnic Institute (California), is dedicated to the education, demonstration, and research of degenerative systems in the areas of shelter, food production, energy, water and…

  7. Applications of regenerative medicine in organ transplantation

    PubMed Central

    Jain, Aditya; Bansal, Ramta

    2015-01-01

    A worldwide shortage of organs for clinical implantation establishes the need to bring forward and test new technologies that will help in solving the problem. The concepts of regenerative medicine hold the potential for augmenting organ function or repairing damaged organ or allowing regeneration of deteriorated organs and tissue. Researchers are exploring possible regenerative medicine applications in organ transplantation so that coming together of the two fields can benefit each other. The present review discusses the strategies that are being implemented to regenerate or bio-engineer human organs for clinical purposes. It also highlights the limitations of the regenerative medicine that needs to be addressed to explore full potential of the field. A web-based research on MEDLINE was done using keywords “regenerative medicine,” “tissue-engineering,” “bio-engineered organs,” “decellularized scaffold” and “three-dimensional printing.” This review screened about 170 articles to get the desired knowledge update. PMID:26229352

  8. Mesenchymal stem cells, aging and regenerative medicine

    PubMed Central

    Raggi, Chiara; Berardi, Anna C.

    2012-01-01

    Summary Tissue maintenance and regeneration is dependent on stem cells and increasing evidence has shown to decline with age. Stem cell based-aging is thought to influence therapeutic efficacy. Mesenchymal stromal cells (MSCs) are involved in tissue regeneration. Here, we discuss the effects of age-related changes on MSC properties considering their possible use in research or regenerative medicine. PMID:23738303

  9. Regenerative nanomedicine: current perspectives and future directions

    PubMed Central

    Chaudhury, Koel; Kumar, Vishu; Kandasamy, Jayaprakash; RoyChoudhury, Sourav

    2014-01-01

    Nanotechnology has considerably accelerated the growth of regenerative medicine in recent years. Application of nanotechnology in regenerative medicine has revolutionized the designing of grafts and scaffolds which has resulted in new grafts/scaffold systems having significantly enhanced cellular and tissue regenerative properties. Since the cell–cell and cell-matrix interaction in biological systems takes place at the nanoscale level, the application of nanotechnology gives an edge in modifying the cellular function and/or matrix function in a more desired way to mimic the native tissue/organ. In this review, we focus on the nanotechnology-based recent advances and trends in regenerative medicine and discussed under individual organ systems including bone, cartilage, nerve, skin, teeth, myocardium, liver and eye. Recent studies that are related to the design of various types of nanostructured scaffolds and incorporation of nanomaterials into the matrices are reported. We have also documented reports where these materials and matrices have been compared for their better biocompatibility and efficacy in supporting the damaged tissue. In addition to the recent developments, future directions and possible challenges in translating the findings from bench to bedside are outlined. PMID:25214780

  10. Self-aliquoting micro-grooves in combination with laser ablation-ICP-mass spectrometry for the analysis of challenging liquids: quantification of lead in whole blood.

    PubMed

    Nischkauer, Winfried; Vanhaecke, Frank; Limbeck, Andreas

    2016-08-01

    We present a technique for the fast screening of the lead concentration in whole blood samples using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The whole blood sample is deposited on a polymeric surface and wiped across a set of micro-grooves previously engraved into the surface. The engraving of the micro-grooves was accomplished with the same laser system used for LA-ICP-MS analysis. In each groove, a part of the liquid blood is trapped, and thus, the sample is divided into sub-aliquots. These aliquots dry quasi instantly and are then investigated by means of LA-ICP-MS. For quantification, external calibration against aqueous standard solutions was relied on, with iron as an internal standard to account for varying volumes of the sample aliquots. The (208)Pb/(57)Fe nuclide ratio used for quantification was obtained via a data treatment protocol so far only used in the context of isotope ratio determination involving transient signals. The method presented here was shown to provide reliable results for Recipe ClinChek® Whole Blood Control levels I-III (nos. 8840-8842), with a repeatability of typically 3 % relative standard deviation (n = 6, for Pb at 442 μg L(-1)). Spiked and non-spiked real whole blood was analysed as well, and the results were compared with those obtained via dilution and sectorfield ICP-MS. A good agreement between both methods was observed. The detection limit (3 s) for lead in whole blood was established to be 10 μg L(-1) for the laser ablation method presented here. Graphical Abstract Micro-grooves are filled with whole blood, dried, and analyzed by laser ablation ICP-mass spectrometry. Notice that the laser moves in perpendicular direction with regard to the micro-grooves.

  11. Regenerative medicine for the treatment of spinal cord injury: more than just promises?

    PubMed Central

    Pêgo, Ana Paula; Kubinova, Sarka; Cizkova, Dasa; Vanicky, Ivo; Mar, Fernando Milhazes; Sousa, Mónica Mendes; Sykova, Eva

    2012-01-01

    Spinal cord injury triggers a complex set of events that lead to tissue healing without the restoration of normal function due to the poor regenerative capacity of the spinal cord. Nevertheless, current knowledge about the intrinsic regenerative ability of central nervous system axons, when in a supportive environment, has made the prospect of treating spinal cord injury a reality. Among the range of strategies under investigation, cell-based therapies offer the most promising results, due to the multifactorial roles that these cells can fulfil. However, the best cell source is still a matter of debate, as are clinical issues that include the optimal cell dose as well as the timing and route of administration. In this context, the role of biomaterials is gaining importance. These can not only act as vehicles for the administered cells but also, in the case of chronic lesions, can be used to fill the permanent cyst, thus creating a more favourable and conducive environment for axonal regeneration in addition to serving as local delivery systems of therapeutic agents to improve the regenerative milieu. Some of the candidate molecules for the future are discussed in view of the knowledge derived from studying the mechanisms that facilitate the intrinsic regenerative capacity of central nervous system neurons. The future challenge for the multidisciplinary teams working in the field is to translate the knowledge acquired in basic research into effective combinatorial therapies to be applied in the clinic. PMID:22805417

  12. Regenerative medicine for the treatment of spinal cord injury: more than just promises?

    PubMed

    Pêgo, Ana Paula; Kubinova, Sarka; Cizkova, Dasa; Vanicky, Ivo; Mar, Fernando Milhazes; Sousa, Mónica Mendes; Sykova, Eva

    2012-11-01

    Spinal cord injury triggers a complex set of events that lead to tissue healing without the restoration of normal function due to the poor regenerative capacity of the spinal cord. Nevertheless, current knowledge about the intrinsic regenerative ability of central nervous system axons, when in a supportive environment, has made the prospect of treating spinal cord injury a reality. Among the range of strategies under investigation, cell-based therapies offer the most promising results, due to the multifactorial roles that these cells can fulfil. However, the best cell source is still a matter of debate, as are clinical issues that include the optimal cell dose as well as the timing and route of administration. In this context, the role of biomaterials is gaining importance. These can not only act as vehicles for the administered cells but also, in the case of chronic lesions, can be used to fill the permanent cyst, thus creating a more favourable and conducive environment for axonal regeneration in addition to serving as local delivery systems of therapeutic agents to improve the regenerative milieu. Some of the candidate molecules for the future are discussed in view of the knowledge derived from studying the mechanisms that facilitate the intrinsic regenerative capacity of central nervous system neurons. The future challenge for the multidisciplinary teams working in the field is to translate the knowledge acquired in basic research into effective combinatorial therapies to be applied in the clinic.

  13. Regenerative Endodontics: A Road Less Travelled

    PubMed Central

    Bansal, Ramta; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

    2014-01-01

    Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients’ quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering. PMID:25478476

  14. Regenerative endodontics: a road less travelled.

    PubMed

    Bansal, Ramta; Jain, Aditya; Mittal, Sunandan; Kumar, Tarun; Kaur, Dilpreet

    2014-10-01

    Although traditional approaches like root canal therapy and apexification procedures have been successful in treating diseased or infected root canals, but these modalities fail to re-establish healthy pulp tissue in treated teeth. Regeneration-based approaches aims to offer high levels of success by replacing diseased or necrotic pulp tissues with healthy pulp tissue to revitalize teeth. The applications of regenerative approaches in dental clinics have potential to dramatically improve patients' quality of life. This review article offers a detailed overview of present regenerative endodontic approaches aiming to revitalize teeth and also outlines the problems to be dealt before this emerging field contributes to clinical treatment protocols. It conjointly covers the basic trilogy elements of tissue engineering.

  15. Micro-Scale Regenerative Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2004-01-01

    A micro-scale regenerative heat exchanger has been designed, optimized and fabricated for use in a micro-Stirling device. Novel design and fabrication techniques enabled the minimization of axial heat conduction losses and pressure drop, while maximizing thermal regenerative performance. The fabricated prototype is comprised of ten separate assembled layers of alternating metal-dielectric composite. Each layer is offset to minimize conduction losses and maximize heat transfer by boundary layer disruption. A grating pattern of 100 micron square non-contiguous flow passages were formed with a nominal 20 micron wall thickness, and an overall assembled ten-layer thickness of 900 microns. Application of the micro heat exchanger is envisioned in the areas of micro-refrigerators/coolers, micropower devices, and micro-fluidic devices.

  16. Chemical transdifferentiation: closer to regenerative medicine.

    PubMed

    Xu, Aining; Cheng, Lin

    2016-06-01

    Cell transdifferentiation, which directly switches one type of differentiated cells into another cell type, is more advantageous than cell reprogramming to generate pluripotent cells and differentiate them into functional cells. This process is crucial in regenerative medicine. However, the cell-converting strategies, which mainly depend on the virus-mediated expression of exogenous genes, have clinical safety concerns. Small molecules with compelling advantages are a potential alternative in manipulating cell fate conversion. In this review, we briefly retrospect the nature of cell transdifferentiation and summarize the current developments in the research of small molecules in promoting cell conversion. Particularly, we focus on the complete chemical compound-induced cell transdifferentiation, which is closer to the clinical translation in cell therapy. Despite these achievements, the mechanisms underpinning chemical transdifferentiation remain largely unknown. More importantly, identifying drugs that induce resident cell conversion in vivo to repair damaged tissue remains to be the end-goal in current regenerative medicine.

  17. Unitized Regenerative Fuel Cell System Model Development

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian

    2003-01-01

    A Unitized Regenerative Fuel Cell (URFC) Energy Storage System is being developed at the NASA Glenn Research Center. This URFC system is unique in that it uses the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The tank surfaces also play an important role in the temperature control of regenerative gas dryers/humidifiers used to dry the hydrogen and oxygen gases produced by electrolysis during the charging and also used to humidify the hydrogen and oxygen gases used by fuel cell during the discharging of the URFCS. A bi- directional pressure controller is used to control the pressure of the oxygen and hydrogen gas inside the URFC stack during both charging and discharging of the URFC system. A water storage accumulator is used to store water reactant and control water pressure inside the URFC stack.

  18. Electrospun Silk Biomaterial Scaffolds for Regenerative Medicine

    PubMed Central

    Zhang, Xiaohui; Reagan, Michaela R; Kaplan, David L.

    2009-01-01

    Electrospinning is a versatile technique that enables the development of nanofiber-based biomaterial scaffolds. Scaffolds can be generated that are useful for tissue engineering and regenerative medicine since they mimic the nanoscale properties of certain fibrous components of the native extracellular matrix in tissues. Silk is a natural protein with excellent biocompatibility, remarkable mechanical properties as well as tailorable degradability. Integrating these protein polymer advantages with electrospinning results in scaffolds with combined biochemical, topographical and mechanical cues with versatility for a range of biomaterial, cell and tissue studies and applications. This review covers research related to electrospinning of silk, including process parameters, post treatment of the spun fibers, functionalization of nanofibers, and the potential applications for these material systems in regenerative medicine. Research challenges and future trends are also discussed. PMID:19643154

  19. Fluorescent Cell Imaging in Regenerative Medicine

    PubMed Central

    Sapoznik, Etai; Niu, Guoguang; Zhou, Yu; Murphy, Sean V.; Soker, Shay

    2016-01-01

    Fluorescent protein imaging, a promising tool in biological research, incorporates numerous applications that can be of specific use in the field of regenerative medicine. To enhance tissue regeneration efforts, scientists have been developing new ways to monitor tissue development and maturation in vitro and in vivo. To that end, new imaging tools and novel fluorescent proteins have been developed for the purpose of performing deep-tissue high-resolution imaging. These new methods, such as intra-vital microscopy and Förster resonance energy transfer, are providing new insights into cellular behavior, including cell migration, morphology, and phenotypic changes in a dynamic environment. Such applications, combined with multimodal imaging, significantly expand the utility of fluorescent protein imaging in research and clinical applications of regenerative medicine. PMID:27158228

  20. Regenerative endodontics: a state of the art.

    PubMed

    Bansal, Rashmi; Bansal, Rajesh

    2011-01-01

    Scientific advances in the creation of restorative biomaterials, in vitro cell culture technology, tissue grafting, tissue engineering, molecular biology and the human genome project provide the basis for the introduction of new technologies into dentistry. Non-vital infected teeth have long been treated with root canal therapy (for mature root apex) and apexification (for immature root apex), or doomed to extraction. Although successful, current treatments fail to re-establish healthy pulp tissue in these teeth. But, what if the non-vital tooth could be made vital once again? That is the hope offered by regenerative endodontics, an emerging field focused on replacing traumatized and diseased pulp with functional pulp tissue. Restoration of vitality of non-vital tooth is based on tissue engineering and revascularization procedures. The purpose of this article is to review these biological procedures and the hurdles that must be overcome to develop regenerative endodontic procedures.

  1. [Progress in stem cells and regenerative medicine].

    PubMed

    Wang, Libin; Zhu, He; Hao, Jie; Zhou, Qi

    2015-06-01

    Stem cells have the ability to differentiate into all types of cells in the body and therefore have great application potential in regenerative medicine, in vitro disease modelling and drug screening. In recent years, stem cell technology has made great progress, and induced pluripotent stem cell technology revolutionizes the whole stem cell field. At the same time, stem cell research in our country has also achieved great progress and becomes an indispensable power in the worldwide stem cell research field. This review mainly focuses on the research progress in stem cells and regenerative medicine in our country since the advent of induced pluripotent stem cell technology, including induced pluripotent stem cells, transdifferentiation, haploid stem cells, and new gene editing tools.

  2. Induced pluripotent stem cells for regenerative medicine.

    PubMed

    Hirschi, Karen K; Li, Song; Roy, Krishnendu

    2014-07-11

    With the discovery of induced pluripotent stem (iPS) cells, it is now possible to convert differentiated somatic cells into multipotent stem cells that have the capacity to generate all cell types of adult tissues. Thus, there is a wide variety of applications for this technology, including regenerative medicine, in vitro disease modeling, and drug screening/discovery. Although biological and biochemical techniques have been well established for cell reprogramming, bioengineering technologies offer novel tools for the reprogramming, expansion, isolation, and differentiation of iPS cells. In this article, we review these bioengineering approaches for the derivation and manipulation of iPS cells and focus on their relevance to regenerative medicine.

  3. Endometrial stem cells in regenerative medicine.

    PubMed

    Verdi, Javad; Tan, Aaron; Shoae-Hassani, Alireza; Seifalian, Alexander M

    2014-01-01

    First described in 2004, endometrial stem cells (EnSCs) are adult stem cells isolated from the endometrial tissue. EnSCs comprise of a population of epithelial stem cells, mesenchymal stem cells, and side population stem cells. When secreted in the menstrual blood, they are termed menstrual stem cells or endometrial regenerative cells. Mounting evidence suggests that EnSCs can be utilized in regenerative medicine. EnSCs can be used as immuno-modulatory agents to attenuate inflammation, are implicated in angiogenesis and vascularization during tissue regeneration, and can also be reprogrammed into induced pluripotent stem cells. Furthermore, EnSCs can be used in tissue engineering applications and there are several clinical trials currently in place to ascertain the therapeutic potential of EnSCs. This review highlights the progress made in EnSC research, describing their mesodermal, ectodermal, and endodermal potentials both in vitro and in vivo.

  4. A solar regenerative thermoelectrochemical converter (RTEC)

    SciTech Connect

    Townsend, C.W.; McHardy, J. )

    1992-02-01

    This is an executive summary of a final subcontract report that describes the successful completion of a closed-loop demonstration of a regenerative thermoelectromechanical device using solar heat input for the production of electricity. The full report, which contains a detailed description of the two-year effort, is currently subject to a government secrecy order which precludes public release of the information. Copies of the full report will be made available for general release whenever the secrecy order is lifted.

  5. Regenerative medicine. The industry comes of age.

    PubMed

    Mason, C

    2007-01-01

    The regenerative medicine industry has moved into a new era in which commercialisation and not research is the number one priority. To achieve its new goal, much has had to change, including the introduction of expert business management, simpler but superior products and scalability of manufacture. Mass public and political support is supplying both long-term resources and the market demand to finally create a sustainable new health-care sector.

  6. Nanostructured polymeric scaffolds for orthopaedic regenerative engineering.

    PubMed

    Deng, Meng; James, Roshan; Laurencin, Cato T; Kumbar, Sangamesh G

    2012-03-01

    Successful regeneration necessitates the development of three-dimensional (3-D) tissue-inducing scaffolds that mimic the hierarchical architecture of native tissue extracellular matrix (ECM). Cells in nature recognize and interact with the surface topography they are exposed to via ECM proteins. The interaction of cells with nanotopographical features such as pores, ridges, groves, fibers, nodes, and their combinations has proven to be an important signaling modality in controlling cellular processes. Integrating nanotopographical cues is especially important in engineering complex tissues that have multiple cell types and require precisely defined cell-cell and cell-matrix interactions on the nanoscale. Thus, in a regenerative engineering approach, nanoscale materials/scaffolds play a paramount role in controlling cell fate and the consequent regenerative capacity. Advances in nanotechnology have generated a new toolbox for the fabrication of tissue-specific nanostructured scaffolds. For example, biodegradable polymers such as polyesters, polyphosphazenes, polymer blends and composites can be electrospun into ECM-mimicking matrices composed of nanofibers, which provide high surface area for cell attachment, growth, and differentiation. This review provides the fundamental guidelines for the design and development of nanostructured scaffolds for the regeneration of various tissue types in human upper and lower extremities such as skin, ligament, tendon, and bone. Examples focusing on the collective work of our laboratory in those areas are discussed to demonstrate the regenerative efficacy of this approach. Furthermore, preliminary strategies and significant challenges to integrate these individual tissues into one complex organ through regenerative engineering-based integrated graft systems are also discussed.

  7. Low temperature thermally regenerative electrochemical system

    DOEpatents

    Loutfy, Raouf O.; Brown, Alan P.; Yao, Neng-Ping

    1983-01-01

    A thermally regenerative electrochemical system including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the complexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  8. Low-temperature thermally regenerative electrochemical system

    DOEpatents

    Loutfy, R.O.; Brown, A.P.; Yao, N.P.

    1982-04-21

    A thermally regenerative electrochemical system is described including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the ocmplexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  9. Single-grain and single-aliquot luminescence measurements of partially bleached modern-river channel sediments: applications to sediment transport

    NASA Astrophysics Data System (ADS)

    McGuire, C. P.; Rhodes, E. J.

    2014-12-01

    Luminescence techniques are an emerging tool to track transport and provenance of grains in Quaternary fluvial and aeolian deposits. The incomplete zeroing of luminescence signals (partial bleaching) in fluvial environments is an obstacle for dating, but proves advantageous for extracting information about grain-transport histories. Luminescence signals from quartz and feldspar sand have been observed to decrease as an exponential or stretched exponential function of distance downriver. A theoretical framework for the reduction in signal of quartz grains in ephemeral rivers has recently been proposed. We present improvements to a simple forward model for reduction in signal observed for small-aliquot multiple elevated temperature post-IR infrared stimulated luminescence (MET-pIRIR) of K-feldspar grains on the Mojave River in Southern California. Specifically, we use USGS historical stream gage records to produce synthetic hydrographs using time-series analysis. The synthetic hydrographs are used as inputs for an iterative model of signal growth (burial period between floods) and signal depletion (light exposure period during floods). From a best fit of this model to small-aliquot MET-pIRIR data, we can estimate virtual velocity of fine-grain (175 - 200 µm) sand from source to sink. Additionally, we present single-grain MET-pIRIR measurements of K-feldspar grains from the Mojave River and the Santa Clara River in Southern California and explore applications of single-grain data to provenance studies.

  10. Mesenchymal stem cells in regenerative rehabilitation

    PubMed Central

    Nurkovic, Jasmin; Dolicanin, Zana; Mustafic, Fahrudin; Mujanovic, Rifat; Memic, Mensur; Grbovic, Vesna; Skevin, Aleksandra Jurisic; Nurkovic, Selmina

    2016-01-01

    [Purpose] Regenerative medicine and rehabilitation contribute in many ways to a specific plan of care based on a patient’s medical status. The intrinsic self-renewing, multipotent, regenerative, and immunosuppressive properties of mesenchymal stem cells offer great promise in the treatment of numerous autoimmune, degenerative, and graft-versus-host diseases, as well as tissue injuries. As such, mesenchymal stem cells represent a therapeutic fortune in regenerative medicine. The aim of this review is to discuss possibilities, limitations, and future clinical applications of mesenchymal stem cells. [Subjects and Methods] The authors have identified and discussed clinically and scientifically relevant articles from PubMed that have met the inclusion criteria. [Results] Direct treatment of muscle injuries, stroke, damaged peripheral nerves, and cartilage with mesenchymal stem cells has been demonstrated to be effective, with synergies seen between cellular and physical therapies. Over the past few years, several researchers, including us, have shown that there are certain limitations in the use of mesenchymal stem cells. Aging and spontaneous malignant transformation of mesenchymal stem cells significantly affect the functionality of these cells. [Conclusion] Definitive conclusions cannot be made by these studies because limited numbers of patients were included. Studies clarifying these results are expected in the near future. PMID:27390452

  11. Common ethical issues in regenerative medicine.

    PubMed

    Awaya, Tsuyoshi

    2005-01-01

    One of the common ethical issues in regenerative medicine is progress in 'componentation' (= being treated as parts) of the human body, and the enhancement of the view of such "human body parts." 'Componentation' of the human body represents a preliminary step toward commodification of the human body. The process of commodification of the human body follows the steps of 'materialization' (= being treated as a material object) [first step] -- 'componentation' [second step] -- 'resourcialization' (= being treated as resources) [third step] -- commodification [fourth step]. Transplantation medicine and artificial organ developments have dramatically exposed the potential of organs and tissues as parts, and regenerative medicine has a role in advancing 'componentation' of the human body and further enhancing the view of human body parts. The 'componentation' of the human body, regardless of the degree of regenerative medicine's contribution to it, is considered as a challenge to the traditional view of human bodies and the abstract value of "Human Dignity" in the same way or alongside the 'resourcialization' and commodification. However, in the future, a new perspective of human bodies that means "a perspective whereby human bodies, organs, tissues, and even the bodies themselves are perceived as disposable tools like disposable cameras, syringes, or contact lens" and therefore a new ethical view, suitable for a new reality, may emerge.

  12. Upconversion Nanoparticles for Bioimaging and Regenerative Medicine

    PubMed Central

    González-Béjar, María; Francés-Soriano, Laura; Pérez-Prieto, Julia

    2016-01-01

    Nanomaterials are proving useful for regenerative medicine in combination with stem cell therapy. Nanoparticles (NPs) can be administrated and targeted to desired tissues or organs and subsequently be used in non-invasive real-time visualization and tracking of cells by means of different imaging techniques, can act as therapeutic agent nanocarriers, and can also serve as scaffolds to guide the growth of new tissue. NPs can be of different chemical nature, such as gold, iron oxide, cadmium selenide, and carbon, and have the potential to be used in regenerative medicine. However, there are still many issues to be solved, such as toxicity, stability, and resident time. Upconversion NPs have relevant properties such as (i) low toxicity, (ii) capability to absorb light in an optical region where absorption in tissues is minimal and penetration is optimal (note they can also be designed to emit in the near-infrared region), and (iii) they can be used in multiplexing and multimodal imaging. An overview on the potentiality of upconversion materials in regenerative medicine is given. PMID:27379231

  13. Regenerative endodontics--Creating new horizons.

    PubMed

    Dhillon, Harnoor; Kaushik, Mamta; Sharma, Roshni

    2016-05-01

    Trauma to the dental pulp, physical or microbiologic, can lead to inflammation of the pulp followed by necrosis. The current treatment modality for such cases is non-surgical root canal treatment. The damaged tissue is extirpated and the root canal system prepared. It is then obturated with an inert material such a gutta percha. In spite of advances in techniques and materials, 10%-15% of the cases may end in failure of treatment. Regenerative endodontics combines principles of endodontics, cell biology, and tissue engineering to provide an ideal treatment for inflamed and necrotic pulp. It utilizes mesenchymal stem cells, growth factors, and organ tissue culture to provide treatment. Potential treatment modalities include induction of blood clot for pulp revascularization, scaffold aided regeneration, and pulp implantation. Although in its infancy, successful treatment of damaged pulp tissue has been performed using principles of regenerative endodontics. This field is dynamic and exciting with the ability to shape the future of endodontics. This article highlights the fundamental concepts, protocol for treatment, and possible avenues for research in regenerative endodontics.

  14. Mesenchymal stem cells in regenerative rehabilitation.

    PubMed

    Nurkovic, Jasmin; Dolicanin, Zana; Mustafic, Fahrudin; Mujanovic, Rifat; Memic, Mensur; Grbovic, Vesna; Skevin, Aleksandra Jurisic; Nurkovic, Selmina

    2016-06-01

    [Purpose] Regenerative medicine and rehabilitation contribute in many ways to a specific plan of care based on a patient's medical status. The intrinsic self-renewing, multipotent, regenerative, and immunosuppressive properties of mesenchymal stem cells offer great promise in the treatment of numerous autoimmune, degenerative, and graft-versus-host diseases, as well as tissue injuries. As such, mesenchymal stem cells represent a therapeutic fortune in regenerative medicine. The aim of this review is to discuss possibilities, limitations, and future clinical applications of mesenchymal stem cells. [Subjects and Methods] The authors have identified and discussed clinically and scientifically relevant articles from PubMed that have met the inclusion criteria. [Results] Direct treatment of muscle injuries, stroke, damaged peripheral nerves, and cartilage with mesenchymal stem cells has been demonstrated to be effective, with synergies seen between cellular and physical therapies. Over the past few years, several researchers, including us, have shown that there are certain limitations in the use of mesenchymal stem cells. Aging and spontaneous malignant transformation of mesenchymal stem cells significantly affect the functionality of these cells. [Conclusion] Definitive conclusions cannot be made by these studies because limited numbers of patients were included. Studies clarifying these results are expected in the near future.

  15. An Improved Method for TIMS High Precision Nd Isotopic Analysis of Very Small Aliquots (1- 10ng) With Example Application in Garnet Sm/Nd Geochronology

    NASA Astrophysics Data System (ADS)

    Baxter, E. F.; Harvey, J.; Mehl, L. Y.; Peterman, E. M.

    2007-12-01

    Technological and scientific developments have demonstrated both the attainability and the utility of very high precision (i.e. 5-20ppm 2 σ) Nd isotopic measurements with TIMS. However such high precision has been limited to relatively large aliquots of Nd, on the order of several hundred nanograms. Several potential applications of precise Nd isotopic measurements, including garnet Sm/Nd geochronology, do not always permit such large samples, instead yielding only a few nanograms of Nd. We have explored and tested an improved method for Nd isotopic analysis of such small (1-10ng) aliquots of Nd using the NdO+ method with a Triton TIMS at Boston University. Analyzing Nd isotopes as the oxide is a well known technique, frequently involving an oxygen bleed valve. Instead, we forego the bleed valve and load samples with a TaO slurry which provides the oxygen source. Using an in-house Nd isotopic standard solution, 4ng loads easily yield stable 2.0-2.5 volt beams resulting in internal precisions of 10ppm 2 σ RSE. Within barrel external precision of 4ng loads of the Nd standard is 13ppm 2 σ RSD (n=20). Long term (6 months, six analysts) external precision of 4ng loads of the standard is currently 23ppm 2 σ RSD (n=55) suggesting that further improvements are possible. As a further test of this method, we dissolved a natural rock sample (a metapelite), separated the Nd using TRU- spec and MLA column chemistry, and loaded nineteen 4ng loads in one barrel. Within barrel external precision was 21ppm 2 σ RSD (n=18). This precision represents a significant advance over previous NdO+ analyses of small samples using an oxygen bleed valve. The TaO loading method for small Nd aliquots is useful in Sm/Nd garnet geochronology as exemplified by two case studies. Garnets from eclogite facies gneisses from Norway ran very well with 2.4-18ng loads and yielded age precision as good as 0.8 million years 2 σ. Conversely, garnets from blueschist facies rocks from Sifnos, Greece, ran

  16. Diode-pumped regenerative Yb:SrF2 amplifier

    NASA Astrophysics Data System (ADS)

    Ricaud, S.; Georges, P.; Camy, P.; Doualan, J.-L.; Moncorgé, R.; Courjaud, A.; Mottay, E.; Druon, F.

    2012-03-01

    We report what we believe to be the first Yb:SrF2 regenerative femtosecond amplifier. The regenerative amplifier produces 325-fs pulses at 100-Hz repetition rate with an energy before compression of 1.4 mJ. The interest of Yb:SrF2 in such regenerative amplifiers and its complementarity to its well-known isotype Yb:CaF2 is also discussed.

  17. Could we also be regenerative superheroes, like salamanders?

    PubMed

    Dall'Agnese, Alessandra; Puri, Pier Lorenzo

    2016-09-01

    Development of methods to reawaken the semi-dormant regenerative potential that lies within adult human tissues would hold promise for the restoration of diseased or damaged organs and tissues. While most of the regeneration potential is suppressed in many vertebrates, including humans, during adult life, urodele amphibians (salamanders) retain their regenerative ability throughout adulthood. Studies in newts and axolotls, two salamander models, have provided significant knowledge about adult limb regeneration. In this review, we present a comparative analysis of salamander and mammalian regeneration and discuss how evolutionarily altered properties of the regenerative environment can be exploited to restore full regenerative potential in the human body.

  18. Platelet rich fibrin - a novel acumen into regenerative endodontic therapy

    PubMed Central

    Sharma, Krishna

    2014-01-01

    Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF) has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy. PMID:24516822

  19. A Regeneratively-Cooled Thrust Chamber for the Fastrac Engine

    NASA Technical Reports Server (NTRS)

    Brown, Kendall; Sparks, Dave; Woodcock, Gordon; Jim Turner (Technical Monitor)

    2000-01-01

    This document consists of presentation slides about the development of the regeneratively cooled thrust chamber for the Fastrac engine. The Fastrac engine was originally developed to demonstrate low cost design and fabrication methods. It was intended to be used in an expendable booster. The regen thrust chamber enables a more cost efficient test program. Using the low cost design and fabrication methodology designed for the 12K regeneratively cooled chamber, the contractor designed, developed and fabricated a regeneratively cooled thrust chamber for the Fastrac engine.

  20. Clinical concepts for regenerative therapy in furcations.

    PubMed

    Sanz, Mariano; Jepsen, Karin; Eickholz, Peter; Jepsen, Søren

    2015-06-01

    Furcation involvements present one of the greatest challenges in periodontal therapy because furcation-involved molar teeth respond less favorably to conventional periodontal therapy compared with noninvolved molar or nonmolar teeth. Various regenerative procedures have been proposed and applied with the aim of eliminating the furcation defect or reducing the furcation depth. An abundance of studies and several systematic reviews have established the effectiveness of membrane therapy (guided tissue regeneration) for buccal Class II furcation involvement of mandibular and maxillary molars compared with open flap surgery. Bone grafts/substitutes may enhance the results of guided tissue regeneration. However, complete furcation closure is not a predictable outcome. Limited data and no meta-analyses are available on the effects of enamel matrix proteins for furcation regeneration. Enamel matrix protein therapy has demonstrated clinical improvements in the treatment of buccal Class II furcation defects in mandibular molars; however, complete closure of the furcation lesion is achieved only in a minority of cases. Neither guided tissue regeneration nor enamel matrix protein therapy have demonstrated predictable results for approximal Class II and for Class III furcations. Promising preclinical data from furcation regeneration studies in experimental animals is available for growth factor- and differentiation factor-based technologies, but very limited data are available from human clinical studies. Although cell-based therapies have received considerable attention in regenerative medicine, their experimental evaluation in the treatment of periodontal furcation lesions is at a very early stage of development. In summary, the indications and the limitations for currently available treatment modalities for furcation defects are well established. New regenerative treatments are clearly needed to improve the predictability of a complete resolution of furcation defects.

  1. Regenerative Blower for EVA Suit Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  2. Regulating the therapeutic translation of regenerative medicine.

    PubMed

    Cuchiara, Maude L; Olive, Jackie K; Matthews, Kirstin

    2015-01-01

    Regenerative medicine and stem cell research are exciting new fields. But as the fields progress toward clinical therapies, controversies emerge. Hype surrounding stem cell research has caused an increase in their use in interventions that are not clinically proven. Furthermore, the regulatory agencies have a lot of difficulty dealing with cell therapies, which are distinctly different from drugs and medical devices they more commonly approve. To move the field forward, advocates, regulators and scientists need to come together to find new options for stem cell research oversight that protects both the patients and the research field.

  3. Regenerative nanotechnology in oral and maxillofacial surgery.

    PubMed

    Shakib, Kaveh; Tan, Aaron; Soskic, Vukic; Seifalian, Alexander M

    2014-12-01

    Regenerative nanotechnology is at the forefront of medical research, and translational medicine is a challenge to both scientists and clinicians. Although there has been an exponential rise in the volume of research generated about it for both medical and surgical uses, key questions remain about its actual benefits. Nevertheless, some people think that therapeutics based on its principles may form the core of applied research for the future. Here we give an account of its current use in oral and maxillofacial surgery, and implications and challenges for the future.

  4. The essential materials paradigms for regenerative medicine

    NASA Astrophysics Data System (ADS)

    Williams, David

    2011-04-01

    Medical technology is changing rapidly. Several disease states can now be treated very effectively by implantable devices that restore mechanical and physical functionality, such as replacement of hip joints or restoration of heart rhythms by pacemakers. These techniques, however, are rather limited, and no biological functionality can be restored through the use of inert materials and devices. This paper explores the role of new types of biomaterials within the emerging area of regenerative medicine, where they are able to play a powerful role in persuading the human body to regenerate itself.

  5. Collagen: a network for regenerative medicine

    PubMed Central

    Pawelec, K. M.; Best, S. M.

    2016-01-01

    The basic building block of the extra-cellular matrix in native tissue is collagen. As a structural protein, collagen has an inherent biocompatibility making it an ideal material for regenerative medicine. Cellular response, mediated by integrins, is dictated by the structure and chemistry of the collagen fibers. Fiber formation, via fibrillogenesis, can be controlled in vitro by several factors: pH, ionic strength, and collagen structure. After formation, fibers are stabilized via cross-linking. The final bioactivity of collagen scaffolds is a result of both processes. By considering each step of fabrication, scaffolds can be tailored for the specific needs of each tissue, improving their therapeutic potential. PMID:27928505

  6. Transpiration And Regenerative Cooling Of Rocket Engine

    NASA Technical Reports Server (NTRS)

    Obrien, Charles J.

    1989-01-01

    Transpiration cooling extends limits of performance. Addition of transpiration cooling to regeneratively-cooled rocket-engine combustion chamber proposed. Modification improves performance of engine by allowing use of higher chamber pressure. Throat section of combustion-chamber wall cooled by transpiration, while chamber and nozzle sections cooled by fluid flowing in closed channels. Concept applicable to advanced, high-performance terrestrial engines or some kinds of industrial combustion chambers. With proper design, cooling scheme makes possible to achieve higher chamber pressure and higher overall performance in smaller engine.

  7. Regenerative fuel cell systems for space station

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  8. The strong financial case for regenerative medicine and the regen industry.

    PubMed

    Mason, Chris; Dunnill, Peter

    2008-05-01

    Although the therapeutic promise of regenerative medicine is immensely exciting, the cost of product development, and particularly of clinical trials, for the more demanding applications will be high. For this reason it is vital for scientists and start-ups who wish to see their ideas implemented to be able to convince established major pharmaceutical or device companies with the necessary 'deep pockets' that the expenditure can yield an appropriate return. It also means that governments and health insurance companies must see a gain in funding regenerative medicine for patients. To address this issue the costs of five major medical conditions that could benefit from regenerative medicine have been defined for the USA as an illustration. This choice of country was made as potentially the largest initial market and one where the billing system for healthcare allows access to individual direct and some indirect costs. The data are complemented by a number of relevant examples of costs per quality-adjusted life year to indicate where current treatment methods are weak or strong. Finally, the relationship of the nascent regen* industry to the pharma and medical device sectors is summarized to assess the challenge of encouraging their involvement.

  9. Scaffolds in regenerative endodontics: A review

    PubMed Central

    Gathani, Kinjal M.; Raghavendra, Srinidhi Surya

    2016-01-01

    Root canal therapy has enabled us to save numerous teeth over the years. The most desired outcome of endodontic treatment would be when diseased or nonvital pulp is replaced with healthy pulp tissue that would revitalize the teeth through regenerative endodontics. ‘A search was conducted using the Pubmed and MEDLINE databases for articles with the criteria ‘Platelet rich plasma’, ‘Platelet rich fibrin’, ‘Stem cells’, ‘Natural and artificial scaffolds’ from 1982–2015’. Tissues are organized as three-dimensional structures, and appropriate scaffolding is necessary to provide a spatially correct position of cell location and regulate differentiation, proliferation, or metabolism of the stem cells. Extracellular matrix molecules control the differentiation of stem cells, and an appropriate scaffold might selectively bind and localize cells, contain growth factors, and undergo biodegradation over time. Different scaffolds facilitate the regeneration of different tissues. To ensure a successful regenerative procedure, it is essential to have a thorough and precise knowledge about the suitable scaffold for the required tissue. This article gives a review on the different scaffolds providing an insight into the new developmental approaches on the horizon. PMID:27857762

  10. Translational science in disinfection for regenerative endodontics.

    PubMed

    Diogenes, Anibal R; Ruparel, Nikita B; Teixeira, Fabricio B; Hargreaves, Kenneth M

    2014-04-01

    The endodontic management of permanent immature teeth is fraught with challenges. Although treatment modalities for vital pulp therapy in these teeth provide long-term favorable outcome, the outcomes from the treatment of pulp necrosis and apical periodontitis are significantly less predictable. Immature teeth diagnosed with pulp necrosis have been traditionally treated with apexification or apexogenesis approaches. Unfortunately, these treatments provide little to no benefit in promoting continued root development. Regenerative endodontic procedures have emerged as an important alternative in treating teeth with otherwise questionable long-term prognosis because of thin, fragile dentinal walls and a lack of immunocompetency. These procedures rely heavily on root canal chemical disinfection of the root canal system. Traditionally, irrigants and medicaments have been chosen for their maximum antimicrobial effect without consideration for their effects on stem cells and the dentinal microenvironment. Translational research has been crucial to provide evidence for treatment modifications that aim to increase favorable outcome while steering away from common pitfalls in the currently used protocols. In this review, recent advances learned from translational research related to disinfection in regenerative endodontics are presented and discussed.

  11. Regenerative fuel cell systems R and D

    SciTech Connect

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

    1998-08-01

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

  12. Multiple excitation regenerative amplifier inertial confinement system

    DOEpatents

    George, Victor E. [Livermore, CA; Haas, Roger A. [Pleasanton, CA; Krupke, William F. [Pleasanton, CA; Schlitt, Leland G. [Livermore, CA

    1980-05-27

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation.

  13. Multiple excitation regenerative amplifier inertial confinement system

    DOEpatents

    George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

    1980-05-27

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation. 11 figs.

  14. Erich Regener - a forgotten cosmic ray pioneer

    NASA Astrophysics Data System (ADS)

    Carlson, Per; Watson, Alan

    2013-04-01

    In the 1930s the German physicist Erich Regener (1881-1955), did important work on the measurement of the rate production of ionisation in the atmosphere and deep under-water. He discovered, along with one of his students, Georg Pfotzer, the altitude at which the production of ionisation in the atmosphere reaches a maximum, often and misleadingly called the Pfotzer maximum. He was one of the first to estimate the energy density of cosmic rays, an estimate used by Baade and Zwicky to postulate that supernovae might be the source of cosmic rays. Yet Regener's name is little known largely because he was forced to take early retirement by the National Socialists in 1937 as his wife had Jewish ancestors. In this paper we review his work on cosmic rays and the subsequent influence that he had on the subject through his son, his son-in-law, his grandson and his students. He was nominated for the Nobel Prize in Physics by Schroedinger in 1938. He died in 1955 at the age of 73.

  15. Engineering growth factors for regenerative medicine applications.

    SciTech Connect

    Mitchell, Aaron C.; Briquez, Priscilla S.; Hubbell, Jeffrey A.; Cochran, Jennifer R.

    2016-01-15

    Growth factors are important morphogenetic proteins that instruct cell behavior and guide tissue repair and renewal. Although their therapeutic potential holds great promise in regenerative medicine applications, translation of growth factors into clinical treatments has been hindered by limitations including poor protein stability, low recombinant expression yield, and suboptimal efficacy. This review highlights current tools, technologies, and approaches to design integrated and effective growth factor-based therapies for regenerative medicine applications. The first section describes rational and combinatorial protein engineering approaches that have been utilized to improve growth factor stability, expression yield, biodistribution, and serum half-life, or alter their cell trafficking behavior or receptor binding affinity. The second section highlights elegant biomaterial-based systems, inspired by the natural extracellular matrix milieu, that have been developed for effective spatial and temporal delivery of growth factors to cell surface receptors. Although appearing distinct, these two approaches are highly complementary and involve principles of molecular design and engineering to be considered in parallel when developing optimal materials for clinical applications.

  16. Integrated regenerative fuel cell experimental evaluation

    NASA Technical Reports Server (NTRS)

    Martin, Ronald E.

    1990-01-01

    An experimental test program was conducted to investigate the performance characteristics of an integrated regenerative fuel cell (IRFC) concept. The IRFC consists of a separate fuel cell unit and electrolysis cell unit in the same structure, with internal storage of fuel cell product water and external storage of electrolysis cell produced hydrogen and oxygen. The fuel cell unit incorporates an enhanced Orbiter-type cell capable of improved performance at reduced weight. The electrolysis cell features a NiCo2O4 catalyst oxygen evolution eletrode with a porous Teflon cover to retard electrolyte loss. Six complete IRFC assemblies were assembled and performance tested at an operating temperature of 200 F (93.3 C) and reactant pressures up to 170 psia (117.2 n/cu cm) on IRFC No. 4. Anomalous pressure charge/discharge characteristics were encountered during performance evaluation. A reversible fuel cell incorporating a proprietary bi-functional oxygen electrode operated satisfactory at 200 F (93.3 C) at reactant pressures up to 50 psia (41.4 n/cu cm) as a regenerative fuel cell for one cycle, before developing an electrical short in the fuel cell mode. Electrolysis cell 300-hour endurance tests demonstrated the electrolyte retention capability of the electrode Teflon cover and the performance stability of the bi-functional oxygen electrode at high potential.

  17. Analysis of Regen Cooling in Rocket Combustors

    NASA Technical Reports Server (NTRS)

    Harper, Brent (Technical Monitor); Merkle, C. L.; Li, D.; Sankaran, V.

    2004-01-01

    The use of detailed CFD modeling for the description of cooling in rocket chambers is discussed. The overall analysis includes a complete three-dimensional analysis of the flow in the regenerative cooling passages, conjugate heat transfer in the combustor walls, and the effects of film cooling on the inside chamber. The results in the present paper omit the effects of film cooling and include only regen cooling and the companion conjugate heat transfer. The hot combustion gases are replaced by a constant temperature wall boundary condition. Load balancing for parallel cluster computations is ensured by using single-block unstructured grids for both fluids and solids, and by using a 'multiple physical zones' to account for differences in the number of equations. Validation of the method is achieved by comparing simple two-dimensional solutions with analytical results. Representative results for cooling passages are presents showing the effects of heat conduction in the copper walls with tube aspect ratios of 1.5:l.

  18. PRMT7 Preserves Satellite Cell Regenerative Capacity.

    PubMed

    Blanc, Roméo Sébastien; Vogel, Gillian; Chen, Taiping; Crist, Colin; Richard, Stéphane

    2016-02-16

    Regeneration of skeletal muscle requires the continued presence of quiescent muscle stem cells (satellite cells), which become activated in response to injury. Here, we report that whole-body protein arginine methyltransferase PRMT7(-/-) adult mice and mice conditionally lacking PRMT7 in satellite cells using Pax7-CreERT2 both display a significant reduction in satellite cell function, leading to defects in regenerative capacity upon muscle injury. We show that PRMT7 is preferentially expressed in activated satellite cells and, interestingly, PRMT7-deficient satellite cells undergo cell-cycle arrest and premature cellular senescence. These defects underlie poor satellite cell stem cell capacity to regenerate muscle and self-renew after injury. PRMT7-deficient satellite cells express elevated levels of the CDK inhibitor p21CIP1 and low levels of its repressor, DNMT3b. Restoration of DNMT3b in PRMT7-deficient cells rescues PRMT7-mediated senescence. Our findings define PRMT7 as a regulator of the DNMT3b/p21 axis required to maintain muscle stem cell regenerative capacity.

  19. 78 FR 43889 - Synergizing Efforts in Standards Development for Cellular Therapies and Regenerative Medicine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... Therapies and Regenerative Medicine Products; Public Workshop AGENCY: Food and Drug Administration, HHS... Development for Cellular Therapies and Regenerative Medicine Products.'' The purpose of the public workshop is... activities involving cellular therapies and regenerative medicine products. Date and Time: The...

  20. Regenerative medicine. Opportunities and challenges: a brief overview.

    PubMed

    Polak, Dame Julia

    2010-12-06

    Regenerative medicine is a new multi-disciplinary field aiming at the repair or replacement of disease body parts. The field is progressing at an unprecedented pace and although the opportunities are immense, many hurdles lie ahead. This brief review analyses the opportunities and challenges faced by regenerative medicine.

  1. Stem cells: intellectual property issues in regenerative medicine.

    PubMed

    Zachariades, Nicholas A

    2013-12-01

    The topic of stem cells for use in regenerative medicine, especially embryonic stem cells, inspires much debate, discussion, and outrage as it slices through the very core moral values of society. These social and moral issues have, in turn, resulted in government policies that have influenced the study of stem cells in regenerative medicine.

  2. Improved Round Trip Efficiency for Regenerative Fuel Cell Systems

    DTIC Science & Technology

    2011-04-04

    advanced membrane materials that enable higher efficiency electrolysis , substantially improving the practical energy density for regenerative fuel cell... electrolysis system for recharging the reactants, and reactant storage. These water- based energy storage systems have been shown to perform...catalyst materials will enable higher efficiency electrolysis , substantially improving the practical energy density for regenerative fuel cell applications

  3. State of the art: stem cells in equine regenerative medicine.

    PubMed

    Lopez, M J; Jarazo, J

    2015-03-01

    According to Greek mythology, Prometheus' liver grew back nightly after it was removed each day by an eagle as punishment for giving mankind fire. Hence, contrary to popular belief, the concept of tissue and organ regeneration is not new. In the early 20th century, cell culture and ex vivo organ preservation studies by Alexis Carrel, some with famed aviator Charles Lindbergh, established a foundation for much of modern regenerative medicine. While early beliefs and discoveries foreshadowed significant accomplishments in regenerative medicine, advances in knowledge within numerous scientific disciplines, as well as nano- and micromolecular level imaging and detection technologies, have contributed to explosive advances over the last 20 years. Virtually limitless preparations, combinations and applications of the 3 major components of regenerative medicine, namely cells, biomaterials and bioactive molecules, have created a new paradigm of future therapeutic options for most species. It is increasingly clear, however, that despite significant parallels among and within species, there is no 'one-size-fits-all' regenerative therapy. Likewise, a panacea has yet to be discovered that completely reverses the consequences of time, trauma and disease. Nonetheless, there is no question that the promise and potential of regenerative medicine have forever altered medical practices. The horse is a relative newcomer to regenerative medicine applications, yet there is already a large body of work to incorporate novel regenerative therapies into standard care. This review focuses on the current state and potential future of stem cells in equine regenerative medicine.

