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Sample records for nuclear hot cell

  1. 48 CFR 952.225-70 - Subcontracting for nuclear hot cell services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... hot cell services. 952.225-70 Section 952.225-70 Federal Acquisition Regulations System DEPARTMENT OF....225-70 Subcontracting for nuclear hot cell services. As prescribed in 925.7004, insert the following clause in solicitations and contracts: Subcontracting for Nuclear Hot Cell Services (MAR 1993)...

  2. 48 CFR 952.225-70 - Subcontracting for nuclear hot cell services. >

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... hot cell services. > 952.225-70 Section 952.225-70 Federal Acquisition Regulations System DEPARTMENT... Clauses 952.225-70 Subcontracting for nuclear hot cell services.> As prescribed in 925.7004, insert the following clause in solicitations and contracts: Subcontracting for Nuclear Hot Cell Services (MAR 1993)...

  3. 48 CFR 952.225-70 - Subcontracting for nuclear hot cell services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... hot cell services. 952.225-70 Section 952.225-70 Federal Acquisition Regulations System DEPARTMENT OF....225-70 Subcontracting for nuclear hot cell services. As prescribed in 925.7004, insert the following clause in solicitations and contracts: Subcontracting for Nuclear Hot Cell Services (MAR 1993)...

  4. 48 CFR 952.225-70 - Subcontracting for nuclear hot cell services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hot cell services. 952.225-70 Section 952.225-70 Federal Acquisition Regulations System DEPARTMENT OF....225-70 Subcontracting for nuclear hot cell services. As prescribed in 925.7004, insert the following clause in solicitations and contracts: Subcontracting for Nuclear Hot Cell Services (MAR 1993)...

  5. 48 CFR 952.225-70 - Subcontracting for nuclear hot cell services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... hot cell services. 952.225-70 Section 952.225-70 Federal Acquisition Regulations System DEPARTMENT OF....225-70 Subcontracting for nuclear hot cell services. As prescribed in 925.7004, insert the following clause in solicitations and contracts: Subcontracting for Nuclear Hot Cell Services (MAR 1993)...

  6. Hot cell remote nuclear scanning of tank core samples

    SciTech Connect

    Beck, M.A.; Blewett, G.R.; Troyer, G.L.; Keele, B.D.; Addleman, R.S.

    1995-11-01

    A Westinghouse Hanford Company (WHC)-designed remote measurement system has been constructed for gamma and beta isotopic characterization of Hanford Site high-level waste tank core sample materials in a hot cell. A small, collimated, planar CdZnTe detector is used for gamma-ray spectroscopy. Spectral resolution of 2% full-width-at-maximum at 662 kiloelectronvolts (keV) has been obtained remotely using risetime compensation and limited pulse shape discrimination (PSD). Isotopic measurement of high-energy beta emitters was accomplished with a ruggedly made, deeply depleted, surface barrier silicon detector. The primary function of the remote nuclear screening system is to provide a fast, qualitative stratigraphic assessment (with isotopic information) of high-level radioactive material. Both gamma spectroscopy and beta measurements have been performed on actual core segments. Differences in radionuclide content, which correspond with color or texture variations, have been seen in constant cross section core samples, although for many samples the activity variation can be ascribed to geometry and/or mass factors. Discussion of the design, implementation, results and potential benefits will be presented.

  7. Reliable Wireless Data Acquisition and Control Techniques within Nuclear Hot Cell Facilities

    SciTech Connect

    Kurtz, J.L.; Tulenko, J.

    2000-09-20

    On this NEER project the University of Florida has investigated and applied advanced communications techniques to address data acquisition and control problems within the Fuel Conditioning Facility (FCF) of Argonne National Laboratory-West (ANL-W) in Idaho Falls. The goals of this project have been to investigate and apply wireless communications techniques to solve the problem of communicating with and controlling equipment and systems within a nuclear hot cell facility with its attendant high radiation levels. Different wireless techniques, including radio frequency, infrared and power line communications were reviewed. For each technique, the challenges of radiation-hardened implementation were addressed. In addition, it has been a project goal to achieve the highest level of system reliability to ensure safe nuclear operations. Achievement of these goals would allow the eventual elimination of through-the-wall, hardwired cabling that is currently employed in the hot cell, along wit h all of the attendant problems that limit measurement mobility and flexibility.

  8. Nuclear Materials Characterization in the Materials and Fuels Complex Analytical Hot Cells

    SciTech Connect

    Michael Rodriquez

    2009-03-01

    As energy prices skyrocket and interest in alternative, clean energy sources builds, interest in nuclear energy has increased. This increased interest in nuclear energy has been termed the “Nuclear Renaissance”. The performance of nuclear fuels, fuels and reactor materials and waste products are becoming a more important issue as the potential for designing new nuclear reactors is more immediate. The Idaho National Laboratory (INL) Materials and Fuels Complex (MFC) Analytical Laboratory Hot Cells (ALHC) are rising to the challenge of characterizing new reactor materials, byproducts and performance. The ALHC is a facility located near Idaho Falls, Idaho at the INL Site. It was built in 1958 as part of the former Argonne National Laboratory West Complex to support the operation of the second Experimental Breeder Reactor (EBR-II). It is part of a larger analytical laboratory structure that includes wet chemistry, instrumentation and radiochemistry laboratories. The purpose of the ALHC is to perform analytical chemistry work on highly radioactive materials. The primary work in the ALHC has traditionally been dissolution of nuclear materials so that less radioactive subsamples (aliquots) could be transferred to other sections of the laboratory for analysis. Over the last 50 years though, the capabilities within the ALHC have also become independent of other laboratory sections in a number of ways. While dissolution, digestion and subdividing samples are still a vitally important role, the ALHC has stand alone capabilities in the area of immersion density, gamma scanning and combustion gas analysis. Recent use of the ALHC for immersion density shows that extremely fine and delicate operations can be performed with the master-slave manipulators by qualified operators. Twenty milligram samples were tested for immersion density to determine the expansion of uranium dioxide after irradiation in a nuclear reactor. The data collected confirmed modeling analysis with very

  9. Hot cell examination table

    DOEpatents

    Gaal, Peter S.; Ebejer, Lino P.; Kareis, James H.; Schlegel, Gary L.

    1991-01-01

    A table for use in a hot cell or similar controlled environment for use in examining specimens. The table has a movable table top that can be moved relative to a table frame. A shaft is fixedly mounted to the frame for axial rotation. A shaft traveler having a plurality of tilted rollers biased against the shaft is connected to the table top such that rotation of the shaft causes the shaft traveler to roll along the shaft. An electromagnetic drive is connected to the shaft and the frame for controllably rotating the shaft.

  10. Hot cell examination table

    SciTech Connect

    Gaal, P.S.; Ebjer, L.P.; Kareis, J.H.; Schlegel, G.L.

    1990-01-01

    This invention is comprised of a table for use in a hot cell or similar controlled environment for use in examining specimens. The table has a movable table top that can be moved relative to a table frame. A shaft is fixedly mounted to the frame for axial rotation. A shaft traveler having a plurality of tilted rollers biased against the shaft is connected to the table top such that rotation of the shaft causes the shaft traveler to roll along the shaft. An electromagnetic drive is connected to the shaft and the frame for controllably rotating the shaft.

  11. Seismic evaluation of a hot cell structure

    SciTech Connect

    Srinivasan, M.G.; Kot, C.A.

    1995-07-01

    The evaluation of the structural capacity of and the seismic demand on an existing hot cell structure in a nuclear facility is described. An ANSYS finite-element model of the cell was constructed, treating the walls as plates and the floor and ceiling as a system of discrete beams. A modal analysis showed that the fundamental frequencies of the cell walls lie far above the earthquake frequency range. An equivalent static analysis of the structure was performed. Based on the analysis it was demonstrated that the hot cell structure, would readily withstand the evaluation basis earthquake.

  12. A hot-cell titration system

    SciTech Connect

    Klatt, L.N.

    1988-07-01

    Operation of nuclear fuel reprocessing plant requires an analytical support laboratory capable of meeting the process control, product quality, and nuclear safeguard requirements. Because of the radioactivity accompanying many of the samples, the analytical instruments must be selected, modified, or specifically developed for use in hot cells. Titrimetric procedures have been successfully used in hot cells and are generally immune to radiation induced bias. This report describes a titration system designed for operation in a hot-cell environment. The potentiometric titration system has operated successfully for four years in support of nuclear fuel reprocessing research and development activities. Details of the hardware, electronic, and software control and data analysis systems are presented. Interchangeable burets with a capacity of 5, 10, and 25 mL are available; the means of the absolute error in delivered volume for these burets are 0.9, 1.1, and 1.8 ..mu..L, respectively. Results of evaluation studies how that the accuracy and precision of analysis results obtained with the potentiometric system are limited by statistical uncertainties associated with the standard titrant, sample preparation procedure, and the equilibrium constant of the titration reaction and not by titrator performance factors. The system is also capable of performing amperometric titrations. Changing between the potentiometric and amperometric modes of operation involves changing the in-cell transducers, the in-cell electronics, and the titrator control program. 22 refs., 13 figs., 9 tabs.

  13. Hot Cell Facility (HCF) Safety Analysis Report

    SciTech Connect

    MITCHELL,GERRY W.; LONGLEY,SUSAN W.; PHILBIN,JEFFREY S.; MAHN,JEFFREY A.; BERRY,DONALD T.; SCHWERS,NORMAN F.; VANDERBEEK,THOMAS E.; NAEGELI,ROBERT E.

    2000-11-01

    This Safety Analysis Report (SAR) is prepared in compliance with the requirements of DOE Order 5480.23, Nuclear Safety Analysis Reports, and has been written to the format and content guide of DOE-STD-3009-94 Preparation Guide for U. S. Department of Energy Nonreactor Nuclear Safety Analysis Reports. The Hot Cell Facility is a Hazard Category 2 nonreactor nuclear facility, and is operated by Sandia National Laboratories for the Department of Energy. This SAR provides a description of the HCF and its operations, an assessment of the hazards and potential accidents which may occur in the facility. The potential consequences and likelihood of these accidents are analyzed and described. Using the process and criteria described in DOE-STD-3009-94, safety-related structures, systems and components are identified, and the important safety functions of each SSC are described. Additionally, information which describes the safety management programs at SNL are described in ancillary chapters of the SAR.

  14. Stress analysis for wall structure in mobile hot cell design

    NASA Astrophysics Data System (ADS)

    Bahrin, Muhammad Hannan; Rahman, Anwar Abdul; Hamzah, Mohd Arif; Mamat, Mohd Rizal; Azman, Azraf; Hasan, Hasni

    2016-01-01

    Malaysian Nuclear Agency is developing a Mobile Hot Cell (MHC) in order to handle and manage Spent High Activity Radioactive Sources (SHARS) such as teletherapy heads and irradiators. At present, there are only two units of MHC in the world, in South Africa and China. Malaysian Mobile Hot cell is developed by Malaysian Nuclear Agency with the assistance of IAEA expert, based on the design of South Africa and China, but with improved features. Stress analysis has been performed on the design in order to fulfil the safety requirement in operation of MHC. This paper discusses the loading analysis effect from the sand to the MHC wall structure.

  15. Hot electron plasmon-protected solar cell.

    PubMed

    Kong, J; Rose, A H; Yang, C; Wu, X; Merlo, J M; Burns, M J; Naughton, M J; Kempa, K

    2015-09-21

    A solar cell based on a hot electron plasmon protection effect is proposed and made plausible by simulations, non-local modeling of the response, and quantum mechanical calculations. In this cell, a thin-film, plasmonic metamaterial structure acts as both an efficient photon absorber in the visible frequency range and a plasmonic resonator in the IR range, the latter of which absorbs and protects against phonon emission the free energy of the hot electrons in an adjacent semiconductor junction. We show that in this structure, electron-plasmon scattering is much more efficient than electron-phonon scattering in cooling-off hot electrons, and the plasmon-stored energy is recoverable as an additional cell voltage. The proposed structure could become a prototype of a new generation of high efficiency solar cells. PMID:26406739

  16. HOT CELL BUILDING, TRA632. HOT CELL AWAITS INSTALLATION OF SHIELDED ...

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

    HOT CELL BUILDING, TRA-632. HOT CELL AWAITS INSTALLATION OF SHIELDED WINDOWS. OVERHEAD MASTER/SLAVE MANIPULATORS (LEFT, ABOVE WORKING WINDOWS) WILL MOVE ACROSS GUIDE RAILS IN SLOT ABOVE THE WINDOWS. CAMERA FACING SOUTHEAST. INL NEGATIVE NO. 8996. Unknown Photographer, 10/28/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. A&M. Hot cell annex (TAN633) interior under construction. Hot cells ...