  4. Stem Cells Applications in Regenerative Medicine and Disease Therapeutics

    PubMed Central

    2016-01-01

    Regenerative medicine, the most recent and emerging branch of medical science, deals with functional restoration of tissues or organs for the patient suffering from severe injuries or chronic disease. The spectacular progress in the field of stem cell research has laid the foundation for cell based therapies of disease which cannot be cured by conventional medicines. The indefinite self-renewal and potential to differentiate into other types of cells represent stem cells as frontiers of regenerative medicine. The transdifferentiating potential of stem cells varies with source and according to that regenerative applications also change. Advancements in gene editing and tissue engineering technology have endorsed the ex vivo remodelling of stem cells grown into 3D organoids and tissue structures for personalized applications. This review outlines the most recent advancement in transplantation and tissue engineering technologies of ESCs, TSPSCs, MSCs, UCSCs, BMSCs, and iPSCs in regenerative medicine. Additionally, this review also discusses stem cells regenerative application in wildlife conservation. PMID:27516776

  5. Stem Cells Applications in Regenerative Medicine and Disease Therapeutics.

    PubMed

    Mahla, Ranjeet Singh

    2016-01-01

    Regenerative medicine, the most recent and emerging branch of medical science, deals with functional restoration of tissues or organs for the patient suffering from severe injuries or chronic disease. The spectacular progress in the field of stem cell research has laid the foundation for cell based therapies of disease which cannot be cured by conventional medicines. The indefinite self-renewal and potential to differentiate into other types of cells represent stem cells as frontiers of regenerative medicine. The transdifferentiating potential of stem cells varies with source and according to that regenerative applications also change. Advancements in gene editing and tissue engineering technology have endorsed the ex vivo remodelling of stem cells grown into 3D organoids and tissue structures for personalized applications. This review outlines the most recent advancement in transplantation and tissue engineering technologies of ESCs, TSPSCs, MSCs, UCSCs, BMSCs, and iPSCs in regenerative medicine. Additionally, this review also discusses stem cells regenerative application in wildlife conservation.

  6. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    PubMed

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%.

  7. Solar Airplanes and Regenerative Fuel Cells

    NASA Technical Reports Server (NTRS)

    Bents, David J.

    2007-01-01

    A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of

  8. Cathepsin K-targeted sub-micron particles for regenerative repair of vascular elastic matrix.

    PubMed

    Jennewine, Brenton; Fox, Jonathan; Ramamurthi, Anand

    2017-04-01

    Abdominal Aortic Aneurysms (AAA) involve slow dilation and weakening of the aortic wall due to breakdown of structural matrix components, such as elastic fibers by chronically overexpressed matrix metalloproteinases (MMPs), primarily, MMPs-2 and -9. Auto-regenerative repair of disrupted elastic fibers by smooth muscle cells (SMCs) at the AAA site is intrinsically poor and together with chronic proteolysis prevents restoration of elastin homeostasis, necessary to enable AAA growth arrest or regression to a healthy state. Oral doxycycline (DOX) therapy can inhibit MMPs to slow AAA growth, but has systemwide side-effects and inhibits new elastin deposition within AAA tissue, diminishing prospects for restoring elastin homeostasis preventing the arrest/regression of AAA growth. We have thus developed cationic amphiphile (DMAB)-modified submicron particles (SMPs) that uniquely exhibit pro-elastogenic and anti-proteolytic properties, separate from similar effects of the encapsulated drug. These SMPs can enable sustained, low dose DOX delivery within AAA tissue to augment elastin regenerative repair. To provide greater specificity of SMP targeting, we have conjugated the DOX-SMP surface with an antibody against cathepsin K, a lysosomal protease that is highly overexpressed within AAA tissue. We have determined conditions for efficient cathepsin K Ab conjugation onto the SMPs, improved SMP binding to aneurysmal SMCs in culture and to injured vessel walls ex vivo, conjugation did not affect DOX release from the SMPs, and improved pro-elastogenic and anti-proteolytic effects due to the SMPs likely due to their increased proximity to cells via binding. Our study results suggest that cathepsin K Ab conjugation is a useful targeting modality for our pro-regenerative SMPs. Future studies will investigate SMP retention and biodistribution following targeting to induced AAAs in rat models through intravenous or catheter-based aortal infusion and thereafter their efficacy for

  9. Liposomes in tissue engineering and regenerative medicine

    PubMed Central

    Monteiro, Nelson; Martins, Albino; Reis, Rui L.; Neves, Nuno M.

    2014-01-01

    Liposomes are vesicular structures made of lipids that are formed in aqueous solutions. Structurally, they resemble the lipid membrane of living cells. Therefore, they have been widely investigated, since the 1960s, as models to study the cell membrane, and as carriers for protection and/or delivery of bioactive agents. They have been used in different areas of research including vaccines, imaging, applications in cosmetics and tissue engineering. Tissue engineering is defined as a strategy for promoting the regeneration of tissues for the human body. This strategy may involve the coordinated application of defined cell types with structured biomaterial scaffolds to produce living structures. To create a new tissue, based on this strategy, a controlled stimulation of cultured cells is needed, through a systematic combination of bioactive agents and mechanical signals. In this review, we highlight the potential role of liposomes as a platform for the sustained and local delivery of bioactive agents for tissue engineering and regenerative medicine approaches. PMID:25401172

  10. Regenerative medicine: the emergence of an industry.

    PubMed

    Nerem, Robert M

    2010-12-06

    Over the last quarter of a century there has been an emergence of a tissue engineering industry, one that has now evolved into the broader area of regenerative medicine. There have been 'ups and downs' in this industry; however, it now appears to be on a track that may be described as 'back to the future'. The latest data indicate that for 2007 the private sector activity in the world for this industry is approaching $2.5 billion, with 167 companies/business units and more than 6000 employee full time equivalents. Although small compared with the medical device and also the pharmaceutical industries, these numbers are not insignificant. Thus, there is the indication that this industry, and the related technology, may still achieve its potential and address the needs of millions of patients worldwide, in particular those with needs that currently are unmet.

  11. Why regenerative medicine needs an extracellular matrix.

    PubMed

    Prestwich, Glenn D; Healy, Kevin E

    2015-01-01

    Regenerative medicine is now coming of age. Many attempts at cell therapy have failed to show significant efficacy, and the umbrella term 'stem cell therapy' is perceived in some quarters as hype or just expensive and unnecessary medical tourism. Here we present a short editorial in three parts. First, we examine the importance of using a semisynthetic extracellular matrix (ECM) mimetic, or sECM, to deliver and retain therapeutic cells at the site of administration. Second, we describe one approach in which biophysical and biochemical properties are tailored to each tissue type, which we call "design for optimal functionality." Third, we describe an alternative approach to sECM design and implementation, called "design for simplicity," in which a deconstructed, minimalist sECM is employed and biology is allowed to perform the customization in situ. We opine that an sECM, whether minimal or instructive, is an essential contributor to improve the outcomes of cell-based therapies.

  12. The international translational regenerative medicine center.

    PubMed

    Alexis, Mardi de Veuve; Grinnemo, Karl-Henrik; Jove, Richard

    2012-11-01

    The International Translational Regenerative Medicine Center, an organizing sponsor of the World Stem Cell Summit 2012, is a global initiative established in 2011 by founding partners Karolinska Institutet (Stockholm, Sweden) and Beckman Research Institute at City of Hope (CA, USA) with a mission to facilitate the acceleration of translational research and medicine on a global scale. Karolinska Institutet, home of the Nobel Prize in Medicine or Physiology, is one of the most prestigious medical research institutions in the world. The Beckman Research Institute/City of Hope is ranked among the leading NIH-designated comprehensive cancer research and treatment institutions in the USA, has the largest academic GMP facility and advanced drug discovery capability, and is a pioneer in diabetes research and treatment.

  13. Regenerative Medicine Strategies for Esophageal Repair

    PubMed Central

    Londono, Ricardo

    2015-01-01

    Pathologies that involve the structure and/or function of the esophagus can be life-threatening. The esophagus is a complex organ comprising nonredundant tissue that does not have the ability to regenerate. Currently available interventions for esophageal pathology have limited success and are typically associated with significant morbidity. Hence, there is currently an unmet clinical need for effective methods of esophageal repair. The present article presents a review of esophageal disease along with the anatomic and functional consequences of each pathologic process, the shortcomings associated with currently available therapies, and the latest advancements in the field of regenerative medicine with respect to strategies for esophageal repair from benchtop to bedside. PMID:25813694

  14. A regenerative approach towards mucosal fenestration closure.

    PubMed

    Gandi, Padma; Anumala, Naveen; Reddy, Amarender; Chandra, Rampalli Viswa

    2013-06-06

    Mucosal fenestration is an opening or an interstice through the oral mucosa. A lesion which occurs with greater frequency than generally realised, its occurrence is attributed to a myriad of causes. Mucogingival procedures including connective tissue grafts, free gingival grafts and lateral pedicle grafts are generally considered to be the treatment of choice in the closure of a mucosal fenestration. More often, these procedures are performed in conjunction with other procedures such as periradicular surgery and with bone grafts. However, the concomitant use of gingival grafts and bone grafts in mucosal fenestrations secondary to infections in sites exhibiting severe bone loss is highly debatable. In this article, we report two cases of mucosal fenestrations secondary to trauma and their management by regenerative periodontal surgery with the placement of guided tissue regeneration membrane and bone graft. The final outcome was a complete closure of the fenestration in both the cases.

  15. Heart Valve Replacements with Regenerative Capacity

    PubMed Central

    Dijkman, Petra E.; Fioretta, Emanuela S.; Frese, Laura; Pasqualini, Francesco S.; Hoerstrup, Simon P.

    2016-01-01

    The incidence of severe valvular dysfunctions (e.g., stenosis and insufficiency) is increasing, leading to over 300,000 valves implanted worldwide yearly. Clinically used heart valve replacements lack the capacity to grow, inherently requiring repetitive and high-risk surgical interventions during childhood. The aim of this review is to present how different tissue engineering strategies can overcome these limitations, providing innovative valve replacements that proved to be able to integrate and remodel in pre-clinical experiments and to have promising results in clinical studies. Upon description of the different types of heart valve tissue engineering (e.g., in vitro, in situ, in vivo, and the pre-seeding approach) we focus on the clinical translation of this technology. In particular, we will deepen the many technical, clinical, and regulatory aspects that need to be solved to endure the clinical adaptation and the commercialization of these promising regenerative valves. PMID:27721704

  16. [Cell transplant and regenerative stem cell therapy].

    PubMed

    Prosper, F

    2008-01-01

    The derivation of the first human embryonic stem cell lines as well as the notion of the unexpected plasticity and potential of the adult stem cells has significantly impacted the biomedical research. Many of the tissues long believe to lack any regenerative capacity has demonstrated otherwise. Patients alike physicians expectations for treatment of incurable diseases have also fuelled this field and in occasions have led to unrealistic expectations. In the next pages I review some of the tissue specific stem cells that have been used either in preclinical models or even in clinical research. Despite the effort of numerous investigators, more questions that answers remain in the field of cell therapy and only careful and independent -not biased- research will allow us to translate some of this findings into clinical application.

  17. Genetic engineering for skeletal regenerative medicine.

    PubMed

    Gersbach, Charles A; Phillips, Jennifer E; García, Andrés J

    2007-01-01

    The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

  18. Regenerative medicine: the emergence of an industry

    PubMed Central

    Nerem, Robert M.

    2010-01-01

    Over the last quarter of a century there has been an emergence of a tissue engineering industry, one that has now evolved into the broader area of regenerative medicine. There have been ‘ups and downs’ in this industry; however, it now appears to be on a track that may be described as ‘back to the future’. The latest data indicate that for 2007 the private sector activity in the world for this industry is approaching $2.5 billion, with 167 companies/business units and more than 6000 employee full time equivalents. Although small compared with the medical device and also the pharmaceutical industries, these numbers are not insignificant. Thus, there is the indication that this industry, and the related technology, may still achieve its potential and address the needs of millions of patients worldwide, in particular those with needs that currently are unmet. PMID:20843840

  19. Carbohydrate engineered cells for regenerative medicine.

    PubMed

    Du, Jian; Yarema, Kevin J

    2010-06-15

    Carbohydrates are integral components of the stem cell niche on several levels; proteoglycans are a major constituent of the extracellular matrix (ECM) surrounding a cell, glycosoaminoglycans (GAGs) help link cells to the ECM and the neighboring cells, and small but informationally-rich oligosaccharides provide a "sugar code" that identifies each cell and provides it with unique functions. This article samples roles that glycans play in development and then describes how metabolic glycoengineering - a technique where monosaccharide analogs are introduced into the metabolic pathways of a cell and are biosynthetically incorporated into the glycocalyx - is overcoming many of the long-standing barriers to manipulating carbohydrates in living cells and tissues and is becoming an intriguing new tool for tissue engineering and regenerative medicine.

  20. Carbohydrate Engineered Cells for Regenerative Medicine

    PubMed Central

    Du, Jian; Yarema, Kevin J.

    2010-01-01

    Carbohydrates are integral components of the stem cell niche on several levels; proteoglycans are a major constituent of the extracellular matrix (ECM) surrounding a cell, glycosoaminoglycans (GAGs) help link cells to the ECM and the neighboring cells, and small but informationally-rich oligosaccharides provide a “sugar code” that identifies each cell and provides it with unique functions. This article samples roles that glycans play in development and then describes how metabolic glycoengineering – a technique where monosaccharide analogs are introduced into the metabolic pathways of a cell and are biosynthetically incorporated into the glycocalyx – is overcoming many of the long-standing barriers to manipulating carbohydrates in living cells and tissues and is becoming an intriguing new tool for tissue engineering and regenerative medicine. PMID:20117158

  1. Power Management in Regenerative Life Support Systems

    NASA Technical Reports Server (NTRS)

    Crawford, Sekou; Pawlowski, Christopher; Finn, Cory; Mead, Susan C. (Technical Monitor)

    1999-01-01

    Effective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.

  2. Regenerative Blower for EVA Suit Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Paul, Heather; Izenson, Mike; Chen, Weibo

    2008-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at low pressures that simulate a PLSS environment. We obtained head/flow performance curves over a range of operating speeds, identified the maximum efficiency point for the blower, and used these results to specify the design and operating conditions for the ventilation fan. We designed a compact motor that can drive the blower under all anticipated operating requirements and operate with high efficiency during normal operation. We identified materials for the blower that will enhance safety for operation in a lunar environment. We produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSS ventilation subsystem while running at 5400 rpm and consuming only 9 W of electric power and using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power blower can meet the performance requirements for future PLSSs.

  3. Heat cascading regenerative sorption heat pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  4. Rejuvenation: an integrated approach to regenerative medicine.

    PubMed

    Kang, Y James; Zheng, Lily

    2013-12-01

    The word "rejuvenate" found in the Merriam-Webster dictionary is (1) to make young or youthful again: give new vigor to, and (2) to restore to an original or new state. Regenerative medicine is the process of creating living, functional tissues to repair or replace tissue or organ function lost due to age, disease, damage, or congenital defects. To accomplish this, approaches including transplantation, tissue engineering, cell therapy, and gene therapy are brought into action. These all use exogenously prepared materials to forcefully mend the failed organ. The adaptation of the materials in the host and their integration into the organ are all uncertain. It is a common sense that tissue injury in the younger is easily repaired and the acute injury is healed better and faster. Why does the elder have a diminished capacity of self-repairing, or why does chronic injury cause the loss of the self-repairing capacity? There must be some critical elements that are involved in the repair process, but are suppressed in the elder or under the chronic injury condition. Rejuvenation of the self-repair mechanism would be an ideal solution for functional recovery of the failed organ. To achieve this, it would involve renewal of the injury signaling, reestablishment of the communication and transportation system, recruitment of the materials for repairing, regeneration of the failed organ, and rehabilitation of the renewed organ. It thus would require a comprehensive understanding of developmental biology and a development of new approaches to activate the critical players to rejuvenate the self-repair mechanism in the elder or under chronic injury condition. Efforts focusing on rejuvenation would expect an alternative, if not a better, accomplishment in the regenerative medicine.

  5. The TMI Regenerative Solid Oxide Fuel Cell

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

    1996-01-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

  6. Materials science tools for regenerative medicine

    NASA Astrophysics Data System (ADS)

    Richardson, Wade Nicholas

    Regenerative therapies originating from recent technological advances in biology could revolutionize medicine in the coming years. In particular, the advent of human pluripotent stem cells (hPSCs), with their ability to become any cell in the adult body, has opened the door to an entirely new way of treating disease. However, currently these medical breakthroughs remain only a promise. To make them a reality, new tools must be developed to surmount the new technical hurdles that have arisen from dramatic departure from convention that this field represents. The collected work presented in this dissertation covers several projects that seek to apply the skills and knowledge of materials science to this tool synthesizing effort. The work is divided into three chapters. The first deals with our work to apply Raman spectroscopy, a tool widely used for materials characterization, to degeneration in cartilage. We have shown that Raman can effectively distinguish the matrix material of healthy and diseased tissue. The second area of work covered is the development of a new confocal image analysis for studying hPSC colonies that are chemical confined to uniform growth regions. This tool has important application in understanding the heterogeneity that may slow the development of hPSC -based treatment, as well as the use of such confinement in the eventually large-scale manufacture of hPSCs for therapeutic use. Third, the use of structural templating in tissue engineering scaffolds is detailed. We have utilized templating to tailor scaffold structures for engineering of constructs mimicking two tissues: cartilage and lung. The work described here represents several important early steps towards large goals in regenerative medicine. These tools show a great deal of potential for accelerating progress in this field that seems on the cusp of helping a great many people with otherwise incurable disease.

  7. Pharmacokinetics of ruminally dosed sodium [36Cl]chlorate in beef cattle.

    PubMed

    Oliver, C E; Craigmill, A L; Caton, J S; Anderson, R C; Smith, D J

    2007-08-01

    The recently recognized potential of sodium chlorate as a possible preharvest food safety tool for pathogen reduction in meat animals has spurred interest in the pharmacokinetics of intraruminally dosed chlorate. Six Loala cattle were assigned (one heifer and one steer per treatment) to one of three intraruminal doses of radiolabeled sodium [36Cl]chlorate (21, 42, or 63 mg/kg body weight) administered in four equal aliquots over a 24-h period. Blood and serum were collected (29 samples in 48 h). Total radioactive residues were measured and the radioactive moieties were speciated. Chlorate appeared rapidly in blood and serum after dosing. For animals administered a dose of 42 or 63 mg/kg, the half-life of absorption was estimated at 0.6-0.9 h. Serum chlorate concentrations progressively increased with aliquot administration until peaking at 6-21 parts per million at 26 h. Between aliquot administrations, serum chlorate levels typically peaked in 3.5 h or less. The half-life of chlorate elimination ranged between 6.9 and 11 h, depending on the dose. Ultimately, absorption of chlorate removes it from its desired site of action, the lower gastrointestinal tract, thereby reducing its efficacy. Further research is needed to develop a chlorate formulation that will allow passage to the lower gastrointestinal tract.

  8. A review of the regenerative endodontic treatment procedure

    PubMed Central

    Lee, Bin-Na; Moon, Jong-Wook; Chang, Hoon-Sang; Hwang, In-Nam; Oh, Won-Mann

    2015-01-01

    Traditionally, apexification has been used to treat immature permanent teeth that have lost pulp vitality. This technique promotes the formation of an apical barrier to close the open apex so that the filling materials can be confined to the root canal. Because tissue regeneration cannot be achieved with apexification, a new technique called regenerative endodontic treatment was presented recently to treat immature permanent teeth. Regenerative endodontic treatment is a treatment procedure designed to replace damaged pulp tissue with viable tissue which restores the normal function of the pulp-dentin structure. After regenerative endodontic treatment, continued root development and hard tissue deposition on the dentinal wall can occur under ideal circumstances. However, it is difficult to predict the result of regenerative endodontic treatment. Therefore, the purpose of this study was to summarize multiple factors effects on the result of regenerative endodontic treatment in order to achieve more predictable results. In this study, we investigated the features of regenerative endodontic treatment in comparison with those of other pulp treatment procedures and analyzed the factors that have an effect on regenerative endodontic treatment. PMID:26295020

  9. Sequential Determination of Free Acidity and Plutonium Concentration in the Dissolver Solution of Fast-Breeder Reactor Spent Fuels in a Single Aliquot.

    PubMed

    Dhamodharan, K; Pius, Anitha

    2016-01-01

    A simple potentiometric method for determining the free acidity without complexation in the presence of hydrolysable metal ions and sequentially determining the plutonium concentration by a direct spectrophotometric method using a single aliquot was developed. Interference from the major fission products, which are susceptible to hydrolysis at lower acidities, had been investigated in the free acidity measurement. This method is applicable for determining the free acidity over a wide range of nitric acid concentrations as well as the plutonium concentration in the irradiated fuel solution prior to solvent extraction. Since no complexing agent is introduced during the measurement of the free acidity, the purification step is eliminated during the plutonium estimation, and the resultant analytical waste is free from corrosive chemicals and any complexing agent. Hence, uranium and plutonium can be easily recovered from analytical waste by the conventional solvent extraction method. The error involved in determining the free acidity and plutonium is within ±1% and thus this method is superior to the complexation method for routine analysis of plant samples and is also amenable for remote analysis.

  10. Dedifferentiation, transdifferentiation, and reprogramming: future directions in regenerative medicine.

    PubMed

    Eguizabal, Cristina; Montserrat, Nuria; Veiga, Anna; Izpisua Belmonte, Juan Carlos

    2013-01-01

    The main goal of regenerative medicine is to replace damaged tissue. To do this it is necessary to understand in detail the whole regeneration process including differentiated cells that can be converted into progenitor cells (dedifferentiation), cells that can switch into another cell type (transdifferentiation), and somatic cells that can be induced to become pluripotent cells (reprogramming). By studying the regenerative processes in both nonmammal and mammal models, natural or artificial processes could underscore the molecular and cellular mechanisms behind these phenomena and be used to create future regenerative strategies for humans.

  11. The Quest toward limb regeneration: a regenerative engineering approach

    PubMed Central

    Laurencin, Cato T.; Nair, Lakshmi S.

    2016-01-01

    The Holy Grail to address the clinical grand challenge of human limb loss is to develop innovative strategies to regrow the amputated limb. The remarkable advances in the scientific understanding of regeneration, stem cell science, material science and engineering, physics and novel surgical approaches in the past few decades have provided a regenerative tool box to face this grand challenge and address the limitations of human wound healing. Here we discuss the convergence approach put forward by the field of Regenerative Engineering to use the regenerative tool box to design and develop novel translational strategies to limb regeneration. PMID:27047679

  12. Regenerative endodontics: barriers and strategies for clinical translation.

    PubMed

    Mao, Jeremy J; Kim, Sahng G; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y; Yang, Rujing; Zhou, Xuedong

    2012-07-01

    Regenerative endodontics has encountered substantial challenges toward clinical translation. The adoption by the American Dental Association of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for most endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation.

  13. Adaptive controller for regenerative and friction braking system

    DOEpatents

    Davis, R.I.

    1990-10-16

    A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

  14. Biomolecule delivery to engineer the cellular microenvironment for regenerative medicine.

    PubMed

    Bishop, Corey J; Kim, Jayoung; Green, Jordan J

    2014-07-01

    To realize the potential of regenerative medicine, controlling the delivery of biomolecules in the cellular microenvironment is important as these factors control cell fate. Controlled delivery for tissue engineering and regenerative medicine often requires bioengineered materials and cells capable of spatiotemporal modulation of biomolecule release and presentation. This review discusses biomolecule delivery from the outside of the cell inwards through the delivery of soluble and insoluble biomolecules as well as from the inside of the cell outwards through gene transfer. Ex vivo and in vivo therapeutic strategies are discussed, as well as combination delivery of biomolecules, scaffolds, and cells. Various applications in regenerative medicine are highlighted including bone tissue engineering and wound healing.

  15. Adaptive controller for regenerative and friction braking system

    SciTech Connect

    Davis, Roy I.

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  16. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect

    Mark J. Bergander

    2005-08-29

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and

  17. [Regenerative medicine in head and neck reconstructive surgery].

    PubMed

    Riedel, F; Goessler, U R; Stern-Straeter, J; Riedel, K; Hörmann, K

    2008-03-01

    Autologous transplantation is regarded as the gold standard in the treatment of congenital or acquired deformities. However, the availability of autologous tissue for transplantation is often limited. Regenerative medicine aims to activate individuals' own intrinsic regenerative mechanisms and embraces tissue engineering, cell/system biology, gene therapy and stem-cell biology. Most approaches in tissue engineering are based on the expansion of small autologous cell aggregates. Tissue engineering supplemented by isolated and amplified stem cells is another very promising option for producing autologous transplants and getting over the limited availability. The association of stem cell-based tissue engineering and gene therapy allows the creation of regenerative tissue in the optimal ambience of regulatory proteins. This leads to great opportunities in the transplantation of skin, bones or cartilage. This paper presents the current status and the possible benefits, but also the limitations, of regenerative medicine in reconstructive surgery of the head and neck.

  18. Science and Ethics: Bridge to the Future for Regenerative Medicine

    PubMed Central

    Patricio, Ventura-Juncá

    2011-01-01

    The objective of this article is to reflect on the relationship between regenerative medicine and ethics, using as references the Aristotelian concept of what is ethical and that of Raessler Van Potter about bioethics. To do this, I will briefly describe the advances in regenerative medicine with stem cells, the strategies for producing pluripotential cells without destroying human embryos, and the great potential of stem cells to improve life for Humanity, noting that for this to be possible, it is necessary to locate the role of regenerative medicine in the context of human values and well being. In this way, this article has a real perspective of the role that regenerative medicine can play in benefitting human beings and engendering respect for human and natural environments. PMID:24298338

  19. Iron serves as diffusion barrier in thermally regenerative galvanic cell

    NASA Technical Reports Server (NTRS)

    Crouthamel, C. E.

    1967-01-01

    Pure iron or iron-coated diaphragm provides a hydrogen diffusion electrode for a thermally regenerative galvanic cell. It allows the gas to diffuse through its interatomic spaces and resists the corrosive action of the cell environment.

  20. 3. INSIDE BATCH FURNACE BUILDING, VIEW LOOKING NORTH AT REGENERATIVE ...

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

    3. INSIDE BATCH FURNACE BUILDING, VIEW LOOKING NORTH AT REGENERATIVE BATCH FURNACES ON LEFT AND 5 TON CAPACITY CHARGING MACHINE ON RIGHT. - U.S. Steel Duquesne Works, 22-Inch Bar Mill, Along Monongahela River, Duquesne, Allegheny County, PA

  1. Advancing pig cloning technologies towards application in regenerative medicine.

    PubMed

    Nagashima, H; Matsunari, H; Nakano, K; Watanabe, M; Umeyama, K; Nagaya, M

    2012-08-01

    Regenerative medicine is expected to make a significant contribution by development of novel therapeutic treatments for intractable diseases and for improving the quality of life of patients. Many advances in regenerative medicine, including basic and translational research, have been developed and tested in experimental animals; pigs have played an important role in various aspects of this work. The value of pigs as a model species is being enhanced by the generation of specially designed animals through cloning and genetic modifications, enabling more sophisticated research to be performed and thus accelerating the clinical application of regenerative medicine. This article reviews the significant aspects of the creation and application of cloned and genetically modified pigs in regenerative medicine research and considers the possible future directions of the technology. We also discuss the importance of reproductive biology as an interface between basic science and clinical medicine.

  2. Cell sheet engineering for regenerative medicine: current challenges and strategies.

    PubMed

    Owaki, Toshiyuki; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo

    2014-07-01

    Substantial progress made in the areas of stem cell research and regenerative medicine has provided a number of innovative methods to repair or regenerate defective tissues and organs. Although previous studies regarding regenerative medicine, especially those involving induced pluripotent stem cells, have been actively promoted in the past decade, there remain some challenges that need to be addressed in order to enable clinical applications. Designed for use in clinical applications, cell sheet engineering has been developed as a unique, scaffold-free method of cell processing utilizing temperature-responsive cell culture vessels. Clinical studies using cell sheets have shown positive outcomes and will be translated into clinical practice in the near future. However, several challenges stand in the way of the industrialization of cell sheet products and the widespread acceptance of regenerative medicine based on cell sheet engineering. This review describes current strategies geared towards the realization of the regenerative medicine approach.

  3. From regenerative dentistry to regenerative medicine: progress, challenges, and potential applications of oral stem cells.

    PubMed

    Xiao, Li; Nasu, Masanori

    2014-01-01

    Adult mesenchymal stem cells (MSCs) and epithelial stem cells play essential roles in tissue repair and self-healing. Oral MSCs and epithelial stem cells can be isolated from adult human oral tissues, for example, teeth, periodontal ligament, and gingiva. Cocultivated adult oral epithelial stem cells and MSCs could represent some developmental events, such as epithelial invagination and tubular structure formation, signifying their potentials for tissue regeneration. Oral epithelial stem cells have been used in regenerative medicine over 1 decade. They are able to form a stratified cell sheet under three-dimensional culture conditions. Both experimental and clinical data indicate that the cell sheets can not only safely and effectively reconstruct the damaged cornea in humans, but also repair esophageal ulcer in animal models. Oral MSCs include dental pulp stem cells (DPSCs), stem cells from exfoliated deciduous teeth (SHED), stem cells from apical papilla (SCAP), periodontal ligament stem cells (PDLSCs), and mesenchymal stem cells from gingiva (GMSCs). They are widely applied in both regenerative dentistry and medicine. DPSCs, SHED, and SCAP are able to form dentin-pulp complex when being transplanted into immunodeficient animals. They have been experimentally used for the regeneration of dental pulp, neuron, bone muscle and blood vessels in animal models and have shown promising results. PDLSCs and GMSCs are demonstrated to be ideal cell sources for repairing the damaged tissues of periodontal, muscle, and tendon. Despite the abovementioned applications of oral stem cells, only a few human clinical trials are now underway to use them for the treatment of certain diseases. Since clinical use is the end goal, their true regenerative power and safety need to be further examined.

  4. Citrate-Based Biomaterials and Their Applications in Regenerative Engineering

    NASA Astrophysics Data System (ADS)

    Tran, Richard T.; Yang, Jian; Ameer, Guillermo A.

    2015-07-01

    Advances in biomaterials science and engineering are crucial to translating regenerative engineering, an emerging field that aims to recreate complex tissues, into clinical practice. In this regard, citrate-based biomaterials have become an important tool owing to their versatile material and biological characteristics including unique antioxidant, antimicrobial, adhesive, and fluorescent properties. This review discusses fundamental design considerations, strategies to incorporate unique functionality, and examples of how citrate-based biomaterials can be an enabling technology for regenerative engineering.

  5. Citrate-Based Biomaterials and Their Applications in Regenerative Engineering

    PubMed Central

    Tran, Richard T.; Yang, Jian; Ameer, Guillermo A.

    2015-01-01

    Advances in biomaterials science and engineering are crucial to translating regenerative engineering, an emerging field that aims to recreate complex tissues, into clinical practice. In this regard, citrate-based biomaterials have become an important tool owing to their versatile material and biological characteristics including unique antioxidant, antimicrobial, adhesive, and fluorescent properties. This review discusses fundamental design considerations, strategies to incorporate unique functionality, and examples of how citrate-based biomaterials can be an enabling technology for regenerative engineering. PMID:27004046

  6. Adipose stem cells: biology, safety, regulation, and regenerative potential.

    PubMed

    Minteer, Danielle M; Marra, Kacey G; Rubin, J Peter

    2015-04-01

    This article discusses adipose-derived stem cell (ASC) biology, describes the current knowledge in the literature for the safety and regulation of ASCs, and provides a brief overview of the regenerative potential of ASCs. It is not an exhaustive listing of all available clinical studies or every study applying ASCs in tissue engineering and regenerative medicine, but is an objective commentary of these topics.

  7. Regenerative life support system research and concepts

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Life support systems that involve recycling of atmospheres, water, food and waste are so complex that models incorporating all the interactions and relationships are vital to design, development, simulations, and ultimately to control of space qualified systems. During early modeling studies, FORTRAN and BASIC programs were used to obtain numerical comparisons of the performance of different regenerative concepts. Recently, models were made by combining existing capabilities with expert systems to establish an Intelligent Design Support Environment for simpliflying user interfaces and to address the need for the engineering aspects. Progress was also made toward modeling and evaluating the operational aspects of closed loop life support systems using Time-step and Dynamic simulations over a period of time. Example models are presented which show the status and potential of developed modeling techniques. For instance, closed loop systems involving algae systeMs for atmospheric purification and food supply augmentation, plus models employing high plants and solid waste electrolysis are described and results of initial evaluations are presented.

  8. PLURIPOTENT STEM CELL APPLICATIONS FOR REGENERATIVE MEDICINE

    PubMed Central

    Angelos, Mathew G.; Kaufman, Dan S.

    2015-01-01

    Purpose of Review In this review, we summarize the current status of clinical trials using therapeutic cells produced from human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs). We also discuss combined cell and gene therapy via correction of defined mutations in human pluripotent stem cells and provide commentary on key obstacles facing wide-scale clinical adoption of pluripotent stem cell-based therapy. Recent Findings Initial data suggest hESC/hiPSC-derived cell products used for retinal repair and spinal cord injury are safe for human use. Early stage studies for treatment of cardiac injury and diabetes are also in progress. However, there remain key concerns regarding the safety and efficacy of these cells that need to be addressed in additional well-designed clinical trials. Advances using the CRISPR/Cas9 gene-editing system offer an improved tool for more rapid and on-target gene correction of genetic diseases. Combined gene and cell therapy using human pluripotent stem cells may provide an additional curative approach for disabling or lethal genetic and degenerative diseases where there are currently limited therapeutic opportunities. Summary Human pluripotent stem cells are emerging as a promising tool to produce cells and tissues suitable for regenerative therapy for a variety of genetic and degenerative diseases. PMID:26536430

  9. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, Lloyd A.; Dane, Clifford B.

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  10. High power, high beam quality regenerative amplifier

    DOEpatents

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  11. Unitized Regenerative Fuel Cell System Development

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    2003-01-01

    Unitized Regenerative Fuel Cells (URFC) have recently been developed by several fuel cell manufacturers. These manufacturers have concentrated their efforts on the development of the cell stack technology itself, and have not up to this point devoted much effort to the design and development of the balance of plant. A fuel cell technology program at the Glenn Research Center (GRC) that has as its goal the definition and feasibility testing of the URFC system balance of plant. Besides testing the feasibility, the program also intends to minimize the system weight, volume, and parasitic power as its goal. The design concept currently being developed uses no pumps to circulate coolant or reactants, and minimizes the ancillary components to only the oxygen and hydrogen gas storage tanks, a water storage tank, a loop heat pipe to control the temperature and two pressure control devices to control the cell stack pressures during operation. The information contained in this paper describes the design and operational concepts employed in this concept. The paper also describes the NASA Glenn research program to develop this concept and test its feasibility.

  12. Introduction to stem cells and regenerative medicine.

    PubMed

    Kolios, George; Moodley, Yuben

    2013-01-01

    Stem cells are a population of undifferentiated cells characterized by the ability to extensively proliferate (self-renewal), usually arise from a single cell (clonal), and differentiate into different types of cells and tissue (potent). There are several sources of stem cells with varying potencies. Pluripotent cells are embryonic stem cells derived from the inner cell mass of the embryo and induced pluripotent cells are formed following reprogramming of somatic cells. Pluripotent cells can differentiate into tissue from all 3 germ layers (endoderm, mesoderm, and ectoderm). Multipotent stem cells may differentiate into tissue derived from a single germ layer such as mesenchymal stem cells which form adipose tissue, bone, and cartilage. Tissue-resident stem cells are oligopotent since they can form terminally differentiated cells of a specific tissue. Stem cells can be used in cellular therapy to replace damaged cells or to regenerate organs. In addition, stem cells have expanded our understanding of development as well as the pathogenesis of disease. Disease-specific cell lines can also be propagated and used in drug development. Despite the significant advances in stem cell biology, issues such as ethical controversies with embryonic stem cells, tumor formation, and rejection limit their utility. However, many of these limitations are being bypassed and this could lead to major advances in the management of disease. This review is an introduction to the world of stem cells and discusses their definition, origin, and classification, as well as applications of these cells in regenerative medicine.

  13. Mesenchymal dental stem cells in regenerative dentistry.

    PubMed

    Rodríguez-Lozano, Francisco-Javier; Insausti, Carmen-Luisa; Iniesta, Francisca; Blanquer, Miguel; Ramírez, María-del-Carmen; Meseguer, Luis; Meseguer-Henarejos, Ana-Belén; Marín, Noemí; Martínez, Salvador; Moraleda, José-María

    2012-11-01

    In the last decade, tissue engineering is a field that has been suffering an enormous expansion in the regenerative medicine and dentistry. The use of cells as mesenchymal dental stem cells of easy access for dentist and oral surgeon, immunosuppressive properties, high proliferation and capacity to differentiate into odontoblasts, cementoblasts, osteoblasts and other cells implicated in the teeth, suppose a good perspective of future in the clinical dentistry. However, is necessary advance in the known of growth factors and signalling molecules implicated in tooth development and regeneration of different structures of teeth. Furthermore, these cells need a fabulous scaffold that facility their integration, differentiation, matrix synthesis and promote multiple specific interactions between cells. In this review, we give a brief description of tooth development and anatomy, definition and classification of stem cells, with special attention of mesenchymal stem cells, commonly used in the cellular therapy for their trasdifferentiation ability, non ethical problems and acceptable results in preliminary clinical trials. In terms of tissue engineering, we provide an overview of different types of mesenchymal stem cells that have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDs), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs), and stem cells from apical papilla (SCAPs), growth factors implicated in regeneration teeth and types of scaffolds for dental tissue regeneration.

  14. How predictable are periodontal regenerative procedures?

    PubMed

    Zohar, Ron; Tenenbaum, Howard C

    2005-10-01

    Periodontal regeneration has become one of the primary objectives of periodontal therapy. The resulting scientific endeavours have elucidated modes of periodontal wound healing, the growth of periodontal cells and their association with the surrounding matrix, and growth-promoting factors. The periodontal regeneration industry is producing better and more expensive devices, but the criteria for evaluating their success have not progressed to the same extent. Although clinical measurements of attachment level and probing depths, along with radiography, are good methods of evaluating tooth survival and prognosis, they do not indicate true biological regeneration. In addition, the regeneration industry may encourage the overuse of allografts and alloplasts which may serve as an impediment to simple wound healing. This review is a critical assessment of the clinical use of various regenerative tools, specifically bone replacements and membranes. The future of the regeneration industry may depend on the merging of various technologies and biological concepts, including the possible use of biological barriers, various bone and periodontal growth inducers, and artificial matrices that will attract or carry the cells necessary for regeneration.

  15. Bioactive nanofibrous scaffolds for regenerative endodontics.

    PubMed

    Bottino, M C; Kamocki, K; Yassen, G H; Platt, J A; Vail, M M; Ehrlich, Y; Spolnik, K J; Gregory, R L

    2013-11-01

    Here we report the synthesis, materials characterization, antimicrobial capacity, and cytocompatibility of novel antibiotic-containing scaffolds. Metronidazole (MET) or Ciprofloxacin/(CIP) was mixed with a polydioxanone (PDS)polymer solution at 5 and 25 wt% and processed into fibers. PDS fibers served as a control. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), tensile testing, and high-performance liquid chromatography (HPLC) were used to assess fiber morphology, chemical structure, mechanical properties, and drug release, respectively. Antimicrobial properties were evaluated against those of Porphyromonas gingivalis/Pg and Enterococcus faecalis/Ef. Cytotoxicity was assessed in human dental pulp stem cells (hDPSCs). Statistics were performed, and significance was set at the 5% level. SEM imaging revealed a submicron fiber diameter. FTIR confirmed antibiotic incorporation. The tensile values of hydrated 25 wt% CIP scaffold were significantly lower than those of all other groups. Analysis of HPLC data confirmed gradual, sustained drug release from the scaffolds over 48 hrs. CIP-containing scaffolds significantly (p < .00001) inhibited biofilm growth of both bacteria. Conversely, MET-containing scaffolds inhibited only Pg growth. Agar diffusion confirmed the antimicrobial properties against specific bacteria for the antibiotic-containing scaffolds. Only the 25 wt% CIP-containing scaffolds were cytotoxic. Collectively, this study suggests that polymer-based antibiotic-containing electrospun scaffolds could function as a biologically safe antimicrobial drug delivery system for regenerative endodontics.

  16. Regenerative Capacity of Macrophages for Remyelination

    PubMed Central

    Rawji, Khalil S.; Mishra, Manoj K.; Yong, V. Wee

    2016-01-01

    White matter injury, consisting of loss of axons, myelin, and oligodendrocytes, is common in many neurological disorders and is believed to underlie several motor and sensory deficits. Remyelination is the process in which the insulative myelin sheath is restored to axons, thereby facilitating recovery from functional loss. Remyelination proceeds with oligodendrocyte precursor cells (OPCs) that differentiate into oligodendrocytes to synthesize the new myelin sheath after demyelination. This process is influenced by several factors, including trophic factors, inhibitory molecules in the lesion microenvironment, age of the subject, as well as the inflammatory response. Currently studied strategies that enhance remyelination consist of pharmacological approaches that directly induce OPC differentiation or using agents to neutralize the inhibitory microenvironment. Another strategy is to harness a reparative inflammatory response. This response, coordinated by central nervous system resident microglia and peripherally-derived infiltrating macrophages, has been shown to be important in the remyelination process. These innate immune cells perform important functions in remyelination, including the proteolysis and phagocytosis of inhibitory molecules present in the lesion microenvironment, the provision of trophic and metabolic factors to OPCs, in addition to iron handling capacity. Additionally, an initial pro-inflammatory phase followed by a regulatory/anti-inflammatory phase has been shown to be important for OPC proliferation and differentiation, respectively. This review will discuss the beneficial roles of macrophages/microglia in remyelination and discuss therapeutic strategies to obtain the optimal regenerative macrophage phenotype for enhanced remyelination. PMID:27243011

  17. Recent advances in acellular regenerative tissue scaffolds.

    PubMed

    Protzman, Nicole M; Brigido, Stephen A

    2015-01-01

    The management of chronic wounds is a considerable challenge for foot and ankle surgeons. The well-established tenets of adequate vascular supply, debridement with eradication of infection, and offloading must be employed in the management of all extremity wounds. Regenerative scaffolds are a viable means of reestablishing a favorable wound environment. The matrix facilitates cell migration, chemoattraction, angiogenesis, wound bed granulation, and expedited wound closure. Although studies have demonstrated success with acellular matrices, a multimodal approach should always be employed to improve healing success. Negative pressure wound therapy, compression, offloading, and antibiotics are advocated to improve outcomes. Acellular graft selection requires a multifactorial analysis, taking into consideration the specific patient and wound characteristics as well as the differences between acellular matrices. Patient age, comorbidities, activity level, and ability to comply with protocol as well as wound etiology, duration, depth, surface area, exudate, bacterial burden, location, vascular status, ischemic status, and presentation are all critical components. To effectively choose a matrix, the clinician must have a comprehensive understanding of the products available and the data validating their use. The mechanisms by which the acellular matrix accelerates wound healing and increases the likelihood of wound healing continue to be investigated. However, it is clear that these acellular biologic tissue scaffolds are incorporating into the host tissue, with resultant revascularization and cellular repopulation. Moving forward, additional investigations examining the effectiveness of acellular biologic tissue scaffolds to improve healing in complex, nondiabetic wounds are warranted.

  18. Liver-Regenerative Transplantation: Regrow and Reset

    PubMed Central

    de l’Hortet, A. Collin; Takeishi, K.; Guzman-Lepe, J.; Handa, K.; Matsubara, K.; Fukumitsu, K.; Dorko, K.; Presnell, S. C.; Yagi, H.; Soto-Gutierrez, A.

    2016-01-01

    Liver transplantation, either a partial liver from a living or deceased donor or a whole liver from a deceased donor, is the only curative therapy for severe end-stage liver disease. Only one-third of those on the liver transplant waiting list will be transplanted, and the demand for livers is projected to increase 23% in the next 20 years. Consequently, organ availability is an absolute constraint on the number of liver transplants that can be performed. Regenerative therapies aim to enhance liver tissue repair and regeneration by any means available (cell repopulation, tissue engineering, biomaterials, proteins, small molecules, and genes). Recent experimental work suggests that liver repopulation and engineered liver tissue are best suited to the task if an unlimited availability of functional induced pluripotent stem (iPS)–derived liver cells can be achieved. The derivation of iPS cells by reprogramming cell fate has opened up new lines of investigation, for instance, the generation of iPS-derived xenogeneic organs or the possibility of simply inducing the liver to reprogram its own hepatocyte function after injury. We reviewed current knowledge about liver repopulation, generation of engineered livers and reprogramming of liver function. We also discussed the numerous barriers that have to be overcome for clinical implementation. PMID:26699680

  19. New biomimetic directions in regenerative ophthalmology.

    PubMed

    Green, David W; Watson, Gregory S; Watson, Jolanta; Abraham, Samuel J K

    2012-03-01

    One of the most complete and permanent ways of treating many causes of visual impairment and blindness is to replace the entire affected tissue with pre-cultured ocular tissues supported and maintained on biomaterial frameworks. One direction towards enhancing ocular tissue regeneration on biomaterials, in the laboratory is by applying biomimicry. Specifically to engineer biomaterials with important functional elements of the native extracellular matrices, such as topography, that support and organise cells into coherent tissues. Further problems in regenerative ophthalmology can be potentially solved through application of biomimicry. They include, more efficient ways of moving and transplanting cultivated tissues into correct therapeutic locations inside the eye and scar-less, non-destructive healing of surgical incisions and wounds, to repair structural integrity of tissues at the ocular surface. Two examples are given to show this potential for redeveloping an ocular epithelium onto a nanostructured insect wing surface and producing an origami membrane modelled on deployable structures in nature. Efforts to harness natural innovation will eventually provide unique designs and structures that cannot for now be made synthetically, for regeneration of clinically acceptable ocular tissues.

  20. Cold end fouling regenerative air preheaters

    SciTech Connect

    Levy, E.; D`Agostini, M.; Sarunac, N.; Yilmaz, A.

    1996-05-01

    Condensation of sulfuric acid occurs in the cold end flow passages of a regenerative air preheater (APH) when local metal temperatures fall beneath the acid dew point of the flue gas. In coal-fired units, the acid condensate acts as an adhesive for fly ash particulate, the deposition of which gradually reduces the cross-sectional area of the passage, leading to higher gas pressure drops and increased fan power requirements. In units which are fan-limited, costly unit derates and forced outages for APH cleaning often occur. Although optimization of APH operation is a highly unit specific issue, the method of approaching the problem is fairly general and can involve combinations of theoretical analysis, field measurements and proper data regression. This paper describes case studies of the APH acid condensation and fouling characteristics at three different coal-fired utility boilers, which illustrate specific applications of the general optimization technique. The approach is also valid for units which employ ammonia injection.

  1. Regenerative medicine as applied to general surgery.

    PubMed

    Orlando, Giuseppe; Wood, Kathryn J; De Coppi, Paolo; Baptista, Pedro M; Binder, Kyle W; Bitar, Khalil N; Breuer, Christopher; Burnett, Luke; Christ, George; Farney, Alan; Figliuzzi, Marina; Holmes, James H; Koch, Kenneth; Macchiarini, Paolo; Mirmalek Sani, Sayed-Hadi; Opara, Emmanuel; Remuzzi, Andrea; Rogers, Jeffrey; Saul, Justin M; Seliktar, Dror; Shapira-Schweitzer, Keren; Smith, Tom; Solomon, Daniel; Van Dyke, Mark; Yoo, James J; Zhang, Yuanyuan; Atala, Anthony; Stratta, Robert J; Soker, Shay

    2012-05-01

    The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues, or organs to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues, and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery. The main challenges for investigators are threefold: Creation of an appropriate microenvironment ex vivo that is able to sustain cell physiology and function in order to generate the desired cells or body parts; identification and appropriate manipulation of cells that have the potential to generate parenchymal, stromal and vascular components on demand, both in vivo and ex vivo; and production of smart materials that are able to drive cell fate.