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

    A&M. Hot cell annex (TAN-633) interior under construction. Hot cells and their doors are along concrete wall. Note side wall of pumice block. Photographer: Jack L. Anderson. Date: October 28, 1957. INEEL negative no. 57-5335 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  18. HOT CELL BUILDING, TRA632, INTERIOR. CONTEXTUAL VIEW OF HOT CELL ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. CONTEXTUAL VIEW OF HOT CELL NO. 2 FROM STAIRWAY ALONG NORTH WALL. OBSERVATION WINDOW ALONG WEST SIDE BENEATH "CELL 2" SIGN. DOORWAY IN LEFT OF VIEW LEADS TO CELL 1 WORK AREA OR TO EXIT OUTDOORS TO NORTH. RADIATION DETECTION MONITOR TO RIGHT OF DOOR. CAMERA FACING SOUTHWEST. INL NEGATIVE NO. HD46-28-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  19. Radioactive hot cell access hole decontamination machine

    DOEpatents

    Simpson, William E.

    1982-01-01

    Radioactive hot cell access hole decontamination machine. A mobile housing has an opening large enough to encircle the access hole and has a shielding door, with a door opening and closing mechanism, for uncovering and covering the opening. The housing contains a shaft which has an apparatus for rotating the shaft and a device for independently translating the shaft from the housing through the opening and access hole into the hot cell chamber. A properly sized cylindrical pig containing wire brushes and cloth or other disks, with an arrangement for releasably attaching it to the end of the shaft, circumferentially cleans the access hole wall of radioactive contamination and thereafter detaches from the shaft to fall into the hot cell chamber.

  20. WESF hot cells waste minimization criteria hot cells window seals evaluation

    SciTech Connect

    Walterskirchen, K.M.

    1997-03-31

    WESF will decouple from B Plant in the near future. WESF is attempting to minimize the contaminated solid waste in their hot cells and utilize B Plant to receive the waste before decoupling. WESF wishes to determine the minimum amount of contaminated waste that must be removed in order to allow minimum maintenance of the hot cells when they are placed in ''laid-up'' configuration. The remaining waste should not cause unacceptable window seal deterioration for the remaining life of the hot cells. This report investigates and analyzes the seal conditions and hot cell history and concludes that WESF should remove existing point sources, replace cerium window seals in F-Cell and refurbish all leaded windows (except for A-Cell). Work should be accomplished as soon as possible and at least within the next three years.

  1. Pressurized water nuclear reactor system with hot leg vortex mitigator

    DOEpatents

    Lau, Louis K. S.

    1990-01-01

    A pressurized water nuclear reactor system includes a vortex mitigator in the form of a cylindrical conduit between the hot leg conduit and a first section of residual heat removal conduit, which conduit leads to a pump and a second section of residual heat removal conduit leading back to the reactor pressure vessel. The cylindrical conduit is of such a size that where the hot leg has an inner diameter D.sub.1, the first section has an inner diameter D.sub.2, and the cylindrical conduit or step nozzle has a length L and an inner diameter of D.sub.3 ; D.sub.3 /D.sub.1 is at least 0.55, D.sub.2 is at least 1.9, and L/D.sub.3 is at least 1.44, whereby cavitation of the pump by a vortex formed in the hot leg is prevented.

  2. Equation of state for {beta}-stable hot nuclear matter

    SciTech Connect

    Moustakidis, Ch. C.; Panos, C. P.

    2009-04-15

    We provide an equation of state for hot nuclear matter in {beta} equilibrium by applying a momentum-dependent effective interaction. We focus on the study of the equation of state of high-density and high-temperature nuclear matter, containing leptons (electrons and muons) under the chemical equilibrium condition in which neutrinos have left the system. The conditions of charge neutrality and equilibrium under the {beta}-decay process lead first to the evaluation of proton and lepton fractions and then to the evaluation of internal energy, free energy, and pressure, and in total to the equation of state of hot nuclear matter. Thermal effects on the properties and equation of state of nuclear matter are assessed and analyzed in the framework of the proposed effective interaction model. Special attention is given to the study of the contribution of the components of {beta}-stable nuclear matter to the entropy per particle, a quantity of great interest in the study of structure and collapse of supernova.

  3. 1. View of rmad from jr. hot cell, facing north ...

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

    1. View of r-mad from jr. hot cell, facing north - Nevada Test Site, Reactor Maintenance & Disassembly Complex, Junior Hot Cell, Jackass Flats, Area 25, South of intersection of Roads F & G, Mercury, Nye County, NV

  4. Long Duration Hot Hydrogen Exposure of Nuclear Thermal Rocket Materials

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Foote, John P.; Hickman, Robert; Dobson, Chris; Clifton, Scooter

    2007-01-01

    An arc-heater driven hyper-thermal convective environments simulator was recently developed and commissioned for long duration hot hydrogen exposure of nuclear thermal rocket materials. This newly established non-nuclear testing capability uses a high-power, multi-gas, wall-stabilized constricted arc-heater to .produce high-temperature pressurized hydrogen flows representative of nuclear reactor core environments, excepting radiation effects, and is intended to serve as a low cost test facility for the purpose of investigating and characterizing candidate fuel/structural materials and improving associated processing/fabrication techniques. Design and engineering development efforts are fully summarized, and facility operating characteristics are reported as determined from a series of baseline performance mapping runs and long duration capability demonstration tests.

  5. HOT CELL BUILDING, TRA632, INTERIOR. HOT CELL NO. 1 (THE ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. HOT CELL NO. 1 (THE FIRST BUILT) IN LABORATORY 101. CAMERA FACES SOUTHEAST. SHIELDED OPERATING WINDOWS ARE ON LEFT (NORTH) SIDE. OBSERVATION WINDOW IS AT LEFT OF VIEW (ON WEST SIDE). PLASTIC COVERS SHROUD MASTER/SLAVE MANIPULATORS AT WINDOWS IN LEFT OF VIEW. NOTE MINERAL OIL RESERVOIR ABOVE "CELL 1" SIGN, INDICATING LEVEL OF THE FLUID INSIDE THE THICK WINDOWS. HOT CELL HAS BEVELED CORNER BECAUSE A SQUARED CORNER WOULD HAVE SUPPLIED UNNECESSARY SHIELDING. NOTE PUMICE BLOCK WALL AT LEFT OF VIEW. INL NEGATIVE NO. HD46-28-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. HOT CELL BUILDING, TRA632. CONTEXTUAL AERIAL VIEW OF HOT CELL ...

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

    HOT CELL BUILDING, TRA-632. CONTEXTUAL AERIAL VIEW OF HOT CELL BUILDING, IN VIEW AT LEFT, AS YET WITHOUT ROOF. PLUG STORAGE BUILDING LIES BETWEEN IT AND THE SOUTH SIDE OF THE MTR BUILDING AND ITS WING. NOTE CONCRETE DRIVE BETWEEN ROLL-UP DOOR IN MTR BUILDING AND CHARGING FACE OF PLUG STORAGE. REACTOR SERVICES BUILDING (TRA-635) WILL COVER THIS DRIVE AND BUTT UP TO CHARGING FACE. DOTTED LINE IS ON ORIGINAL NEGATIVE. TRA PARKING LOT IN LEFT CORNER OF THE VIEW. CAMERA FACING NORTHWESTERLY. INL NEGATIVE NO. 8274. Unknown Photographer, 7/2/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  7. HOT CELL BUILDING, TRA632, INTERIOR. DETAIL OF HOT CELL NO. ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. DETAIL OF HOT CELL NO. 2 SHOWS MANIPULATION INSTRUMENTS AND SHIELDED OPERATING WINDOWS. PENETRATIONS FOR OPERATING INSTRUMENTS GO THROUGH SHIELDING ABOVE WINDOWS. CONDUIT FOR UTILITIES AND CONTROLS IS BEHIND METAL CABINET BELOW WINDOWS NEAR FLOOR. CAMERA FACES WEST. WARNING SIGN LIMITS FISSILE MATERIAL TO SPECIFIED NUMBER OF GRAMS OF URANIUM AND PLUTONIUM. INL NEGATIVE NO. HD46-28-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. JINA Workshop Nuclear Physics in Hot Dense Dynamic Plasmas

    SciTech Connect

    Kritcher, A L; Cerjan, C; Landen, O; Libby, S; Chen, M; Wilson, B; Knauer, J; Mcnabb, D; Caggiano, J; Bleauel, D; Weideking, M; Kozhuharov, C; Brandau, C; Stoehlker, T; Meot, V; Gosselin, G; Morel, P; Schneider, D; Bernstein, L A

    2011-03-07

    Measuring NEET and NEEC is relevant for probing stellar cross-sections and testing atomic models in hot plasmas. Using NEEC and NEET we can excite nuclear levels in laboratory plasmas: (1) NIF: Measure effect of excited nuclear levels on (n,{gamma}) cross-sections, 60% and never been measured; (2) Omega, Test cross-sections for creating these excited levels via NEEC and NEET. Will allow us to test models that estimate resonance overlap of atomic states with the nucleus: (1) Average Atom model (AA) (CEA&LLNL), single average wave-function potential; (2) Super Transition Array (STA) model (LLNL), More realistic individual configuration potentials NEET experimental data is scarce and not in a plasma environment, NEEC has not yet been observed.

  9. Hot cell shield plug extraction apparatus

    DOEpatents

    Knapp, Philip A.; Manhart, Larry K.

    1995-01-01

    An apparatus is provided for moving shielding plugs into and out of holes in concrete shielding walls in hot cells for handling radioactive materials without the use of external moving equipment. The apparatus provides a means whereby a shield plug is extracted from its hole and then swung approximately 90 degrees out of the way so that the hole may be accessed. The apparatus uses hinges to slide the plug in and out and to rotate it out of the way, the hinge apparatus also supporting the weight of the plug in all positions, with the load of the plug being transferred to a vertical wall by means of a bolting arrangement.

  10. Technical safety requirements for the Auxiliary Hot Cell Facility (AHCF).

    SciTech Connect

    Seylar, Roland F.

    2004-02-01

    These Technical Safety Requirements (TSRs) identify the operational conditions, boundaries, and administrative controls for the safe operation of the Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, in compliance with 10 CFR 830, 'Nuclear Safety Management.' The bases for the TSRs are established in the AHCF Documented Safety Analysis (DSA), which was issued in compliance with 10 CFR 830, Subpart B, 'Safety Basis Requirements.' The AHCF Limiting Conditions of Operation (LCOs) apply only to the ventilation system, the high efficiency particulate air (HEPA) filters, and the inventory. Surveillance Requirements (SRs) apply to the ventilation system, HEPA filters, and associated monitoring equipment; to certain passive design features; and to the inventory. No Safety Limits are necessary, because the AHCF is a Hazard Category 3 nuclear facility.

  11. Handling of Highly Radioactive Radiation Sources in a Hot Cell Using a Mechanically Driven Cell Crane - 13452

    SciTech Connect

    Klute, Stefan; Huber, Wolfgang-Bruno

    2013-07-01

    In 2010, Siempelkamp Nukleartechnik GmbH was awarded the contract for design and erection of a Hot Cell for handling and storage of highly radioactive radiation sources. This Hot Cell is part of a new hot cell laboratory, constructed for the NHZ (Neues Handhabungszentrum = New Handling Center) of the Nuclear Engineering Seibersdorf GmbH (NES). All incurring radioactive materials from Austria are collected in the NHZ, where they are safely conditioned and stored temporarily until their final storage. The main tasks of the NES include, apart from the collection, conditioning and storage of radioactive waste, also the reprocessing and the decontamination of facilities and laboratories originating from 45 years of research and development at the Seibersdorf site as well as the operation of the Hot Cell Laboratory [1]. The new Hot Cell Laboratory inside the NHZ consists of the following room areas: - One hot cell, placed in the center, for remote controlled, radiation protected handling of radioactive materials, including an integrated floor storage for the long-term temporary storage of highly radioactive radiation sources; - An anteroom for the loading and unloading of the hot cell; - One control room for the remote controlling of the hot cell equipment; - One floor storage, placed laterally to the hot cell, for burial, interim storage and removal of fissionable radioactive material in leak-proof packed units in 100 l drums. The specific design activity of the hot cell of 1.85 Pbq relating to 1-Me-Radiator including the integrated floor storage influences realization and design of the components used in the cell significantly. (authors)

  12. Verification survey of buildings 200 hot cells

    SciTech Connect

    Sholeen, C.M.