  2. REGENERATIVE MEDICINE AS APPLIED TO GENERAL SURGERY

    PubMed Central

    Orlando, Giuseppe; Wood, Kathryn J; De Coppi, Paolo; Baptista, Pedro M; Binder, Kyle W; Bitar, Khalil N; Breuer, Christopher; Burnett, Luke; Christ, George; Farney, Alan; Figliuzzi, Marina; Holmes, James H; Koch, Kenneth; Macchiarini, Paolo; Sani, Sayed-Hadi Mirmalek; Opara, Emmanuel; Remuzzi, Andrea; Rogers, Jeffrey; Saul, Justin M; Seliktar, Dror; Shapira-Schweitzer, Keren; Smith, Tom; Solomon, Daniel; Van Dyke, Mark; Yoo, James J; Zhang, Yuanyuan; Atala, Anthony; Stratta, Robert J; Soker, Shay

    2012-01-01

    The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues or organs in order to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery. The main challenges for investigators are threefold: Creation of an appropriate microenvironment ex vivo that is able to sustain cell physiology and function in order to generate the desired cells or body parts; identification and appropriate manipulation of cells that have the potential to generate parenchymal, stromal and vascular components on demand, both in vivo and ex vivo; and production of smart materials that are able to drive cell fate. PMID:22330032

  3. Manufacturing Road Map for Tissue Engineering and Regenerative Medicine Technologies

    PubMed Central

    Hunsberger, Joshua; Harrysson, Ola; Shirwaiker, Rohan; Starly, Binil; Wysk, Richard; Cohen, Paul; Allickson, Julie; Yoo, James

    2015-01-01

    Summary The Regenerative Medicine Foundation Annual Conference held on May 6 and 7, 2014, had a vision of assisting with translating tissue engineering and regenerative medicine (TERM)-based technologies closer to the clinic. This vision was achieved by assembling leaders in the field to cover critical areas. Some of these critical areas included regulatory pathways for regenerative medicine therapies, strategic partnerships, coordination of resources, developing standards for the field, government support, priorities for industry, biobanking, and new technologies. The final day of this conference featured focused sessions on manufacturing, during which expert speakers were invited from industry, government, and academia. The speakers identified and accessed roadblocks plaguing the field where improvements in advanced manufacturing offered many solutions. The manufacturing sessions included (a) product development toward commercialization in regenerative medicine, (b) process challenges to scale up manufacturing in regenerative medicine, and (c) infrastructure needs for manufacturing in regenerative medicine. Subsequent to this, industry was invited to participate in a survey to further elucidate the challenges to translation and scale-up. This perspective article will cover the lessons learned from these manufacturing sessions and early results from the survey. We also outline a road map for developing the manufacturing infrastructure, resources, standards, capabilities, education, training, and workforce development to realize the promise of TERM. PMID:25575525

  4. Manufacturing road map for tissue engineering and regenerative medicine technologies.

    PubMed

    Hunsberger, Joshua; Harrysson, Ola; Shirwaiker, Rohan; Starly, Binil; Wysk, Richard; Cohen, Paul; Allickson, Julie; Yoo, James; Atala, Anthony

    2015-02-01

    The Regenerative Medicine Foundation Annual Conference held on May 6 and 7, 2014, had a vision of assisting with translating tissue engineering and regenerative medicine (TERM)-based technologies closer to the clinic. This vision was achieved by assembling leaders in the field to cover critical areas. Some of these critical areas included regulatory pathways for regenerative medicine therapies, strategic partnerships, coordination of resources, developing standards for the field, government support, priorities for industry, biobanking, and new technologies. The final day of this conference featured focused sessions on manufacturing, during which expert speakers were invited from industry, government, and academia. The speakers identified and accessed roadblocks plaguing the field where improvements in advanced manufacturing offered many solutions. The manufacturing sessions included (a) product development toward commercialization in regenerative medicine, (b) process challenges to scale up manufacturing in regenerative medicine, and (c) infrastructure needs for manufacturing in regenerative medicine. Subsequent to this, industry was invited to participate in a survey to further elucidate the challenges to translation and scale-up. This perspective article will cover the lessons learned from these manufacturing sessions and early results from the survey. We also outline a road map for developing the manufacturing infrastructure, resources, standards, capabilities, education, training, and workforce development to realize the promise of TERM.

  5. Platelet derivatives in regenerative medicine: an update.

    PubMed

    De Pascale, Maria Rosaria; Sommese, Linda; Casamassimi, Amelia; Napoli, Claudio

    2015-01-01

    Prior preclinical and clinical studies support the use of platelet-derived products for the treatment of soft and hard tissue lesions. These regenerative effects are controlled by autocrine and paracrine biomolecules including growth factors and cytokines contained in platelet alpha granules. Each growth factor is involved in a phase of the healing process, such as inflammation, collagen synthesis, tissue granulation, and angiogenesis collectively promoting tissue restitution. Platelet derivatives have been prepared as platelet-rich plasma, platelet gel, platelet-rich fibrin, and platelet eye drops. These products vary in their structure, growth factors, composition, and cytokine concentrations. Here, we review the current use of platelet-derived biological products focusing on the rationale for their use and the main requirements for their preparation. Variation in the apparent therapeutic efficacy may have resulted from a lack of reproducible, standardized protocols for preparation. Despite several individual studies showing favorable treatment effects, some randomized controlled trials as well as meta-analyses have found no constant clinical benefit from the application of platelet-derived products for prevention of tissue lesions. Recently, 3 published studies in dentistry showed an improvement in bone density. Seven published studies showed positive results in joint regeneration. Five published studies demonstrated an improvement in the wound healing, and an improvement of eye epithelial healing was observed in 2 reports. Currently, at least 14 ongoing clinical trials in phase 3 or 4 have been designed with large groups of treated patients (n > 100). Because the rationale of the therapy with platelet-derived compounds is still debated, a definitive insight can be acquired only when these large randomized trials will be completed.

  6. Clinical cardiac regenerative studies in children

    PubMed Central

    Pavo, Imre J; Michel-Behnke, Ina

    2017-01-01

    Although the incidence of pediatric heart failure is low, the mortality is relatively high, with severe clinical symptoms requiring repeated hospitalization or intensive care treatment in the surviving patients. Cardiac biopsy specimens have revealed a higher number of resident human cardiac progenitor cells, with greater proliferation and differentiation capacity, in the neonatal period as compared with adults, demonstrating the regeneration potential of the young heart, with rising interest in cardiac regeneration therapy in critically ill pediatric patients. We review here the available literature data, searching the MEDLINE, Google Scholar and EMBASE database for completed, and www.clinicaltrials.gov homepage for ongoing studies involving pediatric cardiac regeneration reports. Because of difficulties conducting randomized blinded clinical trials in pediatric patients, mostly case reports or cohort studies with a limited number of individuals have been published in the field of pediatric regenerative cardiology. The majority of pediatric autologous cell transplantations into the cardiac tissue have been performed in critically ill children with severe or terminal heart failure. Congenital heart disease, myocarditis, and idiopathic hypertrophic or dilated cardiomyopathy leading to congestive heart failure are some possible areas of interest for pediatric cardiac regeneration therapy. Autologous bone marrow mononuclear cells, progenitor cells, or cardiospheres have been applied either intracoronary or percutaneously intramyocardially in severely ill children, leading to a reported clinical benefit of cell-based cardiac therapies. In conclusion, compassionate use of autologous stem cell administration has led to at least short-term improvement in heart function and clinical stability in the majority of the critically ill pediatric patients. PMID:28289528

  7. Clinical cardiac regenerative studies in children.

    PubMed

    Pavo, Imre J; Michel-Behnke, Ina

    2017-02-26

    Although the incidence of pediatric heart failure is low, the mortality is relatively high, with severe clinical symptoms requiring repeated hospitalization or intensive care treatment in the surviving patients. Cardiac biopsy specimens have revealed a higher number of resident human cardiac progenitor cells, with greater proliferation and differentiation capacity, in the neonatal period as compared with adults, demonstrating the regeneration potential of the young heart, with rising interest in cardiac regeneration therapy in critically ill pediatric patients. We review here the available literature data, searching the MEDLINE, Google Scholar and EMBASE database for completed, and www.clinicaltrials.gov homepage for ongoing studies involving pediatric cardiac regeneration reports. Because of difficulties conducting randomized blinded clinical trials in pediatric patients, mostly case reports or cohort studies with a limited number of individuals have been published in the field of pediatric regenerative cardiology. The majority of pediatric autologous cell transplantations into the cardiac tissue have been performed in critically ill children with severe or terminal heart failure. Congenital heart disease, myocarditis, and idiopathic hypertrophic or dilated cardiomyopathy leading to congestive heart failure are some possible areas of interest for pediatric cardiac regeneration therapy. Autologous bone marrow mononuclear cells, progenitor cells, or cardiospheres have been applied either intracoronary or percutaneously intramyocardially in severely ill children, leading to a reported clinical benefit of cell-based cardiac therapies. In conclusion, compassionate use of autologous stem cell administration has led to at least short-term improvement in heart function and clinical stability in the majority of the critically ill pediatric patients.

  8. Plastic Surgery Challenges in War Wounded II: Regenerative Medicine

    PubMed Central

    Valerio, Ian L.; Sabino, Jennifer M.; Dearth, Christopher L.

    2016-01-01

    Background: A large volume of service members have sustained complex injuries during Operations Iraqi Freedom (OIF) and Enduring Freedom (OEF). These injuries are complicated by contamination with particulate and foreign materials, have high rates of bacterial and/or fungal infections, are often composite-type defects with massive soft tissue wounds, and usually have multisystem involvement. While traditional treatment modalities remain a mainstay for optimal wound care, traditional reconstruction approaches alone may be inadequate to fully address the scope and magnitude of such massive complex wounds. As a result of these difficult clinical problems, the use of regenerative medicine therapies, such as autologous adipose tissue grafting, stem cell therapies, nerve allografts, and dermal regenerate templates/extracellular matrix scaffolds, is increased as adjuncts to traditional reconstructive measures. Basic and Clinical Science Advances: The beneficial applications of regenerative medicine therapies have been well characterized in both in vitro studies and in vivo animal studies. The use of these regenerative medicine techniques in the treatment of combat casualty injuries has been increasing throughout the recent war conflicts. Clinical Care Relevance: Military medicine has shown positive results when utilizing certain regenerative medicine modalities in treating complex war wounds. As a result, multi-institution clinical trials are underway to further evaluate these observations and reconstruction measures. Conclusion: Successful combat casualty wound care often requires a combination of traditional aspects of the reconstructive ladder/elevator with adoption of various regenerative medicine therapies. Due to the recent OIF/OEF conflicts, a high volume of combat casualties have benefited from adoption of regenerative medicine therapies and increased access to innovative clinical trials. Furthermore, many of these patients have had long-term follow-up to report

  9. Plastic Surgery Challenges in War Wounded II: Regenerative Medicine.

    PubMed

    Valerio, Ian L; Sabino, Jennifer M; Dearth, Christopher L

    2016-09-01

    Background: A large volume of service members have sustained complex injuries during Operations Iraqi Freedom (OIF) and Enduring Freedom (OEF). These injuries are complicated by contamination with particulate and foreign materials, have high rates of bacterial and/or fungal infections, are often composite-type defects with massive soft tissue wounds, and usually have multisystem involvement. While traditional treatment modalities remain a mainstay for optimal wound care, traditional reconstruction approaches alone may be inadequate to fully address the scope and magnitude of such massive complex wounds. As a result of these difficult clinical problems, the use of regenerative medicine therapies, such as autologous adipose tissue grafting, stem cell therapies, nerve allografts, and dermal regenerate templates/extracellular matrix scaffolds, is increased as adjuncts to traditional reconstructive measures. Basic and Clinical Science Advances: The beneficial applications of regenerative medicine therapies have been well characterized in both in vitro studies and in vivo animal studies. The use of these regenerative medicine techniques in the treatment of combat casualty injuries has been increasing throughout the recent war conflicts. Clinical Care Relevance: Military medicine has shown positive results when utilizing certain regenerative medicine modalities in treating complex war wounds. As a result, multi-institution clinical trials are underway to further evaluate these observations and reconstruction measures. Conclusion: Successful combat casualty wound care often requires a combination of traditional aspects of the reconstructive ladder/elevator with adoption of various regenerative medicine therapies. Due to the recent OIF/OEF conflicts, a high volume of combat casualties have benefited from adoption of regenerative medicine therapies and increased access to innovative clinical trials. Furthermore, many of these patients have had long-term follow-up to report

  10. Advanced biomatrix designs for regenerative therapy of periodontal tissues.

    PubMed

    Kim, J H; Park, C H; Perez, R A; Lee, H Y; Jang, J H; Lee, H H; Wall, I B; Shi, S; Kim, H W

    2014-12-01

    Periodontitis is an inflammatory disease that causes loss of the tooth-supporting apparatus, including periodontal ligament, cementum, and alveolar bone. A broad range of treatment options is currently available to restore the structure and function of the periodontal tissues. A regenerative approach, among others, is now considered the most promising paradigm for this purpose, harnessing the unique properties of stem cells. How to make full use of the body's innate regenerative capacity is thus a key issue. While stem cells and bioactive factors are essential components in the regenerative processes, matrices play pivotal roles in recapitulating stem cell functions and potentiating therapeutic actions of bioactive molecules. Moreover, the positions of appropriate bioactive matrices relative to the injury site may stimulate the innate regenerative stem cell populations, removing the need to deliver cells that have been manipulated outside of the body. In this topical review, we update views on advanced designs of biomatrices-including mimicking of the native extracellular matrix, providing mechanical stimulation, activating cell-driven matrices, and delivering bioactive factors in a controllable manner-which are ultimately useful for the regenerative therapy of periodontal tissues.

  11. A Novel Unitized Regenerative Proton Exchange Membrane Fuel Cell

    NASA Technical Reports Server (NTRS)

    Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

    1996-01-01

    A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel single cell unitized regenerative fuel cell and results obtained on testing it are presented.

  12. A novel unitized regenerative proton exchange membrane fuel cell

    NASA Technical Reports Server (NTRS)

    Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

    1995-01-01

    A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed in work performed at Lynntech. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel unitized regenerative fuel cell and results obtained on testing it will be presented.

  13. Regenerative Medicine: Charting a New Course in Wound Healing

    PubMed Central

    Gurtner, Geoffrey C.; Chapman, Mary Ann

    2016-01-01

    Significance: Chronic wounds are a prevalent and costly problem in the United States. Improved treatments are needed to heal these wounds and prevent serious complications such as infection and amputation. Recent Advances: In wound healing, as in other areas of medicine, technologies that have the potential to regenerate as opposed to repair tissue are gaining ground. These include customizable nanofiber matrices incorporating novel materials; a variety of autologous and allogeneic cell types at various stages of differentiation (e.g., pluripotent, terminally differentiated); peptides; proteins; small molecules; RNA inhibitors; and gene therapies. Critical Issues: Wound healing is a logical target for regenerative medicine due to the accessibility and structure of skin, the regenerative nature of healing, the lack of good limb salvage treatments, and the current use of cell therapies. However, more extensive knowledge of pathophysiologic targets is needed to inform regenerative strategies, and new technologies must demonstrate value in terms of outcomes and related health economic measures to achieve successful market access and penetration. Future Directions: Due to similarities in cell pathways and developmental mechanisms, regenerative technologies developed in one therapeutic area may be applicable to others. Approaches that proceed from human genomic or other big data sources to models are becoming increasingly common and will likely suggest novel therapeutic avenues. To fully capitalize on the advances in regenerative medicine, studies must demonstrate the value of new therapies in identified patient populations, and sponsors must work with regulatory agencies to develop appropriate dossiers supporting timely approval. PMID:27366592

  14. Erich Regener and the ionisation maximum of the atmosphere

    NASA Astrophysics Data System (ADS)

    Carlson, P.; Watson, A. A.

    2014-12-01

    In the 1930s the German physicist Erich Regener (1881-1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

  15. TOPICAL REVIEW: Cell and biomolecule delivery for regenerative medicine

    NASA Astrophysics Data System (ADS)

    Smith, Ian O.; Ma, Peter X.

    2010-02-01

    Regenerative medicine is an exciting field that aims to create regenerative alternatives to harvest tissues for transplantation. In this approach, the delivery of cells and biological molecules plays a central role. The scaffold (synthetic temporary extracellular matrix) delivers cells to the regenerative site and provides three-dimensional environments for the cells. To fulfil these functions, we design biodegradable polymer scaffolds with structural features on multiple size scales. To enhance positive cell-material interactions, we design nano-sized structural features in the scaffolds to mimic the natural extracellular matrix. We also integrate micro-sized pore networks to facilitate mass transport and neo tissue regeneration. We also design novel polymer devices and self-assembled nanospheres for biomolecule delivery to recapitulate key events in developmental and wound healing processes. Herein, we present recent work in biomedical polymer synthesis, novel processing techniques, surface engineering and biologic delivery. Examples of enhanced cellular/tissue function and regenerative outcomes of these approaches are discussed to demonstrate the excitement of the biomimetic scaffold design and biologic delivery in regenerative medicine.

  16. Regenerative Endodontics: Barriers and Strategies for Clinical Translation

    PubMed Central

    Kim, Sahng G.; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y.; Yang, Rujing; Zhou, Xuedong; Mao, Jeremy J.

    2014-01-01

    SYNOPSIS Despite a great deal of enthusiasm and effort, regenerative endodontics has encountered substantial challenges towards clinical translation. Recent adoption by the American Dental Association (ADA) of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for the majority of endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Dental pulp stem cells may appear to be a priori choice for dental pulp regeneration. However, dental pulp stem cells may not be available in a patient who is in need of pulp regeneration. Even if dental pulp stem cells are available autologously or perhaps allogeneically, one must address a multitude of scientific, regulatory and commercialization barriers, and unless these issues are resolved, transplantation of dental pulp stem cells will remain a scientific exercise, rather than a clinical reality. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. Given the functions and scale of dental pulp and dentin, regenerative endodontics is poised to become one of the early biological solutions in regenerative dental medicine. PMID:22835543

  17. The continued promise of stem cell therapy in regenerative medicine.

    PubMed

    Eve, David J

    2011-12-01

    The use of stem cells is galvanizing regenerative medicine research. An analysis of recent trends as typified by articles published between 2009 and 2010 in the journals Cell Transplantation--The Regenerative Medicine Journal and Medical Science Monitor demonstrate the increasing importance of stem cell research as being on the cutting edge of regenerative medicine research. The analysis revealed an even split between transplantation and non-transplantation studies, showing that both the applicability and general research is being pursued. New methods and tissue engineering are also highly important components of regenerative medicine as demonstrated by a number of the stem cell studies being involved with either ex vivo manipulation, or cotransplantation with other cells or biomaterials. This suggests that the best results may be achieved with adjuvant therapies. The non-transplantation studies were more focused on manipulation of transplantable agents including cells and scaffold systems, as well as the use of medicines and dietary supplements. The further elucidation of disease mechanisms was a major contribution. This analysis suggests that regenerative medicine is proceeding at a rapid pace and the next few years should be of considerable interest with the initial results of pioneering stem cell therapies being announced.

  18. Stem cells have the potential to rejuvenate regenerative medicine research.

    PubMed

    Eve, David J; Fillmore, Randolph; Borlongan, Cesar V; Sanberg, Paul R

    2010-10-01

    The increasing number of publications featuring the use of stem cells in regenerative processes supports the idea that they are revolutionizing regenerative medicine research. In an analysis of the articles published in the journal Cell Transplantation - The Regenerative Medicine Journal between 2008 and 2009, which reveals the topics and categories that are on the cutting edge of regenerative medicine research, stem cells are becoming increasingly relevant as the "runner-up" category to "neuroscience" related articles. The high volume of stem cell research casts a bright light on the hope for stem cells and their role in regenerative medicine as a number of reports deal with research using stem cells entering, or seeking approval for, clinical trials. The "methods and new technologies" and "tissue engineering" sections were almost equally as popular, and in part, reflect attempts to maximize the potential of stem cells and other treatments for the repair of damaged tissue. Transplantation studies were again more popular than non-transplantation, and the contribution of stem cell-related transplants was greater than other types of transplants. The non-transplantation articles were predominantly related to new methods for the preparation, isolation and manipulation of materials for transplant by specific culture media, gene therapy, medicines, dietary supplements, and co-culturing with other cells and further elucidation of disease mechanisms. A sizeable proportion of the transplantation articles reported on how previously new methods may have aided the ability of the cells or tissue to exert beneficial effects following transplantation.

  19. Repairing quite swimmingly: advances in regenerative medicine using zebrafish

    PubMed Central

    Goessling, Wolfram; North, Trista E.

    2014-01-01

    Regenerative medicine has the promise to alleviate morbidity and mortality caused by organ dysfunction, longstanding injury and trauma. Although regenerative approaches for a few diseases have been highly successful, some organs either do not regenerate well or have no current treatment approach to harness their intrinsic regenerative potential. In this Review, we describe the modeling of human disease and tissue repair in zebrafish, through the discovery of disease-causing genes using classical forward-genetic screens and by modulating clinically relevant phenotypes through chemical genetic screening approaches. Furthermore, we present an overview of those organ systems that regenerate well in zebrafish in contrast to mammalian tissue, as well as those organs in which the regenerative potential is conserved from fish to mammals, enabling drug discovery in preclinical disease-relevant models. We provide two examples from our own work in which the clinical translation of zebrafish findings is either imminent or has already proven successful. The promising results in multiple organs suggest that further insight into regenerative mechanisms and novel clinically relevant therapeutic approaches will emerge from zebrafish research in the future. PMID:24973747

  20. Proteins and Small Molecules for Cellular Regenerative Medicine

    PubMed Central

    Green, Eric M.

    2013-01-01

    Regenerative medicine seeks to understand tissue development and homeostasis and build on that knowledge to enhance regeneration of injured tissues. By replenishing lost functional tissues and cells, regenerative medicine could change the treatment paradigm for a broad range of degenerative and ischemic diseases. Multipotent cells hold promise as potential building blocks for regenerating lost tissues, but successful tissue regeneration will depend on comprehensive control of multipotent cells–differentiation into a target cell type, delivery to a desired tissue, and integration into a durable functional structure. At each step of this process, proteins and small molecules provide essential signals and, in some cases, may themselves act as effective therapies. Identifying these signals is thus a fundamental goal of regenerative medicine. In this review we discuss current progress using proteins and small molecules to regulate tissue regeneration, both in combination with cellular therapies and as monotherapy. PMID:23303911

  1. Immunosuppression-free transplantation reconsidered from a regenerative medicine perspective.

    PubMed

    Orlando, Giuseppe

    2012-02-01

    Recent groundbreaking progress in regenerative medicine has shown its potential to meet the two major needs of solid organ transplantation, namely the achievement of an immunosuppression-free state (IFS) and the identification of a new, potentially inexhaustible source of organs. This review illustrates how regenerative medicine technology may contribute to the achievement of IFS. There are three possible strategies: organ bioengineering, immuno-isolation and thymus bioengineering. The goal of organ bioengineering is to manufacture organs ex vivo from autologous cells. Immuno-isolation technology implements strategies aiming to prevent recognition of nonself antigens by the host immune system. Thymus organoids have been bioengineered with scaffold-seeding methods to allow deletion of T-cell clones responsible for allograft rejection. Despite the several hurdles that must be overcome, regenerative medicine technologies offer alternative strategies aimed at establishing immediate, stable and durable IFS in solid organ graft recipients.

  2. Nanotechnology and regenerative therapeutics in plastic surgery: The next frontier

    PubMed Central

    Tan, Aaron; Chawla, Reema; Natasha, G; Mahdibeiraghdar, Sara; Jeyaraj, Rebecca; Rajadas, Jayakumar; Hamblin, Michael R.; Seifalian, Alexander M.

    2015-01-01

    Summary The rapid ascent of nanotechnology and regenerative therapeutics as applied to medicine and surgery has seen an exponential rise in the scale of research generated in this field. This is evidenced not only by the sheer volume of papers dedicated to nanotechnology but also in a large number of new journals dedicated to nanotechnology and regenerative therapeutics specifically to medicine and surgery. Aspects of nanotechnology that have already brought benefits to these areas include advanced drug delivery platforms, molecular imaging and materials engineering for surgical implants. Particular areas of interest include nerve regeneration, burns and wound care, artificial skin with nanoelectronic sensors and head and neck surgery. This study presents a review of nanotechnology and regenerative therapeutics, with focus on its applications and implications in plastic surgery. PMID:26422652

  3. Regenerative nanomedicine and the treatment of degenerative retinal diseases.

    PubMed

    Zarbin, Marco A; Montemagno, Carlo; Leary, James F; Ritch, Robert

    2012-01-01

    Regenerative medicine deals with the repair or the replacement of tissues and organs using advanced materials and methodologies. Regenerative nanomedicine uses nanoparticles containing gene transcription factors and other modulating molecules that allow reprogramming of cells in vivo as well as nanomaterials to induce selective differentiation of neural progenitor cells and to create neural-mechanical interfaces. In this article, we consider some applications of nanotechnology that may be useful for the treatment of degenerative retinal diseases, for example, use of nanoparticles for drug and gene therapy, use of nanomaterials for neural interfaces and extracellular matrix construction for cell-based therapy and neural prosthetics, and the use of bionanotechnology to re-engineer proteins and cell behavior for regenerative medicine.

  4. Lightweight pressure vessels and unitized regenerative fuel cells

    SciTech Connect

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

    1996-09-06

    Energy storage systems have been designed using lightweight pressure vessels with unitized regenerative fuel cells (URFCs). The vessels provide a means of storing reactant gases required for URFCs; they use lightweight bladder liners that act as inflatable mandrels for composite overwrap and provide a permeation barrier. URFC systems have been designed for zero emission vehicles (ZEVs); they are cost competitive with primary FC powered vehicles that operate on H/air with capacitors or batteries for power peaking and regenerative braking. URFCs are capable of regenerative braking via electrolysis and power peaking using low volume/low pressure accumulated oxygen for supercharging the power stack. URFC ZEVs can be safely and rapidly (<5 min.) refueled using home electrolysis units. Reversible operation of cell membrane catalyst is feasible without significant degradation. Such systems would have a rechargeable specific energy > 400 Wh/kg.

  5. Genetically modified cells in regenerative medicine and tissue engineering.

    PubMed

    Sheyn, Dima; Mizrahi, Olga; Benjamin, Shimon; Gazit, Zulma; Pelled, Gadi; Gazit, Dan

    2010-06-15

    Regenerative medicine appears to take as its patron, the Titan Prometheus, whose liver was able to regenerate daily, as the field attempts to restore lost, damaged, or aging cells and tissues. The tremendous technological progress achieved during the last decade in gene transfer methods and imaging techniques, as well as recent increases in our knowledge of cell biology, have opened new horizons in the field of regenerative medicine. Genetically engineered cells are a tool for tissue engineering and regenerative medicine, albeit a tool whose development is fraught with difficulties. Gene-and-cell therapy offers solutions to severe problems faced by modern medicine, but several impediments obstruct the path of such treatments as they move from the laboratory toward the clinical setting. In this review we provide an overview of recent advances in the gene-and-cell therapy approach and discuss the main hurdles and bottlenecks of this approach on its path to clinical trials and prospective clinical practice.

  6. Gene delivery in tissue engineering and regenerative medicine.

    PubMed

    Fang, Y L; Chen, X G; W T, Godbey

    2015-11-01

    As a promising strategy to aid or replace tissue/organ transplantation, gene delivery has been used for regenerative medicine applications to create or restore normal function at the cell and tissue levels. Gene delivery has been successfully performed ex vivo and in vivo in these applications. Excellent proliferation capabilities and differentiation potentials render certain cells as excellent candidates for ex vivo gene delivery for regenerative medicine applications, which is why multipotent and pluripotent cells have been intensely studied in this vein. In this review, gene delivery is discussed in detail, along with its applications to tissue engineering and regenerative medicine. A definition of a stem cell is compared to a definition of a stem property, and both provide the foundation for an in-depth look at gene delivery investigations from a germ lineage angle.

  7. 25th Anniversary Article: Supramolecular Materials for Regenerative Medicine

    PubMed Central

    Boekhoven, Job

    2014-01-01

    In supramolecular materials, molecular building blocks are designed to interact with one another via non-covalent interactions in order to create function. This offers the opportunity to create structures similar to those found in living systems that combine order and dynamics through the reversibility of intermolecular bonds. For regenerative medicine there is a great need to develop materials that signal cells effectively, deliver or bind bioactive agents in vivo at controlled rates, have highly tunable mechanical properties, but at the same time, can biodegrade safely and rapidly after fulfilling their function. These requirements make supramolecular materials a great platform to develop regenerative therapies. This review illustrates the emerging science of these materials and their use in a number of applications for regenerative medicine. PMID:24496667

  8. Electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, Susan R.

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  9. Electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  10. Nanotechnology and regenerative therapeutics in plastic surgery: The next frontier.

    PubMed

    Tan, Aaron; Chawla, Reema; G, Natasha; Mahdibeiraghdar, Sara; Jeyaraj, Rebecca; Rajadas, Jayakumar; Hamblin, Michael R; Seifalian, Alexander M

    2016-01-01

    The rapid ascent of nanotechnology and regenerative therapeutics as applied to medicine and surgery has seen an exponential rise in the scale of research generated in this field. This is evidenced not only by the sheer volume of papers dedicated to nanotechnology but also in a large number of new journals dedicated to nanotechnology and regenerative therapeutics specifically to medicine and surgery. Aspects of nanotechnology that have already brought benefits to these areas include advanced drug delivery platforms, molecular imaging and materials engineering for surgical implants. Particular areas of interest include nerve regeneration, burns and wound care, artificial skin with nanoelectronic sensors and head and neck surgery. This study presents a review of nanotechnology and regenerative therapeutics, with focus on its applications and implications in plastic surgery.

  11. [Nodular regenerative hyperplasia as a complication of thiopurine treatment in a patient with inflammatory bowel disease].

    PubMed

    Cohen-Ezra, Oranit; Avni, Yona; Morgenstern, Sara; Ben-Ari, Ziv

    2012-12-01

    Immunomodulator therapy with thiopurine analogues azathioprine or 6-mercaptopurine is commonly prescribed for the treatment of organ transplantation, inflammatory bowel disease, autoimmune diseases and malignancies. Hepatotoxicity due to thiopurine analogues usually presents as an increase in serum transaminase levels. Toxicity is usually not severe, and a dose reduction is effective in most patients. Nodular regenerative hyperplasia (NRH) is a very rare but potentially severe complication of thiopurine-containing therapy. NRH is often asymptomatic, neither biochemical nor molecular markers are indicative for NRH. The suspicion rises when there are clinical symptoms of portal hypertension or increases in transaminases levels orthrombocytopenia. Liver biopsy is essential for definitive diagnosis. This is a case report of a 40-year-old male patient with Crohn's disease who developed increased serum levels of liver enzymes and thrombocytopenia following the administration of thiopurine. Although treatment with thiopurine was discontinued, he has further progressed and presented with acute variceal bleeding due to portal hypertension. The diagnosis of nodular regenerative hyperplasia was proven by a liver biopsy. In conclusion, NRH is a very rare but potentially severe complication of thiopurine-containing immunosuppressive therapy for IBD.

  12. Regenerative medicine and organ transplantation: past, present, and future.

    PubMed

    Orlando, Giuseppe; Wood, Kathryn J; Stratta, Robert J; Yoo, James J; Atala, Anthony; Soker, Shay

    2011-06-27

    This overview traces the history of regenerative medicine pertinent to organ transplantation, illustrates potential clinical applications reported to date, and highlights progress achieved in the field of complex modular organ engineering. Regenerative medicine can now produce relatively simple tissues such as skin, bladders, vessels, urethras, and upper airways, whereas engineering or generation of complex modular organs remains a major challenge. Ex vivo organ engineering may benefit from complementary investigations in the fields of developmental biology and stem cells and transplantation before its full potential can be realized.

  13. Regenerative medicine and stem cell based drug discovery.

    PubMed

    Sakurada, Kazuhiro; McDonald, Fiona M; Shimada, Fumiki

    2008-01-01

    As William Shakespeare beautifully described, increasing age often causes loss of tissue and organ function. The increase in average life expectancy in many countries is generating an aging society and an increase in age-related health problems. Regenerative medicine is expected to be a powerful actor in this drama, and stem cell technology may hold the key to the development of innovative treatments for acute and chronic degenerative conditions. This Review surveys the present situation and some future prospects for regenerative medicine and stem cell based drug discovery.

  14. Reprogramming and transdifferentiation shift the landscape of regenerative medicine.

    PubMed

    Guo, Jingjing; Wang, Hu; Hu, Xingchang

    2013-10-01

    Regenerative medicine is a new interdisciplinary field in biomedical science, which aims at the repair or replacement of the defective tissue or organ by congenital defects, age, injury, or disease. Various cell-related techniques such as stem cell-based biotherapy are a hot topic in the current press, and stem cell research can help us to expand our understanding of development as well as the pathogenesis of disease. In addition, new technology such as reprogramming or dedifferentiation and transdifferentiation open a new area for regenerative medicine. Here we review new approaches of these technologies used for cell-based therapy and discuss future directions and challenges in the field of regeneration.

  15. Regenerative endodontics and tissue engineering: what the future holds?

    PubMed

    Goodis, Harold E; Kinaia, Bassam Michael; Kinaia, Atheel M; Chogle, Sami M A

    2012-07-01

    The work performed by researchers in regenerative endodontics and tissue engineering over the last decades has been superb; however, many questions remain to be answered. The basic biologic mechanisms must be elucidated that will allow the development of dental pulp and dentin in situ. Stress must be placed on the many questions that will lead to the design of effective, safe treatment options and therapies. This article discusses those questions, the answers to which may become the future of regenerative endodontics. The future remains bright, but proper support and patience are required.

  16. A high-power compact regenerative amplifier FEL

    SciTech Connect

    Nguyen, D.C.; Sheffield, R.L.; Fortgang, C.M.; Kinross-Wright, J.M.; Ebrahim, N.A.; Goldstein, J.C.

    1997-08-01

    The Regenerative Amplifier FEL (RAFEL) is a new FEL approach aimed at achieving the highest optical power from a compact rf-linac FEL. The key idea is to feed back a small fraction (< 10%) of the optical power into a high-gain ({approximately}10{sup 5} in single pass) wiggler to enable the FEL to reach saturation in a few passes. This paper summarizes the design of a high-power compact regenerative amplifier FEL and describes the first experimental demonstration of the RAFEL concept.

  17. Ignition feedback regenerative free electron laser (FEL) amplifier

    DOEpatents

    Kim, Kwang-Je; Zholents, Alexander; Zolotorev, Max

    2001-01-01

    An ignition feedback regenerative amplifier consists of an injector, a linear accelerator with energy recovery, and a high-gain free electron laser amplifier. A fraction of the free electron laser output is coupled to the input to operate the free electron laser in the regenerative mode. A mode filter in this loop prevents run away instability. Another fraction of the output, after suitable frequency up conversion, is used to drive the photocathode. An external laser is provided to start up both the amplifier and the injector, thus igniting the system.

  18. Heat-treated (in single aliquot or batch) colostrum outperforms non-heat-treated colostrum in terms of quality and transfer of immunoglobulin G in neonatal Jersey calves.

    PubMed

    Kryzer, A A; Godden, S M; Schell, R

    2015-03-01

    The objective of this randomized clinical trial was to describe the effect on colostrum characteristics and passive transfer of IgG in neonatal calves when using the Perfect Udder colostrum management system (single-aliquot treatment; Dairy Tech Inc., Greeley, CO) compared with a negative control (fresh refrigerated or fresh frozen colostrum) and a positive control (batch heat-treated colostrum). First-milking Jersey colostrum was pooled to achieve 31 unique batches with a minimum of 22.8 L per batch. The batch was then divided into 4 with 3.8 L allocated to each treatment group: (1) heat-treated in Perfect Udder bag at 60°C for 60 min and then stored at -20°C (PU); (2) heat-treated in a batch pasteurizer (Dairy Tech Inc.) at 60°C for 60 min and then stored at -20°C in Perfect Udder bag (DTB; positive control); (3) fresh frozen colostrum stored at -20°C in Perfect Udder bag (FF; negative control); and (4) fresh refrigerated colostrum stored at 4°C in Perfect Udder bag (FR; negative control). Colostrum from all treatments was sampled for analysis of IgG concentration and bacterial culture immediately after batch assembly, after processing, and before feeding. Newborn Jersey calves were randomly assigned to be fed 3.8 L of colostrum from 1 of the 4 treatment groups. A prefeeding, 0-h blood sample was collected, calves were fed by esophageal tube within 2 h of birth, and then a 24-h postfeeding blood sample was collected. Paired serum samples from 0- and 24-h blood samples were analyzed for IgG concentration (mg/mL) using radial immunodiffusion analysis. The overall mean IgG concentration in colostrum was 77.9 g/L and was not affected by treatment. Prefeeding total plate counts (log10 cfu/mL) were significantly different for all 4 treatments and were lower for heat-treated colostrum (PU=4.23, DTB=3.63) compared with fresh colostrum (FF=5.68, FR=6.53). Total coliform counts (log10 cfu/mL) were also significantly different for all 4 treatments and were lower for

  19. DDS for anti-aging and regenerative medicine (review).

    PubMed

    Mizushima, Y; Hoshi, K

    2006-01-01

    In this paper we summarized, first the present status and history of the development of research in anti-aging and regenerative medicine in Japan, and secondly some of our research using DDS in the field of both medicine. The regenerative medicine has been developed in Japan by using the fund from the Government, particularly as the Millennium Project. While anti-aging medicine developed following the social interest on it in Japan and it was influenced by American Society (A4M). Next, we summarized our research on DDS for anti-aging and regenerative medicine. In most cases we used oily or solid nanoparticles as carriers of drug. Those particles have a property of both of targeting and slow release in the DDS technology. The two properties are important for anti-aging and regenerative medicine, since drugs have to be administered safely and for long time. We applied prostaglandin E1, granulocyte-colony stimulate factor (G-CSF), and retinoid into the systems.

  20. Regenerative Snubber For GTO-Commutated SCR Inverter

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E.; Edwards, Dean B.

    1992-01-01

    Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.

  1. A Regeneratively Cooled Thrust Chamber For The Fastrac Engine

    NASA Technical Reports Server (NTRS)

    Brown, Kendall K.; Sparks, Dave; Woodcock, Gordon

    2000-01-01

    Abstract This paper presents the development of a low-cost, regeneratively-cooled thrust chamber for the Fastrac engine. The chamber was fabricated using hydraformed copper tubing to form the coolant jacket and wrapped with a fiber reinforced polymer composite Material to form a structural jacket. The thrust chamber design and fabrication approach was based upon Space America. Inc.'s 12,000 lb regeneratively-cooled LOX/kerosene rocket engine. Fabrication of regeneratively cooled thrust chambers by tubewall construction dates back to the early US ballistic missile programs. The most significant innovations in this design was the development of a low-cost process for fabrication from copper tubing (nickel alloy was the usual practice) and use of graphite composite overwrap as the pressure containment, which yields an easily fabricated, lightweight pressure jacket around the copper tubes A regeneratively-cooled reusable thrust chamber can benefit the Fastrac engine program by allowing more efficient (cost and scheduler testing). A proof-of-concept test article has been fabricated and will he tested at Marshall Space Flight Center in the late Summer or Fall of 2000.

  2. Alkaline regenerative fuel cell systems for energy storage

    SciTech Connect

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

    1981-01-01

    This paper presents the results of a preliminary design study of a Regenerative Fuel Cell Energy Storage system for application to future low-earth orbit space missions. This high energy density storage system is based on state-of-the-art alkaline electrolyte cell technology and incorporates dedicated fuel cell and electrolysis cell modules. 11 refs.

  3. Stem cell bioprinting for applications in regenerative medicine.

    PubMed

    Tricomi, Brad J; Dias, Andrew D; Corr, David T

    2016-11-01

    Many regenerative medicine applications seek to harness the biologic power of stem cells in architecturally complex scaffolds or microenvironments. Traditional tissue engineering methods cannot create such intricate structures, nor can they precisely control cellular position or spatial distribution. These limitations have spurred advances in the field of bioprinting, aimed to satisfy these structural and compositional demands. Bioprinting can be defined as the programmed deposition of cells or other biologics, often with accompanying biomaterials. In this concise review, we focus on recent advances in stem cell bioprinting, including performance, utility, and applications in regenerative medicine. More specifically, this review explores the capability of bioprinting to direct stem cell fate, engineer tissue(s), and create functional vascular networks. Furthermore, the unique challenges and concerns related to bioprinting living stem cells, such as viability and maintaining multi- or pluripotency, are discussed. The regenerative capacity of stem cells, when combined with the structural/compositional control afforded by bioprinting, provides a unique and powerful tool to address the complex demands of tissue engineering and regenerative medicine applications.

  4. Status of the Regenerative ECLS Water Recovery System

    NASA Technical Reports Server (NTRS)

    Carter, Donald Layne

    2010-01-01

    The regenerative Water Recovery System (WRS) has completed its first full year of operation on the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of May 2010, and describes the technical challenges encountered and lessons learned over the past year.

  5. Crewmember repairing the Regenerative Carbon Dioxide Removal System wiring.

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Mission Pilot Ken Bowersox, busy at work on the wiring harness for the Regenerative Carbon Dioxide Removal System located under the mid deck floor. Photo shows Bowersox splicing wires together to 'fool' a faulty sensor that caused the 'air conditioner' to shut down.

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

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. F.

    1990-01-01

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

  7. Planarians: an In Vivo Model for Regenerative Medicine.

    PubMed

    Karami, Ali; Tebyanian, Hamid; Goodarzi, Vahabodin; Shiri, Sajad

    2015-11-01

    The emergence of regenerative medicine has raised the hope of treating an extraordinary range of disease and serious injuries. Understanding the processes of cell proliferation, differentiation and pattern formation in regenerative organisms could help find ways to enhance the poor regenerative abilities shown by many other animals, including humans. Recently, planarians have emerged as an attractive model in which to study regeneration. These animals are considering as in vivo plate, during which we can study the behavior and characristics of stem cells in their own niche. A variety of characteristic such as: simplicity, easy to manipulate experimentally, the existence of more than 100 years of literature, makes these animals an extraordinary model for regenerative medicine researches. Among planarians free-living freshwater hermaphrodite Schmidtea mediterranea has emerged as a suitable model system because it displays robust regenerative properties and, unlike most other planarians, it is a stable diploid with a genome size of about 4.8×10(8) base pairs, nearly half that of other common planarians. Planarian regeneration involves two highly flexible systems: pluripotent neoblasts that can generate any new cell type and muscle cells that provide positional instructions for the regeneration of anybody region. neoblasts represent roughly 25~30 percent of all planarian cells and are scattered broadly through the parenchyma, being absent only from the animal head tips and the pharynx. Two models for neo-blast specification have been proposed; the naive model posits that all neoblasts are stem cells with the same potential and are a largely homogeneous population.

  8. Trends in biomedical engineering: focus on Regenerative Medicine.

    PubMed

    Asnaghi, M Adelaide; Candiani, Gabriele; Farè, Silvia; Fiore, Gianfranco B; Petrini, Paola; Raimondi, Manuela T; Soncini, Monica; Mantero, Sara

    2011-01-01

    Regenerative medicine is a critical frontier in biomedical and clinical research. The major progresses in the last few years were driven by a strong clinical need which could benefit from regenerative medicine outcomes for the treatment of a large number of conditions including birth defects, degenerative and neoplastic diseases, and traumatic injuries. Regenerative medicine applies the principles of engineering and life sciences to enhance the comprehension of the fundamental biological mechanisms underlying the structure-function relationships in physiologic and pathologic tissues and to accomplish alternative strategies for developing in vitro biological substitutes which are able to restore, maintain, or improve tissue, and organ function. This paper reviews selected approaches currently being investigated at Politecnico di Milano in the field of regenerative medicine. Specific tissue-oriented topics are divided in three sections according to each developmental stage: in vitro study, pre-clinical study, and clinical application. In vitro studies investigate the basic phenomena related to gene delivery, stem cell behavior, tissue regeneration, and to explore dynamic culture potentiality in different applications: cardiac and skeletal muscle, cartilage, hematopoietic system, peripheral nerve, and gene delivery. Specific fields of regenerative medicine, i.e., bone, blood vessels, and ligaments engineering have already reached the preclinical stage providing promising insights for further research towards clinical applications. The translation of the results obtained during in vitro and preclinical steps into clinical organ replacement is a very challenging issue, which can offer a valid alternative to fight morbidity, organ shortage, and ethical-social problems associated with allotransplantation as shown in the clinical case reported in this review.

  9. Mesenchymal stem cell secretome and regenerative therapy after cancer.

    PubMed

    Zimmerlin, Ludovic; Park, Tea Soon; Zambidis, Elias T; Donnenberg, Vera S; Donnenberg, Albert D

    2013-12-01

    Cancer treatment generally relies on tumor ablative techniques that can lead to major functional or disfiguring defects. These post-therapy impairments require the development of safe regenerative therapy strategies during cancer remission. Many current tissue repair approaches exploit paracrine (immunomodulatory, pro-angiogenic, anti-apoptotic and pro-survival effects) or restoring (functional or structural tissue repair) properties of mesenchymal stem/stromal cells (MSC). Yet, a major concern in the application of regenerative therapies during cancer remission remains the possible triggering of cancer recurrence. Tumor relapse implies the persistence of rare subsets of tumor-initiating cancer cells which can escape anti-cancer therapies and lie dormant in specific niches awaiting reactivation via unknown stimuli. Many of the components required for successful regenerative therapy (revascularization, immunosuppression, cellular homing, tissue growth promotion) are also critical for tumor progression and metastasis. While bi-directional crosstalk between tumorigenic cells (especially aggressive cancer cell lines) and MSC (including tumor stroma-resident populations) has been demonstrated in a variety of cancers, the effects of local or systemic MSC delivery for regenerative purposes on persisting cancer cells during remission remain controversial. Both pro- and anti-tumorigenic effects of MSC have been reported in the literature. Our own data using breast cancer clinical isolates have suggested that dormant-like tumor-initiating cells do not respond to MSC signals, unlike actively dividing cancer cells which benefited from the presence of supportive MSC. The secretome of MSC isolated from various tissues may partially diverge, but it includes a core of cytokines (i.e. CCL2, CCL5, IL-6, TGFβ, VEGF), which have been implicated in tumor growth and/or metastasis. This article reviews published models for studying interactions between MSC and cancer cells with a focus

  10. Genome-wide expression profile of the response to spinal cord injury in Xenopus laevis reveals extensive differences between regenerative and non-regenerative stages

    PubMed Central

    2014-01-01

    Background Xenopus laevis has regenerative and non-regenerative stages. As a tadpole, it is fully capable of functional recovery after a spinal cord injury, while its juvenile form (froglet) loses this capability during metamorphosis. We envision that comparative studies between regenerative and non-regenerative stages in Xenopus could aid in understanding why spinal cord regeneration fails in human beings. Results To identify the mechanisms that allow the tadpole to regenerate and inhibit regeneration in the froglet, we obtained a transcriptome-wide profile of the response to spinal cord injury in Xenopus regenerative and non-regenerative stages. We found extensive transcriptome changes in regenerative tadpoles at 1 day after injury, while this was only observed by 6 days after injury in non-regenerative froglets. In addition, when comparing both stages, we found that they deployed a very different repertoire of transcripts, with more than 80% of them regulated in only one stage, including previously unannotated transcripts. This was supported by gene ontology enrichment analysis and validated by RT-qPCR, which showed that transcripts involved in metabolism, response to stress, cell cycle, development, immune response and inflammation, neurogenesis, and axonal regeneration were regulated differentially between regenerative and non-regenerative stages. Conclusions We identified differences in the timing of the transcriptional response and in the inventory of regulated transcripts and biological processes activated in response to spinal cord injury when comparing regenerative and non-regenerative stages. These genes and biological processes provide an entry point to understand why regeneration fails in mammals. Furthermore, our results introduce Xenopus laevis as a genetic model organism to study spinal cord regeneration. PMID:24885550

  11. Insurance systems and reimbursement concerning research and development of regenerative medicine in Japan.

    PubMed

    Okada, Kiyoshi; Miyata, Toshio; Sawa, Yoshiki

    2017-03-01

    In Japan, the Act on the Safety of Regenerative Medicine and the Pharmaceuticals, Medical Devices and Other Therapeutic Products Act were enacted in November 2014, creating a new framework for clinical research and products related to regenerative medicine. Together with these regulatory frameworks, new insurance procedures were created for handling regenerative medicine in Japan. For developing regenerative medicine in Japan, understanding medical insurance greatly influences funding and venture success, particularly in the stages between clinical research and market launch. The study aimed to identify the issues and examples surrounding Japan's present medical insurance system, especially for regenerative medicine. We believe that building stronger insurance systems for regenerative medicine is essential for internationally aligning and harmonizing the progress of regenerative medicine.