    1996-03-01

    At the start of this D&D project, the decontamination goals were set at (1) reducing the stack emissions to 10% of the 1991 emissions; (2) reducing the exposure rate in each cell to < 1 mR/h; and (3) reducing the removable contamination to none detectable. Since the contamination can be fixed with paint, the other two goals were given priority. The estimate of the 1995 emissions from K-3 was 20% of the 1991 emissions estimate. However, the 1996 estimates are {approximately}9% of the 1991 emissions estimate. Since in 1991 the K-3 emissions were only 1/2% of the emissions from M-1, even the 20% reduction has little effect on the project reduction. The total emissions have been reduce to {approximately}2 1/4% of the 1991 emissions from the 5 hot cells that were decontaminated. The emissions and exposure rates are presented in Table I below. Cells A-1 and M-1 exceed the exposure rate criteria. For the other cells, the general exposure rate in the middle of the cell meets the criteria. However, near the prefilters, the exposure rates increase. Cell M-1 has extensive floor contamination that penetrated to a 6 inch depth. At 30 cm above the floor, the exposure rate through the lead blanket is 50 mR/h. A more detailed list of acceptance criteria were specified before the final verification survey. Table ii compares the maximum survey results on the wall or floor surface of each cell to these criteria. Cells M-1 and A-1 frequently fail to meet these criteria.

  13. Decontamination of Hot Cells and Hot Pipe Tunnel at NASA's Plum Brook Reactor Facility

    SciTech Connect

    Anderson, M.G.; Halishak, W.F.

    2008-07-01

    The large scale decontamination of the concrete Hot Cells and Hot Pipe Tunnel at NASA's Plum Brook Reactor Facility demonstrates that novel management and innovative methods are crucial to ensuring that the successful remediation of the most contaminated facilities can be achieved with minimal risk to the project stakeholders. (authors)

  14. 15. View of interior, north wall of hot cell featuring ...

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

    15. View of interior, north wall of hot cell featuring radioactive materials containment box, facing east - Nevada Test Site, Reactor Maintenance & Disassembly Complex, Junior Hot Cell, Jackass Flats, Area 25, South of intersection of Roads F & G, Mercury, Nye County, NV

  15. 47. ARAI. Interior view of operating wall of hot cell ...

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

    47. ARA-I. Interior view of operating wall of hot cell in ARA-626. Note stands for operators at viewing windows. Manipulators with hand grips extend cables and other controls into hot cell through ducts above windows. Ineel photo no. 81-27. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  16. HOT CELL BUILDING, TRA632. FIRST FLOOR FOUNDATION PLAN SHOWS SECTIONALIZED ...

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

    HOT CELL BUILDING, TRA-632. FIRST FLOOR FOUNDATION PLAN SHOWS SECTIONALIZED FLOOR LOADINGS AND CONCRETE SLAB THICKNESSES, A TYPICAL FEATURE OF NUCLEAR ARCHITECTURE. IDAHO OPERATIONS OFFICE MTR-632-IDO-2, 11/1952. INL INDEX NO. 531-0632-62-396-110561, REV. 1. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. Functional study of hot pepper 26S proteasome subunit RPN7 induced by Tobacco mosaic virus from nuclear proteome analysis

    SciTech Connect

    Lee, Boo-Ja; Kwon, Sun Jae; Kim, Sung-Kyu; Kim, Ki-Jeong; Park, Chang-Jin; Kim, Young-Jin; Park, Ohkmae K.; Paek, Kyung-Hee . E-mail: khpaek95@korea.ac.kr

    2006-12-15

    Two-dimensional gel electrophoresis (2-DE) was applied for the screening of Tobacco mosaic virus (TMV)-induced hot pepper (Capsicum annuum cv. Bugang) nuclear proteins. From differentially expressed protein spots, we acquired the matched peptide mass fingerprint (PMF) data, analyzed by MALDI-TOF MS, from the non-redundant hot pepper EST protein FASTA database using the VEMS 2.0 software. Among six identified nuclear proteins, the hot pepper 26S proteasome subunit RPN7 (CaRPN7) was subjected to further study. The level of CaRPN7 mRNA was specifically increased during incompatible TMV-P{sub 0} interaction, but not during compatible TMV-P{sub 1.2} interaction. When CaRPN7::GFP fusion protein was targeted in onion cells, the nuclei had been broken into pieces. In the hot pepper leaves, cell death was exacerbated and genomic DNA laddering was induced by Agrobacterium-mediated transient overexpression of CaPRN7. Thus, this report presents that the TMV-induced CaRPN7 may be involved in programmed cell death (PCD) in the hot pepper plant.

  18. Equipment design guidelines for remote hot cell operations.

    SciTech Connect

    Wahlquist, D. R.

    1998-07-10

    Hot cells provide a unique and challenging environment for designing remotely operated equipment. A typical hot cell is an isolated room used to protect operators from highly contaminated and radioactive equipment. Hot cells usually have thick reinforced concrete walk and leaded glass windows. Operations within the hot cell are accomplished using master-slave manipulators and overhead crane or electro-mechanical manipulator systems. The inability to perform hands-on operation and maintenance in hot cells requires special design considerations. Some of these design considerations include operational interfaces, radiation, accessibility, replaceability/interchangeability, decontamination, atmospheric conditions, functionality, operator fatigue, and ease of use. This paper will discuss guidelines for designing hot cell remotely operated equipment that has been used successfully at Argonne National Laboratory. General topics in this paper will include master-slave manipulator types and limitations, overhead handling systems, viewing limitations, types and sizes of typical fasteners, hot cell compatible materials, mockup testing, guide features for mating parts, modularity, labeling, electrical fasteners, and lifting fixtures.

  19. Lattice-Matched Hot Carrier Solar Cell with Energy Selectivity Integrated into Hot Carrier Absorber

    NASA Astrophysics Data System (ADS)

    König, Dirk; Takeda, Yasuhiko; Puthen-Veettil, Binesh; Conibeer, Gavin

    2012-10-01

    We propose a technologically feasible concept of a hot carrier (HC) solar cell (SC) which fulfills the electronic, optical, and to some extent the phononic criteria required. The energy selective process of HCs is implemented into the hot carrier absorber (HCA). Its electronic properties are investigated by a Monte-Carlo code which simulates random deviations of structure thickness and a normal distribution of random elastic electron (e-) scattering. The structure can be grown epitaxially as a HC-SC test device.

  20. Human factors evaluation of the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico.

    SciTech Connect

    Hunter, Regina Lee; Whitehurst, Hugh O.

    2003-11-01

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) is a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material for reuse, recycling, or ultimate disposal. Mixed waste may also be handled at the AHCF. A significant upgrade to a previous facility, the Temporary Hot Cell, was required to perform this mission. A checklist procedure was used to perform a human-factors evaluation of the AHCF modifications. This evaluation resulted in two recommendations, both of which have been implemented.

  1. Characterization report for Building 301 Hot Cell Facility

    SciTech Connect

    1998-07-01

    During the period from October, 1997, through March, 1998, ANL-E Health Physics conducted a pre-D and D characterization of Building 301, referred to as the Hot Cell Facility. While primary emphasis was placed on radiological evaluation, the presence of non-nuclear hazardous and toxic material was also included in the scope of the characterization. This is one of the early buildings on the ANL-E site, and was heavily used in the 1950`s and 1960`s for various nuclear reaction and reactor design studies. Some degree of cleanup and contamination fixation was done in the 1970`s, so that the building could be used with a minimum of risk of personnel contamination. Work records are largely nonexistent for the early history of the building, so that any assumptions about extent and type of contamination had to be kept very open in the survey planning process. The primary contaminant was found to be painted-over Cs-137 embedded in the concrete floors, although a variety of other nuclides consistent with the work said to have been performed were found in smaller quantities. Due to leaks and drips through the floor, a relatively modest amount of soil contamination was found in the service trench under the building, not penetrating deeply. Two contaminated, disconnected drain lines leaving the building could not be traced by site records, and remain a problem for remediation. The D and D Characterization Plan was fulfilled.

  2. Potential of hafnium nitride for the hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    Chung, Simon; Shrestha, Santosh; Xia, Hongze; Gupta, Neeti; Conibeer, Gavin

    2013-12-01

    The Hot Carrier solar cell is a third generation photovoltaic concept which has the potential to achieve high efficiencies, exceeding the Shockley-Queisser limit for a conventional p-n junction solar cell. The theoretical efficiencies achievable for the Hot Carrier solar cell is 65% for non-concentrated solar radiation and 85% for maximally concentrated light, very close to the limits of an infinite tandem solar cell. The approach of the Hot Carrier solar cell is to extract carriers generated before thermalisation to the bandgap edge occurs when their excess energy is lost to the environment as heat. To achieve this, the rate of carrier cooling in the absorber must be slowed down sufficiently enough to allow carriers to be collected while they are hot. This work investigates using hafnium nitride as such an absorber to restrict mechanisms of carrier cooling. Hafnium nitride's phononic properties, where a large `phononic band gap' exist can reduce the carrier cooling rate by means of a phonon bottleneck such that optical phonons cannot decay into acoustic phonons by means of the Klemens' mechanism. Optical phonon-electron scattering can maintain a hot electron population while acoustic phonons are irrecoverable and lost as heat. The electronic and phononic properties of hafnium nitride are evaluated for their suitability to be used in a Hot Carrier solar cell absorber. Recent work on the fabrication of hafnium nitride at UNSW is presented.

  3. Extended Characterization of Chemical Processes in Hot Cells Using Environmental Swipe Samples

    SciTech Connect

    Olsen, Khris B.; Mitroshkov, Alexandre V.; Thomas, M-L; Lepel, Elwood A.; Brunson, Ronald R.; Ladd-Lively, Jennifer

    2012-09-15

    Environmental sampling is used extensively by the International Atomic Energy Agency (IAEA) for verification of information from State declarations or a facility’s design regarding nuclear activities occurring within the country or a specific facility. Environmental sampling of hot cells within a facility under safeguards is conducted using 10.2 cm x 10.2 cm cotton swipe material or cellulose swipes. Traditional target analytes used by the IAEA to verify operations within a facility include a select list of gamma-emitting radionuclides and total and isotopic U and Pu. Analysis of environmental swipe samples collected within a hot-cell facility where chemical processing occurs may also provide information regarding specific chemicals used in fuel processing. However, using swipe material to elucidate what specific chemical processes were/are being used within a hot cell has not been previously evaluated. Staff from Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) teamed to evaluate the potential use of environmental swipe samples as collection media for volatile and semivolatile organic compounds. This evaluation was initiated with sample collection during a series of Coupled End-to-End (CETE) reprocessing runs at ORNL. The study included measurement of gamma emitting radionuclides, total and isotopic U and Pu, and volatile and semivolatile organic compounds. These results allowed us to elucidate what chemical processes used in the hot cells during reprocessing of power reactor and identify other legacy chemicals used in hot cell operations which predate the CETE process.

  4. Preliminary safety analysis report for the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico

    SciTech Connect

    OSCAR,DEBBY S.; WALKER,SHARON ANN; HUNTER,REGINA LEE; WALKER,CHERYL A.

    1999-12-01

    The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) will be a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material and waste for reuse, recycling, or ultimate disposal. A significant upgrade to a previous facility, the Temporary Hot Cell, will be implemented to perform this mission. The following major features will be added: a permanent shield wall; eight floor silos; new roof portals in the hot-cell roof; an upgraded ventilation system; and upgraded hot-cell jib crane; and video cameras to record operations and facilitate remote-handled operations. No safety-class systems, structures, and components will be present in the AHCF. There will be five safety-significant SSCs: hot cell structure, permanent shield wall, shield plugs, ventilation system, and HEPA filters. The type and quantity of radionuclides that could be located in the AHCF are defined primarily by SNL/NM's legacy materials, which include radioactive, transuranic, and mixed waste. The risk to the public or the environment presented by the AHCF is minor due to the inventory limitations of the Hazard Category 3 classification. Potential doses at the exclusion boundary are well below the evaluation guidelines of 25 rem. Potential for worker exposure is limited by the passive design features incorporated in the AHCF and by SNL's radiation protection program. There is no potential for exposure of the public to chemical hazards above the Emergency Response Protection Guidelines Level 2.

  5. Hot isostatic pressing of ceramic waste from spent nuclear fuel.

    SciTech Connect

    Bateman, K.J.; Rigg, R.H.; Wiest, J.D.

    2002-03-08

    Argonne National Laboratory has developed a process to immobilize waste salt containing fission products, uranium, and transuranic elements as chlorides in a glass-bonded ceramic waste form. This salt was generated in the electrorefining operation used in electrometallurgical treatment of spent Experimental Breeder Reactor-II fuel. The ceramic waste process culminated with a hot isostatic pressing operation. This paper reviews the installation and operation of a hot isostatic press in a radioactive environment. Processing conditions for the hot isostatic press are presented for non-irradiated material and irradiated material. Sufficient testing was performed to demonstrate that a hot isostatic press could be used as the final step of the processing of ceramic waste for the electrometallurgical spent fuel treatment process.