  12. Nanotechnologies and regenerative medical approaches for space and terrestrial medicine.

    PubMed

    Grattoni, Alessandro; Tasciotti, Ennio; Fine, Daniel; Fernandez-Moure, Joseph S; Sakamoto, Jason; Hu, Ye; Weiner, Bradley; Ferrari, Mauro; Parazynski, Scott

    2012-11-01

    One purpose of the International Space Station (ISS) is to explore powerful new areas of biomedical science in microgravity. Recent advances in nanotechnology applied to medicine--what we now refer to as nano-medicine--and regenerative medicine have enormous untapped potential for future space and terrestrial medical applications. Novel means for drug delivery and nanoscale screening tools will one day benefit astronauts venturing to Mars and places beyond, while the space laboratory will foster advances in nanotechnologies for diagnostic and therapeutic tools to help our patients here on Earth. Herein we review a series of nanotechnologies and selected regenerative medical approaches and highlight key areas of ongoing and future investigation that will benefit both space and terrestrial medicine. These studies target significant areas of human disease such as osteoporosis, diabetes, radiation injury, and many others.

  13. Investigation of electroforming techniques. [fabrication of regeneratively cooled thrust chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.

    1975-01-01

    Copper and nickel electroforming was examined for the purpose of establishing the necessary processes and procedures for repeatable, successful fabrication of the outer structures of regeneratively cooled thrust chambers. The selection of electrolytes for copper and nickel deposition is described. The development studies performed to refine and complete the processes necessary for successful chamber shell fabrication and the testing employed to verify the applicability of the processes and procedures to small scale hardware are described. Specifications were developed to afford a guideline for the electroforming of high quality outer shells on regeneratively cooled thrust chamber liners. Test results indicated repeatable mechanical properties could be produced in copper deposits from the copper sulfate electrolyte with periodic current reversal and in nickel deposits from the sulfamate solution. Use of inert, removable channel fillers and the conductivizing of such is described. Techniques (verified by test) which produce high integrity bonds to copper and copper alloy liners are discussed.

  14. High-precision buffer circuit for suppression of regenerative oscillation

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Hare, David A.; Tcheng, Ping

    1995-01-01

    Precision analog signal conditioning electronics have been developed for wind tunnel model attitude inertial sensors. This application requires low-noise, stable, microvolt-level DC performance and a high-precision buffered output. Capacitive loading of the operational amplifier output stages due to the wind tunnel analog signal distribution facilities caused regenerative oscillation and consequent rectification bias errors. Oscillation suppression techniques commonly used in audio applications were inadequate to maintain the performance requirements for the measurement of attitude for wind tunnel models. Feedback control theory is applied to develop a suppression technique based on a known compensation (snubber) circuit, which provides superior oscillation suppression with high output isolation and preserves the low-noise low-offset performance of the signal conditioning electronics. A practical design technique is developed to select the parameters for the compensation circuit to suppress regenerative oscillation occurring when typical shielded cable loads are driven.

  15. Trends in the stem cell and regenerative medicine industry.

    PubMed

    Ilic, Dusko

    2012-09-01

    The World Stem Cell Regenerative Medicine Congress series, now in its 7th year, is organized annually in the USA, Europe and Asia by Terrapinn, a business media company with its head office in London, and has grown over the last several years into the largest and probably the most important strategic stem cell conference where regulators, investors, big pharma, and small and medium enterprises gather to share and create synergy in developing and commercializing stem cell applications. The conference, held in London on 21-23 May 2012, only confirmed that this series is the meeting to attend if you want to get a clear understanding of trends in the stem cell and regenerative medicine industry.

  16. The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine

    PubMed Central

    Butler, David L.; Goldstein, Steven A.; Guo, X. Edward; Kamm, Roger; Laurencin, Cato T.; McIntire, Larry V.; Mow, Van C.; Nerem, Robert M.; Sah, Robert L.; Soslowsky, Louis J.; Spilker, Robert L.; Tranquillo, Robert T.

    2009-01-01

    Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges. PMID:19583462

  17. The theory of an active magnetic regenerative refrigerator

    NASA Technical Reports Server (NTRS)

    Barclay, J. A.

    1983-01-01

    The adiabatic temperature change with field which is limited to about 2 K/Tesla for ferromagnets near their Curie temperatures by the change of magnetization with temperature and the lattice heat capacity is discussed. Practical magnetic refrigerators operate on a regenerative cycle such as the Brayton cycle. This cycle can be executed through the use of an active magnetic regenerator, i.e., a regenerator composed of magnetic material that is cycled in an out of a magnetic field with appropriate fluid flows. The theory of these devices is predicted by solving the partial differential equations that describe fluid and the magnetic solid. The active magnetic regenerator is described along with the method of calculation. Temperature profiles for a normal regenerator and a magnetic regenerative refrigerator are shown.

  18. Regenerative Environmental Control and Life Support System Diagram

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This diagram shows the flow of recyclable resources in the International Space Station (ISS). The Environmental Control and Life Support System (ECLSS) Group of the Flight Projects Directorate at the Marshall Space Flight Center is responsible for the regenerative ECLSS hardware, as well as providing technical support for the rest of the system. The regenerative ECLSS, whose main components are the Water Recovery System (WRS), and the Oxygen Generation System (OGS), reclaims and recycles water and oxygen. The ECLSS maintains a pressurized habitation environment, provides water recovery and storage, maintains and provides fire detection / suppression, and provides breathable air and a comfortable atmosphere in which to live and work within the ISS. The ECLSS hardware will be located in the Node 3 module of the ISS.

  19. Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; Schunk, Richard G.

    2011-01-01

    An active thermal control system architecture has been modified to include a regenerative heat exchanger (regenerator) inboard of the radiator. Rather than using a radiator bypass valve a regenerative heat exchanger is placed inboard of the radiators. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold radiator return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest heat load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the radiator inlet temperature well below the system set-point while maintaining full flow through the radiators. By using a regenerator bypass flow control to maintain system setpoint, the required minimum heat load to avoid radiator freezing can be reduced by more than half compared to a radiator bypass system.

  20. Modelling the regenerative niche: a major challenge in biomaterials research†

    PubMed Central

    Kirkpatrick, C. James

    2015-01-01

    By definition, biomaterials are developed for clinical application. In the field of regenerative medicine their principal function is to play a significant, and, if possible, an instructive role in tissue healing. In the last analysis the latter involves targeting the ‘regenerative niche’. The present paper will address the problem of simulating this niche in the laboratory and adopts a life science approach involving the harnessing of heterotypic cellular communication to achieve this, that is, the ability of cells of different types to mutually influence cellular functions. Thus, co-culture systems using human cells are the methodological focus and will concern four exemplary fields of regeneration, namely, bone, soft tissue, lower respiratory tract and airway regeneration. The working hypothesis underlying this approach is that in vitro models of higher complexity will be more clinically relevant than simple monolayer cultures of transformed cell lines in testing innovative strategies with biomaterials for regeneration. PMID:26816650

  1. Regenerative medicine using dental pulp stem cells for liver diseases

    PubMed Central

    Ohkoshi, Shogo; Hara, Hajime; Hirono, Haruka; Watanabe, Kazuhiko; Hasegawa, Katsuhiko

    2017-01-01

    Acute liver failure is a refractory disease and its prognosis, if not treated using liver transplantation, is extremely poor. It is a good candidate for regenerative medicine, where stem cell-based therapies play a central role. Mesenchymal stem cells (MSCs) are known to differentiate into multiple cell lineages including hepatocytes. Autologous cell transplant without any foreign gene induction is feasible using MSCs, thereby avoiding possible risks of tumorigenesis and immune rejection. Dental pulp also contains an MSC population that differentiates into hepatocytes. A point worthy of special mention is that dental pulp can be obtained from deciduous teeth during childhood and can be subsequently harvested when necessary after deposition in a tooth bank. MSCs have not only a regenerative capacity but also act in an anti-inflammatory manner via paracrine mechanisms. Promising efficacies and difficulties with the use of MSC derived from teeth are summarized in this review. PMID:28217369

  2. Cell sheet approach for tissue engineering and regenerative medicine.

    PubMed

    Matsuura, Katsuhisa; Utoh, Rie; Nagase, Kenichi; Okano, Teruo

    2014-09-28

    After the biotech medicine era, regenerative medicine is expected to be an advanced medicine that is capable of curing patients with difficult-to-treat diseases and physically impaired function. Our original scaffold-free cell sheet-based tissue engineering technology enables transplanted cells to be engrafted for a long time, while fully maintaining their viability. This technology has already been applied to various diseases in the clinical setting, including the cornea, esophagus, heart, periodontal ligament, and cartilage using autologous cells. Transplanted cell sheets not only replace the injured tissue and compensate for impaired function, but also deliver growth factors and cytokines in a spatiotemporal manner over a prolonged period, which leads to promotion of tissue repair. Moreover, the integration of stem cell biology and cell sheet technology with sufficient vascularization opens possibilities for fabrication of human three-dimensional vascularized dense and intact tissue grafts for regenerative medicine to parenchymal organs.

  3. Regenerative Fuel Cell Test Rig at Glenn Research Center

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    The regenerative fuel cell development effort at Glenn Research Center (GRC) involves the integration of a dedicated fuel cell and electrolyzer into an energy storage system test rig. The test rig consists of a fuel cell stack, an electrolysis stack, cooling pumps, a water transfer pump, gas recirculation pumps, phase separators, storage tanks for oxygen (O2) and hydrogen (H2), heat exchangers, isolation valves, pressure regulators, interconnecting tubing, nitrogen purge provisions, and instrumentation for control and monitoring purposes. The regenerative fuel cell (RFC) thus formed is a completely closed system which is capable of autonomous cyclic operation. The test rig provides direct current (DC) load and DC power supply to simulate power consumption and solar power input. In addition, chillers are used as the heat sink to dissipate the waste heat from the electrochemical stack operation. Various vents and nitrogen (N2) sources are included in case inert purging is necessary to safe the RFC test rig.

  4. Differentiation of pluripotent stem cells for regenerative medicine.

    PubMed

    Li, Ke; Kong, Yan; Zhang, Mingliang; Xie, Fei; Liu, Peng; Xu, Shaohua

    2016-02-26

    A long-standing goal in regenerative medicine is to obtain scalable functional cells on demand to replenish cells lost in various conditions, including relevant diseases, injuries, and aging. As an unlimited cell source, pluripotent stem cells (PSCs) are invaluable for regenerative medicine, because they have the potential to give rise to any cell type in an organism. For therapeutic purposes, it is important to develop specific approach to directing PSC differentiation towards desired cell types efficiently. Through directed differentiation, PSCs could give rise to scalable, clinically relevant cells for in vivo transplantation, as well as for studying diseases in vitro and discovering drugs to treat them. Over the past few years, significant progress has been made in directing differentiation of PSCs into a variety of cell types. In this review, we discuss recent progress in directed differentiation of PSCs, clinical translation of PSC-based cell replacement therapies, and remaining challenges.

  5. Stem cells: a promising source for vascular regenerative medicine.

    PubMed

    Rammal, Hassan; Harmouch, Chaza; Lataillade, Jean-Jacques; Laurent-Maquin, Dominique; Labrude, Pierre; Menu, Patrick; Kerdjoudj, Halima

    2014-12-15

    The rising and diversity of many human vascular diseases pose urgent needs for the development of novel therapeutics. Stem cell therapy represents a challenge in the medicine of the twenty-first century, an area where tissue engineering and regenerative medicine gather to provide promising treatments for a wide variety of diseases. Indeed, with their extensive regeneration potential and functional multilineage differentiation capacity, stem cells are now highlighted as promising cell sources for regenerative medicine. Their multilineage differentiation involves environmental factors such as biochemical, extracellular matrix coating, oxygen tension, and mechanical forces. In this review, we will focus on human stem cell sources and their applications in vascular regeneration. We will also discuss the different strategies used for their differentiation into both mature and functional smooth muscle and endothelial cells.

  6. Derivation and application of pluripotent stem cells for regenerative medicine.

    PubMed

    Wang, Jiaqiang; Zhou, Qi

    2016-06-01

    Pluripotent stem cells (PSCs) are cells that can differentiate into any type of cells in the body, therefore have valuable promise in regenerative medicine of cell replacement therapies and tissue/organ engineering. PSCs can be derived either from early embryos or directly from somatic cells by epigenetic reprogramming that result in customized cells from patients. Here we summarize the methods of deriving PSCs, the various types of PSCs generated with different status, and their versatile applications in both clinical and embryonic development studies. We also discuss an intriguing potential application of PSCs in constructing tissues/organs in large animals by interspecies chimerism. All these emerging findings are likely to contribute to the breakthroughs in biological research and the prosperous prospects of regenerative medicine.

  7. Regenerative thermal oxidation and alternative technologies for VOC control

    SciTech Connect

    Biedell, E.L.

    1995-12-31

    Thermal oxidation technologies have been used successfully to control VOC`s for many years but the recent 1990 Clean Air Act Amendments have spurred improvements in the established processes and development of economic alternatives. The combination of the regulatory maze and confusion in the selection of the best technology for a particular application has created a potential nightmare for those companies facing a need to reduce their VOC EMISSIONS. The relative advantages and disadvantages of regenerative, recuperative and catalytic oxidizers will be reviewed, with an emphasis on the economic justification for regenerative thermal oxidation (RTO). Control efficiencies of more than 99% have been demonstrated for RTO`s on a multitude of industrial process exhaust streams. Lowest evaluated cost over a fifteen to twenty year effective equipment life is a key selection criteria. This paper describes the underlying principles of thermal oxidation, and discusses the applicability of these and other emerging technologies for VOC control.

  8. Antarctic analogs as a testbed for regenerative life support technologies

    NASA Technical Reports Server (NTRS)

    Roberts, D. R.; Andersen, D. T.; Mckay, C. P.; Wharton, R. A., Jr.; Rummel, J. D.

    1991-01-01

    The feasibility of using Antarctica as a platform for creating earth-based simulations of regenerative life support systems (LSSs) for future space missions is discussed. The requirements for a bioregenerative LSS and the types of technologies that may be used in such a system are examined. Special attention is given to the objectives and the organization of the NASA's CELSS program for the development of regenerative LSSs to support long-duration human missions in space, largely independent of resupply, in a safe and reliable manner. There are two types of locations on the continent of Antarctica suitable for the placement of simulation facilities: the polar plateau and the ice-free dry valleys. The unique attributes that lend each type of location to very different functions as simulation facilities are discussed.

  9. Regenerative medicine for the kidney: stem cell prospects & challenges

    PubMed Central

    2013-01-01

    The kidney has key roles in maintaining human health. There is an escalating medical crisis in nephrology as growing numbers of patients suffer from kidney diseases that culminate in organ failure. While dialysis and transplantation provide life-saving treatments, these therapies are rife with limitations and place significant burdens on patients and healthcare systems. It has become imperative to find alternative ways to treat existing kidney conditions and preemptive means to stave off renal dysfunction. The creation of innovative medical approaches that utilize stem cells has received growing research attention. In this review, we discuss the regenerative and maladaptive cellular responses that occur during acute and chronic kidney disease, the emerging evidence about renal stem cells, and some of the issues that lie ahead in bridging the gap between basic stem cell biology and regenerative medicine for the kidney. PMID:23688352

  10. On the Genealogy of Tissue Engineering and Regenerative Medicine

    PubMed Central

    2015-01-01

    In this article, we identify and discuss a timeline of historical events and scientific breakthroughs that shaped the principles of tissue engineering and regenerative medicine (TERM). We explore the origins of TERM concepts in myths, their application in the ancient era, their resurgence during Enlightenment, and, finally, their systematic codification into an emerging scientific and technological framework in recent past. The development of computational/mathematical approaches in TERM is also briefly discussed. PMID:25343302

  11. SULFUR DIOXIDE - SULFUR TRIOXIDE REGENERATIVE FUEL CELL RESEARCH

    DTIC Science & Technology

    The thermodynamics and electrolytic characteristics are discussed of an SO2-SO3 regenerative, closed-cycle fuel cell , and summarizes the electrolytic...electrochemical, and phase separation research conducted during a study program to determine the practicability of such a fuel cell . The...experimental results obtained were at such wide variance with the theoretical concept that it became apparent that a fuel cell of this type is not feasible. (Author)

  12. Carbon nanotube torsional springs for regenerative braking systems

    NASA Astrophysics Data System (ADS)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  13. The Almost Regenerative Method for Stochastic System Simulations

    DTIC Science & Technology

    1975-12-01

    Wolfowitz rank product-moment test for lag 1 [ Wald and Wolfowitz (1943)]. The central idea is to replace the X ’s in (A.3) by their ranks, where the...of spurious observations. Wald and Wolfowitz showed that the resulting rank product-moment statistic, r , is asymptotically normally...Chapter 4: Using the Almost Regenerative Method to Obtain Order of Magnitude Improvements in MSE Efficiency .... 49 4.1 The M/M/c Tandem Queue

  14. Preventing Vision Loss from Blast Injuries with Regenerative Biomaterial

    DTIC Science & Technology

    2013-08-01

    addition, eye injury is the number one cause of field evacuation in the military. Corneal wounds cause intense pain and may lead to blindness...depending on the severity of injury. Seryx’s regenerative biomaterial accelerates corneal healing and soothes the damaged surface by providing a coating...immortalized human corneal -limbal epithelial (HCLE) cell line. HCLE cells were grown to confluence in culture, and the media was then supplemented

  15. Regen compressors power Capo Bon trans-med station

    SciTech Connect

    de Biasi, V.

    1981-11-01

    It is expected that Algeria will begin deliveries of natural gas from the Hassi-R'Mel gasfield in the Sahara Desert to Italy by the end of 1981 or early 1982. The main station for the Trans-Med natural gas pipeline, powered by five regenerative M5322R gas turbines, has a design throughput of some 1.6 million m/sup 3//hr and serves as the boost station for the submarine section of the pipeline.

  16. A graphite-lined regeneratively cooled thrust chamber

    NASA Technical Reports Server (NTRS)

    Stubbs, V. R.

    1972-01-01

    Design concepts, based on use of graphite as a thermal barrier for regeneratively cooled FLOX-methane thrust chambers, have been screened and concepts selected for detailed thermodynamic, stress, and fabrication analyses. A single design employing AGCarb-101, a fibrous graphite composite material, for a thermal barrier liner and an electroformed nickel structure with integral coolant passages was selected for fabrication and testing. The fabrication processes and the test results are described and illustrated.

  17. Potential Therapeutic Strategies of Regenerative Medicine for Renal Failure.

    PubMed

    Mata-Miranda, Monica Maribel; Delgado-Macuil, Raul Jacobo; Rojas-Lopez, Marlon; Martinez-Flores, Ricardo; Vazquez-Zapien, Gustavo Jesus

    2017-03-17

    Kidney diseases are a public health problem worldwide; the mortality rate is between 50 and 80%. Available therapies include replacement function by dialysis or transplant, associated with a high morbidity and mortality; kidney transplantation is limited by the shortage of donor organs, immune rejection and lifelong treatment with immunosuppressive. Likewise, none of these treatments compensates all kidney functions. There is a great concern in developing more effective therapies with the ability to replace the wide range of renal functions, so that, new researches on developing therapeutic strategies have focused on regenerative medicine, science that includes artificial creation of tissues and organs, in order to repair or replace a tissue or organ function. The aim of this paper is to review the new advances in regenerative medicine strategies for treatment of renal failure. Generally, regenerative medicine comprises two therapeutic strategies: cell therapy and tissue engineering. Cell therapy techniques depend on cell and tissue culture, with the aim to grow specific cells that will replace morphological structures, tissues and functions. In this area, some investigations that include the use of stem cells have been carried out. Tissue engineering complements cell therapy combining techniques of biological sciences and engineering to create structures and devices as scaffolds, matrices or biocompatible materials, which alone or in combination will give support and facilitate the repair of damaged tissue. Even though there is a great advance in regenerative medicine strategies, we are far from using any of its techniques on health institutions, due to it is necessary to evaluate side effects, biodistribution, dosage, type of administration, vehicle of cell therapy, as well as the evaluation of response time and long-term studies, among other studies.

  18. Hydrogen-Oxygen PEM Regenerative Fuel Cell Energy Storage System

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    An introduction to the closed cycle hydrogen-oxygen polymer electrolyte membrane (PEM) regenerative fuel cell (RFC), recently constructed at NASA Glenn Research Center, is presented. Illustrated with explanatory graphics and figures, this report outlines the engineering motivations for the RFC as a solar energy storage device, the system requirements, layout and hardware detail of the RFC unit at NASA Glenn, the construction history, and test experience accumulated to date with this unit.

  19. Regenerative amplification in alexandrite of pulses from specialized oscillators

    SciTech Connect

    Bado, P.; Pessot, M.; Squier, J.; Mourou, G.A.; Harter, D.J.

    1988-06-01

    The authors describe an alexandrite regenerative amplifier used to amplify the output of various specialized oscillators. Nanosecond pulses from a narrow frequency CW-pumped dye laser, picosecond pulses from a gain-switched diode laser, and femtosecond pulses from a synchronously pumped dye laser were amplified by six-ten orders of magnitude in a single stage while conserving the temporal and spectral profiles characteristic to the oscillators.

  20. Design of a regenerative fuel cell system for Space Station

    NASA Technical Reports Server (NTRS)

    Hoberecht, M. A.; Rieker, L. L.

    1985-01-01

    The NASA Space Station will employ alkaline regenerative fuel cells (RFCs) as its sole electrochemical energy storage system, in virtue of demonstrated technology readiness and a high degree of system-level design flexibility. NASA Johnson and NASA Lewis are currently engaged in the development of a 10-kW alkaline engineering model system, for 1987 delivery, which will encompass a fully autonomous 120-V system with 55 percent overall electrical efficiency and a 20,000-hr service life.

  1. Status of the Regenerative ECLSS Water Recovery System

    NASA Technical Reports Server (NTRS)

    Carter, Donald Layne

    2009-01-01

    NASA has completed the delivery of the regenerative Water Recovery System (WRS) for the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the final effort to deliver the hardware to the Kennedy Space Center for launch on STS-126, the on-orbit status as of April 2009, and describes some of the technical challenges encountered and lessons learned over the past year.

  2. The Application of Microwave Incineration to Regenerative Life Support

    NASA Technical Reports Server (NTRS)

    Sun, Sidney C.; Srinivasan, Venkatesh; Covington, Al (Technical Monitor)

    1995-01-01

    Future human exploration missions will require life support systems that are highly regenerative, requiring minimum resupply, enabling the crews to be largely self-sufficient. Solid wastes generated in space will be processed to recover usable material. Researchers at NASA Ames Research Center are studying a commercially-produced microwave incinerator as a solid waste processor. This paper will describe the results of testing to-date.

  3. Leptin effects on the regenerative capacity of human periodontal cells.

    PubMed

    Nokhbehsaim, Marjan; Keser, Sema; Nogueira, Andressa Vilas Boas; Jäger, Andreas; Jepsen, Søren; Cirelli, Joni Augusto; Bourauel, Christoph; Eick, Sigrun; Deschner, James

    2014-01-01

    Obesity is increasing throughout the globe and characterized by excess adipose tissue, which represents a complex endocrine organ. Adipose tissue secrets bioactive molecules called adipokines, which act at endocrine, paracrine, and autocrine levels. Obesity has recently been shown to be associated with periodontitis, a disease characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium, and also with compromised periodontal healing. Although the underlying mechanisms for these associations are not clear yet, increased levels of proinflammatory adipokines, such as leptin, as found in obese individuals, might be a critical pathomechanistic link. The objective of this study was to examine the impact of leptin on the regenerative capacity of human periodontal ligament (PDL) cells and also to study the local leptin production by these cells. Leptin caused a significant downregulation of growth (TGFβ1, and VEGFA) and transcription (RUNX2) factors as well as matrix molecules (collagen, and periostin) and inhibited SMAD signaling under regenerative conditions. Moreover, the local expression of leptin and its full-length receptor was significantly downregulated by inflammatory, microbial, and biomechanical signals. This study demonstrates that the hormone leptin negatively interferes with the regenerative capacity of PDL cells, suggesting leptin as a pathomechanistic link between obesity and compromised periodontal healing.

  4. Thermal regenerative design of a fuel cell cogeneration system

    NASA Astrophysics Data System (ADS)

    Hwang, Jenn-Jiang

    2012-12-01

    The objective of the present work is to design and fabricate a thermal management system (TMS) that commands a proton exchange membrane fuel cell (PEMFC) based cogeneration system to generate the electricity and hot water efficiently. Parametric studies include the external load (PL) and the regenerative temperature (TR). A thermostat valve is employed to optimize the stack operation temperature, while a thermal regenerative unit (TRU) containing a planar heat exchanger is used to recover the heat dissipated by the stack. First, the dynamics of thermal and electrical characteristics such as voltage, current, power, coolant temperature, coolant flow rate, and hydrogen flow rate are measured to check the reliability of the TMS. Then, the effectiveness of the planar heat exchanger is determined to verify the cooling ability of the TRU. Moreover, the transient system efficiencies, including electrical efficiency, thermal efficiency, and overall efficiency are determined. Furthermore, the effect of the regenerative temperature on the time-averaged system efficiencies is examined under different external loads. Finally, an empirical correlation for time-averaged overall efficiency is proposed for helping in design of the PEMFC cogeneration system.

  5. Human dental pulp stem cells: Applications in future regenerative medicine

    PubMed Central

    Potdar, Pravin D; Jethmalani, Yogita D

    2015-01-01

    Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells (MSCs) from various human tissues, peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells (DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and β cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine. PMID:26131314

  6. Adipose Tissue-Derived Stem Cells in Regenerative Medicine

    PubMed Central

    Frese, Laura; Dijkman, Petra E.; Hoerstrup, Simon P.

    2016-01-01

    In regenerative medicine, adult stem cells are the most promising cell types for cell-based therapies. As a new source for multipotent stem cells, human adipose tissue has been introduced. These so called adipose tissue-derived stem cells (ADSCs) are considered to be ideal for application in regenerative therapies. Their main advantage over mesenchymal stem cells derived from other sources, e.g. from bone marrow, is that they can be easily and repeatable harvested using minimally invasive techniques with low morbidity. ADSCs are multipotent and can differentiate into various cell types of the tri-germ lineages, including e.g. osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β-cells, and hepatocytes. Interestingly, ADSCs are characterized by immunosuppressive properties and low immunogenicity. Their secretion of trophic factors enforces the therapeutic and regenerative outcome in a wide range of applications. Taken together, these particular attributes of ADSCs make them highly relevant for clinical applications. Consequently, the therapeutic potential of ADSCs is enormous. Therefore, this review will provide a brief overview of the possible therapeutic applications of ADSCs with regard to their differentiation potential into the tri-germ lineages. Moreover, the relevant advancements made in the field, regulatory aspects as well as other challenges and obstacles will be highlighted. PMID:27721702

  7. Fusion and regenerative therapies: is immortality really recessive?

    PubMed

    Stolzing, Alexandra; Hescheler, Jürgen; Sethe, Sebastian

    2007-12-01

    Harnessing cellular fusion as a potential tool for regenerative therapy has been under tentative investigation for decades. A look back the history of fusion experiments in gerontology reveals that whereas some studies indicate that aging-related changes are conserved in fused cells, others have demonstrated that fusion can be used as a tool to revoke cellular senescence and induce tissue regeneration. Recent findings about the role of fusion processes in tissue homeostasis, replenishment, and repair link insights from fusion studies of previous decades with modern developments in stem cell biology and regenerative medicine. We suggest that age-associated loss of regenerative capacity is associated with a decline of effectiveness in stem cell fusion. We project how studies into the fusion of stem cells with tissue cells, or the fusion between activator stem cells and patient cells might help in the development of applications that "rejuvenate" certain target cells, thereby strategically reinstating a regeneration cascade. The outlook is concluded with a discussion of the next research milestones and the potential hazards of fusion therapies.

  8. Human dental pulp stem cells: Applications in future regenerative medicine.

    PubMed

    Potdar, Pravin D; Jethmalani, Yogita D

    2015-06-26

    Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells (MSCs) from various human tissues, peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells (DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and β cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine.

  9. Arrayed cellular environments for stem cells and regenerative medicine.

    PubMed

    Titmarsh, Drew M; Chen, Huaying; Wolvetang, Ernst J; Cooper-White, Justin J

    2013-02-01

    The behavior and composition of both multipotent and pluripotent stem cell populations are exquisitely controlled by a complex, spatiotemporally variable interplay of physico-chemical, extracellular matrix, cell-cell interaction, and soluble factor cues that collectively define the stem cell niche. The push for stem cell-based regenerative medicine models and therapies has fuelled demands for increasingly accurate cellular environmental control and enhanced experimental throughput, driving an evolution of cell culture platforms away from conventional culture formats toward integrated systems. Arrayed cellular environments typically provide a set of discrete experimental elements with variation of one or several classes of stimuli across elements of the array. These are based on high-content/high-throughput detection, small sample volumes, and multiplexing of environments to increase experimental parameter space, and can be used to address a range of biological processes at the cell population, single-cell, or subcellular level. Arrayed cellular environments have the capability to provide an unprecedented understanding of the molecular and cellular events that underlie expansion and specification of stem cell and therapeutic cell populations, and thus generate successful regenerative medicine outcomes. This review focuses on recent key developments of arrayed cellular environments and their contribution and potential in stem cells and regenerative medicine.

  10. Adipose Tissue-Derived Stem Cells in Regenerative Medicine.

    PubMed

    Frese, Laura; Dijkman, Petra E; Hoerstrup, Simon P

    2016-07-01

    In regenerative medicine, adult stem cells are the most promising cell types for cell-based therapies. As a new source for multipotent stem cells, human adipose tissue has been introduced. These so called adipose tissue-derived stem cells (ADSCs) are considered to be ideal for application in regenerative therapies. Their main advantage over mesenchymal stem cells derived from other sources, e.g. from bone marrow, is that they can be easily and repeatable harvested using minimally invasive techniques with low morbidity. ADSCs are multipotent and can differentiate into various cell types of the tri-germ lineages, including e.g. osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β-cells, and hepatocytes. Interestingly, ADSCs are characterized by immunosuppressive properties and low immunogenicity. Their secretion of trophic factors enforces the therapeutic and regenerative outcome in a wide range of applications. Taken together, these particular attributes of ADSCs make them highly relevant for clinical applications. Consequently, the therapeutic potential of ADSCs is enormous. Therefore, this review will provide a brief overview of the possible therapeutic applications of ADSCs with regard to their differentiation potential into the tri-germ lineages. Moreover, the relevant advancements made in the field, regulatory aspects as well as other challenges and obstacles will be highlighted.

  11. Regulators of pluripotency and their implications in regenerative medicine

    PubMed Central

    El-Badawy, Ahmed; El-Badri, Nagwa

    2015-01-01

    The ultimate goal of regenerative medicine is to replace damaged tissues with new functioning ones. This can potentially be accomplished by stem cell transplantation. While stem cell transplantation for blood diseases has been increasingly successful, widespread application of stem cell therapy in the clinic has shown limited results. Despite successful efforts to refine existing methodologies and to develop better ones for reprogramming, clinical application of stem cell therapy suffers from issues related to the safety of the transplanted cells, as well as the low efficiency of reprogramming technology. Better understanding of the underlying mechanism(s) involved in pluripotency should accelerate the clinical application of stem cell transplantation for regenerative purposes. This review outlines the main decision-making factors involved in pluripotency, focusing on the role of microRNAs, epigenetic modification, signaling pathways, and toll-like receptors. Of special interest is the role of toll-like receptors in pluripotency, where emerging data indicate that the innate immune system plays a vital role in reprogramming. Based on these data, we propose that nongenetic mechanisms for reprogramming provide a novel and perhaps an essential strategy to accelerate application of regenerative medicine in the clinic. PMID:25960670

  12. Bringing regenerative medicines to the clinic: the future for regulation and reimbursement.

    PubMed

    Bubela, Tania; McCabe, Christopher; Archibald, Peter; Atkins, Harold; Bradshaw, Steven E; Kefalas, Panos; Mujoomdar, Michelle; Packer, Claire; Piret, James; Raxworthy, Mike; Soares, Marta; Viswanathan, Sowmya

    2015-01-01

    Significant investments in regenerative medicine necessitate discussion to align evidentiary requirements and decision-making considerations from regulatory, health system payer and developer perspectives. Only with coordinated efforts will the potential of regenerative medicine be realized. We report on discussions from two workshops sponsored by NICE, University of Alberta, Cell Therapy Catapult and Centre for Commercialization of Regenerative Medicine. We discuss methods to support the assessment of value for regenerative medicine products and services and the synergies that exist between market authorization and reimbursement regulations and practices. We discuss the convergence in novel adaptive licensing practices that may promote the development and adoption of novel therapeutics that meet the needs of healthcare payers.

  13. Theoretical and experimental study on regenerative rotary displacer Stirling engine

    SciTech Connect

    Raggi, L.; Katsuta, Masafumi; Isshiki, Naotsugu; Isshiki, Seita

    1997-12-31

    Recently a quite new type of hot air engine called rotary displacer engine, in which the displacer is a rotating disk enclosed in a cylinder, has been conceived and developed. The working gas, contained in a notch excavated in the disk, is heated and cooled alternately, on account of the heat transferred through the enclosing cylinder that is heated at one side and cooled at the opposite one. The gas temperature oscillations cause the pressure fluctuations that get out mechanical power acting on a power piston. In order to attempt to increase the performances for this kind of engine, the authors propose three different regeneration methods. The first one comprises two coaxial disks that, revolving in opposite ways, cause a temperature gradient on the cylinder wall and a regenerative axial heat conduction through fins shaped on the cylinder inner wall. The other two methods are based on the heat transferred by a proper closed circuit that in one case has a circulating liquid inside and in the other one is formed by several heat pipes working each one for different temperatures. An engine based on the first principle, the Regenerative Tandem Contra-Rotary Displacer Stirling Engine, has been realized and experimented. In this paper experimental results with and without regeneration are reported comparatively with a detailed description of the unity. A basic explanation of the working principle of this engine and a theoretical analysis investigating the main influential parameters for the regenerative effect are done. This new rotating displacer Stirling engines, for their simplicity, are expected to attain high rotational speed especially for applications as demonstration and hobby unities.

  14. Regenerative thermal oxidation for non-conventional applications

    SciTech Connect

    Gosselin, G.; Gravel, J.J.O.

    1999-07-01

    Regenerative Thermal Oxidation has been applied by Biothermica to treat non-conventional emissions. These emissions include pollutants as VOC, COC, TRS, PAH, PCB, HCl and odors. In the kraft pulping industry, environmental requirements for reduced emissions of total reduced sulfur (TRS) and volatile organic compounds (VOC) from pulping operations are leading to incinerators of high destruction efficiency and thermal performance. The first installation in Canada of a Regenerative Thermal Oxidation (RTO) was placed in service early in 1997 at a kraft pulp mill in the province of Quebec. Tests have shown a TRS reduction of 99.6% with a thermal efficiency of 88.5% in the RTO. It can be considered the best method to comply with the new norms for TRS atmospheric emissions in the pulp and paper industry. In the primary aluminum process, a marked improvement in anode properties can be gained by preparing the paste at high temperature, followed by cooling with a water addition in an intensive mixer. However, the addition of cooling water results in a large increase in the emissions of VOC and PAH which can prejudice the process. A number of emission control processes were evaluated. An improved Regenerative Thermal Oxidation (RTO) unit was installed in a modern aluminum plant in Canada. The emissions of VOCs and PAHs from an EIRICH intensive mixer-cooler were reduced by more than 99.9% while all troublesome deposits in the fumes collection system were eliminated. This enabled the plant to remain well within the emission levels allowed by the environmental authority while enjoying considerable benefits from improved anode qualities. In the asphalt roofing industry, RTO was applied to treat the VOC and COC emissions and several units have been in operation since 1990. In the United States two units were installed in asphalt shingle plants and new features in the process show a VOC and COC reduction of 99%.

  15. Cell/tissue processing information system for regenerative medicine.

    PubMed

    Iwayama, Daisuke; Yamato, Masayuki; Tsubokura, Tetsuya; Takahashi, Minoru; Okano, Teruo

    2016-11-01

    When conducting clinical studies of regenerative medicine, compliance to good manufacturing practice (GMP) is mandatory, and thus much time is needed for manufacturing and quality management. It is therefore desired to introduce the manufacturing execution system (MES), which is being adopted by factories manufacturing pharmaceutical products. Meanwhile, in manufacturing human cell/tissue processing autologous products, it is necessary to protect patients' personal information, prevent patients from being identified and obtain information for cell/tissue identification. We therefore considered it difficult to adopt conventional MES to regenerative medicine-related clinical trials, and so developed novel software for production/quality management to be used in cell-processing centres (CPCs), conforming to GMP. Since this system satisfies the requirements of regulations in Japan and the USA for electronic records and electronic signatures (ER/ES), the use of ER/ES has been allowed, and the risk of contamination resulting from the use of recording paper has been eliminated, thanks to paperless operations within the CPC. Moreover, to reduce the risk of mix-up and cross-contamination due to contact during production, we developed a touchless input device with built-in radio frequency identification (RFID) reader-writer devices and optical sensors. The use of this system reduced the time to prepare and issue manufacturing instructions by 50% or more, compared to the conventional handwritten system. The system contributes to producing more large-scale production and to reducing production costs for cell and tissue products in regenerative medicine. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Integration of regenerative shock absorber into vehicle electric system

    NASA Astrophysics Data System (ADS)

    Zhang, Chongxiao; Li, Peng; Xing, Shaoxu; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

    2014-03-01

    Regenerative/Energy harvesting shock absorbers have a great potential to increase fuel efficiency and provide suspension damping simultaneously. In recent years there's intensive work on this topic, but most researches focus on electricity extraction from vibration and harvesting efficiency improvement. The integration of electricity generated from regenerative shock absorbers into vehicle electric system, which is very important to realize the fuel efficiency benefit, has not been investigated. This paper is to study and demonstrate the integration of regenerative shock absorber with vehicle alternator, battery and in-vehicle electrical load together. In the presented system, the shock absorber is excited by a shaker and it converts kinetic energy into electricity. The harvested electricity flows into a DC/DC converter which realizes two functions: controlling the shock absorber's damping and regulating the output voltage. The damping is tuned by controlling shock absorber's output current, which is also the input current of DC/DC converter. By adjusting the duty cycles of switches in the converter, its input impedance together with input current can be adjusted according to dynamic damping requirements. An automotive lead-acid battery is charged by the DC/DC converter's output. To simulate the working condition of combustion engine, an AC motor is used to drive a truck alternator, which also charges the battery. Power resistors are used as battery's electrical load to simulate in-vehicle electrical devices. Experimental results show that the proposed integration strategy can effectively utilize the harvested electricity and power consumption of the AC motor is decreased accordingly. This proves the combustion engine's load reduction and fuel efficiency improvement.

  17. High Pressure Regenerative Turbine Engine: 21st Century Propulsion

    NASA Technical Reports Server (NTRS)

    Lear, W. E.; Laganelli, A. L.; Senick, Paul (Technical Monitor)

    2001-01-01

    A novel semi-closed cycle gas turbine engine was demonstrated and was found to meet the program goals. The proof-of-principle test of the High Pressure Regenerative Turbine Engine produced data that agreed well with models, enabling more confidence in designing future prototypes based on this concept. Emission levels were significantly reduced as predicted as a natural attribute of this power cycle. Engine testing over a portion of the operating range allowed verification of predicted power increases compared to the baseline.

  18. Status of the Regenerative ECLSS Water Recovery System

    NASA Technical Reports Server (NTRS)

    Bagdigian, Robert M.; Carter, D. Layne; Bedard, John

    2007-01-01

    NASA is developing a regenerative water recovery system (WRS) for deployment on the International Space Station (ISS), The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). The WPA has been developed by Hamilton Sundstrand Space Systems International (HSSSI), Inc., while the UPA has been developed by the Marshall Space Flight Center (MSFC). Test and verification activities have been completed for the system and planning for launch and on-orbit activation is underway. This paper summarizes the status as of April 2007 and describes some of the technical challenges encountered and lessons learned over the past year.

  19. A Possible Regenerative, Molten-Salt, Thermoelectric Fuel Cell

    NASA Technical Reports Server (NTRS)

    Greenberg, Jacob; Thaller, Lawrence H.; Weber, Donald E.

    1964-01-01

    Molten or fused salts have been evaluated as possible thermoelectric materials because of the relatively good values of their figures of merit, their chemical stability, their long liquid range, and their ability to operate in conjunction with a nuclear reactor to produce heat. In general, molten salts are electrolytic conductors; therefore, there will be a transport of materials and subsequent decomposition with the passage of an electric current. It is possible nonetheless to overcome this disadvantage by using the decomposition products of the molten-salt electrolyte in a fuel cell. The combination of a thermoelectric converter and a fuel cell would lead to a regenerative system that may be useful.

  20. Regenerative Medicine for Epilepsy: From Basic Research to Clinical Application

    PubMed Central

    Yasuhara, Takao; Agari, Takashi; Kameda, Masahiro; Kondo, Akihiko; Kuramoto, Satoshi; Jing, Meng; Sasaki, Tatsuya; Toyoshima, Atsuhiko; Sasada, Susumu; Sato, Kenichiro; Shinko, Aiko; Wakamori, Takaaki; Okuma, Yu; Miyoshi, Yasuyuki; Tajiri, Naoki; Borlongan, Cesario V.; Date, Isao

    2013-01-01

    Epilepsy is a chronic neurological disorder, which presents with various forms of seizures. Traditional treatments, including medication using antiepileptic drugs, remain the treatment of choice for epilepsy. Recent development in surgical techniques and approaches has improved treatment outcomes. However, several epileptic patients still suffer from intractable seizures despite the advent of the multimodality of therapies. In this article, we initially provide an overview of clinical presentation of epilepsy then describe clinically relevant animal models of epilepsy. Subsequently, we discuss the concepts of regenerative medicine including cell therapy, neuroprotective agents, and electrical stimulation, which are reviewed within the context of our data. PMID:24287913

  1. Propellant feed system of a regeneratively cooled scramjet

    SciTech Connect

    Kanda, Takeshi; Masuya, Goro; Wakamatsu, Yoshio )

    1991-04-01

    An expander cycle for an airframe-integrated hydrogen-fueled scramjet is analyzed to study regenerative cooling characteristics and overall specific impulse. Below Mach 10, the specific impulse and thrust coincide with the reference values. At Mach numbers above 10, a reduction of the specific impulse occurs due to the coolant flow rate requirement, which is accompanied by an increase of thrust. It is shown that the thrust may be increased by injecting excess fuel into the combustor to compensate for the decrease of the specific impulse. 9 refs.

  2. An alexandrite regenerative amplifier for water vapor and temperature measurements

    NASA Technical Reports Server (NTRS)

    Thro, P.-Y.; Boesenberg, J.; Wulfmeyer, V.

    1992-01-01

    The Differential Absorption Lidar (DIAL) technique is a powerful method for determining meteorological parameters, but it requires high quality of the laser source: high energy, very narrow bandwidth, high wavelength stability, and spectral purity. Although many efforts have been made to improve the lasers in view of these aspects, a satisfactory solution has not been demonstrated up to now. We describe a regenerative amplifier, using a Ti:sapphire laser as master oscillator and an alexandrite laser as slave amplifier, which is expected to meet the requirements for water vapor concentration and temperature measurements.

  3. Alexandrite-pumped alexandrite regenerative amplifier for femtosecond pulse amplification

    SciTech Connect

    Hariharan, A.; Fermann, M.E.; Stock, M.L.; Harter, D.J.; Squier, J.

    1996-01-01

    We demonstrate a regenerative amplifier incorporating alexandrite as the gain medium that is pumped by an alexandrite laser. Temperature-altered gain permitted the 728-nm alexandrite pump laser, operating at room temperature, to pump a 780{endash}800-nm alexandrite laser that was maintained at elevated temperatures. 200-fs pulses from a Ti:sapphire oscillator were amplified to the millijoule level. This system also amplified femtosecond pulses from a frequency-doubled Er-doped fiber laser. {copyright} {ital 1996 Optical Society of America.}

  4. A regenerative CO2 amplifier with controlled pulse duration

    NASA Astrophysics Data System (ADS)

    Apollonov, V. V.; Kazakov, K. Kh.; Sorochenko, V. R.; Shakir, Iu. A.

    1991-03-01

    The paper reports the development of a regenerative TEA CO2 amplifier with the pulse duration in a train controlled within the range from 10 to 40 ns, the interval between the pulses amounting to 110 ns and their total energy amounting to 4 J. Laser radiation screening by an optical-air-breakdown plasma in a lens telescope focus was used to form the injected pulse. Good reproduction of the temporal parameters of the injected pulse was achieved by virtue of the injection of radiation from a frequency stabilized CW CO2-laser into the master oscillator.

  5. Regenerative fuel cells for space and terrestrial use

    NASA Astrophysics Data System (ADS)

    Tillmetz, Werner; Dietrich, Guenther; Benz, Uwe

    Electrolysis, fuel cell, and energy storage technologies are compared and evaluated. The use of a fuel cell and electrolyzer with an immobilized electrolyte is selected as the most promising technique. A comparison of the batteries demonstrates that a RFCS (regenerative fuel cell system) could be a serious competitor in future space activities, especially with increasing power level and energy to be stored. Also, for many terrestrial applications, highly efficient energy storage systems will be of great interest in the near future. Aspects of the terrestrial use of a RFCS are discussed.

  6. Performance of a transpiration-regenerative cooled rocket thrust chamber

    NASA Technical Reports Server (NTRS)

    Valler, H. W.

    1979-01-01

    The analysis, design, fabrication, and testing of a liquid rocket engine thrust chamber which is gas transpiration cooled in the high heat flux convergent portion of the chamber and water jacket cooled (simulated regenerative) in the barrel and divergent sections of the chamber are described. The engine burns LOX-hydrogen propellants at a chamber pressure of 600 psia. Various transpiration coolant flow rates were tested with resultant local hot gas wall temperatures in the 800 F to 1400 F range. The feasibility of transpiration cooling with hydrogen and helium, and the use of photo-etched copper platelets for heat transfer and coolant metering was successfully demonstrated.

  7. Analysing regenerative potential in zebrafish models of congenital muscular dystrophy.

    PubMed

    Wood, A J; Currie, P D

    2014-11-01

    The congenital muscular dystrophies (CMDs) are a clinically and genetically heterogeneous group of muscle disorders. Clinically hypotonia is present from birth, with progressive muscle weakness and wasting through development. For the most part, CMDs can mechanistically be attributed to failure of basement membrane protein laminin-α2 sufficiently binding with correctly glycosylated α-dystroglycan. The majority of CMDs therefore arise as the result of either a deficiency of laminin-α2 (MDC1A) or hypoglycosylation of α-dystroglycan (dystroglycanopathy). Here we consider whether by filling a regenerative medicine niche, the zebrafish model can address the present challenge of delivering novel therapeutic solutions for CMD. In the first instance the readiness and appropriateness of the zebrafish as a model organism for pioneering regenerative medicine therapies in CMD is analysed, in particular for MDC1A and the dystroglycanopathies. Despite the recent rapid progress made in gene editing technology, these approaches have yet to yield any novel zebrafish models of CMD. Currently the most genetically relevant zebrafish models to the field of CMD, have all been created by N-ethyl-N-nitrosourea (ENU) mutagenesis. Once genetically relevant models have been established the zebrafish has several important facets for investigating the mechanistic cause of CMD, including rapid ex vivo development, optical transparency up to the larval stages of development and relative ease in creating transgenic reporter lines. Together, these tools are well suited for use in live-imaging studies such as in vivo modelling of muscle fibre detachment. Secondly, the zebrafish's contribution to progress in effective treatment of CMD was analysed. Two approaches were identified in which zebrafish could potentially contribute to effective therapies. The first hinges on the augmentation of functional redundancy within the system, such as upregulating alternative laminin chains in the candyfloss

  8. Controlling life: from Jacques Loeb to regenerative medicine.

    PubMed

    Maienschein, Jane

    2009-01-01

    In his 1987 book Controlling Life: Jacques Loeb and the Engineering Ideal in Biology, Philip Pauly presented his readers with the biologist Jacques Loeb and his role in developing an emphasis on control of life processes. Loeb's work on artificial parthenogenesis, for example, provided an example of bioengineering at work. This paper revisits Pauly's study of Loeb and explores the way current research in regenerative medicine reflects the same tradition. A history of regeneration research reveals patterns of thinking and research methods that both echo Loeb's ideology and point the way to modern studies. Pauly's work revealed far more than we readers realized at the time of its publication.

  9. Complement-triggered pathways orchestrate regenerative responses throughout phylogenesis

    PubMed Central

    Mastellos, Dimitrios C.; DeAngelis, Robert A.; Lambris, John D.

    2014-01-01

    Adult tissue plasticity, cell reprogramming, and organ regeneration are major challenges in the field of modern regenerative medicine. Devising strategies to increase the regenerative capacity of tissues holds great promise for dealing with donor organ shortages and low transplantation outcomes and also provides essential impetus to tissue bioengineering approaches for organ repair and replacement. The inherent ability of cells to reprogram their fate by switching into an embryonic-like, pluripotent progenitor state is an evolutionary vestige that in mammals has been retained mostly in fetal tissues and persists only in a few organs of the adult body. Tissue regeneration reflects the capacity of terminally differentiated cells to re-enter the cell cycle and proliferate in response to acute injury or environmental stress signals. In lower vertebrates, this regenerative capacity extends to several organs and remarkably culminates in precise tissue patterning, through cellular transdifferentiation and complex morphogenetic processes that can faithfully reconstruct entire body parts. Many lessons have been learned from robust regeneration models in amphibians such as the newt and axolotl. However, the dynamic interactions between the regenerating tissue, the surrounding stroma, and the host immune response, as it adapts to the actively proliferating tissue, remain ill-defined. The regenerating zone, through a sequence of distinct molecular events, adopts phenotypic plasticity and undergoes rigorous tissue remodeling that, in turn, evokes a significant inflammatory response. Complement is a primordial sentinel of the innate immune response that engages in multiple inflammatory cascades as it becomes activated during tissue injury and remodeling. In this respect, complement proteins have been implicated in tissue and organ regeneration in both urodeles and mammals. Distinct complement-triggered pathways have been shown to modulate critical responses that promote tissue

  10. Hybrid regenerative fuel cell systems for space applications

    NASA Technical Reports Server (NTRS)

    Saucier, David R.

    1988-01-01

    This paper describes a hybrid regenerative fuel cell (RFC) system for space application, which is made up of an alkaline fuel cell (Space Shuttle fuel cell) and an acid electrolysis unit (solid polymer electrolyte). In the RFC, gas produced from the acid electrolysis unit and water produced by the alkaline fuel cell are repeatedly reacted in the other unit. The results of RFC's tests indicate that the system is feasible in terms of fluid/unit compatibility. In addition, the fuel cell thermal-control system proved capable of controlling fuel cell temperatures throughout long open-circuit periods. Diagrams of the RFC and its subsystems are included.

  11. NASA Lewis Evaluation of Regenerative Fuel Cell (RFC) Systems

    NASA Technical Reports Server (NTRS)

    Hagedorn, N. H.; Gonzalez-Sanabria, O. D; Kohout, L. L.

    1986-01-01

    Evaluation of two regenerative fuel cell (RFC) systems was begun in-house, and under contracts and grants. The passive hydrogen-oxygen RFC offers the possibility of a high-energy density, long-life storage system for geosynchronous Earth orbit missions. The hydrogen-bromine RFC offers the combination of high efficiency and moderate energy density that could ideally suit low Earth orbit missions if successfully developed. Either or both of these systems would be attractive additions to the storage options available to designers of future missions.

  12. Long life Regenerative Fuel Cell technology development plan

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  13. Regeneratively cooled rocket engine for space storable propellants

    NASA Technical Reports Server (NTRS)

    Wagner, W. R.; Waldman, B. J.

    1973-01-01

    Analyses and experimental studies were performed with the OF2 (F2/O2)/B2H6 propellant combination over a range in operating conditions to determine suitability for a space storable pressure fed engine configuration for an extended flight space vehicle configuration. The regenerative cooling mode selected for the thrust chamber was explored in detail with the use of both the fuel and oxidizer as coolants in an advanced milled channel construction thrust chamber design operating at 100 psia chamber pressure and a nominal mixture ratio of 3.0 with a 60:1 area ratio nozzle. Benefits of the simultaneous cooling as related to gaseous injection of both fuel and oxidizer propellants were defined. Heat transfer rates, performance and combustor stability were developed for impinging element triplet injectors in uncooled copper calorimeter hardware with flow, pressure and temperature instrumentation. Evaluation of the capabilities of the B2H6 and OF2 during analytical studies and numerous tests with flow through electrically heated blocks provided design criteria for subsequent regenerative chamber design and fabrication.

  14. Regenerative Medicine for Periodontal and Peri-implant Diseases

    PubMed Central

    Larsson, L.; Decker, A.M.; Nibali, L.; Pilipchuk, S.P.; Berglundh, T.; Giannobile, W.V.

    2015-01-01

    The balance between bone resorption and bone formation is vital for maintenance and regeneration of alveolar bone and supporting structures around teeth and dental implants. Tissue regeneration in the oral cavity is regulated by multiple cell types, signaling mechanisms, and matrix interactions. A goal for periodontal tissue engineering/regenerative medicine is to restore oral soft and hard tissues through cell, scaffold, and/or signaling approaches to functional and aesthetic oral tissues. Bony defects in the oral cavity can vary significantly, ranging from smaller intrabony lesions resulting from periodontal or peri-implant diseases to large osseous defects that extend through the jaws as a result of trauma, tumor resection, or congenital defects. The disparity in size and location of these alveolar defects is compounded further by patient-specific and environmental factors that contribute to the challenges in periodontal regeneration, peri-implant tissue regeneration, and alveolar ridge reconstruction. Efforts have been made over the last few decades to produce reliable and predictable methods to stimulate bone regeneration in alveolar bone defects. Tissue engineering/regenerative medicine provide new avenues to enhance tissue regeneration by introducing bioactive models or constructing patient-specific substitutes. This review presents an overview of therapies (e.g., protein, gene, and cell based) and biomaterials (e.g., resorbable, nonresorbable, and 3-dimensionally printed) used for alveolar bone engineering around teeth and implants and for implant site development, with emphasis on most recent findings and future directions. PMID:26608580

  15. Johnson Space Center's Regenerative Life Support Systems Test Bed.

    PubMed

    Barta, D J; Henninger, D L

    1996-01-01

    The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

  16. Repair Injured Heart by Regulating Cardiac Regenerative Signals

    PubMed Central

    Wang, Lei; Paul, Christian

    2016-01-01

    Cardiac regeneration is a homeostatic cardiogenic process by which the sections of malfunctioning adult cardiovascular tissues are repaired and renewed employing a combination of both cardiomyogenesis and angiogenesis. Unfortunately, while high-quality regeneration can be performed in amphibians and zebrafish hearts, mammalian hearts do not respond in kind. Indeed, a long-term loss of proliferative capacity in mammalian adult cardiomyocytes in combination with dysregulated induction of tissue fibrosis impairs mammalian endogenous heart regenerative capacity, leading to deleterious cardiac remodeling at the end stage of heart failure. Interestingly, several studies have demonstrated that cardiomyocyte proliferation capacity is retained in mammals very soon after birth, and cardiac regeneration potential is correspondingly preserved in some preadolescent vertebrates after myocardial infarction. There is therefore great interest in uncovering the molecular mechanisms that may allow heart regeneration during adult stages. This review will summarize recent findings on cardiac regenerative regulatory mechanisms, especially with respect to extracellular signals and intracellular pathways that may provide novel therapeutics for heart diseases. Particularly, both in vitro and in vivo experimental evidences will be presented to highlight the functional role of these signaling cascades in regulating cardiomyocyte proliferation, cardiomyocyte growth, and maturation, with special emphasis on their responses to heart tissue injury. PMID:27799944

  17. Feasibility study of a simple unitized regenerative fuel cell

    NASA Astrophysics Data System (ADS)

    Verma, A.; Basu, S.

    Conventional fuel cells use hydrogen and oxygen as the fuel and oxidant, respectively. Hydrogen and oxygen can be produced through electrolysis of water in an electrochemical cell. A simple unitized regenerative fuel cell (URFC), by combining an electrolyzer and a fuel cell, is constructed to check the feasibility of such a device. In the first cycle, hydrogen and oxygen gases are generated from water containing NaHCO 3 when a given dc voltage is applied across Ni-Co/stainless steel electrodes. A solar photovoltaic cell is also used to provide the power. The generated gases are trapped between their respective electrodes and nylon mesh. In the second cycle, the hydrogen and oxygen gases are used in the same electrochemical cell (fuel cell) to produce electricity under a specific load. The current density and voltage are measured by varying different parameters, e.g., time of electrolysis, magnitude of voltage applied, and electrolyte concentration. An open-circuit voltage (OCV) of 1.3 V is obtained from two regenerative fuel cells in series with a total active electrode area of 300 cm 2. A current density of about 0.5 mA cm -2 is generated using 0.5N NaHCO 3 when 4.5 V is applied for 25 min. A maximum power of 36.5 mW is obtained at 0.21 mA cm -2.

  18. Implications of mesenchymal stem cells in regenerative medicine.

    PubMed

    Kariminekoo, Saber; Movassaghpour, Aliakbar; Rahimzadeh, Amirbahman; Talebi, Mehdi; Shamsasenjan, Karim; Akbarzadeh, Abolfazl

    2016-05-01

    Mesenchymal stem cells (MSCs) are a population of multipotent progenitors which reside in bone marrow, fat, and some other tissues and can be isolated from various adult and fetal tissues. Self-renewal potential and multipotency are MSC's hallmarks. They have the capacity of proliferation and differentiation into a variety of cell lineages like osteoblasts, condrocytes, adipocytes, fibroblasts, cardiomyocytes. MSCs can be identified by expression of some surface molecules like CD73, CD90, CD105, and lack of hematopoietic specific markers including CD34, CD45, and HLA-DR. They are hopeful tools for regenerative medicine for repairing injured tissues. Many studies have focused on two significant features of MSC therapy: (I) systemically administered MSCs home to sites of ischemia or injury, and (II) MSCs can modulate T-cell-mediated immunological responses. MSCs express chemokine receptors and ligands involved in cells migration and homing process. MSCs induce immunomedulatory effects on the innate (dendritic cells, monocyte, natural killer cells, and neutrophils) and the adaptive immune system cells (T helper-1, cytotoxic T lymphocyte, and B lymphocyte) by secreting soluble factors like TGF-β, IL-10, IDO, PGE-2, sHLA-G5, or by cell-cell interaction. In this review, we discuss the main applications of mesenchymal stem in Regenerative Medicine and known mechanisms of homing and Immunomodulation of MSCs.

  19. Stem cells, growth factors and scaffolds in craniofacial regenerative medicine

    PubMed Central

    Tollemar, Viktor; Collier, Zach J.; Mohammed, Maryam K.; Lee, Michael J.; Ameer, Guillermo A.; Reid, Russell R.

    2015-01-01

    Current reconstructive approaches to large craniofacial skeletal defects are often complicated and challenging. Critical-sized defects are unable to heal via natural regenerative processes and require surgical intervention, traditionally involving autologous bone (mainly in the form of nonvascularized grafts) or alloplasts. Autologous bone grafts remain the gold standard of care in spite of the associated risk of donor site morbidity. Tissue engineering approaches represent a promising alternative that would serve to facilitate bone regeneration even in large craniofacial skeletal defects. This strategy has been tested in a myriad of iterations by utilizing a variety of osteoconductive scaffold materials, osteoblastic stem cells, as well as osteoinductive growth factors and small molecules. One of the major challenges facing tissue engineers is creating a scaffold fulfilling the properties necessary for controlled bone regeneration. These properties include osteoconduction, osetoinduction, biocompatibility, biodegradability, vascularization, and progenitor cell retention. This review will provide an overview of how optimization of the aforementioned scaffold parameters facilitates bone regenerative capabilities as well as a discussion of common osteoconductive scaffold materials. PMID:27239485

  20. Renal stem cell reprogramming: Prospects in regenerative medicine

    PubMed Central

    Morales, Elvin E; Wingert, Rebecca A

    2014-01-01

    Stem cell therapy is a promising future enterprise for renal replacement in patients with acute and chronic kidney disease, conditions which affect millions worldwide and currently require patients to undergo lifelong medical treatments through dialysis and/or organ transplant. Reprogramming differentiated renal cells harvested from the patient back into a pluripotent state would decrease the risk of tissue rejection and provide a virtually unlimited supply of cells for regenerative medicine treatments, making it an exciting area of current research in nephrology. Among the major hurdles that need to be overcome before stem cell therapy for the kidney can be applied in a clinical setting are ensuring the fidelity and relative safety of the reprogrammed cells, as well as achieving feasible efficiency in the reprogramming processes that are utilized. Further, improved knowledge about the genetic control of renal lineage development is vital to identifying predictable and efficient reprogramming approaches, such as the expression of key modulators or the regulation of gene activity through small molecule mimetics. Here, we discuss several recent advances in induced pluripotent stem cell technologies. We also explore strategies that have been successful in renal progenitor generation, and explore what these methods might mean for the development of cell-based regenerative therapies for kidney disease. PMID:25258667

  1. Amniotic fluid-derived stem cells in regenerative medicine research.

    PubMed

    Joo, Sunyoung; Ko, In Kap; Atala, Anthony; Yoo, James J; Lee, Sang Jin

    2012-02-01

    The stem cells isolated from amniotic fluid present an exciting possible contribution to the field of regenerative medicine and amniotic fluid-derived stem (AFS) cells have significant potential for research and therapeutic applications. AFS cells are multipotent, showing the ability to differentiate into cell types from all three embryonic germ layers. They express both embryonic and adult stem cell markers, expand extensively without feeder cells, double in 36 h, and are not tumorigenic. The AFS cells can be maintained for over 250 population doublings and preserve their telomere length and a normal karyotype. They differentiate easily into specific cell lineages and do not require human embryo tissue for their isolation, thus avoiding the current controversies associated with the use of human embryonic stem (ES) cells. The discovery of the AFS cells has been recent, and a great deal of work remains to be performed on the characterization and use of these cells. This review describes the various differentiated lineages that AFS cells can form and the future of these promising new stem cells in regenerative medicine research.

  2. Unitized Regenerative Fuel Cell System Gas Storage-Radiator Development

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupta, Ian

    2005-01-01

    High-energy-density regenerative fuel cell systems that are used for energy storage require novel approaches to integrating components in order to preserve mass and volume. A lightweight unitized regenerative fuel cell (URFC) energy storage system concept is being developed at the NASA Glenn Research Center. This URFC system minimizes mass by using the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The waste heat generated by the URFC stack during charging and discharging is transferred from the cell stack to the surface of each tank by loop heat pipes, which are coiled around each tank and covered with a thin layer of thermally conductive carbon composite. The thin layer of carbon composite acts as a fin structure that spreads the heat away from the heat pipe and across the entire tank surface. Two different-sized commercial-grade composite tanks were constructed with integral heat pipes and tested in a thermal vacuum chamber to examine the feasibility of using the storage tanks as system radiators. The storage tank-radiators were subjected to different steady-state heat loads and varying heat load profiles. The surface emissivity and specific heat capacity of each tank were calculated. In the future, the results will be incorporated into a model that simulates the performance of similar radiators using lightweight, spacerated carbon composite tanks.

  3. High Energy Density Regenerative Fuel Cell Systems for Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.

    1999-01-01

    Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology readiness level (TRL of about 2 indicating feasibility has been demonstrated). Commercial development of the Proton Exchange Membrane (PEM) fuel cells for automobiles and other terrestrial applications and improvements in lightweight pressure vessel design to reduce weight and improve performance make possible a high energy density RFCS energy storage system. The results from this study of a lightweight RFCS energy storage system for a remotely piloted, solar-powered, high altitude aircraft indicate an energy density up to 790 w-h/kg with electrical efficiency of 53.4% is attainable. Such an energy storage system would allow a solar-powered aircraft to carry hundreds of kilograms of payload and remain in flight indefinitely for use in atmospheric research, earth observation, resource mapping. and telecommunications. Future developments in the areas of hydrogen and oxygen storage, pressure vessel design, higher temperature and higher- pressure fuel cell operation, unitized regenerative fuel cells, and commercial development of fuel cell technology will improve both the energy density and electrical efficiency of the RFCS.

  4. Regenerative Medicine for Periodontal and Peri-implant Diseases.

    PubMed

    Larsson, L; Decker, A M; Nibali, L; Pilipchuk, S P; Berglundh, T; Giannobile, W V

    2016-03-01

    The balance between bone resorption and bone formation is vital for maintenance and regeneration of alveolar bone and supporting structures around teeth and dental implants. Tissue regeneration in the oral cavity is regulated by multiple cell types, signaling mechanisms, and matrix interactions. A goal for periodontal tissue engineering/regenerative medicine is to restore oral soft and hard tissues through cell, scaffold, and/or signaling approaches to functional and aesthetic oral tissues. Bony defects in the oral cavity can vary significantly, ranging from smaller intrabony lesions resulting from periodontal or peri-implant diseases to large osseous defects that extend through the jaws as a result of trauma, tumor resection, or congenital defects. The disparity in size and location of these alveolar defects is compounded further by patient-specific and environmental factors that contribute to the challenges in periodontal regeneration, peri-implant tissue regeneration, and alveolar ridge reconstruction. Efforts have been made over the last few decades to produce reliable and predictable methods to stimulate bone regeneration in alveolar bone defects. Tissue engineering/regenerative medicine provide new avenues to enhance tissue regeneration by introducing bioactive models or constructing patient-specific substitutes. This review presents an overview of therapies (e.g., protein, gene, and cell based) and biomaterials (e.g., resorbable, nonresorbable, and 3-dimensionally printed) used for alveolar bone engineering around teeth and implants and for implant site development, with emphasis on most recent findings and future directions.

  5. Gaussian-only regenerative stations cannot act as quantum repeaters

    NASA Astrophysics Data System (ADS)

    Namiki, Ryo; Gittsovich, Oleg; Guha, Saikat; Lütkenhaus, Norbert

    2014-12-01

    Higher transmission loss diminishes the performance of optical communication—be it the rate at which classical or quantum data can be sent reliably, or the secure key generation rate of quantum key distribution (QKD). Loss compounds with distance—exponentially in an optical fiber, and inverse square with distance for a free-space channel. In order to boost classical communication rates over long distances, it is customary to introduce regenerative relays at intermediate points along the channel. It is therefore natural to speculate whether untended regenerative stations, such as phase-insensitive or phase-sensitive optical amplifiers, could serve as repeaters for long-distance QKD. The primary result of this paper rules out all bosonic Gaussian channels to be useful as QKD repeaters, which include phase-insensitive and phase-sensitive amplifiers as special cases, for any QKD protocol. We also delineate the conditions under which a Gaussian relay renders a lossy channel entanglement breaking, which in turn makes the channel useless for QKD.

  6. Regeneratively Cooled Liquid Oxygen/Methane Technology Development

    NASA Technical Reports Server (NTRS)

    Robinson, Joel W.; Greene, Christopher B.; Stout, Jeffrey

    2012-01-01

    The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LOX)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon exploration studies. The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. NASA-Marshall Space Flight Center (MSFC) in concert with industry partner Pratt & Whitney Rocketdyne (PWR) utilized a Space Act Agreement to test an oxygen/methane engine system in the Summer of 2010. PWR provided a 5,500 lbf (24,465 N) LOX/LCH4 regenerative cycle engine to demonstrate advanced thrust chamber assembly hardware and to evaluate the performance characteristics of the system. The chamber designs offered alternatives to traditional regenerative engine designs with improvements in cost and/or performance. MSFC provided the test stand, consumables and test personnel. The hot fire testing explored the effective cooling of one of the thrust chamber designs along with determining the combustion efficiency with variations of pressure and mixture ratio. The paper will summarize the status of these efforts.

  7. Extracellular Matrix Scaffolds for Tissue Engineering and Regenerative Medicine.

    PubMed

    Yi, Sheng; Ding, Fei; Gong, Leiiei; Gu, Xiaosong

    2017-01-01

    The extracellular matrix is produced by the resident cells in tissues and organs, and secreted into the surrounding medium to provide biophysical and biochemical support to the surrounding cells due to its content of diverse bioactive molecules. Recently, the extracellular matrix has been used as a promising approach for tissue engineering. Emerging studies demonstrate that extracellular matrix scaffolds are able to create a favorable regenerative microenvironment, promote tissue-specific remodeling, and act as an inductive template for the repair and functional reconstruction of skin, bone, nerve, heart, lung, liver, kidney, small intestine, and other organs. In the current review, we will provide a critical overview of the structure and function of various types of extracellular matrix, the construction of three-dimensional extracellular matrix scaffolds, and their tissue engineering applications, with a focus on translation of these novel tissue engineered products to the clinic. We will also present an outlook on future perspectives of the extracellular matrix in tissue engineering and regenerative medicine.

  8. Three-dimensional bioprinting in tissue engineering and regenerative medicine.

    PubMed

    Gao, Guifang; Cui, Xiaofeng

    2016-02-01

    With the advances of stem cell research, development of intelligent biomaterials and three-dimensional biofabrication strategies, highly mimicked tissue or organs can be engineered. Among all the biofabrication approaches, bioprinting based on inkjet printing technology has the promises to deliver and create biomimicked tissue with high throughput, digital control, and the capacity of single cell manipulation. Therefore, this enabling technology has great potential in regenerative medicine and translational applications. The most current advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review, including vasculature, muscle, cartilage, and bone. In addition, the benign side effect of bioprinting to the printed mammalian cells can be utilized for gene or drug delivery, which can be achieved conveniently during precise cell placement for tissue construction. With layer-by-layer assembly, three-dimensional tissues with complex structures can be printed using converted medical images. Therefore, bioprinting based on thermal inkjet is so far the most optimal solution to engineer vascular system to the thick and complex tissues. Collectively, bioprinting has great potential and broad applications in tissue engineering and regenerative medicine. The future advances of bioprinting include the integration of different printing mechanisms to engineer biphasic or triphasic tissues with optimized scaffolds and further understanding of stem cell biology.

  9. Johnson Space Center's Regenerative Life Support Systems Test Bed

    NASA Technical Reports Server (NTRS)

    Barta, D. J.; Henninger, D. L.

    1996-01-01

    The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

  10. Induced pluripotent stem cells and their implication for regenerative medicine.

    PubMed

    Csobonyeiova, Maria; Polak, Stefan; Koller, Jan; Danisovic, Lubos

    2015-06-01

    In 2006 Yamanaka's group showed that stem cells with properties similar to embryonic stem cells could be generated from mouse fibroblasts by introducing four genes. These cells were termed induced pluripotent stem cells (iPSCs). Because iPSCs avoid many of ethical concerns associated with the use of embryonic material, they have great potential in cell-based regenerative medicine. They are suitable also for other various purposes, including disease modelling, personalized cell therapy, drug or toxicity screening and basic research. Moreover, in the future, there might become possible to generate organs for human transplantation. Despite these progresses, several studies have raised the concern for genetic and epigenetic abnormalities of iPSCs that could contribute to immunogenicity of some cells differentiated from iPSCs. Recent methodological improvements are increasing the ease and efficacy of reprogramming, and reducing the genomic modification. However, to minimize or eliminate genetic alternations in the derived iPSC line creation, factor-free human iPSCs are necessary. In this review we discuss recent possibilities of using iPSCs for clinical applications and new advances in field of their reprogramming methods. The main goal of present article was to review the current knowledge about iPSCs and to discuss their potential for regenerative medicine.

  11. Promissory identities: Sociotechnical representations & innovation in regenerative medicine.

    PubMed

    Gardner, John; Higham, Ruchi; Faulkner, Alex; Webster, Andrew

    2017-02-01

    The field of regenerative medicine (RM) is championed as a potential source of curative treatments and economic wealth, and initiatives have been launched in several countries to facilitate innovation within the field. As a way of examining the social dimensions of innovation within regenerative medicine, this paper explores the sociotechnical representations of RM technologies in the UK, and the tensions, affordances and complexities these representations present for actors within the field. Specifically, the paper uses the Science and Technology Studies-inspired notions of 'technology identity' and 'development space' to examine how particular technologies are framed and positioned by actors, and how these positionings subsequently shape innovation pathways. Four developing RM technologies are used as case studies: bioengineered tracheas; autologous chondrocyte implantation; T-cell therapies; and a 'point-of-care' cell preparation device. Using these case studies we argue that there are particular identity aspects that have powerful performative effects and provide momentum to innovation projects, and we argue that there are particular stakeholders in the UK RM landscape who appear to have considerable power in shaping these technology identities and thus innovation pathways.

  12. Bioluminescence regenerative cycle (BRC) system for nucleic acid quantification assays

    NASA Astrophysics Data System (ADS)

    Hassibi, Arjang; Lee, Thomas H.; Davis, Ronald W.; Pourmand, Nader

    2003-07-01

    A new label-free methodology for nucleic acid quantification has been developed where the number of pyrophosphate molecules (PPi) released during polymerization of the target nucleic acid is counted and correlated to DNA copy number. The technique uses the enzymatic complex of ATP-sulfurylase and firefly luciferase to generate photons from PPi. An enzymatic unity gain positive feedback is also implemented to regenerate the photon generation process and compensate any decay in light intensity by self regulation. Due to this positive feedback, the total number of photons generated by the bioluminescence regenerative cycle (BRC) can potentially be orders of magnitude higher than typical chemiluminescent processes. A system level kinetic model that incorporates the effects of contaminations and detector noise was used to show that the photon generation process is in fact steady and also proportional to the nucleic acid quantity. Here we show that BRC is capable of detecting quantities of DNA as low as 1 amol (10-18 mole) in 40μlit aqueous solutions, and this enzymatic assay has a controllable dynamic range of 5 orders of magnitude. The sensitivity of this technology, due to the excess number of photons generated by the regenerative cycle, is not constrained by detector performance, but rather by possible PPi or ATP (adenosine triphosphate) contamination, or background bioluminescence of the enzymatic complex.

  13. Regenerative medicine: advances in new methods and technologies.

    PubMed

    Park, Dong-Hyuk; Eve, David J

    2009-11-01

    The articles published in the journal Cell Transplantation - The Regenerative Medicine Journal over the last two years reveal the recent and future cutting-edge research in the fields of regenerative and transplantation medicine. 437 articles were published from 2007 to 2008, a 17% increase compared to the 373 articles in 2006-2007. Neuroscience was still the most common section in both the number of articles and the percentage of all manuscripts published. The increasing interest and rapid advance in bioengineering technology is highlighted by tissue engineering and bioartificial organs being ranked second again. For a similar reason, the methods and new technologies section increased significantly compared to the last period. Articles focusing on the transplantation of stem cell lineages encompassed almost 20% of all articles published. By contrast, the non-stem cell transplantation group which is made up primarily of islet cells, followed by biomaterials and fetal neural tissue, etc. comprised less than 15%. Transplantation of cells pre-treated with medicine or gene transfection to prolong graft survival or promote differentiation into the needed phenotype, was prevalent in the transplantation articles regardless of the kind of cells used. Meanwhile, the majority of non-transplantation-based articles were related to new devices for various purposes, characterization of unknown cells, medicines, cell preparation and/or optimization for transplantation (e.g. isolation and culture), and disease pathology.

  14. AMR (Active Magnetic Regenerative) refrigeration for low temperature

    NASA Astrophysics Data System (ADS)

    Jeong, Sangkwon

    2014-07-01

    This paper reviews AMR (Active Magnetic Regenerative) refrigeration technology for low temperature applications that is a novel cooling method to expand the temperature span of magnetic refrigerator. The key component of the AMR system is a porous magnetic regenerator which allows a heat transfer medium (typically helium gas) to flow through it and therefore obviate intermittently operating an external heat switch. The AMR system alternatingly heats and cools the heat transfer medium by convection when the magneto-caloric effect is created under varying magnetic field. AMR may extend the temperature span for wider range than ADR (Adiabatic Demagnetization Refrigerator) at higher temperatures above 10 K because magneto-caloric effects are typically concentrated in a small temperature range in usual magnetic refrigerants. The regenerative concept theoretically enables each magnetic refrigerant to experience a pseudo-Carnot magnetic refrigeration cycle in a wide temperature span if it is properly designed, although adequate thermodynamic matching of strongly temperature-dependent MCE (magneto-caloric effect) of the regenerator material and the heat capacity of fluid flow is often tricky due to inherent characteristics of magnetic materials. This paper covers historical developments, fundamental concepts, key components, applications, and recent research trends of AMR refrigerators for liquid helium or liquid hydrogen temperatures.

  15. Methods to validate tooth-supporting regenerative therapies.

    PubMed

    Padial-Molina, Miguel; Marchesan, Julie T; Taut, Andrei D; Jin, Qiming; Giannobile, William V; Rios, Hector F

    2012-01-01

    In humans, microbially induced inflammatory periodontal diseases are the primary initiators that disrupt the functional and structural integrity of the periodontium (i.e., the alveolar bone, the periodontal ligament, and the cementum). The reestablishment of its original structure, properties, and function constitutes a significant challenge in the development of new therapies to regenerate tooth-supporting defects. Preclinical models represent an important in vivo tool to critically evaluate and analyze the key aspects of novel regenerative therapies, including (1) safety, (2) effectiveness, (3) practicality, and (4) functional and structural stability over time. Therefore, these models provide foundational data that supports the clinical validation and the development of novel innovative regenerative periodontal technologies. Steps are provided on the use of the root fenestration animal model for the proper evaluation of periodontal outcome measures using the following parameters: descriptive histology, histomorphometry, immunostaining techniques, three-dimensional imaging, electron microscopy, gene expression analyses, and safety assessments. These methods will prepare investigators and assist them in identifying the key end points that can then be adapted to later stage human clinical trials.

  16. Clinical concepts for regenerative therapy in intrabony defects.

    PubMed

    Cortellini, Pierpaolo; Tonetti, Maurizio S

    2015-06-01

    Evidence indicates that periodontal regeneration is an efficacious and predictable procedure for the treatment of isolated and multiple intrabony defects. Meta-analyses from systematic reviews indicate an added benefit, in terms of clinical attachment level gain, when demineralized freeze-dried bone allograft, barrier membranes and active biologic products/compounds are applied in addition to open flap debridement. On the other hand, a consistent amount of variability of the outcomes is evident among different studies and within the experimental population of each study. This variability is explained, at least in part, by different patient and defect characteristics. Patient-related factors include smoking habit, compliance with home oral hygiene and residual inflammation after cause-related therapy. Defect-associated factors include defect depth and radiographic angle, the number of residual bony walls, pocket depth and the degree of hypermobility. In addition, surgical-related variables, such as surgical skill, clinical experience and knowledge, and application of the different regenerative materials, have a significant impact on clinical outcomes. This paper presents a strategy to optimize the clinical outcomes of periodontal regeneration. The surgical design of the flap, the use of different regenerative materials and the application of appropriate passive sutures are discussed in this review along with the scientific foundations.

  17. Johnson Space Center's regenerative life support systems test bed

    NASA Technical Reports Server (NTRS)

    Henninger, Donald L.; Tri, Terry O.; Barta, Daniel J.; Stahl, Randal S.

    1991-01-01

    The Regenerative Life Support System (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for the evaluation of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. When completed, the facility will be comprised of two large scale plant growth chambers, each with approximately 10 m(exp 2) growing area. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), will be capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in Lunar or Martian habitats; the other chamber, the Ambient Pressure Growth Chamber (APGC) will operate at ambient atmospheric pressure. The root zone in each chamber will be configurable for hydroponic or solid state media systems. Research will focus on: (1) in situ resource utilization for CELSS systems, in which simulated lunar soils will be used in selected crop growth studies; (2) integration of biological and physicochemical air and water revitalization systems; (3) effect of atmospheric pressure on system performance; and (4) monitoring and control strategies.

  18. Particle assemblies: toward new tools for regenerative medicine.

    PubMed

    Roux, R; Ladavière, C; Montembault, A; Delair, T

    2013-04-01

    Regenerative medicine is a demanding field in terms of design and elaboration of materials able to meet the specifications that this application imposes. The regeneration of tissue is a multiscale issue, from the signaling molecule through cell expansion and finally tissue growth requiring a large variety of cues that should be delivered in place and time. Hence, the materials should be able to accommodate cells with respect to their phenotypes, to allow cell division to the right tissue, to maintain the integrity of the surrounding sane tissue, and eventually use their signaling machinery to serve the development of the appropriate neo-tissue. They should also present the ability to deliver growth factors and regulate tissue development, to be degraded into safe products, in order not to impede tissue development, and finally be easily implanted/injected into the patients. In this context, colloid-based materials represent a very promising family of products because one can take advantage of their high specific area, their capability to carry/deliver bio-active molecules, and their capacity of assembling (eventually in vivo) into materials featuring other mechanical, rheological, physicochemical properties. Other benefits of great interest would be their ease of production even via high through-put processes and their potential manufacturing from safe, biodegradable and biocompatible parent raw material. This review describes the state-of-the-art of processes leading to complex materials from the assembly of colloids meeting, at least partially, the above-described specifications for tissue engineering and regenerative medicine.

  19. Regenerative fuel cell energy storage system for a low Earth orbit space station

    SciTech Connect

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

    1984-08-01

    Results of a study to define the characteristics of a regenerative fuel cell energy storage system for a large space station operating in low earth orbit (LEO) are presented. The regenerative fuel cell system employs an alkaline electrolyte fuel cell with the option of employing either an alkaline or a solid polymer electrolyte electrolyzer.

  20. The rational use of animal models in the evaluation of novel bone regenerative therapies.

    PubMed

    Peric, Mihaela; Dumic-Cule, Ivo; Grcevic, Danka; Matijasic, Mario; Verbanac, Donatella; Paul, Ruth; Grgurevic, Lovorka; Trkulja, Vladimir; Bagi, Cedo M; Vukicevic, Slobodan

    2015-01-01

    Bone has a high potential for endogenous self-repair. However, due to population aging, human diseases with impaired bone regeneration are on the rise. Current strategies to facilitate bone healing include various biomolecules, cellular therapies, biomaterials and different combinations of these. Animal models for testing novel regenerative therapies remain the gold standard in pre-clinical phases of drug discovery and development. Despite improvements in animal experimentation, excessive poorly designed animal studies with inappropriate endpoints and inaccurate conclusions are being conducted. In this review, we discuss animal models, procedures, methods and technologies used in bone repair studies with the aim to assist investigators in planning and performing scientifically sound experiments that respect the wellbeing of animals. In the process of designing an animal study for bone repair investigators should consider: skeletal characteristics of the selected animal species; a suitable animal model that mimics the intended clinical indication; an appropriate assessment plan with validated methods, markers, timing, endpoints and scoring systems; relevant dosing and statistically pre-justified sample sizes and evaluation methods; synchronization of the study with regulatory requirements and additional evaluations specific to cell-based approaches. This article is part of a Special Issue entitled "Stem Cells and Bone".

  1. Cryptomphalus aspersa Mollusc Egg Extract Promotes Regenerative Effects in Human Dermal Papilla Stem Cells

    PubMed Central

    Alameda, María Teresa; Morel, Esther; Parrado, Concepción; González, Salvador; Juarranz, Ángeles

    2017-01-01

    The aim of this study was to test, by an in vitro approach, whether a natural extract derived from eggs of the mollusc Cryptomphalus aspersa (e-CAF) that seems to present regenerative properties, can enhance the mobilization of human hair dermal papilla cells (HHDPCs) and play a role on tissue repair and regeneration. We have tested HHDPCs proliferation by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium-bromide (MTT) assay; cell migration by using a wound healing assay, as well as the modulation of the expression of cytoskeletal (F-actin and vimentin) and cell adhesion to the extracellular matrix (ECM) (vinculin and P-FAK) proteins. We also explored whether e-CAF could lead HHDPCs to keratinocytes and/or fibroblasts by evaluating the expression of specific markers. We have compared these e-CAF effects with those induced by TGFβ1, implicated in regulation of cell proliferation and migration. e-CAF promotes proliferation and migration of HHDPCs cells in a time- and dose-dependent manner; it also increases the migratory behavior and the expression of adhesion molecules. These results support the fact that e-CAF could play a role on skin regeneration and be used for the prevention or repair of damaged tissue, either due to external causes or as a result of cutaneous aging. PMID:28230777

  2. Local circadian clock gates cell cycle progression of transient amplifying cells during regenerative hair cycling

    PubMed Central

    Plikus, Maksim V.; Vollmers, Christopher; de la Cruz, Damon; Chaix, Amandine; Ramos, Raul; Panda, Satchidananda; Chuong, Cheng-Ming

    2013-01-01

    Regenerative cycling of hair follicles offers an unique opportunity to explore the role of circadian clock in physiological tissue regeneration. We focused on the role of circadian clock in actively proliferating transient amplifying cells, as opposed to quiescent stem cells. We identified two key sites of peripheral circadian clock activity specific to regenerating anagen hair follicles, namely epithelial matrix and mesenchymal dermal papilla. We showed that peripheral circadian clock in epithelial matrix cells generates prominent daily mitotic rhythm. As a consequence of this mitotic rhythmicity, hairs grow faster in the morning than in the evening. Because cells are the most susceptible to DNA damage during mitosis, this cycle leads to a remarkable time-of-day–dependent sensitivity of growing hair follicles to genotoxic stress. Same doses of γ-radiation caused dramatic hair loss in wild-type mice when administered in the morning, during mitotic peak, compared with the evening, when hair loss is minimal. This diurnal radioprotective effect becomes lost in circadian mutants, consistent with asynchronous mitoses in their hair follicles. Clock coordinates cell cycle progression with genotoxic stress responses by synchronizing Cdc2/Cyclin B-mediated G2/M checkpoint. Our results uncover diurnal mitotic gating as the essential protective mechanism in highly proliferative hair follicles and offer strategies for minimizing or maximizing cytotoxicity of radiation therapies. PMID:23690597

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  4. Engineering model system study for a regenerative fuel cell: study report

    SciTech Connect

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

    1984-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1984-09-01

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

  6. ``HYTEC''—A thermally regenerative fuel cell

    NASA Astrophysics Data System (ADS)

    Roy, Prodyot; Salamah, Samir A.; Maldonado, Jerry; Narkiewicz, Regina S.

    1993-01-01

    HYTEC (Hydrogen Thermo-Electrochemical Converter) is a thermally regenerative fuel cell for direct conversion of heat into electricity. The principles of basic cell operation involve ionic transport of hydrogen through a hydride-ion (H-) conducting, molten electrolyte, and reaction with alkali metals, oxygen, or air. In order to operate HYTEC in a thermally regenerative mode, pure Li and Na, or a mixture of Li/Na alloy, is used for reaction with hydrogen, to form metal hydride which is subsequently decomposed to metal and hydrogen at higher temperatures. The reactants are then separated and redirected to the electrochemical cell. In the cell the molten, H--conducting electrolyte is immobilized between two thin hydrogen-permeable, solid, metallic electrodes which also act as current collectors. The H2 gas first diffuses through the cathode electrode and forms a hydride ion (H+e→H-) at the cathode-electrolyte interface. The H- ion subsequently migrated through the electrolyte under a chemical potential gradient created by the presence of the alkali metal in the anode chamber. The H- ion releases the electron to form hydrogen atoms (H-→H+e) at the anode-electrolyte interface. The hydrogen atom diffuses through the anode electrode and reacts with the alkali metal to form metal hydride. The electron released passes through the load circuit to complete the cycle. In the regeneration scheme, the fuel cell is operated at temperature T1. The metal hydride formed at the anode is pumped to the decomposition chamber through a recuperator. The metal hydride is decomposed at a higher temperature, T2, by an external heat source. The H2 gas is separated from the alkali metal by a H2-permeable, solid, metallic membrane and fed into the anode chamber of the cell. The hydrogen-depleted alkali metal is directed to the cathode chamber of the cell, via the recuperator, to complete the cycle. To date, electrochemical feasibility of the concept has been experimentally demonstrated. A

  7. Nanotechnology-based approaches for regenerative medicine and biosensing

    NASA Astrophysics Data System (ADS)

    Solanki, Aniruddh P.

    The recent emergence of nanotechnology has set high expectations in many fields of science, especially in biology and medicine. Nanotechnology-based approaches are expected to solve key questions in the emerging field of regenerative medicine. Regenerative medicine essentially deals with regeneration of cells, ultimately leading to the formation of tissues and organs. For this purpose, stem cells, embryonic stem cells or adult stem cells, are thought to be ideal resources. However, many challenges need to be addressed before the full therapeutic potential of stem cells can be harnessed. Controlling the differentiation of stem cells into cells of a specific lineage is extremely vital and challenging. Addressing this challenge, in this work, novel nanotechnology-based approaches for controlling the differentiation of neural stem cells (NSCs) into neurons has been presented. Regeneration of damaged neurons, due to traumatic injuries or degenerative diseases, is extremely challenging. For this purpose, NSCs can be used as resources that can differentiate into neurons, thus having great potential in solving needs of many patients suffering from such conditions. For controlling the differentiation of stem cells, soluble cues (comprising of small molecules and biomolecules) and insoluble cues (cell-cell interactions and cell-microenvironment interactions) play a very important role. The delivery of soluble cues, such as genetic material, into stem cells is extremely challenging. The initial part of this work presents the use of nanomaterials for efficiently delivering soluble cues such as small molecules and small interfering RNA (siRNA) into NSCs for controlling their differentiation into neurons. However, for regenerative purposes, it is preferred that least amounts of the delivery vehicle be used. Thus, the following part of the thesis presents the development and applications of nanotechnology-based approaches for enhancing the differentiation of NSCs into neurons

  8. Adipose-derived stem cells retain their regenerative potential after methotrexate treatment

    SciTech Connect

    Beane, Olivia S.; Fonseca, Vera C.; Darling, Eric M.

    2014-10-01

    In musculoskeletal tissues like bone, chemotherapy can impair progenitor cell differentiation and proliferation, resulting in decreased bone growth and mineralization throughout a patient's lifetime. In the current study, we investigated the effects of chemotherapeutics on adipose-derived stem cell (ASC) function to determine whether this cell source could be a candidate for repairing, or even preventing, chemotherapy-induced tissue damage. Dose-dependent proliferation rates of ASCs and normal human fibroblasts (NHFs) were quantified after treatment with cytarabine (CY), etoposide (ETO), methotrexate (MTX), and vincristine (VIN) using a fluorescence-based assay. The influence of MTX on the multipotency of ASCs and freshly isolated stromal vascular fraction (SVF) cells was also evaluated using lineage-specific stains and spectrophotometry. ASC and NHF proliferation were equally inhibited by exposure to CY and ETO; however, when treated with MTX and VIN, ASCs exhibited greater resistance. This was especially apparent for MTX-treated samples, with ASC proliferation showing no inhibition for clinically relevant MTX doses ranging from 0.1 to 50 μM. Additional experiments revealed that the differentiation potential of ASCs was not affected by MTX treatment and that upregulation of dihydrofolate reductase possibly contributed to this response. Moreover, SVF cells, which include ASCs, exhibited similar resistance to MTX impairment, with respect to cellular proliferation, clonogenicity, and differentiation capability. Therefore, we have shown that the regenerative properties of ASCs resist the cytotoxicity of MTX, identifying these cells as a potential key for repairing musculoskeletal damage in patients undergoing chemotherapy. - Highlights: • Long-term effects of chemotherapeutics can include musculoskeletal dysfunction. • A screen of common drugs showed disparate effects on ASCs and fibroblasts. • One drug, methotrexate, did not impair ASC growth characteristics

  9. Development of a Regenerative PEM Fuel Cell System

    NASA Astrophysics Data System (ADS)

    Balomenou, Stella; Papazisi, Kalliopi-Maria; Tsiplakides, Dimitrios; Schrotti, Nivedita; Niakolas, Dimitrios; Geormezy, Maria; Theodorakopoulou, Eleni; Neophytides, Stylianos; Schautz, Max

    2014-08-01

    The objective of the current project was the development of a regenerative high temperature PEM fuel cell stack combined with a high pressure PEM water electrolyser. For that purpose, a complete closed loop system was designed and constructed, consisting of a storage system for reactants (H2, O2 and H2O), a fuel cell, and an electrolyser. The HT-PEM fuel cell stack was based on Advent's TPS® high temperature polymeric membranes (150-200oC). The electrolyser stack employed FuMA-Tech low temperature membranes and in-house synthesized high surface area IrO2 electrocatalyst as anode and Pt/C as cathode electrodes. The RPEMFC system delivered multiple cycles of fuel cell and electrolysis operation under the predefined load profile. This paper summarizes the results obtained during the long term testing of the RPEMFC system.

  10. Recent Developments of Regenerative Fuel Cell Systems for Satellites

    NASA Astrophysics Data System (ADS)

    Farnes, Jarle; Vik, Arild; Bokach, Dmitry; Svendsen, Tjalve; Schautz, Max; Geneste, Xavier

    2014-08-01

    Next generation telecommunication satellites will demand increasingly more power. Power levels of 30 kW or more are foreseen for the next 10 years. Battery technology that can sustain 30 kW for eclipse lengths of up to 72 minutes will represent a major impact on the total mass of the satellite, even with new Li-ion battery technologies. Regenerative fuel cell systems (RFCS) were identified years ago as a possible alternative to rechargeable batteries. CMR Prototech has investigated this technology in a series of projects initiated by ESA focusing on both the essential fuel cell technology, demonstration of cycle performance of a RFCS, corresponding to 15 years in orbit, as well as the very important reactants storage systems. This paper includes the main results from this work from the past 5 years.

  11. Regenerative fuel cell study for satellites in GEO orbit

    NASA Technical Reports Server (NTRS)

    Vandine, Leslie; Gonzalez-Sanabria, Olga; Levy, Alexander

    1987-01-01

    The results of a 12 month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application are summarized. Emphasis was placed on concepts with the potential for high energy density 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. Results indicate that using near term technology energy densities between 46 and 52 watt-hour/lb can be achieved at efficiencies of 55 percent. Using advanced light weight cell construction which was achieved in experimental cells, composite tankage material for the reactant gases and the reversible stack concept, system energy densities of 115 watt-hours/lb can be projected.

  12. Regenerative medicine for the treatment of heart disease.

    PubMed

    Hansson, E M; Lendahl, U

    2013-03-01

    Heart failure is a major cause of mortality worldwide with a steady increase in prevalence. There is currently no available cure beyond orthotopic heart transplantation, which for a number of reasons is an option only for a small fraction of all patients. Considerable hope has therefore been placed on the possibility of treating a failing heart by replacing lost cardiomyocytes, either through transplantation of various types of stem cells or by boosting endogenous regenerative mechanisms in the heart. Here, we review the current status of stem and progenitor cell-based therapies for heart disease. We discuss the pros and cons of different stem and progenitor cell types that can be considered for transplantation and describe recent advances in the understanding of how cardiomyocytes normally differentiate and how these cells can be generated from more immature cells ex vivo. Finally, we consider the possibility of activation of endogenous stem and progenitor cells to treat heart failure.

  13. Cell fusion: biological perspectives and potential for regenerative medicine.

    PubMed

    Alvarez-Dolado, Manuel

    2007-01-01

    Cell fusion has emerged as a powerful subject of debate in the last few years. Adult stem cell plasticity and the search for mechanisms to explain this process have led to the "rediscovery" of cell fusion. In nature, cell fusion is a normal process involved in sexual reproduction, tissue formation, and immune response. The recent observation that bone marrow derived cells fuse with several cell types introduces new and provocative questions. In this review, I shall recapitulate what is known about cell fusion and discuss its more controversial aspects. I shall highlight the most exciting open questions; its biological potential; pros and cons; and their implications on stem cell plasticity, regenerative medicine, and development.

  14. Alkaline regenerative fuel cell systems for energy storage

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  15. Regenerative flywheel energy storage system. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    1980-06-01

    The development, fabrication, and test of a regenerative flywheel energy storage and recovery system for a battery/flywheel electric vehicle of the 3000 pound class are described. The vehicle propulsion system was simulated on a digital computer in order to determine the optimum system operating strategies and to establish a calculated range improvement over a nonregenerative, all electric vehicle. Fabrication of the inductor motor, the flywheel, the power conditioner, and the system control are described. Test results of the system operating over the SAE J227a Schedule D driving cycle are given and are compared to the calculated value. The flywheel energy storage system consists of a solid rotor, synchronous, inductor type, flywheel drive machine electrically coupled to a dc battery electric propulsion system through a load commutated inverter. The motor/alternator unit is coupled mechanically to a small steel flywheel which provides a portion of the vehicle's accelerating energy and regenerates the vehicle's braking energy.