  6. Fundamental Limitations to Plasmonic Hot-Carrier Solar Cells.

    PubMed

    Zhang, Yu; Yam, ChiYung; Schatz, George C

    2016-05-19

    Detailed balance between photon-absorption and energy loss constrains the efficiency of conventional solar cells to the Shockley-Queisser limit. However, if solar illumination can be absorbed over a wide spectrum by plasmonic structures, and the generated hot-carriers can be collected before relaxation, the efficiency of solar cells may be greatly improved. In this work, we explore the opportunities and limitations for making plasmonic solar cells, here considering a design for hot-carrier solar cells in which a conventional semiconductor heterojunction is attached to a plasmonic medium such as arrays of gold nanoparticles. The underlying mechanisms and fundamental limitations of this cell are studied using a nonequilibrium Green's function method, and the numerical results indicate that this cell can significantly improve the absorption of solar radiation without reducing open-circuit voltage, as photons can be absorbed to produce mobile carriers in the semiconductor as long as they have energy larger than the Schottky barrier rather than above the bandgap. However, a significant fraction of the hot-carriers have energies below the Schottky barrier, which makes the cell suffer low internal quantum efficiency. Moreover, quantum efficiency is also limited by hot-carrier relaxation and metal-semiconductor coupling. The connection of these results to recent experiments is described, showing why plasmonic solar cells can have less than 1% efficiency. PMID:27136049

  7. Fundamental Limitations to Plasmonic Hot-Carrier Solar Cells.

    PubMed

    Zhang, Yu; Yam, ChiYung; Schatz, George C

    2016-05-19

    Detailed balance between photon-absorption and energy loss constrains the efficiency of conventional solar cells to the Shockley-Queisser limit. However, if solar illumination can be absorbed over a wide spectrum by plasmonic structures, and the generated hot-carriers can be collected before relaxation, the efficiency of solar cells may be greatly improved. In this work, we explore the opportunities and limitations for making plasmonic solar cells, here considering a design for hot-carrier solar cells in which a conventional semiconductor heterojunction is attached to a plasmonic medium such as arrays of gold nanoparticles. The underlying mechanisms and fundamental limitations of this cell are studied using a nonequilibrium Green's function method, and the numerical results indicate that this cell can significantly improve the absorption of solar radiation without reducing open-circuit voltage, as photons can be absorbed to produce mobile carriers in the semiconductor as long as they have energy larger than the Schottky barrier rather than above the bandgap. However, a significant fraction of the hot-carriers have energies below the Schottky barrier, which makes the cell suffer low internal quantum efficiency. Moreover, quantum efficiency is also limited by hot-carrier relaxation and metal-semiconductor coupling. The connection of these results to recent experiments is described, showing why plasmonic solar cells can have less than 1% efficiency.

  8. Diffusion of dark matter in a hot and dense nuclear environment

    NASA Astrophysics Data System (ADS)

    Cermeño, Marina; Pérez-García, M. Ángeles; Silk, Joseph

    2016-07-01

    We calculate the mean free path in a hot and dense nuclear environment for a fermionic dark matter particle candidate in the ˜GeV mass range interacting with nucleons via scalar and vector effective couplings. We focus on the effects of density and temperature in the nuclear medium in order to evaluate the importance of the final state blocking in the scattering process. We discuss qualitatively possible implications for opacities in stellar nuclear scenarios, where dark matter may be gravitationally accreted.

  9. HOT CELL BUILDING, TRA632, INTERIOR. CELL 3, "HEAVY" CELL. CAMERA ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. CELL 3, "HEAVY" CELL. CAMERA FACES WEST TOWARD BUILDING EXIT. OBSERVATION WINDOW AT LEFT EDGE OF VIEW. INL NEGATIVE NO. HD46-28-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. Zirconium Recycle Test Equipment for Hot Cell Operations

    SciTech Connect

    Collins, Emory D.; DelCul, Guillermo Daniel; Spencer, Barry B.; Bradley, Eric Craig; Brunson, Ronald Ray

    2015-01-30

    The equipment components and assembly support work were modified for optimized, remote hot cell operations to complete this milestone. The modifications include installation of a charging door, Swagelok connector for the off-gas line between the reactor and condenser, and slide valve installation to permit attachment/replacement of the product salt collector bottle.

  11. Raman system for radioactive waste materials in a hot cell

    SciTech Connect

    Reich, F.R.; Douglas, J.G.; Lopez, T.

    1994-12-31

    A remote, fiber-optic Raman system is being developed for the chemical characterization of Hanford Site high-level radioactive wastes. These wastes resulted from the chemical processing of nuclear weapons material during the years 1943 through 1987; the wastes are stored in underground storage tanks. Hanford Site cleanup and restoration are the major drivers for the development of the Raman work described in this paper. The Raman system uses a remote, fiber-optic probe with radiation resistant optical fibers. A {open_quotes}mash{close_quote} probe, with two optical fibers and a sensing tip finished in a chisel shape, was used to obtain Raman data from real tank material and simulants. Selection of the Raman system components and design of the fiber optic probe were based upon comparison data from various probe designs and the results of radiation-damage tests on optical fibers. The chemical and physical characteristics of Hanford Site tank wastes were also factors in designing the remote Raman system. Reference spectra have been obtained from a number of pure materials that are suspected to be in the tank wastes. Detection limits for ferrocyanide species in simulated tank waste will be presented. Additional spectra obtained from archived samples of actual tank waste will be presented; these spectra demonstrate the feasibility of using fiber-optic Raman spectroscopy to remotely characterize tank waste materials both in the hot cell and in the waste tank itself. The U.S. Department of Energy`s Office of Technology Development, Underground Storage Tank, Integrated Demonstration and Tank Waste Remediation Systems programs funded this work.

  12. Bovine somatic cell nuclear transfer.

    PubMed

    Ross, Pablo J; Cibelli, Jose B

    2010-01-01

    Somatic cell nuclear transfer (SCNT) is a technique by which the nucleus of a differentiated cell is introduced into an oocyte from which its genetic material has been removed by a process called enucleation. In mammals, the reconstructed embryo is artificially induced to initiate embryonic development (activation). The oocyte turns the somatic cell nucleus into an embryonic nucleus. This process is called nuclear reprogramming and involves an important change of cell fate, by which the somatic cell nucleus becomes capable of generating all the cell types required for the formation of a new individual, including extraembryonic tissues. Therefore, after transfer of a cloned embryo to a surrogate mother, an offspring genetically identical to the animal from which the somatic cells where isolated, is born. Cloning by nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. Cattle were the second mammalian species to be cloned after Dolly the sheep, and it is probably the most widely used species for SCNT experiments. This is, in part due to the high availability of bovine oocytes and the relatively higher efficiency levels usually obtained in cattle. Given the wide utilization of this species for cloning, several alternatives to this basic protocol can be found in the literature. Here we describe a basic protocol for bovine SCNT currently being used in our laboratory, which is amenable for the use of the nuclear transplantation technique for research or commercial purposes. PMID:20336522

  13. Analysis of Material Sample Heated by Impinging Hot Hydrogen Jet in a Non-Nuclear Tester

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Foote, John; Litchford, Ron

    2006-01-01

    A computational conjugate heat transfer methodology was developed and anchored with data obtained from a hot-hydrogen jet heated, non-nuclear materials tester, as a first step towards developing an efficient and accurate multiphysics, thermo-fluid computational methodology to predict environments for hypothetical solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, thermally radiating, unstructured-grid, and pressure-based formulation. The multiphysics invoked in this study include hydrogen dissociation kinetics and thermodynamics, turbulent flow, convective and thermal radiative, and conjugate heat transfers. Predicted hot hydrogen jet and material surface temperatures were compared with those of measurement. Predicted solid temperatures were compared with those obtained with a standard heat transfer code. The interrogation of physics revealed that reactions of hydrogen dissociation and recombination are highly correlated with local temperature and are necessary for accurate prediction of the hot-hydrogen jet temperature.

  14. Modified Dihadron Fragmentation Functions in Hot and Nuclear Matter

    SciTech Connect

    Majumder, A.; Wang Enke; Wang Xinnian

    2007-10-12

    Medium modification of dihadron fragmentation functions due to gluon bremsstrahlung induced by multiple partonic scattering is studied in both deep-inelastic scattering (DIS) off large nuclei and high-energy heavy-ion collisions within the same framework of twist expansion. The modification for dihadrons is found to closely follow that for single hadrons, leading to a weak nuclear suppression of their ratios in DIS experiments. A mild enhancement of the near-side correlation of two high transverse momentum hadrons with increasing centrality is found in heavy-ion collisions due to trigger bias and the rise in parton energy loss with centrality. Successful comparisons between theory and experiment for multihadron observables in both confining and deconfined media offer comprehensive evidence for partonic energy loss as the mechanism of jet modification in dense matter.

  15. Nitrogen assimilation by single cells in hot springs

    NASA Astrophysics Data System (ADS)

    Poret-peterson, A. T.; Romaniello, S. J.; Bose, M.; Williams, P.; Elser, J. J.; Shock, E.; Anbar, A. D.; Hartnett, H. E.

    2012-12-01

    Microorganisms drive biogeochemical cycles and require nutrients, such as ammonium and nitrate, to function. As a result, following nutrient flows provides opportunities to study how microbial activity influences ecosystem-level processes. Most past measurements of microbial nutrient uptake rely on bulk measurements, which are informative but provide little information about heterogeneity among community members involved in elemental transformations, nor about possible effects of physiological state or taxonomic identity. Since microbial communities tend to be phylogenetically and physiologically diverse, it is reasonable to expect that community members will respond differently to nutrient addition. Here, we examine nitrogen assimilation (via addition of 15N-labeled ammonium or nitrate) in Yellowstone hot spring microbial communities. Using the NanoSIMS, we imaged cells at a very high spatial resolution (nanometer scale) necessary to determine 15N enrichments in single micron-sized cells. We compare the N isotopic enrichments observed in single cells to that determined in bulk sediments by standard isotope ratio mass spectrometry. NanoSIMS imaging of 56 individual cells from sediments of an acidic hot spring (pH 4.7, T=67oC) incubated with 15N-ammonium shows that about two-thirds of the cells (38) exhibited 15N-enrichment. Most cells had 15N enrichments from 0.39 to 0.91 atom %, while some cells were much more significantly enriched. Bulk analyses of sediments show that ammonium assimilation and nitrate assimilation readily occurred at this spring. These findings show that microbes in this hot spring may differentially take up ammonium, which may arise from a number of factors including differences in cellular N requirements, growth rates, and the ability to transport ammonium. This work represents some of the first single-cell isotopic measurements from an extreme environment. Efforts are underway to image sediment samples from other hot springs and to pair Nano

  16. Formation of hot particles during the Chernobyl nuclear power plant accident

    SciTech Connect

    Kashparov, V.A.; Ivanov, Y.A.; Zvarisch, S.I.; Protsak, V.P.; Khomutinin, Y.V.; Kurepin, A.D.; Pazukhin, E.M.

    1996-05-01

    The oxidation of irradiated Chernobyl nuclear fuel at 670 to 1,170 K for 3 to 21 h resulted in its destruction into fine particles, the dispersal composition of which is well described by lognormal distribution regularity. The median radius of the formed particles does not depend on the annealing temperature and decreases with the increase of the annealing period from 10 to 3 {micro}m. Proceeding from the dispersal composition and matrix composition of the Chernobyl hot fuel particles, it can be concluded that the oxidation of nuclear fuel was one of the basic mechanisms of hot fuel particle formation during the accident at the Chernobyl nuclear power plant. With oxidation in air and the dispersal of irradiated oxide nuclear fuel at as low as 670 K, ruthenium, located on the granular borders, is released. Ruthenium is oxidized to volatile RuO{sub 4}, sublimated, and condensed on materials of iron. Nickel and stainless steel can be efficiently used at high temperatures (tested to 1,200 K) for radioruthenium adsorption in accidents and for some technological operations. As the temperature of hot fuel particles annealed in inert media increases from 1,270 to 2,270 K, the relative release of radionuclides increases in the following sequence: cesium isotopes; europium isotopes; cerium isotopes; americium isotopes; and ruthenium, plutonium, and curium isotopes.

  17. Environmental Assessment for decontaminating and decommissioning the General Atomics Hot Cell Facility. Final [report

    SciTech Connect

    1995-08-01

    This EA evaluates the proposed action to decontaminate and decommission GA`s hot cell facility in northern San Diego, CA. This facility has been used for DOE and commercial nuclear R&D for > 30 years. About 30,000 cubic feet of decontamination debris and up to 50,000 cubic feet of contaminated soil are to be removed. Low-level radioactive waste would be shipped for disposal. It was determined that the proposal does not constitute a major federal action significantly affecting the human environment according to NEPA; therefore, a finding of no significant impact is made, and an environmental impact statement is not required.

  18. Decontamination of the Plum Brook Reactor Facility Hot Cells

    SciTech Connect

    Peecook, K.M.

    2008-07-01

    The NASA Plum Brook Reactor Facility decommissioning project recently completed a major milestone with the successful decontamination of seven hot cells. The cells included thick concrete walls and leaded glass windows, manipulator arms, inter cell dividing walls, and roof slabs. There was also a significant amount of embedded conduit and piping that had to be cleaned and surveyed. Prior to work starting evaluation studies were performed to determine whether it was more cost effective to do this work using a full up removal approach (rip and ship) or to decontaminate the cells to below required clean up levels, leaving the bulk of the material in place. This paper looks at that decision process, how it was implemented, and the results of that effort including the huge volume of material that can now be used as fill during site restoration rather than being disposed of as LLRW. (authors)

  19. On the road toward a hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    Taylor, P. C.; Fields, J. D.; Collins, R. T.

    2015-09-01

    We suggest a new paradigm for solar cells that uses a nanostructured crystalline collector (silicon) in an amorphous absorber matrix (hydrogenated amorphous silicon). Previously amorphous absorbers have received no serious consideration because of their low carrier mobilities. Specifically, we demonstrate that carriers generated in the amorphous region are transported out of this region before losing their energy to heat. This result establishes the possibility of using a wide range of nanostructured amorphous matrices to dramatically increase the efficiencies of solar cells. The use of an amorphous absorber provides a highly desirable and flexible approach to producing low-cost, hot carrier solar cells. Since amorphous materials can be grown over a much wider composition space than crystalline materials, this surprising result greatly broadens the absorbing materials that can be used to dramatically increase the efficiencies of solar cells.

  20. MAGNETICALLY CONFINED INTERSTELLAR HOT PLASMA IN THE NUCLEAR BULGE OF OUR GALAXY

    SciTech Connect

    Nishiyama, Shogo; Kwon, Jungmi; Tamura, Motohide; Yasui, Kazuki; Nagata, Tetsuya; Yoshikawa, Tatsuhito; Uchiyama, Hideki; Schödel, Rainer; Hatano, Hirofumi; Sato, Shuji; Sugitani, Koji; Suenaga, Takuya

    2013-06-01

    The origin of the Galactic center diffuse X-ray emission (GCDX) is still under intense investigation. In particular, the interpretation of the hot (kT ≈ 7 keV) component of the GCDX, characterized by the strong Fe 6.7 keV line emission, has been contentious. If the hot component originates from a truly diffuse interstellar plasma, not a collection of unresolved point sources, such plasma cannot be gravitationally bound, and its regeneration would require a huge amount of energy. Here, we show that the spatial distribution of the GCDX does not correlate with the number density distribution of an old stellar population traced by near-infrared light, strongly suggesting a significant contribution of the diffuse interstellar plasma. Contributions of the old stellar population to the GCDX are implied to be ∼50% and ∼20% in the nuclear stellar disk (NSD) and nuclear star cluster, respectively. For the NSD, a scale height of 0.°32 ± 0.°02 is obtained for the first time from the stellar number density profiles. We also show the results of the extended near-infrared polarimetric observations in the central 3° × 2° region of our Galaxy, and confirm that the GCDX region is permeated by a large scale, toroidal magnetic field (MF) as previously claimed. Together with observed MF strengths close to energy equipartition, the hot plasma could be magnetically confined, reducing the amount of energy required to sustain it.

  1. Hot Cell Examination of Weapons-Grade MOX Fuel

    SciTech Connect

    Morris, Robert Noel; Bevard, Bruce Balkcom; McCoy, Kevin

    2010-01-01

    The U.S. Department of Energy has decided to dispose of a portion of the nation s surplus weapons-grade plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. Four lead assemblies were manufactured with weapons-grade MOX and irradiated to a maximum fuel rod burnup of 47.3 MWd/kg. As part of the fuel qualification process, five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This is the first hot cell examination of weapons-grade MOX fuel. The rods have been examined nondestructively with the ADEPT apparatus and are currently being destructively examined. Examinations completed to date include length measurements, visual examination, gamma scanning, profilometry, eddy-current testing, gas measurement and analysis, and optical metallography. Representative results of these examinations are reviewed and found to be consistent with predictions and with prior experience with reactor-grade MOX fuel. The results will be used to support licensing of weapons-grade MOX for batch use in commercial power reactors.

  2. Nuclear Mechanics and Stem Cell Differentiation.

    PubMed

    Mao, Xinjian; Gavara, Nuria; Song, Guanbin

    2015-12-01

    Stem cells are characterized by their self-renewal and multi-lineage differentiation potential. Stem cell differentiation is a prerequisite for the application of stem cells in regenerative medicine and clinical therapy. In addition to chemical stimulation, mechanical cues play a significant role in regulating stem cell differentiation. The integrity of mechanical sensors is necessary for the ability of cells to respond to mechanical signals. The nucleus, the largest and stiffest cellular organelle, interacts with the cytoskeleton as a key mediator of cell mechanics. Nuclear mechanics are involved in the complicated interactions of lamins, chromatin and nucleoskeleton-related proteins. Thus, stem cell differentiation is intimately associated with nuclear mechanics due to its indispensable role in mechanotransduction and mechanical response. This paper reviews several main contributions of nuclear mechanics, highlights the hallmarks of the nuclear mechanics of stem cells, and provides insight into the relationship between nuclear mechanics and stem cell differentiation, which may guide clinical applications in the future.

  3. Signals of Bose Einstein condensation and Fermi quenching in the decay of hot nuclear systems

    NASA Astrophysics Data System (ADS)

    Marini, P.; Zheng, H.; Boisjoli, M.; Verde, G.; Chbihi, A.; Napolitani, P.; Ademard, G.; Augey, L.; Bhattacharya, C.; Borderie, B.; Bougault, R.; Frankland, J. D.; Fable, Q.; Galichet, E.; Gruyer, D.; Kundu, S.; La Commara, M.; Lombardo, I.; Lopez, O.; Mukherjee, G.; Parlog, M.; Rivet, M. F.; Rosato, E.; Roy, R.; Spadaccini, G.; Vigilante, M.; Wigg, P. C.; Bonasera, A.

    2016-05-01

    We report on first experimental observations of nuclear fermionic and bosonic components displaying different behaviours in the decay of hot Ca projectile-like sources produced in mid-peripheral collisions at sub-Fermi energies. The experimental setup, constituted by the coupling of the INDRA 4π detector array to the forward angle VAMOS magnetic spectrometer, allowed to reconstruct the mass, charge and excitation energy of the decaying hot projectile-like sources. By means of quantum-fluctuation analysis techniques, temperatures and local partial densities of bosons and fermions could be correlated to the excitation energy of the reconstructed system. The results are consistent with the production of dilute mixed systems of bosons and fermions, where bosons experience higher phase-space and energy density as compared to the surrounding fermionic gas. Our findings recall phenomena observed in the study of Bose condensates and Fermi gases in atomic traps despite the different scales.

  4. Development of monolithic nuclear fuels for RERTR by hot isostatic pressing

    SciTech Connect

    Jue, J.-F.; Park, Blair; Chapple, Michael; Moore, Glenn; Keiser, Dennis

    2008-07-15

    The RERTR Program (Reduced Enrichment for Research and Test Reactors) is developing advanced nuclear fuels for high power test reactors. Monolithic fuel design provides a higher uranium loading than that of the traditional dispersion fuel design. In order to bond monolithic fuel meat to aluminum cladding, several bonding methods such as roll bonding, friction stir bonding and hot isostatic pressing, have been explored. Hot isostatic pressing is a promising process for low cost, batch fabrication of monolithic RERTR fuel plates. The progress on the development of this process at the Idaho National Laboratory will be presented. Due to the relatively high processing temperature used, the reaction between fuel meat and aluminum cladding to form brittle intermetallic phases may be a concern. The effect of processing temperature and time on the fuel/cladding reaction will be addressed. The influence of chemical composition on the reaction will also be discussed. (author)

  5. Locating hot and cold-legs in a nuclear powered steam generation system

    DOEpatents

    Ekeroth, D.E.; Corletti, M.M.

    1993-11-16

    A nuclear reactor steam generator includes a reactor vessel for heating water and a steam generator with a pump casing at the lowest point on the steam generator. A cold-leg pipe extends horizontally between the steam generator and the reactor vessel to return water from the steam generator to the reactor vessel. The bottom of the cold-leg pipe is at a first height above the bottom of the reactor vessel. A hot-leg pipe with one end connected to the steam generator and a second end connected to the reactor vessel has a first pipe region extending downwardly from the steam generator to a location between the steam generator and the reactor vessel at which a bottom of the hot-leg pipe is at a second height above the bottom of the reactor vessel. A second region extends from that location in a horizontal direction at the second height to the point at which the hot-leg pipe connects to the reactor vessel. A pump is attached to the casing at a location below the first and second heights and returns water from the steam generator to the reactor vessel over the cold-leg. The first height is greater than the second height and the bottom of the steam generator is at a height above the bottom of the reactor vessel that is greater than the first and second heights. A residual heat recovery pump is below the hot-leg and has an inlet line from the hot-leg that slopes down continuously to the pump inlet. 2 figures.

  6. Locating hot and cold-legs in a nuclear powered steam generation system

    DOEpatents

    Ekeroth, Douglas E.; Corletti, Michael M.

    1993-01-01

    A nuclear reactor steam generator includes a reactor vessel for heating water and a steam generator with a pump casing at the lowest point on the steam generator. A cold-leg pipe extends horizontally between the steam generator and the reactor vessel to return water from the steam generator to the reactor vessel. The bottom of the cold-leg pipe is at a first height above the bottom of the reactor vessel. A hot-leg pipe with one end connected to the steam generator and a second end connected to the reactor vessel has a first pipe region extending downwardly from the steam generator to a location between the steam generator and the reactor vessel at which a bottom of the hot-leg pipe is at a second height above the bottom of the reactor vessel. A second region extends from that location in a horizontal direction at the second height to the point at which the hot-leg pipe connects to the reactor vessel. A pump is attached to the casing at a location below the first and second heights and returns water from the steam generator to the reactor vessel over the cold-leg. The first height is greater than the second height and the bottom of the steam generator is at a height above the bottom of the reactor vessel that is greater than the first and second heights. A residual heat recovery pump is below the hot-leg and has an inlet line from the hot-leg that slopes down continuously to the pump inlet.

  7. Arc-Heater Facility for Hot Hydrogen Exposure of Nuclear Thermal Rocket Materials

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Foote, John P.; Wang,Ten-See; Hickman, Robert; Panda, Binayak; Dobson, Chris; Osborne, Robin; Clifton, Scooter

    2006-01-01

    A hyper-thermal environment simulator is described for hot hydrogen exposure of nuclear thermal rocket material specimens and component development. This newly established testing capability uses a high-power, multi-gas, segmented arc-heater to produce high-temperature pressurized hydrogen flows representative of practical reactor core environments and is intended to serve. as a low cost test facility for the purpose of investigating and characterizing candidate fueUstructura1 materials and improving associated processing/fabrication techniques. Design and development efforts are thoroughly summarized, including thermal hydraulics analysis and simulation results, and facility operating characteristics are reported, as determined from a series of baseline performance mapping tests.

  8. Remote System Technologies for Deactivating Hanford Hot Cells

    SciTech Connect

    Berlin, G.; Walton, T.

    2003-02-25

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

  9. HOT DIFFUSE EMISSION IN THE NUCLEAR STARBURST REGION OF NGC 2903

    SciTech Connect

    Yukita, Mihoko; Irwin, Jimmy A.; Swartz, Douglas A.; Tennant, Allyn F.; Soria, Roberto

    2012-10-20

    We present a deep Chandra observation of the central regions of the late-type barred spiral galaxy NGC 2903. The Chandra data reveal soft (kT{sub e} {approx} 0.2-0.5 keV) diffuse emission in the nuclear starburst region and extending {approx}2' ({approx}5 kpc) to the north and west of the nucleus. Much of this soft hot gas is likely to be from local active star-forming regions; however, besides the nuclear region, the morphology of hot gas does not strongly correlate with the bar or other known sites of active star formation. The central {approx}650 pc radius starburst zone exhibits much higher surface brightness diffuse emission than the surrounding regions and a harder spectral component in addition to a soft component similar to the surrounding zones. We interpret the hard component as also being of thermal origin with kT{sub e} {approx} 3.6 keV and to be directly associated with a wind fluid produced by supernovae and massive star winds similar to the hard diffuse emission seen in the starburst galaxy M82. The inferred terminal velocity for this hard component, {approx}1100 km s{sup -1}, exceeds the local galaxy escape velocity suggesting a potential outflow into the halo and possibly escape from the galaxy gravitational potential. Morphologically, the softer extended emission from nearby regions does not display an obvious outflow geometry. However, the column density through which the X-rays are transmitted is lower in the zone to the west of the nucleus compared to that from the east and the surface brightness is relatively higher suggesting some of the soft hot gas originates from above the disk: viewed directly from the western zone but through the intervening disk of the host galaxy along sight lines from the eastern zone. There are several point-like sources embedded in the strong diffuse nuclear emission zone. Their X-ray spectra show them to likely be compact binaries. None of these detected point sources are coincident with the mass center of the

  10. Moving Cell Boundaries Drive Nuclear Shaping during Cell Spreading

    PubMed Central

    Li, Yuan; Lovett, David; Zhang, Qiao; Neelam, Srujana; Kuchibhotla, Ram Anirudh; Zhu, Ruijun; Gundersen, Gregg G.; Lele, Tanmay P.; Dickinson, Richard B.