  16. The clinical use of regenerative therapy in COPD.

    PubMed

    Lipsi, Roberto; Rogliani, Paola; Calzetta, Luigino; Segreti, Andrea; Cazzola, Mario

    2014-01-01

    Regenerative or stem cell therapy is an emerging field of treatment based on stimulation of endogenous resident stem cells or administration of exogenous stem cells to treat diseases or injury and to replace malfunctioning or damaged tissues. Current evidence suggests that in the lung, these cells may participate in tissue homeostasis and regeneration after injury. Animal and human studies have demonstrated that tissue-specific stem cells and bone marrow-derived cells contribute to lung tissue regeneration and protection, and thus administration of exogenous stem/progenitor cells or humoral factors responsible for the activation of endogenous stem/progenitor cells may be a potent next-generation therapy for chronic obstructive pulmonary disease. The use of bone marrow-derived stem cells could allow repairing and regenerate the damaged tissue present in chronic obstructive pulmonary disease by means of their engraftment into the lung. Another approach could be the stimulation of resident stem cells by means of humoral factors or photobiostimulation.

  17. Microbiological characterization of a regenerative life support system

    NASA Technical Reports Server (NTRS)

    Koenig, D. W.; Bruce, R. J.; Mishra, S. K.; Barta, D. J.; Pierson, D. L.

    1994-01-01

    A Variable Pressure Plant Growth Chamber (VPGC), at the Johnson Space Center's (JSC) ground based Regenerative Life Support Systems (RLSS) test bed, was used to produce crops of soil-grown lettuce. The crops and chamber were analyzed for microbiological diversity during lettuce growth and after harvest. Bacterial counts for the rhizosphere, spent nutrient medium, heat exchanger condensate, and atmosphere were approximately 10(exp 11) Colony Forming Units (CFU)/g, 10(exp 5) CFU/ml, 10(exp 5)CFU/ml, and 600 CFU/m sq, repectively. Pseudomonas was the predominant bacterial genus. Numbers of fungi were about 10(exp 5) CFU/g in the rhizosphere, 4-200 CFU/ml in the spent nutient medium, 110 CFU/ml in the heat exchanger condensate, and 3 CFU/cu m in the atmosphere. Fusarium and Trichoderma were the predominant fungal genera.

  18. Regenerative multi-pass beam breakup in two dimensions

    SciTech Connect

    Eduard Pozdeyev

    2004-12-01

    In this paper, a formula, describing a threshold of the regenerative multi-pass Beam Breakup (BBU) for a single dipole higher order mode with arbitrary polarization in a two-pass accelerator with a general-form, 4x4 recirculation matrix, is derived. Also a new two-dimensional BBU code is introduced. To illustrate specifics of the BBU in two dimensions, the formula is used to calculate the threshold in several cases including two-dimensional uncoupled optics, reflecting optics, and rotating optics. The analytical results are compared to results of simulation obtained with the new code. At the end of the paper, a mathematical relation between transfer matrices between cavities of the accelerating structure and recirculation matrices for each cavity, which must be satisfied in order to successfully suppress the BBU by reflection or rotation in several cavities, is presented.

  19. Current overview on dental stem cells applications in regenerative dentistry

    PubMed Central

    Bansal, Ramta; Jain, Aditya

    2015-01-01

    Teeth are the most natural, noninvasive source of stem cells. Dental stem cells, which are easy, convenient, and affordable to collect, hold promise for a range of very potential therapeutic applications. We have reviewed the ever-growing literature on dental stem cells archived in Medline using the following key words: Regenerative dentistry, dental stem cells, dental stem cells banking, and stem cells from human exfoliated deciduous teeth. Relevant articles covering topics related to dental stem cells were shortlisted and the facts are compiled. The objective of this review article is to discuss the history of stem cells, different stem cells relevant for dentistry, their isolation approaches, collection, and preservation of dental stem cells along with the current status of dental and medical applications. PMID:25810631

  20. Simple Signaling Molecules for Inductive Bone Regenerative Engineering

    PubMed Central

    Nelson, Stephen J.; Deng, Meng; Sethuraman, Swaminathan; Doty, Stephen B.; Lo, Kevin W. H.; Khan, Yusuf M.; Laurencin, Cato T.

    2014-01-01

    With greater than 500,000 orthopaedic procedures performed in the United States each year requiring a bone graft, the development of novel graft materials is necessary. We report that some porous polymer/ceramic composite scaffolds possess intrinsic osteoinductivity as shown through their capacity to induce in vivo host osteoid mineralization and in vitro stem cell osteogenesis making them attractive synthetic bone graft substitutes. It was discovered that certain low crystallinity ceramics partially dissociate into simple signaling molecules (i.e., calcium and phosphate ions) that induce stem cells to endogenously produce their own osteoinductive proteins. Review of the literature has uncovered a variety of simple signaling molecules (i.e., gases, ions, and redox reagents) capable of inducing other desirable stem cell differentiation through endogenous growth factor production. Inductive simple signaling molecules, which we have termed inducerons, represent a paradigm shift in the field of regenerative engineering where they can be utilized in place of recombinant protein growth factors. PMID:25019622

  1. Treatment Options: Biological Basis of Regenerative Endodontic Procedures

    PubMed Central

    Hargreaves, Kenneth M.; Diogenes, Anibal; Teixeira, Fabricio B.

    2013-01-01

    Dental trauma occurs frequently in children and often can lead to pulpal necrosis. The occurrence of pulpal necrosis in the permanent but immature tooth represents a challenging clinical situation since the thin and often short roots increase the risk of subsequent fracture. Current approaches for treating the traumatized immature tooth with pulpal necrosis do not reliably achieve the desired clinical outcomes, consisting of healing of apical periodontitis, promotion of continued root development and restoration of the functional competence of pulpal tissue. An optimal approach for treating the immature permanent tooth with a necrotic pulp would be to regenerate functional pulpal tissue. This review summarizes the current literature supporting a biological rationale for considering regenerative endodontic treatment procedures in treating the immature permanent tooth with pulp necrosis. PMID:23439043

  2. miRNA Inhibition in Tissue Engineering and Regenerative Medicine

    PubMed Central

    Beavers, Kelsey R.; Nelson, Christopher E.; Duvall, Craig L.

    2014-01-01

    MicroRNA (miRNA) are noncoding RNA that provide an endogenous negative feedback mechanism for translation of messenger RNA (mRNA) into protein. Single miRNAs can regulate hundreds of mRNAs, enabling miRNAs to orchestrate robust biological responses by simultaneously impacting multiple gene networks. MiRNAs can act as master regulators of normal and pathological tissue development, homeostasis, and repair, which has recently motivated expanding efforts toward development of technologies for therapeutically modulating miRNA activity for regenerative medicine and tissue engineering applications. This review highlights the tools currently available for miRNA inhibition and their recent therapeutic applications for improving tissue repair. PMID:25553957

  3. Regenerative Life Support Systems Test Bed performance - Lettuce crop characterization

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Edeen, Marybeth A.; Eckhardt, Bradley D.

    1992-01-01

    System performance in terms of human life support requirements was evaluated for two crops of lettuce (Lactuca sative cv. Waldmann's Green) grown in the Regenerative Life Support Systems Test Bed. Each crop, grown in separate pots under identical environmental and cultural conditions, was irrigated with half-strength Hoagland's nutrient solution, with the frequency of irrigation being increased as the crop aged over the 30-day crop tests. Averaging over both crop tests, the test bed met the requirements of 2.1 person-days of oxygen production, 2.4 person-days of CO2 removal, and 129 person-days of potential potable water production. Gains in the mass of water and O2 produced and CO2 removed could be achieved by optimizing environmental conditions to increase plant growth rate and by optimizing cultural management methods.

  4. Regenerative braking device with rotationally mounted energy storage means

    DOEpatents

    Hoppie, Lyle O.

    1982-03-16

    A regenerative braking device for an automotive vehicle includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (30) and an output shaft (32), clutches (50, 56) and brakes (52, 58) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. In a second embodiment the clutches and brakes are dispensed with and the variable ratio transmission is connected directly across the input and output shafts. In both embodiments the rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft rotates faster or relative to the output shaft and are torsionally relaxed to deliver energy to the vehicle when the output shaft rotates faster or relative to the input shaft.

  5. Chitosan and fish collagen as biomaterials for regenerative medicine.

    PubMed

    Hayashi, Yoshihiko; Yamada, Shizuka; Yanagi Guchi, Kajiro; Koyama, Zenya; Ikeda, Takeshi

    2012-01-01

    This chapter focuses and reviews on the characteristics and biomedical application of chitosan and collagen from marine products and advantages and disadvantages of regeneration medicine. The understanding of the production processes of chitosan and collagen and the conformation of these biomaterials are indispensable for promoting the theoretical and practical availability. The initial inflammatory reactions associated with chitosan application to hard and soft tissues need to be controlled before it can be considered for clinical application as scaffold. Further, as chitosan takes too long for biodegradation in vivo, generally it is not suitable for the scaffold for degenerative medicine in especially dental pulp tissue. The collagen extract from the scales of tropical fish has been reported to have a degeneration temperature of 35°C. The properties of biocompatibility and biodegradation of fish atelocollagen are suitable for the scaffold in regenerative medicine.

  6. Free-piston regenerative hot gas hydraulic engine

    NASA Technical Reports Server (NTRS)

    Beremand, D. G. (Inventor)

    1980-01-01

    A displacer piston which is driven pneumatically by a high-pressure or low-pressure gas is included in a free-piston regenerative hydraulic engine. Actuation of the displacer piston circulates the working fluid through a heater, a regenerator and a cooler. The present invention includes an inertial mass such as a piston or a hydraulic fluid column to effectively store and supply energy during portions of the cycle. Power is transmitted from the working fluid to a hydraulic fluid across a diaphragm or lightweight piston to achieve a hydraulic power out-put. The displacer piston of the present invention may be driven pneumatically, hydraulically or electromagnetically. In addition, the displacer piston and the inertial mass of the present invention may be positioned on the same side of the diaphragm member or may be separated by the diaphragm member.

  7. Preserving human cells for regenerative, reproductive, and transfusion medicine

    PubMed Central

    Asghar, Waseem; Assal, Rami El; Shafiee, Hadi; Anchan, Raymond M.; Demirci, Utkan

    2014-01-01

    Cell cryopreservation enables maintaining cellular life at sub-zero temperatures by slowing down biochemical processes. Various cell types are routinely cryopreserved in modern reproductive, regenerative, and transfusion medicine. Current cell cryopreservation methods involve freezing (slow/rapid) or vitrifying cells in the presence of a cryoprotective agent (CPA). Although these methods are clinically utilized, cryo-injury due to ice crystals, osmotic shock, and CPA toxicity cause loss of cell viability and function. Recent approaches using minimum volume vitrification provide alternatives to the conventional cryopreservation methods. Minimum volume vitrification provides ultra-high cooling and rewarming rates that enable preserving cells without ice crystal formation. Herein, we review recent advances in cell cryopreservation technology and provide examples of techniques that are utilized in oocyte, stem cell, and red blood cell cryopreservation. PMID:24995723

  8. Regenerative fuel cells for use in Space Stations

    NASA Astrophysics Data System (ADS)

    Benz, Uwe; Tillmetz, Werner

    1990-10-01

    The conversion and storage of energy with high efficiency and high energy density, respectively, will be an important factor in future space activities as well as for terrestrial applications. The basic concepts of a regenerative fuel cell system (RFCS) based on the immobile alkaline electrolyte technology, which has been identified as the most promising technology for space application, are presented. A system optimization with respect to a minimum overall mass has been performed, and the main design data are given. Some system engineering aspects are discussed, as well as possible interfaces to other space systems. A brief comparison shows that even from a system-mass point of view the RFCS has an advantage over batteries.

  9. Bioengineering Heart Muscle: A Paradigm for Regenerative Medicine

    PubMed Central

    Lui, Kathy O.; Tandon, Nina

    2012-01-01

    The idea of extending the lifetime of our organs is as old as humankind, fueled by major advances in organ transplantation, novel drugs, and medical devices. However, true regeneration of human tissue has becoming increasingly plausible only in recent years. The human heart has always been a focus of such efforts, given its notorious inability to repair itself following injury or disease. We discuss here the emerging bioengineering approaches to regeneration of heart muscle as a paradigm for regenerative medicine. Our focus is on biologically inspired strategies for heart regeneration, knowledge gained thus far about how to make a “perfect” heart graft, and the challenges that remain to be addressed for tissue-engineered heart regeneration to become a clinical reality. We emphasize the need for interdisciplinary research and training, as recent progress in the field is largely being made at the interfaces between cardiology, stem cell science, and bioengineering. PMID:21568715

  10. MiRNA inhibition in tissue engineering and regenerative medicine.

    PubMed

    Beavers, Kelsey R; Nelson, Christopher E; Duvall, Craig L

    2015-07-01

    MicroRNAs (miRNAs) are noncoding RNAs that provide an endogenous negative feedback mechanism for translation of messenger RNA (mRNA) into protein. Single miRNAs can regulate hundreds of mRNAs, enabling miRNAs to orchestrate robust biological responses by simultaneously impacting multiple gene networks. MiRNAs can act as master regulators of normal and pathological tissue development, homeostasis, and repair, which has motivated expanding efforts toward the development of technologies for therapeutically modulating miRNA activity for regenerative medicine and tissue engineering applications. This review highlights the tools currently available for miRNA inhibition and their recent therapeutic applications for improving tissue repair.

  11. Microbiological characterization of a regenerative life support system

    NASA Astrophysics Data System (ADS)

    Koenig, D. W.; Bruce, R. J.; Mishra, S. K.; Barta, D. J.; Pierson, D. L.

    1994-11-01

    A Variable Pressure Plant Growth Chamber (VPGC), at the Johnson Space Center's (JSC) ground-based Regenerative Life Support Systems (RLSS) test bed, was used to produce crops of soil-grown lettuce. The crops and chamber were analyzed for microbiological diversity during lettuce growth and after harvest. Bacterial counts for the rhizosphere, spent nutrient medium, heat exchanger condensate, and atmosphere were approximately 1011 Colony Forming Units (CFU) g-1, 105 CFU ml-1, 105 CFU ml-1, and 600 CFU m-3, respectively. Pseudomonas was the predominant bacterial genus. Numbers of fungi were about 105 CFU g-1 in the rhizosphere, 4-200 CFU ml-1 in thespent nutrient medium, 110 CFU ml-1 in the heat exchanger condensate, and 3 CFU m-3 in the atmosphere. Fusarium and Trichoderma were the predominant fungal genera.

  12. Noise optimization of a regenerative automotive fuel pump

    NASA Astrophysics Data System (ADS)

    Wang, J. F.; Feng, H. H.; Mou, X. L.; Huang, Y. X.

    2017-03-01

    The regenerative pump used in automotive is facing a noise problem. To understand the mechanism in detail, Computational Fluid Dynamics (CFD) and Computational Acoustic Analysis (CAA) together were used to understand the fluid and acoustic characteristics of the fuel pump using ANSYS-CFX 15.0 and LMS Virtual. Lab Rev12, respectively. The CFD model and acoustical model were validated by mass flow rate test and sound pressure test, respectively. Comparing the computational and experimental results shows that sound pressure levels at the observer position are consistent at high frequencies, especially at blade passing frequency. After validating the models, several numerical models were analyzed in the study for noise improvement. It is observed that for configuration having greater number of impeller blades, noise level was significantly improved at blade passing frequency, when compared to that of the original model.

  13. Quantification of regenerative potential in primary human mammary epithelial cells

    PubMed Central

    Linnemann, Jelena R.; Miura, Haruko; Meixner, Lisa K.; Irmler, Martin; Kloos, Uwe J.; Hirschi, Benjamin; Bartsch, Harald S.; Sass, Steffen; Beckers, Johannes; Theis, Fabian J.; Gabka, Christian; Sotlar, Karl; Scheel, Christina H.

    2015-01-01

    We present an organoid regeneration assay in which freshly isolated human mammary epithelial cells are cultured in adherent or floating collagen gels, corresponding to a rigid or compliant matrix environment. In both conditions, luminal progenitors form spheres, whereas basal cells generate branched ductal structures. In compliant but not rigid collagen gels, branching ducts form alveoli at their tips, express basal and luminal markers at correct positions, and display contractility, which is required for alveologenesis. Thereby, branched structures generated in compliant collagen gels resemble terminal ductal-lobular units (TDLUs), the functional units of the mammary gland. Using the membrane metallo-endopeptidase CD10 as a surface marker enriches for TDLU formation and reveals the presence of stromal cells within the CD49fhi/EpCAM− population. In summary, we describe a defined in vitro assay system to quantify cells with regenerative potential and systematically investigate their interaction with the physical environment at distinct steps of morphogenesis. PMID:26071498

  14. Microbiological characterization of a regenerative life support system.

    PubMed

    Koenig, D W; Bruce, R J; Mishra, S K; Barta, D J; Pierson, D L

    1994-11-01

    A Variable Pressure Plant Growth Chamber (VPGC), at the Johnson Space Center's (JSC) ground-based Regenerative Life Support Systems (RLSS) test bed, was used to produce crops of soil-grown lettuce. The crops and chamber were analyzed for microbiological diversity during lettuce growth and after harvest. Bacterial counts for the rhizosphere, spent nutrient medium, heat exchanger condensate, and atmosphere were approximately 10(11) Colony Forming Units (CFU) g-1 10(5) CFU ml-1, 10(5) CFU ml-1, and 600 CFU m-3, respectively. Pseudomonas was the predominant bacterial genus. Numbers of fungi were about 10(5) CFU g-1 in the rhizosphere, 4-200 CFU ml-1 in the spent nutrient medium, 110 CFU ml-1 in the heat exchanger condensate, and 3 CFU m-3 in the atmosphere. Fusarium and Trichoderma were the predominant fungal genera.

  15. Quantification of regenerative potential in primary human mammary epithelial cells.

    PubMed

    Linnemann, Jelena R; Miura, Haruko; Meixner, Lisa K; Irmler, Martin; Kloos, Uwe J; Hirschi, Benjamin; Bartsch, Harald S; Sass, Steffen; Beckers, Johannes; Theis, Fabian J; Gabka, Christian; Sotlar, Karl; Scheel, Christina H

    2015-09-15

    We present an organoid regeneration assay in which freshly isolated human mammary epithelial cells are cultured in adherent or floating collagen gels, corresponding to a rigid or compliant matrix environment. In both conditions, luminal progenitors form spheres, whereas basal cells generate branched ductal structures. In compliant but not rigid collagen gels, branching ducts form alveoli at their tips, express basal and luminal markers at correct positions, and display contractility, which is required for alveologenesis. Thereby, branched structures generated in compliant collagen gels resemble terminal ductal-lobular units (TDLUs), the functional units of the mammary gland. Using the membrane metallo-endopeptidase CD10 as a surface marker enriches for TDLU formation and reveals the presence of stromal cells within the CD49f(hi)/EpCAM(-) population. In summary, we describe a defined in vitro assay system to quantify cells with regenerative potential and systematically investigate their interaction with the physical environment at distinct steps of morphogenesis.

  16. Regenerative fuel cell architectures for lunar surface power

    NASA Astrophysics Data System (ADS)

    Harris, D. W.; Gill, S. P.; Nguyen, T. M.; Vrolyk, J. J.

    1991-09-01

    Various Regenerative Fuel Cell (RFC) configurations for the stationary lunar missions were examined using a RFC computer model. For the stationary applications, a GaAs/Ge photovoltaic (PV) array with a 3000 psi gas storage proton exchange membrane (PEM) RFC providing 25 kWe during the day and 12.5 kWe at night was designed. PV/RFC systems utilizing supercritical H2/O2 storage and cryogenic H2/O2 storage for the RFCs were then compared with the baseline high pressure gas storage RFC system. Preliminary results indicate that for long duration nighttime operation missions, the supercritical H2/O2 storage RFC systems offer over 20 percent mass advantage over the high pressure gas storage while the mass savings for the cryogenic H2/O2 storage RFC systems can be as high as 30 percent.

  17. Regenerative fuel cell architectures for lunar surface power

    NASA Technical Reports Server (NTRS)

    Harris, D. W.; Gill, S. P.; Nguyen, T. M.; Vrolyk, J. J.

    1991-01-01

    Various Regenerative Fuel Cell (RFC) configurations for the stationary lunar missions were examined using a RFC computer model. For the stationary applications, a GaAs/Ge photovoltaic (PV) array with a 3000 psi gas storage proton exchange membrane (PEM) RFC providing 25 kWe during the day and 12.5 kWe at night was designed. PV/RFC systems utilizing supercritical H2/O2 storage and cryogenic H2/O2 storage for the RFCs were then compared with the baseline high pressure gas storage RFC system. Preliminary results indicate that for long duration nighttime operation missions, the supercritical H2/O2 storage RFC systems offer over 20 percent mass advantage over the high pressure gas storage while the mass savings for the cryogenic H2/O2 storage RFC systems can be as high as 30 percent.

  18. Compact Water Vapor Exchanger for Regenerative Life Support Systems

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Anderson, Molly; Hodgson, Edward

    2012-01-01

    Thermal and environmental control systems for future exploration spacecraft must meet challenging requirements for efficient operation and conservation of resources. Regenerative CO2 removal systems are attractive for these missions because they do not use consumable CO2 absorbers. However, these systems also absorb and vent water to space along with carbon dioxide. This paper describes an innovative device designed to minimize water lost from regenerative CO2 control systems. Design studies and proof-of-concept testing have shown the feasibility of a compact, efficient membrane water vapor exchanger (WVX) that will conserve water while meeting challenging requirements for operation on future spacecraft. Compared to conventional WVX designs, the innovative membrane WVX described here has the potential for high water recovery efficiency, compact size, and very low pressure losses. The key innovation is a method for maintaining highly uniform flow channels in a WVX core built from water-permeable membranes. The proof-of-concept WVX incorporates all the key design features of a prototypical unit, except that it is relatively small scale (1/23 relative to a unit sized for a crew of six) and some components were fabricated using non-prototypical methods. The proof-of-concept WVX achieved over 90% water recovery efficiency in a compact core in good agreement with analysis models. Furthermore the overall pressure drop is very small (less than 0.5 in. H2O, total for both flow streams) and meets requirements for service in environmental control and life support systems on future spacecraft. These results show that the WVX provides very uniform flow through flow channels for both the humid and dry streams. Measurements also show that CO2 diffusion through the water-permeable membranes will have negligible effect on the CO2 partial pressure in the spacecraft atmosphere.

  19. Development of a Microwave Regenerative Sorbent-Based Hydrogen Purifier

    NASA Technical Reports Server (NTRS)

    Wheeler, Richard R., Jr.; Dewberry, Ross H.; McCurry, Bryan D.; Abney, Morgan B.; Greenwood, Zachary W.

    2016-01-01

    This paper describes the design and fabrication of a Microwave Regenerative Sorbent-based Hydrogen Purifier (MRSHP). This unique microwave powered technology was developed for the purification of a hydrogen stream produced by the Plasma Pyrolysis Assembly (PPA). The PPA is a hydrogen recovery (from methane) post processor for NASA's Sabatier-based carbon dioxide reduction process. Embodied in the Carbon dioxide Reduction Assembly (CRA), currently aboard the International Space Station (ISS), the Sabatier reaction employs hydrogen to catalytically recover oxygen, in the form of water, from respiratory carbon dioxide produced by the crew. This same approach is base-lined for future service in the Air Revitalization system on extended missions into deep space where resupply is not practical. Accordingly, manned exploration to Mars may only become feasible with further closure of the air loop as afforded by the greater hydrogen recovery permitted by the PPA with subsequent hydrogen purification. By utilizing the well-known high sorbate loading capacity of molecular sieve 13x, coupled with microwave dielectric heating phenomenon, MRSHP technology is employed as a regenerative filter for a contaminated hydrogen gas stream. By design, freshly regenerated molecular sieve 13x contained in the MRSHP will remove contaminants from the effluent of a 1-CM scale PPA for several hours prior to breakthrough. By reversing flow and pulling a relative vacuum the MRSHP prototype then uses 2.45 GHz microwave power, applied through a novel coaxial antenna array, to rapidly heat the sorbent bed and drive off the contaminants in a short duration vacuum/thermal contaminant desorption step. Finally, following rapid cooling via room temperature cold plates, the MRSHP is again ready to serve as a hydrogen filter.

  20. Tissue-engineering-based Strategies for Regenerative Endodontics

    PubMed Central

    Albuquerque, M.T.P.; Valera, M.C.; Nakashima, M.; Nör, J.E.; Bottino, M.C.

    2014-01-01

    Stemming from in vitro and in vivo pre-clinical and human models, tissue-engineering-based strategies continue to demonstrate great potential for the regeneration of the pulp-dentin complex, particularly in necrotic, immature permanent teeth. Nanofibrous scaffolds, which closely resemble the native extracellular matrix, have been successfully synthesized by various techniques, including but not limited to electrospinning. A common goal in scaffold synthesis has been the notion of promoting cell guidance through the careful design and use of a collection of biochemical and physical cues capable of governing and stimulating specific events at the cellular and tissue levels. The latest advances in processing technologies allow for the fabrication of scaffolds where selected bioactive molecules can be delivered locally, thus increasing the possibilities for clinical success. Though electrospun scaffolds have not yet been tested in vivo in either human or animal pulpless models in immature permanent teeth, recent studies have highlighted their regenerative potential both from an in vitro and in vivo (i.e., subcutaneous model) standpoint. Possible applications for these bioactive scaffolds continue to evolve, with significant prospects related to the regeneration of both dentin and pulp tissue and, more recently, to root canal disinfection. Nonetheless, no single implantable scaffold can consistently guide the coordinated growth and development of the multiple tissue types involved in the functional regeneration of the pulp-dentin complex. The purpose of this review is to provide a comprehensive perspective on the latest discoveries related to the use of scaffolds and/or stem cells in regenerative endodontics. The authors focused this review on bioactive nanofibrous scaffolds, injectable scaffolds and stem cells, and pre-clinical findings using stem-cell-based strategies. These topics are discussed in detail in an attempt to provide future direction and to shed light on

  1. Tissue-engineering-based strategies for regenerative endodontics.

    PubMed

    Albuquerque, M T P; Valera, M C; Nakashima, M; Nör, J E; Bottino, M C

    2014-12-01

    Stemming from in vitro and in vivo pre-clinical and human models, tissue-engineering-based strategies continue to demonstrate great potential for the regeneration of the pulp-dentin complex, particularly in necrotic, immature permanent teeth. Nanofibrous scaffolds, which closely resemble the native extracellular matrix, have been successfully synthesized by various techniques, including but not limited to electrospinning. A common goal in scaffold synthesis has been the notion of promoting cell guidance through the careful design and use of a collection of biochemical and physical cues capable of governing and stimulating specific events at the cellular and tissue levels. The latest advances in processing technologies allow for the fabrication of scaffolds where selected bioactive molecules can be delivered locally, thus increasing the possibilities for clinical success. Though electrospun scaffolds have not yet been tested in vivo in either human or animal pulpless models in immature permanent teeth, recent studies have highlighted their regenerative potential both from an in vitro and in vivo (i.e., subcutaneous model) standpoint. Possible applications for these bioactive scaffolds continue to evolve, with significant prospects related to the regeneration of both dentin and pulp tissue and, more recently, to root canal disinfection. Nonetheless, no single implantable scaffold can consistently guide the coordinated growth and development of the multiple tissue types involved in the functional regeneration of the pulp-dentin complex. The purpose of this review is to provide a comprehensive perspective on the latest discoveries related to the use of scaffolds and/or stem cells in regenerative endodontics. The authors focused this review on bioactive nanofibrous scaffolds, injectable scaffolds and stem cells, and pre-clinical findings using stem-cell-based strategies. These topics are discussed in detail in an attempt to provide future direction and to shed light on

  2. Modality-Specific Axonal Regeneration: Toward Selective Regenerative Neural Interfaces

    PubMed Central

    Lotfi, Parisa; Garde, Kshitija; Chouhan, Amit K.; Bengali, Ebrahim; Romero-Ortega, Mario I.

    2011-01-01

    Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control of robotic prosthetic devices. However, sensory and motor axons at the neural interface are of mixed sub-modality types, which difficult the specific recording from motor axons and the eliciting of precise sensory modalities through selective stimulation. Here we evaluated the possibility of using type specific neurotrophins to preferentially entice the regeneration of defined axonal populations from transected peripheral nerves into separate compartments. Segregation of mixed sensory fibers from dorsal root ganglion neurons was evaluated in vitro by compartmentalized diffusion delivery of nerve growth factor (NGF) and neurotrophin-3 (NT-3), to preferentially entice the growth of TrkA+ nociceptive and TrkC+ proprioceptive subsets of sensory neurons, respectively. The average axon length in the NGF channel increased 2.5-fold compared to that in saline or NT-3, whereas the number of branches increased threefold in the NT-3 channels. These results were confirmed using a 3D “Y”-shaped in vitro assay showing that the arm containing NGF was able to entice a fivefold increase in axonal length of unbranched fibers. To address if such segregation can be enticed in vivo, a “Y”-shaped tubing was used to allow regeneration of the transected adult rat sciatic nerve into separate compartments filled with either NFG or NT-3. A significant increase in the number of CGRP+ pain fibers were attracted toward the sural nerve, while N-52+ large-diameter axons were observed in the tibial and NT-3 compartments. This study demonstrates the guided enrichment of sensory axons in specific regenerative chambers, and supports the notion that neurotrophic factors can be used to segregate sensory and perhaps motor axons in separate peripheral interfaces. PMID:22016734

  3. Stem cells and regenerative medicine for diabetes mellitus.

    PubMed

    Sumi, Shoichiro; Gu, Yuanjun; Hiura, Akihito; Inoue, Kazutomo

    2004-10-01

    A profound knowledge of the development and differentiation of pancreatic tissues, especially islets of Langerhans, is necessary for developing regenerative therapy for severe diabetes mellitus. A recent developmental study showed that PTF-1a is expressed in almost all parts of pancreatic tissues, in addition to PDX-1, a well-known transcription factor that is essential for pancreas development. Another study suggested that alpha cells and beta cells individually, but not sequentially, differentiated from neurogenin-3--expressing precursor cells. Under strong induction of pancreas regeneration, it is likely that pancreatic duct cells dedifferentiate to grow, express PDX-1, and re-differentiate toward other cell types including islet cells. Duct epithelium-like cells can be cultivated from crude pancreatic exocrine cells and can be induced to differentiate toward islet-like cell clusters under some culture conditions. These cell clusters made from murine pancreas have been shown to control hyperglycemia when transplanted into diabetic mice. Liver-derived oval cells and their putative precursor H-CFU-C have been shown to differentiate toward pancreatic cells. Furthermore, extrapancreatic cells contained in bone marrow and amniotic membrane are reported to become insulin-producing cells. However, their exact characterization and relationship between these cell types remain to be elucidated. Our recent study has shown that islet-like cell clusters can be differentiated from mouse embryonic stem cells. Transplantation of these clusters could ameliorate hyperglycemia of STZ-induced diabetic mice without forming teratomas. Interestingly, these cells expressed several genes specific to exocrine pancreatic tissue in addition to islet-related genes, suggesting that stable and efficient differentiation toward certain tissues can only be achieved through a process mimicking normal development of the tissue. Perhaps recent developments in these fields may rapidly lead to an

  4. Mesenchymal stem cell and regenerative medicine: regeneration versus immunomodulatory challenges

    PubMed Central

    Law, Sujata; Chaudhuri, Samaresh

    2013-01-01

    Mesenchymal Stem cells (MSC) are now presented with the opportunities of multifunctional therapeutic approaches. Several reports are in support of their self-renewal, capacity for multipotent differentiation, and immunomodulatory properties. They are unique to contribute to the regeneration of mesenchymal tissues such as bone, cartilage, muscle, ligament, tendon, and adipose. In addition to promising trials in regenerative medicine, such as in the treatment of major bone defects and myocardial infarction, MSC has shown a therapeutic effect other than direct hematopoiesis support in hematopoietic reconstruction. MSCs are identified by the expression of many molecules including CD105 (SH2) and CD73(SH3/4) and are negative for the hematopoietic markers CD34, CD45, and CD14. Manufacturing of MSC for clinical trials is also an important aspect as their differentiation, homing and Immunomodulatory properties may differ. Their suppressive effects on immune cells, including T cells, B cells, NK cells and DC cells, suggest MSCs as a novel therapy for GVHD and other autoimmune disorders. Since the cells by themselves are non-immunogenic, tissue matching between MSC donor and recipient is not essential and, MSC may be the first cell type able to be used as an “off-the-shelf” therapeutic product. Following a successful transplantation, the migration of MSC to the site of injury refers to the involvement of chemokines and chemokine receptors of respective specificity. It has been demonstrated that cultured MSCs have the ability to engraft into healthy as well as injured tissue and can differentiate into several cell types in vivo, which facilitates MSC to be an ideal tool for regenerative therapy in different disease types. However, some observations have raised questions about the limitations for proper use of MSC considering some critical factors that warn regular clinical use. PMID:23671814

  5. Performance analysis of reciprocating regenerative magnetic heat pumping

    NASA Astrophysics Data System (ADS)

    Chen, D. T.; Murphy, R. W.; Mei, V. C.; Chen, F. C.; Lue, J. W.; Lubell, M. S.

    1994-02-01

    Transient flow phenomena in the regenerator tube of reciprocating magnetic heat pumps have been studied numerically and experimentally. In the numerical study, two approaches were taken: (1) solving the energy balance equations for fluid through a porous bed directly and (2) solving the Navier-Stokes equations with a buoyancy force term in the momentum equation. A flow thermal mixing problem was found in both approaches because of the piston-like motion of the regenerator tube that hinders the development of the temperature. The numerical study results show that a 45 K temperature span can be reached in 10 minutes of charge time through the use of a 7-Tesla magnetic field. Using the second numerical approach, temperature stratification in the regenerator fluid column was clearly indicated through temperature rasters. The study also calculates regenerator efficiency and energy delivery rates when heating load and cooling load are applied. Piecewise variation of the regenerator tube moving speed has been used in the present numerical study to control the mass flow rate, reduce thermal mixing of the flow and thus the regenerative losses. The gadolinium's adiabatic temperature has been measured under 6.5 Tesla of magnet field and different of operating temperatures ranging from 285 K to 320 K. Three regenerative heat pumping tests have also been conducted based on the Reynolds number of the regenerator tube flow, namely Re=300, Re=450, and Re=750 without loads. Maximum temperature span are 12 & 11 K and 9 K for the case of Re=300, Re=450 and Re=750, respectively. Experimental data are in good agreement with the numerical calculation results, and have been used to calibrate the numerical results and to develop a design database for reciprocating-type room-temperature magnetic heat pumps.

  6. Performance analysis of reciprocating regenerative magnetic heat pumping. Final report

    SciTech Connect

    Chen, D.T.; Murphy, R.W.; Mei, V.C.; Chen, F.C.; Lue, J.W.; Lubell, M.S.

    1994-02-01

    Transient flow phenomena in the regenerator tube of reciprocating magnetic heat pumps have been studied numerically and experimentally. In the numerical study, two approaches were taken: (1) solving the energy balance equations for fluid through a porous bed directly and (2) solving the Navier-Stokes equations with a buoyancy force term in the momentum equation. A flow thermal mixing problem was found in both approaches because of the piston-like motion of the regenerator tube that hinders the development of the temperature. The numerical study results show that a 45 K temperature span can be reached in 10 minutes of charge time through the use of a 7-Tesla magnetic field. Using the second numerical approach, temperature stratification in the regenerator fluid column was clearly indicated through temperature rasters. The study also calculates regenerator efficiency and energy delivery rates when heating load and cooling load are applied. Piecewise variation of the regenerator tube moving speed has been used in the present numerical study to control the mass flow rate, reduce thermal mixing of the flow and thus the regenerative losses. The gadolinium`s adiabatic temperature has been measured under 6.5 Tesla of magnet field and different of operating temperatures ranging from 285 K to 320 K. Three regenerative heat pumping tests have also been conducted based on the Reynolds number of the regenerator tube flow, namely Re=300, Re=450, and Re=750 without loads. Maximum temperature span are 12 & 11 K and 9 K for the case of Re=300, Re=450 and Re=750, respectively. Experimental data are in good agreement with the numerical calculation results, and have been used to calibrate the numerical results and to develop a design database for reciprocating-type room-temperature magnetic heat pumps.

  7. Free radical scavenging injectable hydrogels for regenerative therapy.

    PubMed

    Komeri, Remya; Thankam, Finosh Gnanaprakasam; Muthu, Jayabalan

    2017-02-01

    Pathological free radicals generated from inflamed and infarcted cardiac tissues interferes natural tissue repair mechanisms. Hypoxic microenvironment at the injured zone of non-regenerating cardiac tissues hinders the therapeutic attempts including cell therapy. Here we report an injectable, cytocompatible, free radical scavenging synthetic hydrogel formulation for regenerative therapy. New hydrogel (PEAX-P) is prepared with D-xylitol-co-fumarate-co-poly ethylene adipate-co-PEG comaromer (PEAX) and PEGDiacrylate. PEAX-P hydrogel swells 4.9 times the initial weight and retains 100.07kPa Young modulus at equilibrium swelling, which is suitable for cardiac applications. PEAX-P hydrogel retains elastic nature even at 60% compressive strain, which is favorable to fit with the dynamic and elastic natural tissue counterparts. PEAX-P hydrogel scavenges 51% DPPH radical, 40% hydroxyl radicals 41% nitrate radicals with 31% reducing power. The presence of hydrogel protects 62% cardiomyoblast cells treated with stress inducing media at LD 50 concentration. The free hydroxyl groups in sugar alcohols of the comacromer influence the free radical scavenging. Comparatively, PEAX-P hydrogel based on xylitol evinces slightly lower scavenging characteristics than with previously reported PEAM-P hydrogel containing mannitol having more hydroxyl groups. The possible free radical scavenging mechanism of the present hydrogel relies on the free π electrons associated with uncrosslinked fumarate bonds, hydrogen atoms associated with sugar alcohols/PEG and radical dilution by free water in the matrix. Briefly, the present PEAX-P hydrogel is a potential injectable system for combined antioxidant and regenerative therapy.

  8. Regenerative biology and engineering: strategies for tissue restoration.

    PubMed

    Stocum, D L

    1998-01-01

    Over the past 50 years, we have made remarkable advances in the use of bionic devices and solid organ transplants as replacement parts for failing tissues and organs. These approaches to tissue restoration, however, have a number of drawbacks. Thus, a new approach, regenerative biology and engineering, has been developed, consisting of the strategies of cell transplantation, bioartificial tissue constructs, and stimulation of regeneration in vivo. Cell transplants have been successfully used to restore articular cartilage and to treat Parkinson's disease in humans. In rats, transplanted fetal and embryonic stem cell line-derived cardiomyocytes have been shown to differentiate and integrate well with the ventricular myocardium, suggesting the feasibility of using such transplants to restore damaged cardiac muscle. Diabetic symptoms in humans have been alleviated by implanting a bioartificial pancreas consisting of islet cells microencapsulated in alginate. Hydroxyapatite matrixes can stimulate the regeneration of bone across large gaps. Collagenous artificial matrixes can stimulate the regeneration of dermis, and peripheral nerve grafts embedded in a fibrin clot containing fibroblast growth factor-1 stimulate some regeneration of spinal cord axons in adult rats. Future research in regenerative biology will focus on several issues: (1) providing adequate sources of cells for transplantation and bioartificial tissue construction and determining ways to prevent these cells from coming under attack by the immune system, (2) developing new and better materials to build better bionic devices and bioartificial constructs and to stimulate regeneration in vivo, (3) determining how many tissues of the body might contain reserve cells for regeneration in vivo, (4) analyzing the molecular differences between cells and environments of regenerating versus nonregenerating tissues, and (5) understanding the factors and mechanisms involved in the proliferation and patterning of

  9. Cartilage repair: past and future – lessons for regenerative medicine

    PubMed Central

    Van Osch, Gerjo J V M; Brittberg, Mats; Dennis, James E; Bastiaansen-Jenniskens, Yvonne M; Erben, Reinhold G; Konttinen, Yrjö T; Luyten, Frank P

    2009-01-01

    Abstract Since the first cell therapeutic study to repair articular cartilage defects in the knee in 1994, several clinical studies have been reported. An overview of the results of clinical studies did not conclusively show improvement over conventional methods, mainly because few studies reach level I of evidence for effects on middle or long term. However, these explorative trials have provided valuable information about study design, mechanisms of repair and clinical outcome and have revealed that much is still unknown and further improvements are required. Furthermore, cellular and molecular studies using new technologies such as cell tracking, gene arrays and proteomics have provided more insight in the cell biology and mechanisms of joint surface regeneration. Besides articular cartilage, cartilage of other anatomical locations as well as progenitor cells are now considered as alternative cell sources. Growth Factor research has revealed some information on optimal conditions to support cartilage repair. Thus, there is hope for improvement. In order to obtain more robust and reproducible results, more detailed information is needed on many aspects including the fate of the cells, choice of cell type and culture parameters. As for the clinical aspects, it becomes clear that careful selection of patient groups is an important input parameter that should be optimized for each application. In addition, the study outcome parameters should be improved. Although reduced pain and improved function are, from the patient's perspective, the most important outcomes, there is a need for more structure/tissue-related outcome measures. Ideally, criteria and/or markers to identify patients at risk and responders to treatment are the ultimate goal for these more sophisticated regenerative approaches in joint surface repair in particular, and regenerative medicine in general. PMID:19453519

  10. Emdogain in regenerative periodontal therapy. A review of the literature.

    PubMed

    Sculean, Anton; Windisch, Péter; Döri, Ferenc; Keglevich, Tibor; Molnár, Balint; Gera, István

    2007-10-01

    The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i.e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of the enamel matrix protein derivative (EMD) in the periodontal wound healing. Histological results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of the current overview is to present, based on the existing evidence, the clinical indications for regenerative therapy with EMD. Surgical periodontal treatment of deep intrabony defects with EMD promotes periodontal regeneration. The application of EMD in the context of non-surgical periodontal therapy has failed to result in periodontal regeneration. Surgical periodontal therapy of deep intrabony defects with EMD may lead to significantly higher improvements of the clinical parameters than open flap debridement alone. The results obtained following treatment with EMD are comparable to those following treatment with GTR and can be maintained over a longer period. Treatment of intrabony defects with a combination of EMD + GTR does not seem to additionally improve the results compared to treatment with EMD alone or GTR alone. The combination of EMD and some types of bone grafts/bone substitutes may result in certain improvements in the soft and hard tissue parameters compared to treatment with EMD alone. Treatment of recession-type defects with coronally repositioned flaps and EMD may promote formation of cementum, periodontal ligament and bone, and may significantly increase the width of the keratinized tissue. Application of EMD seems to provide better long-term results than coronally repositioned flaps alone. Application of EMD may enhance periodontal regeneration in mandibular Class II

  11. Preconditioning boosts regenerative programmes in the adult zebrafish heart

    PubMed Central

    de Preux Charles, Anne-Sophie; Bise, Thomas; Baier, Felix; Sallin, Pauline; Jaźwińska, Anna

    2016-01-01

    During preconditioning, exposure to a non-lethal harmful stimulus triggers a body-wide increase of survival and pro-regenerative programmes that enable the organism to better withstand the deleterious effects of subsequent injuries. This phenomenon has first been described in the mammalian heart, where it leads to a reduction of infarct size and limits the dysfunction of the injured organ. Despite its important clinical outcome, the actual mechanisms underlying preconditioning-induced cardioprotection remain unclear. Here, we describe two independent models of cardiac preconditioning in the adult zebrafish. As noxious stimuli, we used either a thoracotomy procedure or an induction of sterile inflammation by intraperitoneal injection of immunogenic particles. Similar to mammalian preconditioning, the zebrafish heart displayed increased expression of cardioprotective genes in response to these stimuli. As zebrafish cardiomyocytes have an endogenous proliferative capacity, preconditioning further elevated the re-entry into the cell cycle in the intact heart. This enhanced cycling activity led to a long-term modification of the myocardium architecture. Importantly, the protected phenotype brought beneficial effects for heart regeneration within one week after cryoinjury, such as a more effective cell-cycle reentry, enhanced reactivation of embryonic gene expression at the injury border, and improved cell survival shortly after injury. This study reveals that exposure to antecedent stimuli induces adaptive responses that render the fish more efficient in the activation of the regenerative programmes following heart damage. Our results open a new field of research by providing the adult zebrafish as a model system to study remote cardiac preconditioning. PMID:27440423

  12. Regenerative potential of human muscle stem cells in chronic inflammation

    PubMed Central

    2011-01-01

    Introduction Chronic inflammation is a profound systemic modification of the cellular microenvironment which could affect survival, repair and maintenance of muscle stem cells. The aim of this study was to define the role of chronic inflammation on the regenerative potential of satellite cells in human muscle. Methods As a model for chronic inflammation, 11 patients suffering from rheumatoid arthritis (RA) were included together with 16 patients with osteoarthritis (OA) as controls. The mean age of both groups was 64 years, with more females in the RA group compared to the OA group. During elective knee replacement surgery, a muscle biopsy was taken from the distal musculus vastus medialis. Cell populations from four RA and eight OA patients were used for extensive phenotyping because these cell populations showed no spontaneous differentiation and myogenic purity greater than 75% after explantation. Results After mononuclear cell explantation, myogenic purity, viability, proliferation index, number of colonies, myogenic colonies, growth speed, maximum number of population doublings and fusion index were not different between RA and OA patients. Furthermore, the expression of proteins involved in replicative and stress-induced premature senescence and apoptosis, including p16, p21, p53, hTERT and cleaved caspase-3, was not different between RA and OA patients. Mean telomere length was shorter in the RA group compared to the OA group. Conclusions In the present study we found evidence that chronic inflammation in RA does not affect the in vitro regenerative potential of human satellite cells. Identification of mechanisms influencing muscle regeneration by modulation of its microenvironment may, therefore, be more appropriate. PMID:22171690

  13. Regenerative medicine for diseases of the head and neck: principles of in vivo regeneration.

    PubMed

    Löwenheim, H

    2003-09-01

    The application of endogenous regeneration in regenerative medicine is based on the concept of inducing regeneration of damaged or lost tissues from residual tissues in situ. Therefore, endogenous regeneration is also termed in vivo regeneration as opposed to mechanisms of ex vivo regeneration which are applied, for example, in the field of tissue engineering. The basic science foundation for mechanisms of endogenous regeneration is provided by the field of regenerative biology. The ambitious vision for the application of endogenous regeneration in regenerative medicine is stimulated by investigations in the model organisms of regenerative biology, most notably hydra, planarians and urodeles. These model organisms demonstrate remarkable regenerative capabilities, which appear to be conserved over large phylogenetical stretches with convincing evidence for a homologue origin of an endogenous regenerative capability. Although the elucidation of the molecular and cellular mechanisms of these endogenous regenerative phenomena is still in its beginning, there are indications that these processes have potential to become useful for human benefit. Such indications also exist for particular applications in diseases of the head and neck region. As such epimorphic regeneration without blastema formation may be relevant to regeneration of sensorineural epithelia of the inner ear or the olphactory epithelium. Complex tissue lesions of the head and neck as they occur after trauma or tumor resections may be approached on the basis of relevant mechanisms in epimorphic regeneration with blastema formation.

  14. Understanding Mechanobiology: Physical Therapists as a Force in Mechanotherapy and Musculoskeletal Regenerative Rehabilitation.

    PubMed

    Thompson, William R; Scott, Alexander; Loghmani, M Terry; Ward, Samuel R; Warden, Stuart J

    2016-04-01

    Achieving functional restoration of diseased or injured tissues is the ultimate goal of both regenerative medicine approaches and physical therapy interventions. Proper integration and healing of the surrogate cells, tissues, or organs introduced using regenerative medicine techniques are often dependent on the co-introduction of therapeutic physical stimuli. Thus, regenerative rehabilitation represents a collaborative approach whereby rehabilitation specialists, basic scientists, physicians, and surgeons work closely to enhance tissue restoration by creating tailored rehabilitation treatments. One of the primary treatment regimens that physical therapists use to promote tissue healing is the introduction of mechanical forces, or mechanotherapies. These mechanotherapies in regenerative rehabilitation activate specific biological responses in musculoskeletal tissues to enhance the integration, healing, and restorative capacity of implanted cells, tissues, or synthetic scaffolds. To become future leaders in the field of regenerative rehabilitation, physical therapists must understand the principles of mechanobiology and how mechanotherapies augment tissue responses. This perspective article provides an overview of mechanotherapy and discusses how mechanical signals are transmitted at the tissue, cellular, and molecular levels. The synergistic effects of physical interventions and pharmacological agents also are discussed. The goals are to highlight the critical importance of mechanical signals on biological tissue healing and to emphasize the need for collaboration within the field of regenerative rehabilitation. As this field continues to emerge, physical therapists are poised to provide a critical contribution by integrating mechanotherapies with regenerative medicine to restore musculoskeletal function.