    2015-01-01

    The nucleus has a smooth, regular appearance in normal cells, and its shape is greatly altered in human pathologies. Yet, how the cell establishes nuclear shape is not well understood. We imaged the dynamics of nuclear shaping in NIH3T3 fibroblasts. Nuclei translated toward the substratum and began flattening during the early stages of cell spreading. Initially, nuclear height and width correlated with the degree of cell spreading, but over time, reached steady-state values even as the cell continued to spread. Actomyosin activity, actomyosin bundles, microtubules, and intermediate filaments, as well as the LINC complex, were all dispensable for nuclear flattening as long as the cell could spread. Inhibition of actin polymerization as well as myosin light chain kinase with the drug ML7 limited both the initial spreading of cells and flattening of nuclei, and for well-spread cells, inhibition of myosin-II ATPase with the drug blebbistatin decreased cell spreading with associated nuclear rounding. Together, these results show that cell spreading is necessary and sufficient to drive nuclear flattening under a wide range of conditions, including in the presence or absence of myosin activity. To explain this observation, we propose a computational model for nuclear and cell mechanics that shows how frictional transmission of stress from the moving cell boundaries to the nuclear surface shapes the nucleus during early cell spreading. Our results point to a surprisingly simple mechanical system in cells for establishing nuclear shapes. PMID:26287620

  11. Hot wire deposited hydrogenated amorphous silicon solar cells

    SciTech Connect

    Mahan, A.H.; Iwaniczko, E.; Nelson, B.P.; Reedy, R.C. Jr.; Crandall, R.S.

    1996-05-01

    This paper details the results of a study in which low H content, high deposition rate hot wire (HW) deposited amorphous silicon (a-Si:H) has been incorporated into a substrate solar cell. The authors find that the treatment of the top surface of the HW i layer while it is being cooled from its high deposition temperature is crucial to device performance. They present data concerning these surface treatments, and correlate these treatments with Schottky device performance. The authors also present first generation HW n-i-p solar cell efficiency data, where a glow discharge (GD) {mu}c-Si(p) layer was added to complete the partial devices. No light trapping layer was used to increase the device Jsc. Their preliminary investigations have yielded efficiencies of up to 6.8% for a cell with a 4000 {Angstrom} thick HW i-layer, which degrade less than 10% after a 900 hour light soak. The authors suggest avenues for further improvement of their devices.

  12. Shell effects in hot nuclei and their influence on nuclear composition in supernova matter

    NASA Astrophysics Data System (ADS)

    Nishimura, Suguru; Takano, Masatoshi

    2014-05-01

    We calculate nuclear composition in supernova (SN) matter explicitly taking into account the temperature dependence of nuclear shell effects. The abundance of nuclei in SN matter is important in the dynamics of core-collapse supernovae and, in recently constructed equations of state (EOS) for SN matter, the composition of nuclei are calculated assuming nuclear statistical equilibrium wherein the nuclear internal free energies govern the composition. However, in these EOS, thermal effects on the shell energy are not explicitly taken into account. To address this shortfall, we calculate herein the shell energies of hot nuclei and examine their influence on the composition of SN matter. Following a simplified macroscopic-microscopic approach, we first calculate single-particle (SP) energies by using a spherical Woods-Saxon potential. Then we extract shell energies at finite temperatures using Strutinsky method with the Fermi distribution as the average occupation probability of the SP levels. The results show that at relatively low temperatures, shell effects are still important and magic nuclei are abundant. However, at temperatures above approximately 2 MeV, shell effects are almost negligible, and the mass fractions with shell energies including the thermal effect are close to those obtained from a simple liquid drop model at finite temperatures.

  13. Workshop on instrumentation and analyses for a nuclear fuel reprocessing hot pilot plant

    SciTech Connect

    Babcock, S.M.; Feldman, M.J.; Wymer, R.G.; Hoffman, D.

    1980-05-01

    In order to assist in the study of instrumentation and analytical needs for reprocessing plants, a workshop addressing these needs was held at Oak Ridge National Laboratory from May 5 to 7, 1980. The purpose of the workshop was to incorporate the knowledge of chemistry and of advanced measurement techniques held by the nuclear and radiochemical community into ideas for improved and new plant designs for both process control and inventory and safeguards measurements. The workshop was athended by experts in nuclear and radiochemistry, in fuel recycle plant design, and in instrumentation and analysis. ORNL was a particularly appropriate place to hold the workshop since the Consolidated Fuel Reprocessing Program (CFRP) is centered there. Requirements for safeguarding the special nuclear materials involved in reprocessing, and for their timely measurement within the process, within the reprocessing facility, and at the facility boundaries are being studied. Because these requirements are becoming more numerous and stringent, attention is also being paid to the analytical requirements for these special nuclear materials and to methods for measuring the physical parameters of the systems containing them. In order to provide a focus for the consideration of the workshop participants, the Hot Experimental Facility (HEF) being designed conceptually by the CFRP was used as a basis for consideration and discussions.

  14. Shell effects in hot nuclei and their influence on nuclear composition in supernova matter

    SciTech Connect

    Nishimura, Suguru; Takano, Masatoshi

    2014-05-02

    We calculate nuclear composition in supernova (SN) matter explicitly taking into account the temperature dependence of nuclear shell effects. The abundance of nuclei in SN matter is important in the dynamics of core-collapse supernovae and, in recently constructed equations of state (EOS) for SN matter, the composition of nuclei are calculated assuming nuclear statistical equilibrium wherein the nuclear internal free energies govern the composition. However, in these EOS, thermal effects on the shell energy are not explicitly taken into account. To address this shortfall, we calculate herein the shell energies of hot nuclei and examine their influence on the composition of SN matter. Following a simplified macroscopic-microscopic approach, we first calculate single-particle (SP) energies by using a spherical Woods-Saxon potential. Then we extract shell energies at finite temperatures using Strutinsky method with the Fermi distribution as the average occupation probability of the SP levels. The results show that at relatively low temperatures, shell effects are still important and magic nuclei are abundant. However, at temperatures above approximately 2 MeV, shell effects are almost negligible, and the mass fractions with shell energies including the thermal effect are close to those obtained from a simple liquid drop model at finite temperatures.

  15. Nuclear equivalence, nuclear transfer, and the cell cycle.

    PubMed

    Campbell, K H

    1999-01-01

    The last 20 years have seen the development of techniques for the production of mammals by nuclear transfer. Originally limited to the swapping of pronuclei and the use of early cleavage-stage embryos as nuclear donors, nuclear transfer came of age in 1995 with the birth of 2 Welsh Mountain lambs, Megan and Morag, that were produced using cultured differentiated cells as donors of genetic material. In 1996, Dolly was the first animal to be produced using the genetic material from an adult-derived somatic cell. The techniques used in the production of these animals have now been reproduced in both sheep and cattle, and as predicted, successful development has been obtained using donor cells taken directly ex vivo. This article reviews the current status of mammalian nuclear transfer and the biological background to these successes. PMID:16218826

  16. 116. ARAI Details of hot cell section of building ARA626. ...

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

    116. ARA-I Details of hot cell section of building ARA-626. Shows manipulator openings in operating face of hot cell, start/stop buttons, and other details. Norman Engineering Company 961/area/SF-626-E-6. Date: January 1959. Ineel index code no. 068-0626-10-613-102731. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  17. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 7, Safety operation procedure for hot cell

    SciTech Connect

    Not Available

    1993-08-01

    This volume contains the interim change notice for the safety operation procedure for hot cell. It covers the master-slave manipulators, dry waste removal, cell transfers, hoists, cask handling, liquid waste system, and physical characterization of fluids.

  18. Remote real time x-ray examination of fuel elements in a hot cell environment

    SciTech Connect

    Yapuncich, F.L.

    1993-03-01

    This report discusses the Remote Real Time X-ray System which will allow for detailed examination of fuel elements. This task will be accomplished in a highly radioactive hot cell environment. Two remote handling systems win be utilized at the examination station. One handling system will transfer the fuel element to and from the shielded x-ray system. A second handling system will allow for vertical and rotational inspection of the fuel elements. The process win include removing a single nuclear fuel element from a element fabrication magazine(EFM), positioning the fuel element within the shielding envelope of the x-ray system and transferring the fuel element from the station manipulator to the x-ray system manipulator, performing the x-ray inspection, and then transferring the fuel element to either the element storage magazine(ESM) or a reject bin.

  19. Remote real time x-ray examination of fuel elements in a hot cell environment

    SciTech Connect

    Yapuncich, F.L.

    1993-01-01

    This report discusses the Remote Real Time X-ray System which will allow for detailed examination of fuel elements. This task will be accomplished in a highly radioactive hot cell environment. Two remote handling systems win be utilized at the examination station. One handling system will transfer the fuel element to and from the shielded x-ray system. A second handling system will allow for vertical and rotational inspection of the fuel elements. The process win include removing a single nuclear fuel element from a element fabrication magazine(EFM), positioning the fuel element within the shielding envelope of the x-ray system and transferring the fuel element from the station manipulator to the x-ray system manipulator, performing the x-ray inspection, and then transferring the fuel element to either the element storage magazine(ESM) or a reject bin.

  20. Thermal Stress in HFEF Hot Cell Windows Due to an In-Cell Metal Fire

    DOE PAGES

    Solbrig, Charles W.; Warmann, Stephen A.

    2016-01-01

    This work investigates an accident during the pyrochemical extraction of Uranium and Plutonium from PWR spent fuel in an argon atmosphere hot cell. In the accident, the heavy metals (U and Pu) being extracted are accidentally exposed to air from a leaky instrument penetration which goes through the cell walls. The extracted pin size pieces of U and Pu metal readily burn when exposed to air. Technicians perform the electrochemical extraction using manipulators through a 4 foot thick hot cell concrete wall which protects them from the radioactivity of the spent fuel. Four foot thick windows placed in the wallmore » allow the technicians to visually control the manipulators. These windows would be exposed to the heat of the metal fire. As a result, this analysis determines if the thermal stress caused by the fire would crack the windows and if the heat would degrade the window seals allowing radioactivity to escape from the cell.« less

  1. Thermal Stress in HFEF Hot Cell Windows Due to an In-Cell Metal Fire

    SciTech Connect

    Solbrig, Charles W.; Warmann, Stephen A.

    2016-01-01

    This work investigates an accident during the pyrochemical extraction of Uranium and Plutonium from PWR spent fuel in an argon atmosphere hot cell. In the accident, the heavy metals (U and Pu) being extracted are accidentally exposed to air from a leaky instrument penetration which goes through the cell walls. The extracted pin size pieces of U and Pu metal readily burn when exposed to air. Technicians perform the electrochemical extraction using manipulators through a 4 foot thick hot cell concrete wall which protects them from the radioactivity of the spent fuel. Four foot thick windows placed in the wall allow the technicians to visually control the manipulators. These windows would be exposed to the heat of the metal fire. As a result, this analysis determines if the thermal stress caused by the fire would crack the windows and if the heat would degrade the window seals allowing radioactivity to escape from the cell.

  2. Analysis of hot and cold Kritz benchmark with MCNP5 and temperature-specific nuclear data libraries

    SciTech Connect

    Mosteller, R. D.; MacFarlane, R. E.; White, M. C.

    2003-01-01

    One of the longstanding obstacles to the use of the MCNP Monte Carlo code' for reactor physics calculations has been its requirement for nuclear data libraries at the temperature associated with the application of interest. Recently, however, an auxiliary code, named 'doppler,' has been developed that uses an existing nuclear data library as the basis for generating a new library at the desired temperature. doppler has simple input and is straightforward to use. Libraries generated with doppler and based on the existing ENDF66 library have been developed for three hot Kritz benchmark. Results obtained from MCNPS for those hot benchmarks and their cold (ie., room-temperature) counterparts are presented herein.

  3. HOT CELL BUILDING, TRA632. EAST END OF BUILDING. CAMERA FACING ...

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

    HOT CELL BUILDING, TRA-632. EAST END OF BUILDING. CAMERA FACING WEST. TRUCK ENCLOSURE (1986) TO THE LEFT, SMALL ADDITION IN ITS SHADOW IS ENCLOSURE OVER METAL PORT INTO HOT CELL NO. 1 (THE OLDEST HOT CELL). NOTE PERSONNEL LADDER AND PLATFORM AT LOFT LEVEL USED WHEN SERVICING AIR FILTERS AND VENTS OF CELL NO. 1. INL NEGATIVE NO. HD46-32-4. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. Temperature and momentum dependence of single-particle properties in hot asymmetric nuclear matter

    SciTech Connect

    Moustakidis, Ch. C.

    2008-11-15

    We have studied the effects of momentum-dependent interactions on the single-particle properties of hot asymmetric nuclear matter. In particular, the single-particle potential of protons and neutrons as well as the symmetry potential have been studied within a self-consistent model using a momentum-dependent effective interaction. In addition, the isospin splitting of the effective mass has been derived from the above model. In each case temperature effects have been included and analyzed. The role of the specific parametrization of the effective interaction used in the present work has been investigated. It has been concluded that the behavior of the symmetry potential depends strongly on the parametrization of the interaction part of the energy density and the momentum dependence of the regulator function. The effects of the parametrization have been found to be less pronounced on the isospin mass splitting.

  5. Reversible electron-hole separation in a hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    Limpert, S.; Bremner, S.; Linke, H.

    2015-09-01

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron-hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron-hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We thus focus our analysis on the internal operation of the hot-carrier solar cell itself, and in this work do not consider the photon-mediated coupling to the Sun. After deriving an expression for the voltage of a hot-carrier solar cell valid under conditions of both reversible and irreversible electrical operation, we identify separate contributions to the voltage from the thermoelectric effect and the photovoltaic effect. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. Our results help explore the fundamental limitations of hot-carrier solar cells, and provide a first step towards providing experimentalists with a guide to the optimal configuration of devices.

  6. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    SciTech Connect

    Poshusta, Joseph C; Booten, Charles W; Martin, Jerry L

    2013-12-24

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  7. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    SciTech Connect

    Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.

    2012-11-06

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  8. Solid oxide fuel cell systems with hot zones having improved reactant distribution

    DOEpatents

    Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.

    2016-05-17

    A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.

  9. Post-irradiation-examination of irradiated fuel outside the hot cell

    SciTech Connect

    Dawn E. Janney; Adam B. Robinson; Thomas P. O'Holleran; R. Paul Lind; Marc Babcock; Laurence C. Brower; Julie Jacobs; Pamela K. Hoggan

    2007-09-01

    Because of their high radioactivity, irradiated fuels are commonly examined in a hot cell. However, the Idaho National Laboratory (INL) has recently investigated irradiated U-Mo-Al metallic fuel from the Reduced Enrichment for Research and Test Reactors (RERTR) project using a conventional unshielded scanning electron microscope outside a hot cell. This examination was possible because of a two-step sample-preparation approach in which a small volume of fuel was isolated in a hot cell and shielding was introduced during later stages of sample preparation. The resulting sample contained numerous sample-preparation artifacts but allowed analysis of microstructures from selected areas.

  10. Hot compression process for making edge seals for fuel cells

    DOEpatents

    Dunyak, Thomas J.; Granata, Jr., Samuel J.

    1994-01-01

    A hot compression process for forming integral edge seals in anode and cade assemblies wherein the assemblies are made to a nominal size larger than a finished size, beads of AFLAS are applied to a band adjacent the peripheral margins on both sides of the assemblies, the assemblies are placed in a hot press and compressed for about five minutes with a force sufficient to permeate the peripheral margins with the AFLAS, cooled and cut to finished size.

  11. Nonplasmonic Hot-Electron Photocurrents from Mn-Doped Quantum Dots in Photoelectrochemical Cells.

    PubMed

    Dong, Yitong; Rossi, Daniel; Parobek, David; Son, Dong Hee

    2016-03-01

    We report the measurement of the hot-electron current in a photoelectrochemical cell constructed from a glass/ITO/Al2 O3 (ITO=indium tin oxide) electrode coated with Mn-doped quantum dots, where hot electrons with a large excess kinetic energy were produced through upconversion of the excitons into hot electron hole pairs under photoexcitation at 3 eV. In our recent study (J. Am. Chem. Soc. 2015, 137, 5549), we demonstrated the generation of hot electrons in Mn-doped II-VI semiconductor quantum dots and their usefulness in photocatalytic H2 production reaction, taking advantage of the more efficient charge transfer of hot electrons compared with band-edge electrons. Here, we show that hot electrons produced in Mn-doped CdS/ZnS quantum dots possess sufficient kinetic energy to overcome the energy barrier from a 5.4-7.5 nm thick Al2 O3 layer producing a hot-electron current in photoelectrochemical cell. This work demonstrates the possibility of harvesting hot electrons not only at the interface of the doped quantum dot surface, but also far away from it, thus taking advantage of the capability of hot electrons for long-range electron transfer across a thick energy barrier.

  12. Human somatic cell nuclear transfer and cloning.

    PubMed

    2012-10-01

    This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer (cloning)," last published in Fertil Steril 2000;74:873-6.

  13. Robot Work Platform for Large Hot Cell Deactivation

    SciTech Connect

    BITTEN, E.J.

    2000-05-01

    The 324 Building, located at the Hanford Site near Richland, Washington, is being deactivated to meet state and federal cleanup commitments. The facility is currently in its third year of a nine-year project to complete deactivation and closure for long-term surveillance and maintenance. The 324 building contains large hot cells that were used for high-radiation, high-contamination chemical process development and demonstrations. A major obstacle for the 324 deactivation project is the inability to effectively perform deactivation tasks within highly radioactive, contaminated environments. Current strategies use inefficient, resource intensive technologies that significantly impact the cost and schedule for deactivation. To meet mandated cleanup commitments, there is a need to deploy rapid, more efficient remote/robot technologies to minimize worker exposure, accelerate work tasks, and eliminate the need for multiple specialized tool design and procurement efforts. This paper describes the functions and performance requirements for a crane-deployed remote/robot Work Platform possessing full access capabilities. The remote/robot Work Platform will deploy commercially available off-the-shelf tools and end effectors to support Project cleanup goals and reduce overall project risk and cost. The intent of this system is to maximize the use of off-the-shelf technologies that minimize additional new, unproven, or novel designs. This paper further describes procurement strategy, the selection process, the selected technology, and the current status of the procurement and lessons learned. Funding, in part, has been provided by the US Department of Energy, Office of Science and Technology, Deactivation and Decommissioning Focus Area.

  14. Evaluation of a Mobile Hot Cell Technology for Processing Idaho National Laboratory Remote-Handled Wastes

    SciTech Connect

    B.J. Orchard; L.A. Harvego; R.P. Miklos; F. Yapuncich; L. Care

    2009-03-01

    The Idaho National Laboratory (INL) currently does not have the necessary capabilities to process all remote-handled wastes resulting from the Laboratory’s nuclear-related missions. Over the years, various U.S. Department of Energy (DOE)-sponsored programs undertaken at the INL have produced radioactive wastes and other materials that are categorized as remote-handled (contact radiological dose rate > 200 mR/hr). These materials include Spent Nuclear Fuel (SNF), transuranic (TRU) waste, waste requiring geological disposal, low-level waste (LLW), mixed waste (both radioactive and hazardous per the Resource Conservation and Recovery Act [RCRA]), and activated and/or radioactively-contaminated reactor components. The waste consists primarily of uranium, plutonium, other TRU isotopes, and shorter-lived isotopes such as cesium and cobalt with radiological dose rates up to 20,000 R/hr. The hazardous constituents in the waste consist primarily of reactive metals (i.e., sodium and sodium-potassium alloy [NaK]), which are reactive and ignitable per RCRA, making the waste difficult to handle and treat. A smaller portion of the waste is contaminated with other hazardous components (i.e., RCRA toxicity characteristic metals). Several analyses of alternatives to provide the required remote-handling and treatment capability to manage INL’s remote-handled waste have been conducted over the years and have included various options ranging from modification of existing hot cells to construction of new hot cells. Previous analyses have identified a mobile processing unit as an alternative for providing the required remote-handled waste processing capability; however, it was summarily dismissed as being a potentially viable alternative based on limitations of a specific design considered. In 2008 INL solicited expressions of interest from Vendors who could provide existing, demonstrated technology that could be applied to the retrieval, sorting, treatment (as required), and

  15. Remote System Technologies for Deactivating Hanford Hot Cells (for WM'03 - abstract included)

    SciTech Connect

    BERLIN, G.T.

    2003-01-28

    Remote system technologies are being deployed by Fluor Hanford to help accelerate the deactivation of highly-radioactive hot cell facilities. This paper highlights the application of several remotely deployed technologies enabling the deactivation tasks.

  16. Somatic Rearrangement in B Cells: It's (Mostly) Nuclear Physics.

    PubMed

    Aiden, Erez Lieberman; Casellas, Rafael

    2015-08-13

    We discuss how principles of nuclear architecture drive typical gene rearrangements in B lymphocytes, whereas translocation hot spots and recurrent lesions reflect the extent of AID-mediated DNA damage and selection.

  17. HOT CELL BUILDING, TRA632. WHILE STEEL BEAMS DEFINE FUTURE WALLS ...

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

    HOT CELL BUILDING, TRA-632. WHILE STEEL BEAMS DEFINE FUTURE WALLS OF THE BUILDING, SHEET STEEL DEFINES THE HOT CELL "BOX" ITSELF. THREE OPERATING WINDOWS ON LEFT; ONE VIEWING WINDOW ON RIGHT. TUBES WILL CONTAIN SERVICE AND CONTROL LEADS. SPACE BETWEEN INNER AND OUTER BOX WALLS WILL BE FILLED WITH SHIELDED WINDOWS AND BARETES CONCRETE. CAMERA FACES SOUTHEAST. INL NEGATIVE NO. 7933. Unknown Photographer, ca. 5/1953 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  18. A&M. Hot cell addition (TAN633). Floor plan, elevations. Arrangement of ...

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

    A&M. Hot cell addition (TAN-633). Floor plan, elevations. Arrangement of monorail along corridor, four hot cells, plug access openings, viewing windows, photo darkroom. Ralph M. Parsons 1229-13-ANP/GE-3-633-A-1. Date: December 1956 as redrawn in August 1998. Approved by INEEL Classification Office for public release. INEEL index code no. 034-0633-00-693-107315 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  19. HOT CELL BUILDING, TRA632, INTERIOR. OPEN CORRIDOR ALONG SOUTH WALL ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. OPEN CORRIDOR ALONG SOUTH WALL OF BUILDING. CAMERA IS NEAR HOT CELL NO. 1, FACES WEST TOWARDS WALL OF TEST-TRAIN ASSEMBLY (TRA-632A). NOTE MOTORIZED RAIL CRANE ABOVE STAIRWAY. INL NEGATIVE NO. HD46-29-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  20. DQO Summary Report for 324 and 327 Building Hot Cells D4 Project Waste Characterization

    SciTech Connect

    T.A. Lee

    2006-02-06

    This data quality objective (DQO) summary report provides the results of the DQO process conducted for waste characterization activities for the 324 and 327 Building hot cells decommission, deactivate, decontaminate, and demolish activities. This DQO summary report addresses the systems and processes related to the hot cells, air locks, vaults, tanks, piping, basins, air plenums, air ducts, filters, an adjacent elements that have high dose rates, high contamination levels, and/or suspect transuranic waste, which will require nonstandard D4 techniques.

  1. 113. ARAI Hot cell (ARA626) Building wall sections and details ...

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

    113. ARA-I Hot cell (ARA-626) Building wall sections and details of radio chemistry lab. Shows high-bay roof over hot cells and isolation rooms below grade storage pit for fuel elements. Norman Engineering Company: 961-area/SF-626-A-4. Date: January 1959. Ineel index code no. 068-0626-00-613-102724. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  2. Evaluation of Alternatives for Hanford 327 Building Hot Cell Removal and Transport

    SciTech Connect

    Stevens, Ray W.; Jasen, William G.