  15. Understanding Mechanobiology: Physical Therapists as a Force in Mechanotherapy and Musculoskeletal Regenerative Rehabilitation

    PubMed Central

    Thompson, William R.; Scott, Alexander; Loghmani, M. Terry; Ward, Samuel R.

    2016-01-01

    Achieving functional restoration of diseased or injured tissues is the ultimate goal of both regenerative medicine approaches and physical therapy interventions. Proper integration and healing of the surrogate cells, tissues, or organs introduced using regenerative medicine techniques are often dependent on the co-introduction of therapeutic physical stimuli. Thus, regenerative rehabilitation represents a collaborative approach whereby rehabilitation specialists, basic scientists, physicians, and surgeons work closely to enhance tissue restoration by creating tailored rehabilitation treatments. One of the primary treatment regimens that physical therapists use to promote tissue healing is the introduction of mechanical forces, or mechanotherapies. These mechanotherapies in regenerative rehabilitation activate specific biological responses in musculoskeletal tissues to enhance the integration, healing, and restorative capacity of implanted cells, tissues, or synthetic scaffolds. To become future leaders in the field of regenerative rehabilitation, physical therapists must understand the principles of mechanobiology and how mechanotherapies augment tissue responses. This perspective article provides an overview of mechanotherapy and discusses how mechanical signals are transmitted at the tissue, cellular, and molecular levels. The synergistic effects of physical interventions and pharmacological agents also are discussed. The goals are to highlight the critical importance of mechanical signals on biological tissue healing and to emphasize the need for collaboration within the field of regenerative rehabilitation. As this field continues to emerge, physical therapists are poised to provide a critical contribution by integrating mechanotherapies with regenerative medicine to restore musculoskeletal function. PMID:26637643

  16. Space Station Freedom ECLSS: A step toward autonomous regenerative life support systems

    NASA Technical Reports Server (NTRS)

    Dewberry, Brandon S.

    1990-01-01

    The Environmental Control and Life Support System (ECLSS) is a Freedom Station distributed system with inherent applicability to extensive automation primarily due to its comparatively long control system latencies. These allow longer contemplation times in which to form a more intelligent control strategy and to prevent and diagnose faults. The regenerative nature of the Space Station Freedom ECLSS will contribute closed loop complexities never before encountered in life support systems. A study to determine ECLSS automation approaches has been completed. The ECLSS baseline software and system processes could be augmented with more advanced fault management and regenerative control systems for a more autonomous evolutionary system, as well as serving as a firm foundation for future regenerative life support systems. Emerging advanced software technology and tools can be successfully applied to fault management, but a fully automated life support system will require research and development of regenerative control systems and models. The baseline Environmental Control and Life Support System utilizes ground tests in development of batch chemical and microbial control processes. Long duration regenerative life support systems will require more active chemical and microbial feedback control systems which, in turn, will require advancements in regenerative life support models and tools. These models can be verified using ground and on orbit life support test and operational data, and used in the engineering analysis of proposed intelligent instrumentation feedback and flexible process control technologies for future autonomous regenerative life support systems, including the evolutionary Space Station Freedom ECLSS.

  17. A 100-W class regenerative fuel cell system for lunar and planetary missions

    NASA Astrophysics Data System (ADS)

    Sone, Yoshitsugu

    The Japan Aerospace Exploration Agency (JAXA) is developing polymer electrolyte fuel cell (PEFC) systems that can be operated under isolated low-gravity and closed environments. In the present study, we combine the PEFC with an electrolyzer in order to realize a regenerative fuel cell. Ideally, if a single cell can be operated as a fuel cell and the cell can be made reversible through the electrolysis reaction, then compact, lightweight regenerative fuel cell systems can be realized. A unitized regenerative fuel cell was prepared, and its operability was demonstrated. During 100-W class operations, a stable fuel cell and electrolysis reaction was observed.

  18. Scaffold characterization using NLO multimodal microscopy in metrology for regenerative medicine

    NASA Astrophysics Data System (ADS)

    Mortati, Leonardo; Divieto, Carla; Boffitto, Monica; Sartori, Susanna; Ciardelli, Gianluca; Sassi, Maria Paola

    2013-09-01

    Metrology in regenerative medicine aims to develop traceable measurement technologies for characterizing cellular and macromolecule behaviour in regenerative medicine products and processes. One key component in regenerative medicine is using three-dimensional porous scaffolds to guide cells during the regeneration process. The regeneration of specific tissues guided by tissue analogous substrates is dependent on diverse scaffold architectural properties that can be derived quantitatively from scaffolds images. This paper discuss the results obtained with the multimodal NLO microscope recently realized in our laboratory in characterizing 3D tissue engineered (TE) scaffolds colonized from human Mesenchimal stem cells (hMSC), focusing on the study of the three-dimensional metrological parameters.

  19. Time-resolved protein dynamics using synchronized Ti sapphire regenerative amplifier/infrared FEL

    SciTech Connect

    Stanley, R.J.; Haar, P.; Boxer, S.G.

    1995-12-31

    We have synchronized a femtosecond 5 kHz Ti Sapphire regenerative amplifier (regen) to the Stanford Superconducting Accelerator/Free Electron laser (SCA/FEL) to within 2 picoseconds time jitter. We are using this capability to measure the time resolved spectral evolution of the radical cation band of the initial electron donor from bacterial reaction centers (Rb sphaeroides) after the initiation of electron transfer using a {approximately} 120 fs NIR pulse from the regen. The FEL is used to probe for the appearance of the radical cation band at {approximately} 4 {mu}m.

  20. Bile Ducts in Regenerative Liver Nodules of Alagille Patients Are Not the Result of Genetic Mosaicism.

    PubMed

    Rougemont, Anne-Laure; Alvarez, Fernando; McLin, Valérie A; Guiochon-Mantel, Anne; Bouligand, Jérome; Clément, Sophie; Tonson La Tour, Aude; Wildhaber, Barbara E; Rubbia-Brandt, Laura; Sartelet, Hervé

    2015-07-01

    Alagille syndrome (ALGS) is a complex, multisystem disease associated with mutations in the JAG1 gene. In the liver, ALGS is characterized by paucity of intrahepatic bile ducts. Gene dosage analysis performed on a large, central regenerative nodule with preserved interlobular bile ducts of 2 unrelated ALGS patients, and on surrounding cirrhotic and ductopenic liver parenchyma, showed in both cases complete JAG1 heterozygous deletion in the regenerative nodule and the ductopenic liver, with no differences in gene dosage. Thus, JAG1 mosaicism and differential haploinsufficiency do not explain the presence of bile ducts in centrally located regenerative nodules.

  1. JAK‐STAT pathway activation in response to spinal cord injury in regenerative and non‐regenerative stages of Xenopus laevis

    PubMed Central

    Tapia, Victor S.; Herrera‐Rojas, Mauricio

    2017-01-01

    Abstract Xenopus laevis tadpoles can regenerate the spinal cord after injury but this capability is lost during metamorphosis. Comparative studies between pre‐metamorphic and metamorphic Xenopus stages can aid towards understanding the molecular mechanisms of spinal cord regeneration. Analysis of a previous transcriptome‐wide study suggests that, in response to injury, the JAK‐STAT pathway is differentially activated in regenerative and non‐regenerative stages. We characterized the activation of the JAK‐STAT pathway and found that regenerative tadpoles have an early and transient activation. In contrast, the non‐regenerative stages have a delayed and sustained activation of the pathway. We found that STAT3 is activated in response to injury mainly in Sox2/3+ ependymal cells, motoneurons and sensory neurons. Finally, to study the role of temporal activation we generated a transgenic line to express a constitutively active version of STAT3. The sustained activation of the JAK‐STAT pathway in regenerative tadpoles reduced the expression of pro‐neurogenic genes normally upregulated in response to spinal cord injury, suggesting that activation of the JAK‐STAT pathway modulates the fate of neural progenitors. PMID:28316792

  2. Feeding and healing the world: through regenerative agriculture and permaculture.

    PubMed

    Rhodes, Christopher J

    2012-01-01

    The study of soil is a mature science, whereas related practical methods of regenerative agriculture and permaculture are not. However, despite a paucity of detailed peer reviewed research published on these topics, there is overwhelming evidence both that the methods work and they may offer the means to address a number of prevailing environmental challenges, e.g. peak oil, climate change, carbon capture, unsustainable agriculture and food shortages, peak phosphorus (phosphate), water shortages, environmental pollution, desert reclamation, and soil degradation. What is lacking is a proper scientific study, made in hand with actual development projects. By elucidating the scientific basis of these remarkable phenomena, we may obtain the means for solving some of the otherwise insurmountable problems confronting humanity, simply by observing, and working with, the patterns and forces of nature. This article is intended as a call to arms to make serious investment in researching and actualising these methods on a global scale. Despite claims that peak oil is no longer a threat because vast resources of gas and shale oil (tight oil) can now be recovered by fracking (hydraulic fracturing) combined with horizontal drilling, the reality is that proven actual reserves are only adequate to delay the peak by a few years. Furthermore, because of the rapid depletion rates of flow from gas wells and oil wells that are accessed by fracking, it will be necessary to drill continuously and relentlessly to maintain output, and there are material limits of equipment, technology and trained personnel to do this. Moreover, to make any sensible difference to the liquid fuel crisis, which is the most immediate consequence of peak oil, it would be necessary to convert the worlds one billion vehicles to run on natural gas rather than liquid fuels refined from crude oil, and this would take some considerable time and effort. The loss of widespread personalised transportation is thus

  3. Soy Protein Scaffold Biomaterials for Tissue Engineering and Regenerative Medicine

    NASA Astrophysics Data System (ADS)

    Chien, Karen B.

    Developing functional biomaterials using highly processable materials with tailorable physical and bioactive properties is an ongoing challenge in tissue engineering. Soy protein is an abundant, natural resource with potential use for regenerative medicine applications. Preliminary studies show that soy protein can be physically modified and fabricated into various biocompatible constructs. However, optimized soy protein structures for tissue regeneration (i.e. 3D porous scaffolds) have not yet been designed. Furthermore, little work has established the in vivo biocompatibility of implanted soy protein and the benefit of using soy over other proteins including FDA-approved bovine collagen. In this work, freeze-drying and 3D printing fabrication processes were developed using commercially available soy protein to create porous scaffolds that improve cell growth and infiltration compared to other soy biomaterials previously reported. Characterization of scaffold structure, porosity, and mechanical/degradation properties was performed. In addition, the behavior of human mesenchymal stem cells seeded on various designed soy scaffolds was analyzed. Biological characterization of the cell-seeded scaffolds was performed to assess feasibility for use in liver tissue regeneration. The acute and humoral response of soy scaffolds implanted in an in vivo mouse subcutaneous model was also investigated. All fabricated soy scaffolds were modified using thermal, chemical, and enzymatic crosslinking to change properties and cell growth behavior. 3D printing allowed for control of scaffold pore size and geometry. Scaffold structure, porosity, and degradation rate significantly altered the in vivo response. Freeze-dried soy scaffolds had similar biocompatibility as freeze-dried collagen scaffolds of the same protein content. However, the soy scaffolds degraded at a much faster rate, minimizing immunogenicity. Interestingly, subcutaneously implanted soy scaffolds affected blood

  4. Surface Fine Grinding via a Regenerative Grinding Methodology

    NASA Astrophysics Data System (ADS)

    Lai, Hsin-Yi; Chen, Chao'-Kuang

    2006-10-01

    This paper presents a regenerative surface fine grinding methodology to remove grinding defects of traditional operations and to improve the quality of surface flatness. All possible surface defects produced by traditional and creep-feed grinding operations are carefully reviewed and circumvented. These defects include non -uniform traces, pitting spots, scratches, burnouts, and quenching breakage. To alleviate these traditional grinding defects, the paper presents a new approach by designing and constructing a regenerative surface fine grinding system that includes a mechanism that carries the submerged workpart in an oil-contained open box. The fine grinding tool held by the spindle-chuck unit of the CNC machine is moved in relative to the workpart surfaces by a combined trajectory of a cycloid path, a linear feed and a lateral travel. Some numerical simulations for selecting appropriate grinding trajectories are presented and simulated. The trajectory is selected based upon the resulting quality of contact uniformity and homogeneity as expressed in terms of contact frequency to each point on the workpart surface. The simulation model is then used to characterize appropriate working range of each grinding parameter. Different grinding paths are thus generated and superposed. A working machine is designed and built based upon the simulation results. Several experiments are carried out on the constructed grinding system with the grinding tool mounted to the spindle-chuck unit of the CNC machine. The surface quality of the ground workpart is measured. Tests on different system parameters demonstrate the importance of choosing the correct grinding wheel and grit size and an illustration of the proper selection of process and system parameters are presented. The experimental results are compared with those of analytical solutions. Good agreement between them is observed. In ninety minutes fine-grinding operations using the proposed method, the workpart surfaces

  5. A new class of IJF-OQPSK modems for regenerative satellite systems

    NASA Astrophysics Data System (ADS)

    Le-Ngoc, T.; Feher, K.

    The potential applications of a new class of Intersymbol-Interference and Jitter Free Offset-Keyed Quadrature Phase Shift Keying (IJF-OQPSK) modems to regenerative satellite systems are presented. The properties of IJF-OQPSK signals in linear and hardlimited channels are summarized. The spectral spreading and probability of error (Pe) performance of IJF-OQPSK modems in conventional and regenerative satellite channels are studied and compared to those of QPSK modems using computer simulation techniques. The results show that IJF-OQPSK modems perform much better than QPSK in both cascaded nonlinear channels and regenerative satellite links, specially with saturated earth station HPA and transponder TWTA. It is also indicated that a gain of more than 2 dB at a Pe of 10 to the -6th can be obtained with regenerative satellite systems, relative to conventional cascaded nonlinear channels with IJF-OQPSK modems.

  6. Definition study for an extended manned test of a regenerative life support system, preliminary test plan

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A preliminary plan and procedure are presented for conducting an extended manned test program for a regenerative life support system. Emphasis will be placed on elements associated with long-term system operation and long-term uninterrupted crew confinement.

  7. Effect of the exposure to metal lead on the regenerative ability of Lumbriculus variegatus (Oligochaeta).

    PubMed

    Sardo, Ana Margarida; Pereira, Lourdes; Gerhardt, Almut; Soares, Amadeu M V M

    2011-01-01

    Lumbriculus variegatus is a recommended species for use in sediment toxicity tests and is known to have a remarkable power of segmental regeneration. Here, we tested the effects of a chemical stressor on the regenerative ability of L. variegatus and investigated the potential of regenerative ability as an additional new parameter in standard toxicity tests. The worms were cut into two equal segments, and exposed to various concentrations of lead. Two assays were performed: one with sediment spiked with lead and the other with water spiked with lead. The endpoints were segmental regeneration, survival and behaviour. Regenerative ability was clearly affected by exposure to lead-contaminated sediment and lead-contaminated water. Organisms exposed to lead grew more slowly than those not exposed; worms exposed to contaminated water showed higher mortalities than those exposed to contaminated sediment. Results showed that L. variegatus' regenerative ability, as a developmental test parameter, is more sensitive than mortality.

  8. Extracellular matrix considerations for scar-free repair and regeneration: insights from regenerative diversity among vertebrates.

    PubMed

    Godwin, James; Kuraitis, Drew; Rosenthal, Nadia

    2014-11-01

    The extracellular matrix (ECM) is an essential feature of development, tissue homeostasis and recovery from injury. How the ECM responds dynamically to cellular and soluble components to support the faithful repair of damaged tissues in some animals but leads to the formation of acellular fibrotic scar tissue in others has important clinical implications. Studies in highly regenerative organisms such as the zebrafish and the salamander have revealed a specialist formulation of ECM components that support repair and regeneration, while avoiding scar tissue formation. By comparing a range of different contexts that feature scar-less healing and full regeneration vs. scarring through fibrotic repair, regenerative therapies that incorporate ECM components could be significantly enhanced to improve both regenerative potential and functional outcomes. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation.

  9. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, Susan R.

    1994-01-01

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

  10. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    SciTech Connect

    Cikanek, S.R.

    1994-10-25

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

  11. AmeriFlux US-SP2 Slashpine-Mize-clearcut-3yr,regen

    SciTech Connect

    Martin, Tim

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-SP2 Slashpine-Mize-clearcut-3yr,regen. Site Description - Even aged slash pine (Pinus elliottii) plantation. Planted in Jan. 1999.

  12. Pharmacological inhibition of myostatin/TGF-β receptor/pSmad3 signaling rescues muscle regenerative responses in mouse model of type 1 diabetes

    PubMed Central

    Jeong, Jaemin; Conboy, Michael J; Conboy, Irina M

    2013-01-01

    Aim: To study the influence of acute experimental diabetes on the regenerative potential of muscle stem (satellite) cells in mice. Methods: Male C57BL/6 young mice were injected with a single dose of streptozotocin (STZ, 180 mg/kg, ip) to induce diabetes. The diabetic mice were treated with insulin (0.75 U/kg, ip), follistatin (12 μg/kg, im) or Alk5 inhibitor (5 μmol/L per kg, sc) once a day. On the first day when high glucose levels were found, cardiotoxin (CTX) was focally injected into tibialis anterior and gastronemius muscles of the mice. The muscles were harvested 3 d and 5 d after CTX injection, and myofibers and satellite cells were isolated. Quantitative ex-vivo and in-vivo assays of myogenic potential were used to evaluate the muscle regenerative responses. Results: The satellite cells from the diabetic mice 3 d after CTX injection fail to activate, and the repair of muscle deteriorates, resembling that observed in old control mice. Furthermore, the satellite cells have excessive levels of myostatin, TGF-β receptor 1, pSmad3 and the cell cycle inhibitor p15, while the level of TGF-β1 remain unchanged. Treatment of the diabetic mice with insulin rescued muscle regenerative responses, and restored the expression levels of myostatin, TGF-β receptor 1, pSmad3, and p15 to those similar of healthy controls. Treatment of the diabetic mice with the myostatin antagonist follistatin, or with the Alk5 inhibitor of TGF-β receptor 1 (which did not diminish the blood glucose levels) rescued muscle regenerative responses and attenuated the myostatin/TGFβ receptor/pSmad3 signaling. Conclusion: The muscle regenerative responses are incapacitated and repair of the tissue fails within hours after the initiation of hyperglycemia in a mouse model of type 1 diabetes, but stem cell function is rescued by insulin, as well as follistatin or an Alk5 inhibitor that blocks TGF-β receptor signaling. PMID:23770987

  13. TOPICAL REVIEW: Powering MEMS portable devices—a review of non-regenerative and regenerative power supply systems with special emphasis on piezoelectric energy harvesting systems

    NASA Astrophysics Data System (ADS)

    Cook-Chennault, K. A.; Thambi, N.; Sastry, A. M.

    2008-08-01

    Power consumption is forecast by the International Technology Roadmap of Semiconductors (ITRS) to pose long-term technical challenges for the semiconductor industry. The purpose of this paper is threefold: (1) to provide an overview of strategies for powering MEMS via non-regenerative and regenerative power supplies; (2) to review the fundamentals of piezoelectric energy harvesting, along with recent advancements, and (3) to discuss future trends and applications for piezoelectric energy harvesting technology. The paper concludes with a discussion of research needs that are critical for the enhancement of piezoelectric energy harvesting devices.

  14. Regenerative ophthalmology: Technologic and pharmacologic approaches to restoring sight via retinal prosthesis.

    PubMed

    Iezzi, R

    2016-01-01

    Retinal prosthesis technology can restore rudimentary form vision in patients with retinitis pigmentosa (RP) who have lost all eyesight. This continually advancing field within regenerative ophthalmology represents the merger of micro-electromechanical systems technology with neurosensory retina. This man-machine interface is reliant upon the long-term health of a neurosensory retina undergoing progressive pathophysiologic changes. Pharmacologic approaches that address the pathophysiologic consequences of RP will likely play an important role for all regenerative treatment strategies.

  15. Tissue engineering and regenerative medicine in applied research: a year in review of 2014.

    PubMed

    Lin, Xunxun; Huang, Jia; Shi, Yuan; Liu, Wei

    2015-04-01

    Tissue engineering and regenerative medicine (TERM) remains to be one of the fastest growing fields, which covers a wide scope of topics of both basic and applied biological researches. This overview article summarized the advancements in applied researches of TERM area, including stem cell-mediated tissue regeneration, material science, and TERM clinical trial. These achievements demonstrated the great potential of clinical regenerative therapy of tissue/organ disease or defect through stem cells and tissue engineering approaches.

  16. Pressure Oscillations during the Interior Ballistic Firing of Regenerative Liquid Propellant Guns

    DTIC Science & Technology

    1992-03-01

    Modes. The analysis depends on taking FFTs of the pressure records to identify the frequency content of the data. Both the frequency and the relative...A248 622 TECHNICAL REPORT BRL-TR-3322 BRL PRESSURE OSCILLATIONS DURING THE INTERIOR BALLISTIC FIRING OF REGENERATIVE LIQUID PROPELLANT GUNS J. D...March 1992 IFinal Jan85 - 1av 86 4. TITLE AND SUBTITLE S. FUNDING NUMBERS Pressure Oscillations During the Interior Ballistic Firing of Regenerative PR

  17. Regenerative Endodontic Treatment: Report of Two Cases with Different Clinical Management and Outcomes

    PubMed Central

    Khoshkhounejad, Mehrfam; Shokouhinejad, Noushin

    2015-01-01

    Endodontic intervention in necrotic immature permanent teeth is usually a clinical challenge. With appropriate case selection, regenerative treatment can be effective, providing a desirable outcome. However, there is still no consensus on the optimal disinfection protocol or the method to achieve predictable clinical outcome. This article presents two cases of regenerative treatment in necrotic immature teeth, using mineral trioxide aggregate (MTA) and BiodentineTM as coronal barriers and different irrigants, which led to different clinical outcomes. PMID:26884781

  18. 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.

  19. CCRM: cultivating a culture of cooperation to advance the global regenerative medicine industry.

    PubMed

    Evans, Alanna; Johnson, Stacey

    2016-12-01

    Launched in June 2011, CCRM is a unique, Canadian, not-for-profit group that is solely focused on developing and commercializing regenerative medicine, cell and gene therapy technologies. Its mission is to generate sustainable health and economic benefits through global collaborations, and its vision is to be the preferred destination for the best people and companies, technologies, clinical trials and investments in cell and gene therapies, and regenerative medicine.

  20. Periodically pulsed excimer master oscillator-regenerative amplifier laser set

    NASA Astrophysics Data System (ADS)

    Ageyev, V. P.; Atezhev, V. V.; Bukreyev, V. S.; Vartapetov, S. K.; Zhukov, A. I.; Konov, V. I.; Savelyev, A. D.

    1987-06-01

    A periodically pulsed excimer laser set consisting of a master oscillator and a regenerative amplifier is proposed for improvement of laser beam characteristics, particularly decreasing divergence in the case of short pumping pulses and attendant high gain. Each active medium is pumped by electric discharge, both discharge circuits using magnetic switches with a common commutator so that the laser energy characteristics and the time separation between gain buildup in the two lasers can be simultaneously optimized. An experimental set was built with a Model 170 excimer laser as amplifier and a compact excimer laser as oscillator. Tests were performed with F2 + Kr + He mixtures lasing at lambda = 248, with and without injection. Emission pulses were produced at a repetition rate of 20 Hz and the beam divergence was measured through a lens with a focal length of 300 cm. The oscillator beam with a divergence of 600 microrad carried an energy of 700 microJ per pulse and was amplified to 35 mJ. The divergence of the amplified beam in the direction parallel to that of the discharge current was 140 microrad without injection and 80 microrad with injection. Divergence in the perpendicular direction was 90 microrad without and with injection.

  1. 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.

  2. Regenerative biology of tendon: mechanisms for renewal and repair

    PubMed Central

    Dyment, Nathaniel A.; Galloway, Jenna L.

    2015-01-01

    Understanding the molecular and cellular mechanisms underlying tissue turnover and repair are essential towards addressing pathologies in aging, injury and disease. Each tissue has distinct means of maintaining homeostasis and healing after injury. For some, resident stem cell populations mediate both of these processes. These stem cells, by definition, are self renewing and give rise to all the differentiated cells of that tissue. However, not all organs fit with this traditional stem cell model of regeneration, and some do not appear to harbor somatic stem or progenitor cells capable of multilineage in vivo reconstitution. Despite recent progress in tendon progenitor cell research, our current knowledge of the mechanisms regulating tendon cell homeostasis and injury response is limited. Understanding the role of resident tendon cell populations is of great importance for regenerative medicine based approaches to tendon injuries and disease. The goal of this review is to bring to light our current knowledge regarding tendon progenitor cells and their role in tissue maintenance and repair. We will focus on pressing questions in the field and the new tools, including model systems, available to address them. PMID:26389023

  3. Regenerative life support technology challenges for the Space Exploration Initiative

    NASA Technical Reports Server (NTRS)

    Bilardo, Vincent J., Jr.; Theis, Ronald L. A.

    1992-01-01

    Regenerative life support systems have been identified as one of the critical enabling technologies for future human exploration of space. This discipline encompasses processes and subsystems which regenerate the air, water, solid waste, and food streams typical of human habitation so as to minimize the mass and volume of stored consumables which must accompany the humans on a mission. A number of key technology challenges within this broad discipline are described, ranging from the development of new physical, chemical, and biological processes for regenerating the air, water, solid waste, and food streams to the development of improved techniques for monitoring and controlling microbial and trace constituent contamination. A continuing challenge overarching the development of these new technologies is the need to minimize the mass, volume, and electrical power consumption of the flight hardware. More important for long duration exploration missions, however, is the development of highly reliable, long-lived, self- sufficient systems which absolutely minimize the logistics resupply and operational maintenance requirements of the life support system and which ensure human safety through their robust, reliable operating characteristics.

  4. Chromatin signaling in muscle stem cells: interpreting the regenerative microenvironment

    PubMed Central

    Brancaccio, Arianna; Palacios, Daniela

    2015-01-01

    Muscle regeneration in the adult occurs in response to damage at expenses of a population of adult stem cells, the satellite cells. Upon injury, either physical or genetic, signals released within the satellite cell niche lead to the commitment, expansion and differentiation of the pool of muscle progenitors to repair damaged muscle. To achieve this goal satellite cells undergo a dramatic transcriptional reprogramming to coordinately activate and repress specific subset of genes. Although the epigenetics of muscle regeneration has been extensively discussed, less emphasis has been put on how extra-cellular cues are translated into the specific chromatin reorganization necessary for progression through the myogenic program. In this review we will focus on how satellite cells sense the regenerative microenvironment in physiological and pathological circumstances, paying particular attention to the mechanism through which the external stimuli are transduced to the nucleus to modulate chromatin structure and gene expression. We will discuss the pathways involved and how alterations in this chromatin signaling may contribute to satellite cells dysfunction during aging and disease. PMID:25904863

  5. Engineering mesenchymal stem cells for regenerative medicine and drug delivery.

    PubMed

    Park, Ji Sun; Suryaprakash, Smruthi; Lao, Yeh-Hsing; Leong, Kam W

    2015-08-01

    Researchers have applied mesenchymal stem cells (MSC) to a variety of therapeutic scenarios by harnessing their multipotent, regenerative, and immunosuppressive properties with tropisms toward inflamed, hypoxic, and cancerous sites. Although MSC-based therapies have been shown to be safe and effective to a certain degree, the efficacy remains low in most cases when MSC are applied alone. To enhance their therapeutic efficacy, researchers have equipped MSC with targeted delivery functions using genetic engineering, therapeutic agent incorporation, and cell surface modification. MSC can be genetically modified virally or non-virally to overexpress therapeutic proteins that complement their innate properties. MSC can also be primed with non-peptidic drugs or magnetic nanoparticles for enhanced efficacy and externally regulated targeting, respectively. Furthermore, MSC can be functionalized with targeting moieties to augment their homing toward therapeutic sites using enzymatic modification, chemical conjugation, or non-covalent interactions. These engineering techniques are still works in progress, requiring optimization to improve the therapeutic efficacy and targeting effectiveness while minimizing any loss of MSC function. In this review, we will highlight the advanced techniques of engineering MSC, describe their promise and the challenges of translation into clinical settings, and suggest future perspectives on realizing their full potential for MSC-based therapy.

  6. Regenerative Gas Dryer for In-Situ Propellant Production

    NASA Technical Reports Server (NTRS)

    Paz, Aaron

    2017-01-01

    Rocket propellant can be produced anywhere that water is found by splitting it into hydrogen and oxygen, potentially saving several tons of mass per mission and enabling the long term presence of humans in space beyond LEO. When water is split into hydrogen and oxygen, the gaseous products can be very humid (several thousand ppm). Propellant-grade gases need to be extremely dry before being converted into cryogenic liquids (less than 26 ppm water for grade B Oxygen). The primary objective of this project is to design, build and test a regenerative gas drying system that can take humid gas from a water electrolysis system and provide dry gas (less than 26ppm water) to the inlet of a liquefaction system for long durations. State of the art work in this area attempted to use vacuum as a means to regenerate desiccant, but it was observed that water would migrate to the dry zone without a sweep gas present to direct the desorbed vapor. Further work attempted to use CO2 as a sweep gas, but this resulted in a corrosive carbonic acid. In order for in-situ propellant production to work, we need a way to continuously dry humid gas that addresses these issues.

  7. Mechanical cues in orofacial tissue engineering and regenerative medicine.

    PubMed

    Brouwer, Katrien M; Lundvig, Ditte M S; Middelkoop, Esther; Wagener, Frank A D T G; Von den Hoff, Johannes W

    2015-01-01

    Cleft lip and palate patients suffer from functional, aesthetical, and psychosocial problems due to suboptimal regeneration of skin, mucosa, and skeletal muscle after restorative cleft surgery. The field of tissue engineering and regenerative medicine (TE/RM) aims to restore the normal physiology of tissues and organs in conditions such as birth defects or after injury. A crucial factor in cell differentiation, tissue formation, and tissue function is mechanical strain. Regardless of this, mechanical cues are not yet widely used in TE/RM. The effects of mechanical stimulation on cells are not straight-forward in vitro as cellular responses may differ with cell type and loading regime, complicating the translation to a therapeutic protocol. We here give an overview of the different types of mechanical strain that act on cells and tissues and discuss the effects on muscle, and skin and mucosa. We conclude that presently, sufficient knowledge is lacking to reproducibly implement external mechanical loading in TE/RM approaches. Mechanical cues can be applied in TE/RM by fine-tuning the stiffness and architecture of the constructs to guide the differentiation of the seeded cells or the invading surrounding cells. This may already improve the treatment of orofacial clefts and other disorders affecting soft tissues.

  8. A dual function of copper in designing regenerative implants.

    PubMed

    Burghardt, Ines; Lüthen, Frank; Prinz, Cornelia; Kreikemeyer, Bernd; Zietz, Carmen; Neumann, Hans-Georg; Rychly, Joachim

    2015-03-01

    The supply of titanium implants which are widely used in orthopaedics with both regenerative and anti-microbial properties will achieve a great progress in bone regeneration. We asked, whether by appropriate concentrations of copper ions it will be possible both to inhibit growth of bacteria and stimulate biological responses in mesenchymal stem cells (MSC). Using titanium material which released galvanically deposited copper at concentrations from 0.3 to 1.75 mM, growth of planktonic Staphylococcus aureus was blocked and more importantly adherent bacteria were cleared from the material surface within 24 h. To test biological responses of human bone marrow derived MSC due to copper ions, we found that copper stimulated the proliferation of MSC in a narrow concentration range around 0.1 mM. Similar copper concentrations enhanced osteogenic differentiation of MSC when cells were cultured in osteogenic differentiation medium. We observed increased activity of alkaline phosphatase (ALP), higher expression of collagen I, osteoprotegerin, osteopontin and finally mineralization of the cells. We conclude that titanium implants that release copper ions can be effective against bacterial infections at higher concentrations of copper near the implant surface and can promote bone regeneration when its concentration becomes lower due to diffusion.

  9. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    NASA Astrophysics Data System (ADS)

    Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey; Curley, Suzanne

    The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle's Environmental Control and Life Support System (ECLSS). Termed the Carbon Diox-ide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were per-formed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic sim-ulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

  10. Is a regenerative approach viable for the treatment of COPD?

    PubMed

    Hind, Matthew; Maden, Malcolm

    2011-05-01

    Degenerative lung diseases such as chronic obstructive pulmonary disease (COPD) are common with huge worldwide morbidity. Anti-inflammatory drug development strategies have proved disappointing and current treatment is aimed at symptomatic relief. Only lung transplantation with all its attendant difficulties offers hope of cure and the outlook for affected patients is bleak. Lung regeneration therapies aim to reverse the structural and functional deficits in COPD either by delivery of exogenous lung cells to replace lost tissue, delivery of exogenous stem cells to induce a local paracrine effect probably through an anti-inflammatory action or by the administration of small molecules to stimulate the endogenous regenerative ability of lung cells. In animal models of emphysema and disrupted alveolar development each of these strategies has shown some success but there are potential tumour-inducing dangers with a cellular approach. Small molecules such as all-trans retinoic acid have been successful in animal models although the mechanism is not completely understood. There are currently two Pharma-sponsored trials in progress concerning patients with COPD, one of a specific retinoic acid receptor gamma agonist and another using mesenchymal stem cells.

  11. Potency of Fish Collagen as a Scaffold for Regenerative Medicine

    PubMed Central

    Yamamoto, Kohei; Yanagiguchi, Kajiro

    2014-01-01

    Cells, growth factors, and scaffold are the crucial factors for tissue engineering. Recently, scaffolds consisting of natural polymers, such as collagen and gelatin, bioabsorbable synthetic polymers, such as polylactic acid and polyglycolic acid, and inorganic materials, such as hydroxyapatite, as well as composite materials have been rapidly developed. In particular, collagen is the most promising material for tissue engineering due to its biocompatibility and biodegradability. Collagen contains specific cell adhesion domains, including the arginine-glycine-aspartic acid (RGD) motif. After the integrin receptor on the cell surface binds to the RGD motif on the collagen molecule, cell adhesion is actively induced. This interaction contributes to the promotion of cell growth and differentiation and the regulation of various cell functions. However, it is difficult to use a pure collagen scaffold as a tissue engineering material due to its low mechanical strength. In order to make up for this disadvantage, collagen scaffolds are often modified using a cross-linker, such as gamma irradiation and carbodiimide. Taking into account the possibility of zoonosis, a variety of recent reports have been documented using fish collagen scaffolds. We herein review the potency of fish collagen scaffolds as well as associated problems to be addressed for use in regenerative medicine. PMID:24982861

  12. [Regenerative medicine: orthopaedical applications and medico legal questions].

    PubMed

    Ricci, S; Ricci, O; Tucci, C E; Massoni, F; Sarra, M V; Ricci, S

    2012-01-01

    Over the last decades, the increase in the global population's mean age has implied a corresponding increase in degenerative disease affecting various anatomical areas and tissues, including bones and cartilages, thus provoking a rising number of disabilities and a wider usage of drugs, mostly anti-inflammatory and cortisone. New developments in technologic and biomedical fields gave birth to new subjects, such as tissue engineering, cell therapy, gene therapy that, by and large, create a knowledge network falling under the concept of Regenerative Medicine. This science is essentially based on the usage of stem cells that can replicate and renovate themselves originating, if adequately stimulated, a number of cell types. Inter alia, in orthopaedic field a particular type of adult stem cells is used, the mesenchymal stem cells (MSCs). If combined with synthetic material produced in laboratories, the usage of these cells has provided inspiration for new study interests; today, it can be applied in various degenerative and post-traumatic pathologies, with great therapeutic benefits for the patient. Actually, many studies write about an improvement in patients' life quality. In this sense appear significant reflections on legal medicine, both in accidents and insurance, of this innovative therapeutic alternative and is hopefully an equally valid process of improvement of regulatory and case law.

  13. The thymus and tail regenerative capacity in Xenopus laevis tadpoles.

    PubMed

    Franchini, Antonella; Bertolotti, Evelina

    2012-07-01

    A morphofunctional analysis of the thymus from differently aged Xenopus laevis tadpoles during regeneration of the tail is reported. In stage 50 larvae, competent to regenerate, the appendage cut provoked thymic structural modifications that affected the medullary microenvironment cells and changes in TNF-α immunoreactivity. Mucocyte-like cells, multicellular epithelial cysts, myoid cells and cells immunoreactive to TNF-α increased in number. Increased numbers of lymphocytes were also found in regenerating areas and, at the end of regeneration, thymic structural and immunocytochemical patterns were restored to control levels. The observed cellular responses and the induction of molecules critical for thymus constitutive processes suggest a stimulation of thymic function after tail amputation. In older larvae, whose capacity to form a new complete and correctly patterned tail was reduced, thymic morphological changes were more severe and may persist throughout the regeneration process with a significant reduction in organ size. In these larvae the histological patterns and the marked thymic decrease may be related to the events occurring during regeneration, i.e. the higher inflammatory response and the reduced tail regenerative potential.

  14. Engineering Mesenchymal Stem Cells for Regenerative Medicine and Drug Delivery

    PubMed Central

    Park, Ji Sun; Suryaprakash, Smruthi; Lao, Yeh-Hsing; Leong, Kam W.

    2015-01-01

    Researchers have applied mesenchymal stem cells (MSC) to a variety of therapeutic scenarios by harnessing their multipotent, regenerative, and immunosuppressive properties with tropisms toward inflamed, hypoxic, and cancerous sites. Although MSC-based therapies have been shown to be safe and effective to a certain degree, the efficacy remains low in most cases when MSC are applied alone. To enhance their therapeutic efficacy, researchers have equipped MSC with targeted delivery functions using genetic engineering, therapeutic agent incorporation, and cell surface modification. MSC can be genetically modified virally or non-virally to overexpress therapeutic proteins that complement their innate properties. MSC can also be primed with non-peptidic drugs or magnetic nanoparticles for enhanced efficacy and externally regulated targeting, respectively. Furthermore, MSC can be functionalized with targeting moieties to augment their homing toward therapeutic sites using enzymatic modification, chemical conjugation, or non-covalent interactions. These engineering techniques are still works in progress, requiring optimization to improve the therapeutic efficacy and targeting effectiveness while minimizing any loss of MSC function. In this review, we will highlight the advanced techniques of engineering MSC, describe their promise and the challenges of translation into clinical settings, and suggest future perspectives on realizing their full potential for MSC-based therapy. PMID:25770356

  15. Dedifferentiated fat cells: A cell source for regenerative medicine.

    PubMed

    Jumabay, Medet; Boström, Kristina I

    2015-11-26

    The identification of an ideal cell source for tissue regeneration remains a challenge in the stem cell field. The ability of progeny cells to differentiate into other cell types is important for the processes of tissue reconstruction and tissue engineering and has clinical, biochemical or molecular implications. The adaptation of stem cells from adipose tissue for use in regenerative medicine has created a new role for adipocytes. Mature adipocytes can easily be isolated from adipose cell suspensions and allowed to dedifferentiate into lipid-free multipotent cells, referred to as dedifferentiated fat (DFAT) cells. Compared to other adult stem cells, the DFAT cells have unique advantages in their abundance, ease of isolation and homogeneity. Under proper condition in vitro and in vivo, the DFAT cells have exhibited adipogenic, osteogenic, chondrogenic, cardiomyogenc, angiogenic, myogenic, and neurogenic potentials. In this review, we first discuss the phenomena of dedifferentiation and transdifferentiation of cells, and then dedifferentiation of adipocytes in particular. Understanding the dedifferentiation process itself may contribute to our knowledge of normal growth processes, as well as mechanisms of disease. Second, we highlight new developments in DFAT cell culture and summarize the current understanding of DFAT cell properties. The unique features of DFAT cells are promising for clinical applications such as tissue regeneration.

  16. Dedifferentiated fat cells: A cell source for regenerative medicine

    PubMed Central

    Jumabay, Medet; Boström, Kristina I

    2015-01-01

    The identification of an ideal cell source for tissue regeneration remains a challenge in the stem cell field. The ability of progeny cells to differentiate into other cell types is important for the processes of tissue reconstruction and tissue engineering and has clinical, biochemical or molecular implications. The adaptation of stem cells from adipose tissue for use in regenerative medicine has created a new role for adipocytes. Mature adipocytes can easily be isolated from adipose cell suspensions and allowed to dedifferentiate into lipid-free multipotent cells, referred to as dedifferentiated fat (DFAT) cells. Compared to other adult stem cells, the DFAT cells have unique advantages in their abundance, ease of isolation and homogeneity. Under proper condition in vitro and in vivo, the DFAT cells have exhibited adipogenic, osteogenic, chondrogenic, cardiomyogenc, angiogenic, myogenic, and neurogenic potentials. In this review, we first discuss the phenomena of dedifferentiation and transdifferentiation of cells, and then dedifferentiation of adipocytes in particular. Understanding the dedifferentiation process itself may contribute to our knowledge of normal growth processes, as well as mechanisms of disease. Second, we highlight new developments in DFAT cell culture and summarize the current understanding of DFAT cell properties. The unique features of DFAT cells are promising for clinical applications such as tissue regeneration. PMID:26640620

  17. Design and test of a regenerative satellite transmultiplexer

    NASA Astrophysics Data System (ADS)

    Hung, Kenny King-Ming

    1993-05-01

    In a multiple access scheme for regenerative satellite communications, the bulk frequency division multiple access (FDMA) uplink signal is demodulated on board the satellite and then remodulated for time division multiplexing (TDM) downlink transmission. Conversion from frequency to time division multiplex format requires that the uplink signal be frequency demultiplexed and each individual carrier be subsequently demodulated. For thin-route application which consists of a large number of channels with fixed data rate, multicarrier demodulation can be accomplished efficiently by a digital transmultiplexer (TMUX) using a fast Fourier transform processor followed by a bank of per-channel processors. A time domain description of the TMUX algorithm is derived which elucidates how the TMUX functions. The per-channel processor performs timing and carrier recovery for optimum and coherent data detection. Timing recovery is necessarily achieved asynchronously by a filter coefficient interpolation. Carrier recovery is performed using an all-digital phase-locked loop. The combination of both timing and carrier loops is investigated for a multi-user system. The performance of the overall system is assessed over a multi-user, additive white Gaussian noise channel for a bit energy to noise power spectral density ratio down to zero dB.

  18. [Ethical principles in research related to regenerative therapy].

    PubMed

    López Moratalla, Natalia

    2008-01-01

    Recently published data on the function and properties of stem cells are examined and analyzed. This knowledge enhances our understanding of human development: stem cells follow a precise hierarchical pattern both in time and space, and they are part of the symbiosis of fetus and mother. The data do not support the idea of the existence of an early stage of the embryo development lacking a personal character. It has been suggested that an early embryo lacks an entity of sufficient ontological autonomy, which would be acquired with organogenesis at later stages. It is an ethical commitment of the scientific community to provide serious and precise information about the advances, problems and solutions involved an regenerative therapy. The use of autologous or heterologous human cells in this field demands of rules which determine their use and commercial potential. The induced reprogramming of adult cells to an embryonic stage (iPS) opens up new important perspectives both in basic research and for clinical treatments. The ethical commitment of Yamanaka, developer of this technology, with regard to its use in clinical treatments, is an example of the researcher's responsibility of the researcher, and, at the same time, an illustration of how that science may render a service to mankind only through ethical principles.

  19. Molecular genetic system for regenerative studies using newts.

    PubMed

    Hayashi, Toshinori; Yokotani, Naoki; Tane, Shoji; Matsumoto, Akira; Myouga, Ayumi; Okamoto, Mitsumasa; Takeuchi, Takashi

    2013-02-01

    Urodele newts have the remarkable capability of organ regeneration, and have been used as a unique experimental model for more than a century. However, the mechanisms underlying regulation of the regeneration are not well understood, and gene functions in particular remain largely unknown. To elucidate gene function in regeneration, molecular genetic analyses are very powerful. In particular, it is important to establish transgenic or knockout (mutant) lines, and systematically cross these lines to study the functions of the genes. In fact, such systems have been developed for other vertebrate models. However, there is currently no experimental model system using molecular genetics for newt regenerative research due to difficulties with respect to breeding newts in the laboratory. Here, we show that the Iberian ribbed newt (Pleurodeles waltl) has outstanding properties as a laboratory newt. We developed conditions under which we can obtain a sufficient number and quality of eggs throughout the year, and shortened the period required for sexual maturation from 18 months to 6 months. In addition, P. waltl newts are known for their ability, like other newts, to regenerate various tissues. We revealed that their ability to regenerate various organs is equivalent to that of Japanese common newts. We also developed a method for efficient transgenesis. These studies demonstrate that P. waltl newts are a suitable model animal for analysis of regeneration using molecular genetics. Establishment of this experimental model will enable us to perform comparable studies using these newts and other vertebrate models.

  20. Energy regenerative suspension test for EEV and hybrid vehicle

    NASA Astrophysics Data System (ADS)

    Abdullah, M. A.; Jamil, J. F.; Muhammad, N. S.

    2015-12-01

    The world is demanding on the alternative fuel and reducing the fuel consumption of land transportation especially in the automotive industries. This paper emphasizes the development of the energy regenerative suspension system (EReSS) for energy efficient vehicle (EEV) or hybrid. The EReSS product is fabricated and tested on the laboratory and real vehicle. The test is conducted to test the function of the EReSS system on real vehicle. The test is done using the multimeter to record the reading of voltage produces by the EReSS system that is attached to the vehicle suspension system. The experiment starts by setting the parameters in the EReSS system which is the number of windings with a standard magnet. Road irregularity is one of the important parts of the experiment which is set to be various types of road condition and driving style. A domestic car model is selected for the EReSS test that the system can be installed. The test of the EReSS gives out the maximum output voltage of 5.6 V with 530 windings. Improvement on the material can increase the output voltage. The EReSS is function on the real vehicle by producing voltage by harvesting the kinetic energy from the suspension vibration.

  1. Regenerative orthopaedics: in vitro, in vivo...in silico.

    PubMed

    Geris, Liesbet

    2014-09-01

    In silico, defined in analogy to in vitro and in vivo as those studies that are performed on a computer, is an essential step in problem-solving and product development in classical engineering fields. The use of in silico models is now slowly easing its way into medicine. In silico models are already used in orthopaedics for the planning of complicated surgeries, personalised implant design and the analysis of gait measurements. However, these in silico models often lack the simulation of the response of the biological system over time. In silico models focusing on the response of the biological systems are in full development. This review starts with an introduction into in silico models of orthopaedic processes. Special attention is paid to the classification of models according to their spatiotemporal scale (gene/protein to population) and the information they were built on (data vs hypotheses). Subsequently, the review focuses on the in silico models used in regenerative orthopaedics research. Contributions of in silico models to an enhanced understanding and optimisation of four key elements-cells, carriers, culture and clinics-are illustrated. Finally, a number of challenges are identified, related to the computational aspects but also to the integration of in silico tools into clinical practice.

  2. Unitized Regenerative Fuel Cell System Gas Storage/Radiator Development

    NASA Technical Reports Server (NTRS)

    Jakupca, Ian; Burke, Kenneth A.

    2003-01-01

    The ancillary components for Unitized Regenerative Fuel Cell (URFC) Energy Storage System are being developed at the NASA Glenn Research Center. This URFC system is unique in that it uses the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The waste heat generated by the URFC stack during charging and discharging is transferred from the cell stack to the surface of each tank by loop heat pipes. The heat pipes are coiled around each tank and covered with a thin layer of thermally conductive layer of carbon composite. The thin layer of carbon composite acts as a fin structure that spreads the heat away from the heat pipe and across the entire tank surface. Two different sized commercial grade composite tanks were constructed with integral heat pipes and tested in a thermal vacuum chamber to examine the feasibility of using the storage tanks as system radiators. The storage radiators were subjected to different steady-state heat loads and varying heat load profiles. The surface emissivity and specific heat capacity of each tank were calculated. The results were incorporated into a model that simulates the performance of similar radiators using lightweight, space rated carbon composite tanks.

  3. The clinical use of regenerative therapy in COPD

    PubMed Central

    Lipsi, Roberto; Rogliani, Paola; Calzetta, Luigino; Segreti, Andrea; Cazzola, Mario

    2014-01-01

    Regenerative or stem cell therapy is an emerging field of treatment based on stimulation of endogenous resident stem cells or administration of exogenous stem cells to treat diseases or injury and to replace malfunctioning or damaged tissues. Current evidence suggests that in the lung, these cells may participate in tissue homeostasis and regeneration after injury. Animal and human studies have demonstrated that tissue-specific stem cells and bone marrow-derived cells contribute to lung tissue regeneration and protection, and thus administration of exogenous stem/progenitor cells or humoral factors responsible for the activation of endogenous stem/progenitor cells may be a potent next-generation therapy for chronic obstructive pulmonary disease. The use of bone marrow-derived stem cells could allow repairing and regenerate the damaged tissue present in chronic obstructive pulmonary disease by means of their engraftment into the lung. Another approach could be the stimulation of resident stem cells by means of humoral factors or photobiostimulation. PMID:25548520

  4. Lightweight pressure vessels and unitized regenerative fuel cells

    SciTech Connect

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

    1996-12-31

    High specific energy (>400 Wh/kg) energy storage systems have been designed using lightweight pressure vessels in conjunction with unitized regenerative fuel cells (URFCs). URFCs produce power and electrolytically regenerate their reactants using a single stack of reversible cells. Although a rechargeable energy storage system with such high specific energy has not yet been fabricated, we have made progress towards this goal. A primary fuel cell (FC) test rig with a single cell (0.05 ft{sup 2} active area) has been modified and operated reversibly as a URFC. This URFC uses bifunctional electrodes (oxidation and reduction electrodes reverse roles when switching from charge to discharge, as with a rechargeable battery) and cathode feed electrolysis (water is fed from the oxygen side of the cell). Lightweight pressure vessels with state-of-the-art performance factors (burst pressure * internal volume/tank weight = Pb V/W) have been designed and fabricated. These vessels provide a lightweight means of storing reactant gases required for fuel cells (FCs) or URFCs. The vessels use lightweight bladder liners that act as inflatable mandrels for composite overwrap and provide the permeation barrier for gas storage. The bladders are fabricated using materials that are compatible with humidified gases which may be created by the electrolysis of water and are compatible with elevated temperatures that occur during fast fills.

  5. Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine.

    PubMed

    Nowakowski, Adam; Walczak, Piotr; Janowski, Miroslaw; Lukomska, Barbara

    2015-10-01

    Mesenchymal stem cells (MSCs), which can be obtained from various organs and easily propagated in vitro, are one of the most extensively used types of stem cells and have been shown to be efficacious in a broad set of diseases. The unique and highly desirable properties of MSCs include high migratory capacities toward injured areas, immunomodulatory features, and the natural ability to differentiate into connective tissue phenotypes. These phenotypes include bone and cartilage, and these properties predispose MSCs to be therapeutically useful. In addition, MSCs elicit their therapeutic effects by paracrine actions, in which the metabolism of target tissues is modulated. Genetic engineering methods can greatly amplify these properties and broaden the therapeutic capabilities of MSCs, including transdifferentiation toward diverse cell lineages. However, cell engineering can also affect safety and increase the cost of therapy based on MSCs; thus, the advantages and disadvantages of these procedures should be discussed. In this review, the latest applications of genetic engineering methods for MSCs with regenerative medicine purposes are presented.

  6. Restoration of Nrf2 Signaling Normalizes the Regenerative Niche

    PubMed Central

    Soares, Marc A.; Cohen, Oriana D.; Low, Yee Cheng; Sartor, Rita A.; Ellison, Trevor; Anil, Utkarsh; Anzai, Lavinia; Chang, Jessica B.; Saadeh, Pierre B.; Rabbani, Piul S.

    2016-01-01

    Chronic hyperglycemia impairs intracellular redox homeostasis and contributes to impaired diabetic tissue regeneration. The Keap1/Nrf2 pathway is a critical regulator of the endogenous antioxidant response system, and its dysfunction has been implicated in numerous pathologies. Here we characterize the effect of chronic hyperglycemia on Nrf2 signaling within a diabetic cutaneous regeneration model. We characterized the effects of chronic hyperglycemia on the Keap1/Nrf2 pathway within models of diabetic cutaneous wound regeneration. We assessed reactive oxygen species (ROS) production and antioxidant gene expression following alterations in the Nrf2 suppressor Keap1 and the subsequent changes in Nrf2 signaling. We also developed a topical small interfering RNA (siRNA)–based therapy to restore redox homeostasis within diabetic wounds. Western blotting demonstrated that chronic hyperglycemia–associated oxidative stress inhibits nuclear translocation of Nrf2 and impairs activation of antioxidant genes, thus contributing to ROS accumulation. Keap1 inhibition increased Nrf2 nuclear translocation, increased antioxidant gene expression, and reduced ROS production to normoglycemic levels, both in vitro and in vivo. Topical siKeap1 therapy resulted in improved regenerative capacity of diabetic wounds and accelerated closure. We report that chronic hyperglycemia weakens the endogenous antioxidant response, and the consequences of this defect are manifested by intracellular redox dysregulation, which can be restored by Keap1 inhibition. Targeted siRNA-based therapy represents a novel, efficacious strategy to reestablish redox homeostasis and accelerate diabetic cutaneous tissue regeneration. PMID:26647385

  7. Induced Pluripotent Stem Cell Technology in Regenerative Medicine and Biology

    NASA Astrophysics Data System (ADS)

    Pei, Duanqing; Xu, Jianyong; Zhuang, Qiang; Tse, Hung-Fat; Esteban, Miguel A.

    The potential of human embryonic stem cells (ESCs) for regenerative medicine is unquestionable, but practical and ethical considerations have hampered clinical application and research. In an attempt to overcome these issues, the conversion of somatic cells into pluripotent stem cells similar to ESCs, commonly termed nuclear reprogramming, has been a top objective of contemporary biology. More than 40 years ago, King, Briggs, and Gurdon pioneered somatic cell nuclear reprogramming in frogs, and in 1981 Evans successfully isolated mouse ESCs. In 1997 Wilmut and collaborators produced the first cloned mammal using nuclear transfer, and then Thomson obtained human ESCs from in vitro fertilized blastocysts in 1998. Over the last 2 decades we have also seen remarkable findings regarding how ESC behavior is controlled, the importance of which should not be underestimated. This knowledge allowed the laboratory of Shinya Yamanaka to overcome brilliantly conceptual and technical barriers in 2006 and generate induced pluripotent stem cells (iPSCs) from mouse fibroblasts by overexpressing defined combinations of ESC-enriched transcription factors. Here, we discuss some important implications of human iPSCs for biology and medicine and also point to possible future directions.

  8. Tissue engineering and regenerative medicine: history, progress, and challenges.

    PubMed

    Berthiaume, François; Maguire, Timothy J; Yarmush, Martin L

    2011-01-01

    The past three decades have seen the emergence of an endeavor called tissue engineering and regenerative medicine in which scientists, engineers, and physicians apply tools from a variety of fields to construct biological substitutes that can mimic tissues for diagnostic and research purposes and can replace (or help regenerate) diseased and injured tissues. A significant portion of this effort has been translated to actual therapies, especially in the areas of skin replacement and, to a lesser extent, cartilage repair. A good amount of thoughtful work has also yielded prototypes of other tissue substitutes such as nerve conduits, blood vessels, liver, and even heart. Forward movement to clinical product, however, has been slow. Another offshoot of these efforts has been the incorporation of some new exciting technologies (e.g., microfabrication, 3D printing) that may enable future breakthroughs. In this review we highlight the modest beginnings of the field and then describe three application examples that are in various stages of development, ranging from relatively mature (skin) to ongoing proof-of-concept (cartilage) to early stage (liver). We then discuss some of the major issues that limit the development of complex tissues, some of which are fundamentals-based, whereas others stem from the needs of the end users.

  9. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey J.; Curley, Suzanne

    2010-01-01

    The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle s Environmental Control and Life Support System (ECLSS). Termed the Carbon Dioxide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were performed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic simulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

  10. Stem cells from amniotic fluid--Potential for regenerative medicine.

    PubMed

    Loukogeorgakis, Stavros P; De Coppi, Paolo

    2016-02-01

    Regenerative medicine has recently been established as an emerging field focussing on repair, replacement or regeneration of cells, tissues and whole organs. The significant recent advances in the field have intensified the search for novel sources of stem cells with potential for therapy. Recently, researchers have identified the amniotic fluid as an untapped source of stem cells that are multipotent, possess immunomodulatory properties and do not have the ethical and legal limitations of embryonic stem cells. Stem cells from the amniotic fluid have been shown to differentiate into cell lineages representing all three embryonic germ layers without generating tumours, which make them an ideal candidate for tissue engineering applications. In addition, their ability to engraft in injured organs and modulate immune and repair responses of host tissues suggest that transplantation of such cells may be useful for the treatment of various degenerative and inflammatory diseases affecting major tissues/organs. This review summarises the evidence on amniotic fluid cells over the past 15 years and explores the potential therapeutic applications of amniotic fluid stem cells and amniotic fluid mesenchymal stem cells.

  11. Harnessing the potential of lung stem cells for regenerative medicine.

    PubMed

    McQualter, Jonathan L; Anthony, Desiree; Bozinovski, Steven; Prêle, Cecilia M; Laurent, Geoffrey J

    2014-11-01

    In response to recurrent exposure to environmental insults such as allergens, pollution, irritants, smoke and viral/bacterial infection, the epithelium of the lung is continually damaged. Homeostasis of the lung requires a balance between immune regulation and promotion of tissue regeneration, which requires the co-ordinated proliferation and differentiation of stem and progenitor cells. In this review we reflect on the current understanding of lung epithelial stem and progenitor cells and advocate a model hierarchy in which self-renewing multipotent lung epithelial stem cells give rise to lineage restricted progenitor cells that repopulate airway and alveolar epithelial cell lineages during homeostasis and repair. We also discuss the role of mesenchymal progenitor cells in maintaining the structural integrity of the lung and propose a model in which mesenchymal cells act as the quintessential architects of lung regeneration by providing molecular signals, such as FGF-10, to regulate the fate and specificity of epithelial stem and progenitor cells. Moreover, we discuss the current status and future prospects for translating lung stem cell therapies to the clinic to replace, repair, or regenerate diseased lung tissue. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation.

  12. Adipose tissue-derived stem cells in neural regenerative medicine.

    PubMed

    Yeh, Da-Chuan; Chan, Tzu-Min; Harn, Horng-Jyh; Chiou, Tzyy-Wen; Chen, Hsin-Shui; Lin, Zung-Sheng; Lin, Shinn-Zong

    2015-01-01

    Adipose tissue-derived stem cells (ADSCs) have two essential characteristics with regard to regenerative medicine: the convenient and efficient generation of large numbers of multipotent cells and in vitro proliferation without a loss of stemness. The implementation of clinical trials has prompted widespread concern regarding safety issues and has shifted research toward the therapeutic efficacy of stem cells in dealing with neural degeneration in cases such as stroke, amyotrophic lateral sclerosis, Parkinson's disease, Alzheimer's disease, Huntington's disease, cavernous nerve injury, and traumatic brain injury. Most existing studies have reported that cell therapies may be able to replenish lost cells and promote neuronal regeneration, protect neuronal survival, and play a role in overcoming permanent paralysis and loss of sensation and the recovery of neurological function. The mechanisms involved in determining therapeutic capacity remain largely unknown; however, this concept can still be classified in a methodical manner by citing current evidence. Possible mechanisms include the following: 1) the promotion of angiogenesis, 2) the induction of neuronal differentiation and neurogenesis, 3) reductions in reactive gliosis, 4) the inhibition of apoptosis, 5) the expression of neurotrophic factors, 6) immunomodulatory function, and 7) facilitating neuronal integration. In this study, several human clinical trials using ADSCs for neuronal disorders were investigated. It is suggested that ADSCs are one of the choices among various stem cells for translating into clinical application in the near future.

  13. Experimentally induced metamorphosis in axolotls reduces regenerative rate and fidelity

    PubMed Central

    Stier, Adrian C.; Michonneau, François; Smith, Matthew D.; Pasch, Bret; Maden, Malcolm

    2014-01-01

    Abstract While most tetrapods are unable to regenerate severed body parts, amphibians display a remarkable ability to regenerate an array of structures. Frogs can regenerate appendages as larva, but they lose this ability around metamorphosis. In contrast, salamanders regenerate appendages as larva, juveniles, and adults. However, the extent to which fundamental traits (e.g., metamorphosis, body size, aging, etc.) restrict regenerative ability remains contentious. Here we utilize the ability of normally paedomorphic adult axolotls (Ambystoma mexicanum) to undergo induced metamorphosis by thyroxine exposure to test how metamorphosis and body size affects regeneration in age‐matched paedomorphic and metamorphic individuals. We show that body size does not affect regeneration in adult axolotls, but metamorphosis causes a twofold reduction in regeneration rate, and lead to carpal and digit malformations. Furthermore, we find evidence that metamorphic blastemal cells may take longer to traverse the cell cycle and display a lower proliferative rate. This study identifies the axolotl as a powerful system to study how metamorphosis restricts regeneration independently of developmental stage, body size, and age; and more broadly how metamorphosis affects tissue‐specific changes. PMID:27499857

  14. Polymer-based microparticles in tissue engineering and regenerative medicine.

    PubMed

    Oliveira, Mariana B; Mano, João F

    2011-07-01

    Different types of biomaterials, processed into different shapes, have been proposed as temporary support for cells in tissue engineering (TE) strategies. The manufacturing methods used in the production of particles in drug delivery strategies have been adapted for the development of microparticles in the fields of TE and regenerative medicine (RM). Microparticles have been applied as building blocks and matrices for the delivery of soluble factors, aiming for the construction of TE scaffolds, either by fusion giving rise to porous scaffolds or as injectable systems for in situ scaffold formation, avoiding complicated surgery procedures. More recently, organ printing strategies have been developed by the fusion of hydrogel particles with encapsulated cells, aiming the production of organs in in vitro conditions. Mesoscale self-assembly of hydrogel microblocks and the use of leachable particles in three-dimensional (3D) layer-by-layer (LbL) techniques have been suggested as well in recent works. Along with innovative applications, new perspectives are open for the use of these versatile structures, and different directions can still be followed to use all the potential that such systems can bring. This review focuses on polymeric microparticle processing techniques and overviews several examples and general concepts related to the use of these systems in TE and RE applications. The use of materials in the development of microparticles from research to clinical applications is also discussed.

  15. Satellite cells from dystrophic muscle retain regenerative capacity.

    PubMed

    Boldrin, Luisa; Zammit, Peter S; Morgan, Jennifer E

    2015-01-01

    Duchenne muscular dystrophy is an inherited disorder that is characterized by progressive skeletal muscle weakness and wasting, with a failure of muscle maintenance/repair mediated by satellite cells (muscle stem cells). The function of skeletal muscle stem cells resident in dystrophic muscle may be perturbed by being in an increasing pathogenic environment, coupled with constant demands for repairing muscle. To investigate the contribution of satellite cell exhaustion to this process, we tested the functionality of satellite cells isolated from the mdx mouse model of Duchenne muscular dystrophy. We found that satellite cells derived from young mdx mice contributed efficiently to muscle regeneration within our in vivo mouse model. To then test the effects of long-term residence in a dystrophic environment, satellite cells were isolated from aged mdx muscle. Surprisingly, they were as functional as those derived from young or aged wild type donors. Removing satellite cells from a dystrophic milieu reveals that their regenerative capacity remains both intact and similar to satellite cells derived from healthy muscle, indicating that the host environment is critical for controlling satellite cell function.

  16. Computational immuno-biology for organ transplantation and regenerative medicine.

    PubMed

    Vásquez-Montoya, Gustavo A; Danobeitia, Juan S; Fernández, Luis A; Hernández-Ortiz, Juan P

    2016-10-01

    Organ transplantation and regenerative medicine are adopted platforms that provide replacement tissues and organs from natural or engineered sources. Acceptance, tolerance and rejection depend greatly on the proper control of the immune response against graft antigens, motivating the development of immunological and genetical therapies that prevent organ failure. They rely on a complete, or partial, understanding of the immune system. Ultimately, they are innovative technologies that ensure permanent graft tolerance and indefinite graft survival through the modulation of the immune system. Computational immunology has arisen as a tool towards a mechanistic understanding of the biological and physicochemical processes surrounding an immune response. It comprehends theoretical and computational frameworks that simulate immuno-biological systems. The challenge is centered on the multi-scale character of the immune system that spans from atomistic scales, during peptide-epitope and protein interactions, to macroscopic scales, for lymph transport and organ-organ reactions. In this paper, we discuss, from an engineering perspective, the biological processes that are involved during the immune response of organ transplantation. Previous computational efforts, including their characteristics and visible limitations, are described. Finally, future perspectives and challenges are listed to motivate further developments.

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

    SciTech Connect

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

    1999-06-01

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

  18. Regenerative fuel cell study for satellites in GEO orbit

    NASA Astrophysics Data System (ADS)

    Levy, Alexander; Vandine, Leslie L.; Stedman, James K.

    1987-07-01

    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.

  19. Induced pluripotent stem cell technology in regenerative medicine and biology.

    PubMed

    Pei, Duanqing; Xu, Jianyong; Zhuang, Qiang; Tse, Hung-Fat; Esteban, Miguel A

    2010-01-01

    The potential of human embryonic stem cells (ESCs) for regenerative medicine is unquestionable, but practical and ethical considerations have hampered clinical application and research. In an attempt to overcome these issues, the conversion of somatic cells into pluripotent stem cells similar to ESCs, commonly termed nuclear reprogramming, has been a top objective of contemporary biology. More than 40 years ago, King, Briggs, and Gurdon pioneered somatic cell nuclear reprogramming in frogs, and in 1981 Evans successfully isolated mouse ESCs. In 1997 Wilmut and collaborators produced the first cloned mammal using nuclear transfer, and then Thomson obtained human ESCs from in vitro fertilized blastocysts in 1998. Over the last 2 decades we have also seen remarkable findings regarding how ESC behavior is controlled, the importance of which should not be underestimated. This knowledge allowed the laboratory of Shinya Yamanaka to overcome brilliantly conceptual and technical barriers in 2006 and generate induced pluripotent stem cells (iPSCs) from mouse fibroblasts by overexpressing defined combinations of ESC-enriched transcription factors. Here, we discuss some important implications of human iPSCs for biology and medicine and also point to possible future directions.

  20. Tissue engineering and regenerative medicine: past, present, and future.

    PubMed

    Salgado, António J; Oliveira, Joaquim M; Martins, Albino; Teixeira, Fábio G; Silva, Nuno A; Neves, Nuno M; Sousa, Nuno; Reis, Rui L

    2013-01-01

    Tissue and organ repair still represents a clinical challenge. Tissue engineering and regenerative medicine (TERM) is an emerging field focused on the development of alternative therapies for tissue/organ repair. This highly multidisciplinary field, in which bioengineering and medicine merge, is based on integrative approaches using scaffolds, cell populations from different sources, growth factors, nanomedicine, gene therapy, and other techniques to overcome the limitations that currently exist in the clinics. Indeed, its overall objective is to induce the formation of new functional tissues, rather than just implanting spare parts. This chapter aims at introducing the reader to the concepts and techniques of TERM. It begins by explaining how TERM have evolved and merged into TERM, followed by a short overview of some of its key aspects such as the combinations of scaffolds with cells and nanomedicine, scaffold processing, and new paradigms of the use of stem cells for tissue repair/regeneration, which ultimately could represent the future of new therapeutic approaches specifically aimed at clinical applications.

  1. Regenerative braking systems with torsional springs made of carbon nanotube yarn

    NASA Astrophysics Data System (ADS)

    Liu, S.; Martin, C.; Lashmore, D.; Schauer, M.; Livermore, C.

    2014-11-01

    The demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as an energy-storing actuator for regenerative braking systems. Originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing until failure. The maximum extractable energy density is measured to be as high as 6.13 kJ/kg. The tests also reveal structural reorganization and hysteresis in the torsional loading curves. A regenerative braking system is built to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yam's twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking system are up to 4.69 kJ/kg and 1.21 kW/kg, respectively. A slightly lower energy density of up to 1.23 kJ/kg and a 0.29 kW/kg mean power density are measured for the CNT yarns in a more complex system that mimics a unidirectional rotating regenerative braking mechanism. The lower energy densities for CNT yarns in the regenerative braking systems as compared with the yarns themselves reflect the frictional losses of the regenerative systems.

  2. REGene: a literature-based knowledgebase of animal regeneration that bridge tissue regeneration and cancer

    PubMed Central

    Zhao, Min; Rotgans, Bronwyn; Wang, Tianfang; Cummins, S. F.

    2016-01-01

    Regeneration is a common phenomenon across multiple animal phyla. Regeneration-related genes (REGs) are critical for fundamental cellular processes such as proliferation and differentiation. Identification of REGs and elucidating their functions may help to further develop effective treatment strategies in regenerative medicine. So far, REGs have been largely identified by small-scale experimental studies and a comprehensive characterization of the diverse biological processes regulated by REGs is lacking. Therefore, there is an ever-growing need to integrate REGs at the genomics, epigenetics, and transcriptome level to provide a reference list of REGs for regeneration and regenerative medicine research. Towards achieving this, we developed the first literature-based database called REGene (REgeneration Gene database). In the current release, REGene contains 948 human (929 protein-coding and 19 non-coding genes) and 8445 homologous genes curated from gene ontology and extensive literature examination. Additionally, the REGene database provides detailed annotations for each REG, including: gene expression, methylation sites, upstream transcription factors, and protein-protein interactions. An analysis of the collected REGs reveals strong links to a variety of cancers in terms of genetic mutation, protein domains, and cellular pathways. We have prepared a web interface to share these regeneration genes, supported by refined browsing and searching functions at http://REGene.bioinfo-minzhao.org/. PMID:26975833

  3. Restoration of anterior regeneration in a planarian with limited regenerative ability.

    PubMed

    Sikes, James M; Newmark, Phillip A

    2013-08-01

    Variability of regenerative potential among animals has long perplexed biologists. On the basis of their exceptional regenerative abilities, planarians have become important models for understanding the molecular basis of regeneration. However, planarian species with limited regenerative abilities are also found. Despite the importance of understanding the differences between closely related, regenerating and non-regenerating organisms, few studies have focused on the evolutionary loss of regeneration, and the molecular mechanisms leading to such regenerative loss remain obscure. Here we examine Procotyla fluviatilis, a planarian with restricted ability to replace missing tissues, using next-generation sequencing to define the gene expression programs active in regeneration-permissive and regeneration-deficient tissues. We found that Wnt signalling is aberrantly activated in regeneration-deficient tissues. Notably, downregulation of canonical Wnt signalling in regeneration-deficient regions restores regenerative abilities: blastemas form and new heads regenerate in tissues that normally never regenerate. This work reveals that manipulating a single signalling pathway can reverse the evolutionary loss of regenerative potential.

  4. Regenerative endodontics: a review of current status and a call for action.

    PubMed

    Murray, Peter E; Garcia-Godoy, Franklin; Hargreaves, Kenneth M

    2007-04-01

    Millions of teeth are saved each year by root canal therapy. Although current treatment modalities offer high levels of success for many conditions, an ideal form of therapy might consist of regenerative approaches in which diseased or necrotic pulp tissues are removed and replaced with healthy pulp tissue to revitalize teeth. Researchers are working toward this objective. Regenerative endodontics is the creation and delivery of tissues to replace diseased, missing, and traumatized pulp. This review provides an overview of regenerative endodontics and its goals, and describes possible techniques that will allow regenerative endodontics to become a reality. These potential approaches include root-canal revascularization, postnatal (adult) stem cell therapy, pulp implant, scaffold implant, three-dimensional cell printing, injectable scaffolds, and gene therapy. These regenerative endodontic techniques will possibly involve some combination of disinfection or debridement of infected root canal systems with apical enlargement to permit revascularization and use of adult stem cells, scaffolds, and growth factors. Although the challenges of introducing endodontic tissue engineering therapies are substantial, the potential benefits to patients and the profession are equally ground breaking. Patient demand is staggering both in scope and cost, because tissue engineering therapy offers the possibility of restoring natural function instead of surgical placement of an artificial prosthesis. By providing an overview of the methodological issues required to develop potential regenerative endodontic therapies, we hope to present a call for action to develop these therapies for clinical use.

  5. Mesenchymal Stem and Progenitor Cells in Regeneration: Tissue Specificity and Regenerative Potential

    PubMed Central

    Pieber, Thomas Rudolf

    2017-01-01

    It has always been an ambitious goal in medicine to repair or replace morbid tissues for regaining the organ functionality. This challenge has recently gained momentum through considerable progress in understanding the biological concept of the regenerative potential of stem cells. Routine therapeutic procedures are about to shift towards the use of biological and molecular armamentarium. The potential use of embryonic stem cells and invention of induced pluripotent stem cells raised hope for clinical regenerative purposes; however, the use of these interventions for regenerative therapy showed its dark side, as many health concerns and ethical issues arose in terms of using these cells in clinical applications. In this regard, adult stem cells climbed up to the top list of regenerative tools and mesenchymal stem cells (MSC) showed promise for regenerative cell therapy with a rather limited level of risk. MSC have been successfully isolated from various human tissues and they have been shown to offer the possibility to establish novel therapeutic interventions for a variety of hard-to-noncurable diseases. There have been many elegant studies investigating the impact of MSC in regenerative medicine. This review provides compact information on the role of stem cells, in particular, MSC in regeneration. PMID:28286525

  6. The role of heparan sulfate and perlecan in bone-regenerative procedures.

    PubMed

    DeCarlo, A A; Whitelock, J M

    2006-02-01

    Tissue engineering, grafting procedures, regeneration, and tissue remodeling are developing therapeutic modalities with great potential medical value, but these regenerative modalities are not as effective or predictable as clinicians and patients would like. Greater understanding of growth factors, cytokines, extracellular matrix molecules, and their roles in cell-mediated healing processes have made these regenerative therapies more clinically viable and will continue advancing the fields of tissue engineering and grafting. However, millions of oral and non-oral bone-grafting procedures are performed annually, and only a small percentage yield the most desirable results. Here we review the heparan-sulfate-decorated extracellular biomolecule named perlecan and the research relating to its potential as an adjunct in bone-regenerative procedures. The review includes an overview of bone graft substitutes and biological adjuncts to bone-regenerative procedures in medicine as they apply to periodontal disease, alveolar ridge augmentation, and barrier membrane therapy. Perlecan is discussed as a potential biological adjunct in terms of growth factor sequestration and delivery, and promoting cell adhesion, proliferation, differentiation, and angiogenesis. Further, we propose delivery and application schemes for perlecan and/or its domains in bone-regenerative procedures, with particular emphasis on its heparan-sulfate-decorated domain I. The perlecan molecule, with its heparan sulfate glycosylation, may provide a multi-faceted approach for the delivery of a more comprehensive stimulus than other single potential adjuncts currently available for bone-regenerative procedures.

  7. RegenBase: a knowledge base of spinal cord injury biology for translational research

    PubMed Central

    Callahan, Alison; Abeyruwan, Saminda W.; Al-Ali, Hassan; Sakurai, Kunie; Ferguson, Adam R.; Popovich, Phillip G.; Shah, Nigam H.; Visser, Ubbo; Bixby, John L.; Lemmon, Vance P.

    2016-01-01

    Spinal cord injury (SCI) research is a data-rich field that aims to identify the biological mechanisms resulting in loss of function and mobility after SCI, as well as develop therapies that promote recovery after injury. SCI experimental methods, data and domain knowledge are locked in the largely unstructured text of scientific publications, making large scale integration with existing bioinformatics resources and subsequent analysis infeasible. The lack of standard reporting for experiment variables and results also makes experiment replicability a significant challenge. To address these challenges, we have developed RegenBase, a knowledge base of SCI biology. RegenBase integrates curated literature-sourced facts and experimental details, raw assay data profiling the effect of compounds on enzyme activity and cell growth, and structured SCI domain knowledge in the form of the first ontology for SCI, using Semantic Web representation languages and frameworks. RegenBase uses consistent identifier schemes and data representations that enable automated linking among RegenBase statements and also to other biological databases and electronic resources. By querying RegenBase, we have identified novel biological hypotheses linking the effects of perturbagens to observed behavioral outcomes after SCI. RegenBase is publicly available for browsing, querying and download. Database URL: http://regenbase.org PMID:27055827

  8. Magnetically-responsive, multifunctional drug delivery nanoparticles for elastic matrix regenerative repair.

    PubMed

    Sivaraman, Balakrishnan; Swaminathan, Ganesh; Moore, Lee; Fox, Jonathan; Seshadri, Dhruv; Dahal, Shataakshi; Stoilov, Ivan; Zborowski, Maciej; Mecham, Robert; Ramamurthi, Anand

    2017-04-01

    Arresting or regressing growth of abdominal aortic aneurysms (AAAs), localized expansions of the abdominal aorta are contingent on inhibiting chronically overexpressed matrix metalloproteases (MMPs)-2 and -9 that disrupt elastic matrix within the aortic wall, concurrent with providing a stimulus to augmenting inherently poor auto-regeneration of these matrix structures. In a recent study we demonstrated that localized, controlled and sustained delivery of doxycycline (DOX; a tetracycline-based antibiotic) from poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs), enhances elastic matrix deposition and MMP-inhibition at a fraction of the therapeutically effective oral dose. The surface functionalization of these NPs with cationic amphiphiles, which enhances their arterial uptake, was also shown to have pro-matrix regenerative and anti-MMP effects independent of the DOX. Based on the hypothesis that the incorporation of superparamagnetic iron oxide NPs (SPIONs) within these PLGA NPs would enhance their targetability to the AAA site under an applied external magnetic field, we sought to evaluate the functional effects of NPs co-encapsulating DOX and SPIONs (DOX-SPION NPs) on elastic matrix regeneration and MMP synthesis/activity in vitro within aneurysmal smooth muscle cell (EaRASMC) cultures. The DOX-SPION NPs were mobile under an applied external magnetic field, while enhancing elastic matrix deposition 1.5-2-fold and significantly inhibiting MMP-2 synthesis and MMP-2 and -9 activities, compared to NP-untreated control cultures. These results illustrate that the multifunctional benefits of NPs are maintained following SPION co-incorporation. Additionally, preliminary studies carried out demonstrated enhanced targetability of SPION-loaded NPs within proteolytically-disrupted porcine carotid arteries ex vivo, under the influence of an applied external magnetic field. Thus, this dual-agent loaded NP system proffers a potential non-surgical option for treating small

  9. Novel proresolving and tissue-regenerative resolvin and protectin sulfido-conjugated pathways

    PubMed Central

    Dalli, Jesmond; Ramon, Sesquile; Norris, Paul C.; Colas, Romain A.; Serhan, Charles N.

    2015-01-01

    Local mediators orchestrate the host response to both sterile and infectious challenge and resolution. Recent evidence demonstrates that maresin sulfido-conjugates actively resolve acute inflammation and promote tissue regeneration. In this report, we investigated self-limited infectious exudates for novel bioactive chemical signals in tissue regeneration and resolution. By use of spleens from Escherichia coli infected mice, self-resolving infectious exudates, human spleens, and blood from patients with sepsis, we identified 2 new families of potent molecules. Characterization of their physical properties and isotope tracking demonstrated that the bioactive structures contained a docosahexaenoate backbone and sulfido-conjugated triene or tetraene double-bond systems. Activated human phagocytes converted 17-hydro(peroxy)-4Z,7Z,10Z,13Z,15E,19Z-docosahexaenoic acid to these bioactive molecules. Regeneration of injured planaria was accelerated with nanomolar amounts of 16-glutathionyl, 17-hydroxy-4Z,7Z,10,12,14,19Z-docosahexaenoic acid and 16-cysteinylglycinyl, 17-hydroxy-4Z,7Z,10,12,14,19Z-docosahexaenoic acid (Protectin sulfido-conjugates) or 8-glutathionyl, 7,17-dihydroxy-4Z,9,11,13Z,15E,19Z-docosahexaenoic acid and 8-cysteinylglycinyl, 7,17-dihydroxy-4Z,9,11,13Z,15E,19Z-docosahexaenoic acid (Resolvin sulfido-conjugates). Each protectin and resolvin sulfido-conjugate dose dependently (0.1–10 nM) stimulated human macrophage bacterial phagocytosis, phagolysosomal acidification, and efferocytosis. Together, these results identify 2 novel pathways and provide evidence for structural elucidation of new resolution moduli. These resolvin and protectin conjugates identified in mice and human infected tissues control host responses promoting catabasis.—Dalli, J., Ramon, S., Norris, P. C., Colas, R. A., Serhan, C. N. Novel proresolving and tissue-regenerative resolvin and protectin sulfido-conjugated pathways. PMID:25713027

  10. Acoustic dose and acoustic dose-rate.

    PubMed

    Duck, Francis

    2009-10-01

    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  11. Stem cells and vascular regenerative medicine: A mini review.

    PubMed

    Stoltz, J-F; Bensoussan, D; De Isla, N; Zhang, L; Han, Z; Magdalou, J; Huselstein, C; Ye, J S; Leballe, B; Decot, V; Reppel, L

    2016-01-01

    Most human tissues do not regenerate spontaneously, which is why "cell therapy" are promising alternative treatments. The Principe is simple: patients' or donors' cells are collected and introduced into the injured tissues or organs directly or in a porous 3D material, with or without modification of their properties. This concept of regenerative medicine is an emerging field which can be defined as "the way to improve health and quality of life by restoring, maintaining, or enhancing tissue and organ functions".There is an extraordinarily wide range of opportunities for clinical applications: artheropathies, diabetes, cartilage defects, bone repair, burns, livers or bladder regeneration, organs reconstruction (lung, heart, liver ...) neurodegenerative disorders, sepsis ...  Different stem cells (SC) with different potential can be used and characterised (totipotent, mesenchymal of different origins, especially those present in tissues...). Today it is undeniable that cells like bone marrow, adipose tissue or Wharton Jelly stem cells, are of potential interest for clinical applications because they are easily separated and prepared and no ethical problems are involved in their use.In this paper some potential clinical applications in the vascular field are considered: peripheral arteriopathy in diabetic patients, cardiac insufficiency, traitment of erectile dysfunction, or organ regeneration with liver as example. But the regeneration of tissue or organ is and will remain a challenge for the future development of cell therapy. Many problems remain to be solved that could lead to the development of innovative strategies to facilitate cell differentiation, increase the yield of cells and ensure a standardised product, overcome the risks of teratogenic effects and/or immune reactions, enable grafting via direct cell or biotissue transplantation and avoid legal issues involved in national regulations.

  12. Porous tantalum and tantalum oxide nanoparticles for regenerative medicine.

    PubMed

    Mohandas, Gokhuldass; Oskolkov, Nikita; McMahon, Michael T; Walczak, Piotr; Janowski, Miroslaw

    2014-01-01

    For centuries, inflammatory/foreign body reactions have plagued the attempts of clinicians to use metals for tissue and bone reconstructions. Since corrosion contributes to the rejection of metal by the body, an extremely bioinert metal - tantalum - has been successfully used in medicine. The outstanding biocompatibility and flexibility of tantalum established the basis for a growing cadre of clinical applications. One important application which benefited from the introduction of powder (particle) metallurgy is use of tantalum as bone implants. Porous materials have re-shaped the landscape of bone implants, as they allow for bone ingrowth and biological fixation, and eliminate implant loosening and related treatment failures. The unique bone-mimicking properties of porous tantalum enabled the use of tantalum as a material for bulk implants, and not only for coatings, as is the case with other porous metals. Moreover, porous tantalum also facilitates the ingrowth of soft tissue, including the formation of blood vessels that were found to assemble on the surface and within the structure of the porous tantalum. Also, since tantalum is strongly radiopaque due its high atomic number, this property is widely employed for marking in orthopedics and in endovascular medical devices. Another important development was the production of nanoparticles based on tantalum. These particles have been shown to be superior to iodinated contrast agents for blood pool imaging applications due to their longer circulation time. Their properties are similar to gold nanoparticles, but are far more cost-effective, and thus, well-positioned to replace gold in regenerative medicine for labeling and tracking of cell grafts through x-ray-based imaging. However, the amount of tantalum nanoparticles that can be taken up by stem cells is not enough to make individual cells visible in x-ray images. Thus, alternative strategies are needed, such as hydrogel or nanofiber scaffolds, which can be loaded

  13. Regenerative Fuel Cell System As Alternative Energy Storage For Space

    NASA Astrophysics Data System (ADS)

    Lucas, J.; Bockstahler, K.; Funke, H.; Jehle, W.; Markgraf, S.; Henn, N.; Schautz, M.

    2011-10-01

    Next generation telecommunication satellites will demand more power. Power levels of 20 to 30kW are foreseen for the next 10 years. Battery technology that can sustain 30kW for eclipse lengths of up to 72 minutes (equals amount of stored energy of 36kWh) will represent a major impact on the total mass of the satellite, even with Li-ion battery technologies, which are estimated to reach an energy density of 250Wh/kg (begin of life) on cell level i.e. 150Wh/kg on subsystem level in 10 years. For the high power level another technology is needed to reach the next goal of 300 - 350Wh/kg on subsystem level. One candidate is the Regenerative Fuel Cell (RFC) technology which proves to be superior to batteries with increasing power demand and increasing discharge time. Such an RFC system based on hydrogen and oxygen technology consists of storage for the reactants (H2, O2 and H2O), a fuel cell (FC) and an electrolyser (ELY). In charge mode, the electrolyser splits water in hydrogen and oxygen using electrical power from solar cells. The gases are stored in appropriate tanks. In discharge mode, during time intervals of power demand, O2 and H2 are converted in the fuel cell to generate electricity under formation of water as by-product. The water is stored in tanks and during charge mode rerouted to the electrolyser thus creating a closed-loop process. Today Astrium is developing an RFCS as energy storage and supply unit for some future ESA missions. A complete RFCS breadboard has been established and the operational behaviour of the system is being tested. First test results, dedicated experience gained from system testing and a comparison with the analytical prediction will be discussed and presented.

  14. In vivo characterization of regenerative peripheral nerve interface function

    NASA Astrophysics Data System (ADS)

    Ursu, Daniel C.; Urbanchek, Melanie G.; Nedic, Andrej; Cederna, Paul S.; Gillespie, R. Brent

    2016-04-01

    Objective. Regenerative peripheral nerve interfaces (RPNIs) are neurotized free autologous muscle grafts equipped with electrodes to record myoelectric signals for prosthesis control. Viability of rat RPNI constructs have been demonstrated using evoked responses. In vivo RPNI characterization is the next critical step for assessment as a control modality for prosthetic devices. Approach. Two RPNIs were created in each of two rats by grafting portions of free muscle to the ends of divided peripheral nerves (peroneal in the left and tibial in the right hind limb) and placing bipolar electrodes on the graft surface. After four months, we examined in vivo electromyographic signal activity and compared these signals to muscular electromyographic signals recorded from autologous muscles in two rats serving as controls. An additional group of two rats in which the autologous muscles were denervated served to quantify cross-talk in the electrode recordings. Recordings were made while rats walked on a treadmill and a motion capture system tracked the hind limbs. Amplitude and periodicity of signals relative to gait were quantified, correlation between electromyographic and motion recording were assessed, and a decoder was trained to predict joint motion. Main Results. Raw RPNI signals were active during walking, with amplitudes of 1 mVPP, and quiet during standing, with amplitudes less than 0.1 mVPP. RPNI signals were periodic and entrained with gait. A decoder predicted bilateral ankle motion with greater than 80% reliability. Control group signal activity agreed with literature. Denervated group signals remained quiescent throughout all evaluations. Significance. In vivo myoelectric RPNI activity encodes neural activation patterns associated with gait. Signal contamination from muscles adjacent to the RPNI is minimal, as demonstrated by the low amplitude signals obtained from the Denervated group. The periodicity and entrainment to gait of RPNI recordings suggests the

  15. The regenerative effects of electromagnetic field on spinal cord injury.

    PubMed

    Ross, Christina L; Syed, Ishaq; Smith, Thomas L; Harrison, Benjamin S

    2017-01-01

    Traumatic spinal cord injury (SCI) is typically the result of direct mechanical impact to the spine, leading to fracture and/or dislocation of the vertebrae along with damage to the surrounding soft tissues. Injury to the spinal cord results in disruption of axonal transmission of signals. This primary trauma causes secondary injuries that produce immunological responses such as neuroinflammation, which perpetuates neurodegeneration and cytotoxicity within the injured spinal cord. To date there is no FDA-approved pharmacological agent to prevent the development of secondary SCI and induce regenerative processes aimed at healing the spinal cord and restoring neurological function. An alternative method to electrically activate spinal circuits is the application of a noninvasive electromagnetic field (EMF) over intact vertebrae. The EMF method of modulating molecular signaling of inflammatory cells emitted in the extra-low frequency range of <100 Hz, and field strengths of <5 mT, has been reported to decrease inflammatory markers in macrophages, and increase endogenous mesenchymal stem cell (MSC) proliferation and differentiation rates. EMF has been reported to promote osteogenesis by improving the effects of osteogenic media, and increasing the proliferation of osteoblasts, while inhibiting osteoclast formation and increasing bone matrix in vitro. EMF has also been shown to increase chondrogenic markers and collagen and induce neural differentiation, while increasing cell viability by over 50%. As advances are made in stem cell technologies, stabilizing the cell line after differentiation is crucial to SCI repair. Once cell-seeded scaffolds are implanted, EMF may be applied outside the wound for potential continued adjunct treatment during recovery.

  16. Cryogenic reactant storage for lunar base regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Kohout, Lisa L.

    1989-02-01

    There are major advantages to be gained by integrating a cryogenic reactant storage system with a hydrogen-oxygen regenerative fuel cell (RFC) to provide on-site electrical power during the lunar night. Although applicable to any power system using hydrogen-oxygen RFC's for energy storage, cryogenic reactant storage offers a significant benefit whenever the sun/shade cycle and energy storage period approach hundreds of hours. For solar power installations on the moon, cryogenic reactant storage reduces overall specific mass and meteoroid vulnerability of the system. In addition, it offers synergistic benefits to on-site users, such as availability of primary fuel cell reactants for surface rover vehicles and cryogenic propellants for OTV's. The integration involves processing and storing the RFC reactant streams as cryogenic liquids rather than pressurized gases, so that reactant containment (tankage per unit mass of reactants) can be greatly reduced. Hydrogen-oxygen alkaline RFC's, GaAs photovoltaic (PV) arrays, and space cryogenic processing/refrigeration technologies are assumed to be available for the conceptual system design. Advantages are demonstrated by comparing the characteristics of two power system concepts: a conventional lunar surface PV/RFC power system using pressurized gas storage in SOA filament wound pressure vessels and, that same system with gas liquefaction and storage replacing the pressurized storage. Comparisons are made at 20 and 250 kWe. Although cryogenic storage adds a processing plant (drying and liquefaction) to the system plus 30 percent more solar array to provide processing power, the approximate order of magnitude reduction in tankage mass, confirmed by this analysis, results in a reduction in overall total system mass of approximately 50 percent.

  17. Cryogenic reactant storage for lunar base regenerative fuel cells

    NASA Astrophysics Data System (ADS)

    Kohout, Lisa L.

    There are major advantages to be gained by integrating a cryogenic reactant storage system with a hydrogen-oxygen regenerative fuel cell (RFC) to provide on-site electrical power during the lunar night. Although applicable to any power system using hydrogen-oxygen RFC's for energy storage, cryogenic reactant storage offers a significant benefit whenever the sun/shade cycle and energy storage period approach hundreds of hours. For solar power installations on the moon, cryogenic reactant storage reduces overall specific mass and meteoroid vulnerability of the system. In addition, it offers synergistic benefits to on-site users, such as availability of primary fuel cell reactants for surface rover vehicles and cryogenic propellants for OTV's. The integration involves processing and storing the RFC reactant streams as cryogenic liquids rather than pressurized gases, so that reactant containment (tankage per unit mass of reactants) can be greatly reduced. Hydrogen-oxygen alkaline RFC's, GaAs photovoltaic (PV) arrays, and space cryogenic processing/refrigeration technologies are assumed to be available for the conceptual system design. Advantages are demonstrated by comparing the characteristics of two power system concepts: a conventional lunar surface PV/RFC power system using pressurized gas storage in SOA filament wound pressure vessels and, that same system with gas liquefaction and storage replacing the pressurized storage. Comparisons are made at 20 and 250 kWe. Although cryogenic storage adds a processing plant (drying and liquefaction) to the system plus 30 percent more solar array to provide processing power, the approximate order of magnitude reduction in tankage mass, confirmed by this analysis, results in a reduction in overall total system mass of approximately 50 percent.

  18. Transforming growth factor beta 1, a cytokine with regenerative functions

    PubMed Central

    Sulaiman, Wale; Nguyen, Doan H.

    2016-01-01

    We review the biology and role of transforming growth factor beta 1 (TGF-β1) in peripheral nerve injury and regeneration, as it relates to injuries to large nerve trunks (i.e., sciatic nerve, brachial plexus), which often leads to suboptimal functional recovery. Experimental studies have suggested that the reason for the lack of functional recovery resides in the lack of sufficient mature axons reaching their targets, which is a result of the loss of the growth-supportive environment provided by the Schwann cells in the distal stump of injured nerves. Using an established chronic nerve injury and delayed repair animal model that accurately mimics chronic nerve injuries in humans, we summarize our key findings as well as others to better understand the pathophysiology of poor functional recovery. We demonstrated that 6 month TGF-β1 treatment for chronic nerve injury significantly improved Schwann cell capacity to support axonal regeneration. When combined with forskolin, the effect was additive, as evidenced by a near doubling of regenerated axons proximal to the repair site. We showed that in vivo application of TGF-β1 and forskolin directly onto chronically injured nerves reactivated chronically denervated Schwann cells, induced their proliferation, and upregulated the expression of regeneration-associated proteins. The effect of TGF-β1 and forskolin on old nerve injuries is quite impressive and the treatment regiment appears to mediate a growth-supportive milieu in the injured peripheral nerves. In summary, TGF-β1 and forskolin treatment reactivates chronically denervated Schwann cells and could potentially be used to extend and prolong the regenerative responses to promote axonal regeneration. PMID:27904475

  19. Cryogenic reactant storage for lunar base regenerative fuel cells

    NASA Technical Reports Server (NTRS)

    Kohout, Lisa L.

    1989-01-01

    There are major advantages to be gained by integrating a cryogenic reactant storage system with a hydrogen-oxygen regenerative fuel cell (RFC) to provide on-site electrical power during the lunar night. Although applicable to any power system using hydrogen-oxygen RFC's for energy storage, cryogenic reactant storage offers a significant benefit whenever the sun/shade cycle and energy storage period approach hundreds of hours. For solar power installations on the moon, cryogenic reactant storage reduces overall specific mass and meteoroid vulnerability of the system. In addition, it offers synergistic benefits to on-site users, such as availability of primary fuel cell reactants for surface rover vehicles and cryogenic propellants for OTV's. The integration involves processing and storing the RFC reactant streams as cryogenic liquids rather than pressurized gases, so that reactant containment (tankage per unit mass of reactants) can be greatly reduced. Hydrogen-oxygen alkaline RFC's, GaAs photovoltaic (PV) arrays, and space cryogenic processing/refrigeration technologies are assumed to be available for the conceptual system design. Advantages are demonstrated by comparing the characteristics of two power system concepts: a conventional lunar surface PV/RFC power system using pressurized gas storage in SOA filament wound pressure vessels and, that same system with gas liquefaction and storage replacing the pressurized storage. Comparisons are made at 20 and 250 kWe. Although cryogenic storage adds a processing plant (drying and liquefaction) to the system plus 30 percent more solar array to provide processing power, the approximate order of magnitude reduction in tankage mass, confirmed by this analysis, results in a reduction in overall total system mass of approximately 50 percent.

  20. The promise of perfect adult tissue repair and regeneration in mammals: Learning from regenerative amphibians and fish.

    PubMed

    Godwin, James

    2014-09-01

    Regenerative medicine promises to greatly impact on human health by improving repair outcomes in a range of tissues and injury contexts. Successful therapies will rely on identifying both intrinsic and extrinsic biological circuits that control wound healing, proliferation, cell survival, and developmental cell fate. Animals such as the zebrafish and the salamander display powerful examples of near-perfect regeneration and scar-free healing in a range of injury contexts not attained in mammals. By studying regeneration in a range of highly regenerative species that maintain regenerative potential throughout life, many instructive and permissive factors have been identified that could assist in the development of regenerative therapies. This review highlights some of the recent observations in immune regulation, epigenetic regulation, stem cell mobilization, and regenerative signatures that have improved our understanding of the regenerative process. Potential opportunities in harnessing this knowledge for future translation into the clinic are discussed.