    2003-02-27

    The Department of Energy (DOE) Hanford site 327 Building, built in 1953, played a key role in reactor material and fuel research programs. The facility includes nine shielded hot cells, a fuel storage basin, dry sample storage, and a large inerted hot (SERF) cell. In 1996, the 327 Building was transferred from Pacific Northwest National Laboratory (PNNL) to Fluor Hanford, Inc., to begin the transition from the mission of irradiated fuel examination to stabilization and deactivation. In 2001, a multi-contractor team conducted a review of the concept of intact (one piece) removal, packaging, and disposal of the 327 hot cells. This paper focuses on challenges related to preparing the 327 Building hot cells for intact one-piece disposal as Low Level Waste (LLW) at the Hanford Site. These challenges, described in this paper, are threefold and include: Sampling and characterization of the cells for low level waste designation; Packaging of the cells for transportation and waste disposal; Transportation from the facility to the disposal site. The primary technical challenges in one-piece removal, packaging, and disposal of the hot cells involve the techniques required to characterize, remove, handle, package and transport a large (approximately up to 12-feet long and 8-feet high) contaminated object that weighs 35 to 160 tons. Specific characterization results associated with two hot cells, G and H cells will be reported. A review of the activities and plans to stabilize and deactivate the 327 Building provides insight into the technical challenges faced by this project and identifies a potential opportunity to modify the baseline strategy by removing the hot cells in one piece instead of decontaminating and dismantling the cells.

  3. Nuclear receptors in stem cell biology.

    PubMed

    Shi, Yanhong; Sun, Guoqiang; Stewart, Richard

    2006-01-01

    Batteries of transcription factors have been proposed to control stem cell self-renewal and lineage progression by eliciting cascades of gene expression. Nuclear receptors provide an ideal model to study the transcriptional regulation of gene expression because they can activate as well as repress gene expression through ligand binding and recruitment of transcriptional coactivators or corepressors. Recent progress in defining specific roles of some nuclear receptors and their coregulators in stem cell self-renewal and differentiation provides a first glimpse of the regulatory events involved and is the beginning of a very promising area of research. This review summarizes the current state of knowledge regarding nuclear receptors and their roles in stem cell biology. These studies not only facilitate an understanding of stem cell biology but also provide a basis for the development of therapeutic drugs for the treatment of a variety of diseases.

  4. Antistrange meson-baryon interaction in hot and dense nuclear matter

    NASA Astrophysics Data System (ADS)

    Cabrera, D.; Tolós, L.; Aichelin, J.; Bratkovskaya, E.

    2014-11-01

    We present a study of in-medium cross sections and (off-shell) transition rates for the most relevant binary reactions for strange pseudoscalar meson production close to threshold in heavy-ion collisions at energies available at the Facility for Antiproton and Ion Research. Our results rely on a chiral unitary approach in coupled channels which incorporates the s and p waves of the kaon-nucleon interaction. The formalism, which is modified in the hot and dense medium to account for Pauli blocking effects, mean-field binding on baryons, and pion and kaon self-energies, has been improved to implement unitarization and self-consistency for both the s - and the p -wave interactions at finite temperature and density. This gives access to in-medium amplitudes in several elastic and inelastic coupled channels with strangeness content S =-1 . The obtained total cross sections mostly reflect the fate of the Λ (1405 ) resonance, which melts in the nuclear environment, whereas the off-shell transition probabilities are also sensitive to the in-medium properties of the hyperons excited in the p -wave amplitudes [Λ ,Σ , and Σ*(1385 ) ]. The single-particle potentials of these hyperons at finite momentum, density, and temperature are also discussed in connection with the pertinent scattering amplitudes. Our results are the basis for future implementations in microscopic transport approaches accounting for off-shell dynamics of strangeness production in nucleus-nucleus collisions.

  5. A micro hot test of the Chalmers-GANEX extraction system on used nuclear fuel

    SciTech Connect

    Bauhn, L.; Hedberg, M.; Aneheim, E.; Ekberg, C.; Loefstroem-Engdahl, E.; Skarnemark, G.

    2013-07-01

    In the present study, a 'micro hot test' has been performed using the Chalmers-GANEX (Group Actinide Extraction) system for partitioning of used nuclear fuel. The test included a pre-extraction step using N,N-di-2- ethylhexyl-butyramide (DEHBA) in n-octanol to remove the bulk part of the uranium. This pre-extraction was followed by a group extraction of actinides using the mixture of TBP and CyMe{sub 4}-BTBP in cyclohexanone as suggested in the Chalmers-GANEX process, and a three stage stripping of the extracted actinides. Distribution ratios for the extractions and stripping were determined based on a combination of γ- and α-spectrometry, as well as ICP-MS measurements. Successful extraction of uranium, plutonium and the minor actinides neptunium, americium and curium was achieved. However, measurements also indicated that co-extraction of europium occurs to some extent during the separation. These results were expected based on previous experiments using trace concentrations of actinides and lanthanides. Since this test was only performed in one stage with respect to the group actinide extraction, it is expected that multi stage tests will give even better results. (authors)

  6. Prestressed nuclear organization in living cells.

    PubMed

    Mazumder, Aprotim; Roopa, T; Kumar, Abhishek; Iyer, K Venkatesan; Ramdas, Nisha M; Shivashankar, G V

    2010-01-01

    The nucleus is maintained in a prestressed state within eukaryotic cells, stabilized mechanically by chromatin structure and other nuclear components on its inside, and cytoskeletal components on its outside. Nuclear architecture is emerging to be critical to the governance of chromatin assembly, regulation of genome function and cellular homeostasis. Elucidating the prestressed organization of the nucleus is thus important to understand how the nuclear architecture impinges on its function. In this chapter, various chemical and mechanical methods have been described to probe the prestressed organization of the nucleus.

  7. Charge transfer state versus hot exciton dissociation in polymer-fullerene blended solar cells.

    PubMed

    Lee, Jiye; Vandewal, Koen; Yost, Shane R; Bahlke, Matthias E; Goris, Ludwig; Baldo, Marc A; Manca, Jean V; Van Voorhis, Troy

    2010-09-01

    We examine the significance of hot exciton dissociation in two archetypical polymer-fullerene blend solar cells. Rather than evolving through a bound charge transfer state, hot processes are proposed to convert excitons directly into free charges. But we find that the internal quantum yields of carrier photogeneration are similar for both excitons and direct excitation of charge transfer states. The internal quantum yield, together with the temperature dependence of the current-voltage characteristics, is consistent with negligible impact from hot exciton dissociation.

  8. Advanced Manufacturing Technologies (AMT): Additive Manufactured Hot Fire Planning and Testing in GRC Cell 32 Project

    NASA Technical Reports Server (NTRS)

    Fikes, John C.

    2014-01-01

    The objective of this project is to hot fire test an additively manufactured thrust chamber assembly TCA (injector and thrust chamber). GRC will install the additively manufactured Inconel 625 injector, two additively manufactured (SLM) water cooled Cu-Cr thrust chamber barrels and one additively manufactured (SLM) water cooled Cu-Cr thrust chamber nozzle on the test stand in Cell 32 and perform hot fire testing of the integrated TCA.

  9. Submerged RadBall® deployments in Hanford Site hot cells containing 137CsCl capsules.

    PubMed

    Farfán, Eduardo B; Coleman, J Rusty; Stanley, Steven; Adamovics, John; Oldham, Mark; Thomas, Andrew

    2012-07-01

    The overall objective of this study was to demonstrate that a new technology, known as RadBall®, could locate submerged radiological hazards. RadBall® is a novel, passive, radiation detection device that provides a 3-D visualization of radiation from areas where measurements have not been previously possible due to lack of access or extremely high radiation doses. This technology has been under development during recent years, and all of its previous tests have included dry deployments. This study involved, for the first time, underwater RadBall® deployments in hot cells containing 137CsCl capsules at the U.S. Department of Energy's Hanford Site. RadBall® can be used to characterize a contaminated room, hot cell, or glovebox by providing the locations of the radiation sources and hazards, identifying the radionuclides present within the cell, and determining the radiation sources' strength (e.g., intensities or dose rates). These parameters have been previously determined for dry deployments; however, only the location of radiation sources and hazards can be determined for an underwater RadBall® deployment. The results from this study include 3-D images representing the location of the radiation sources within the Hanford Site cells. Due to RadBall®'s unique deployability and non-electrical nature, this technology shows significant promise for future characterization of radiation hazards prior to and during the decommissioning of contaminated nuclear facilities.

  10. Submerged RadBall® deployments in Hanford Site hot cells containing 137CsCl capsules.

    PubMed

    Farfán, Eduardo B; Coleman, J Rusty; Stanley, Steven; Adamovics, John; Oldham, Mark; Thomas, Andrew

    2012-07-01

    The overall objective of this study was to demonstrate that a new technology, known as RadBall®, could locate submerged radiological hazards. RadBall® is a novel, passive, radiation detection device that provides a 3-D visualization of radiation from areas where measurements have not been previously possible due to lack of access or extremely high radiation doses. This technology has been under development during recent years, and all of its previous tests have included dry deployments. This study involved, for the first time, underwater RadBall® deployments in hot cells containing 137CsCl capsules at the U.S. Department of Energy's Hanford Site. RadBall® can be used to characterize a contaminated room, hot cell, or glovebox by providing the locations of the radiation sources and hazards, identifying the radionuclides present within the cell, and determining the radiation sources' strength (e.g., intensities or dose rates). These parameters have been previously determined for dry deployments; however, only the location of radiation sources and hazards can be determined for an underwater RadBall® deployment. The results from this study include 3-D images representing the location of the radiation sources within the Hanford Site cells. Due to RadBall®'s unique deployability and non-electrical nature, this technology shows significant promise for future characterization of radiation hazards prior to and during the decommissioning of contaminated nuclear facilities. PMID:22647921

  11. HOT CELL BUILDING, TRA632, INTERIOR. WRIGHT 3TON HOIST ON EAST ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. WRIGHT 3-TON HOIST ON EAST SIDE OF CELL 2. SIGN AT LEFT OF VIEW SAYS, "...DO NOT BRING FISSILE MATERIAL INTO AREA WITHOUT APPROVAL." CAMERA FACES NORTHWEST. INL NEGATIVE NO. HD46-29-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  12. HOT CELL BUILDING, TRA632. FLOOR PLAN OF EXPANSION SHOWS LOCATION ...

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

    HOT CELL BUILDING, TRA-632. FLOOR PLAN OF EXPANSION SHOWS LOCATION OF NEW CELLS, "HEAVY" CELL AT WEST END, "LIGHT" CELLS AT EAST. MOCK-UP AND STORAGE AREAS IN SOUTH HALF OF FLOOR. H.K. FERGUSON 895-MTR-ETR-632-A1, 12/1958. INL INDEX NO. 531-0632-00-279-101924, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. Nuclear myosin I regulates cell membrane tension.

    PubMed

    Venit, Tomáš; Kalendová, Alžběta; Petr, Martin; Dzijak, Rastislav; Pastorek, Lukáš; Rohožková, Jana; Malohlava, Jakub; Hozák, Pavel

    2016-08-02

    Plasma membrane tension is an important feature that determines the cell shape and influences processes such as cell motility, spreading, endocytosis and exocytosis. Unconventional class 1 myosins are potent regulators of plasma membrane tension because they physically link the plasma membrane with adjacent cytoskeleton. We identified nuclear myosin 1 (NM1) - a putative nuclear isoform of myosin 1c (Myo1c) - as a new player in the field. Although having specific nuclear functions, NM1 localizes predominantly to the plasma membrane. Deletion of NM1 causes more than a 50% increase in the elasticity of the plasma membrane around the actin cytoskeleton as measured by atomic force microscopy. This higher elasticity of NM1 knock-out cells leads to 25% higher resistance to short-term hypotonic environment and rapid cell swelling. In contrast, overexpression of NM1 in wild type cells leads to an additional 30% reduction of their survival. We have shown that NM1 has a direct functional role in the cytoplasm as a dynamic linker between the cell membrane and the underlying cytoskeleton, regulating the degree of effective plasma membrane tension.

  14. Nuclear myosin I regulates cell membrane tension

    PubMed Central

    Venit, Tomáš; Kalendová, Alžběta; Petr, Martin; Dzijak, Rastislav; Pastorek, Lukáš; Rohožková, Jana; Malohlava, Jakub; Hozák, Pavel

    2016-01-01

    Plasma membrane tension is an important feature that determines the cell shape and influences processes such as cell motility, spreading, endocytosis and exocytosis. Unconventional class 1 myosins are potent regulators of plasma membrane tension because they physically link the plasma membrane with adjacent cytoskeleton. We identified nuclear myosin 1 (NM1) - a putative nuclear isoform of myosin 1c (Myo1c) - as a new player in the field. Although having specific nuclear functions, NM1 localizes predominantly to the plasma membrane. Deletion of NM1 causes more than a 50% increase in the elasticity of the plasma membrane around the actin cytoskeleton as measured by atomic force microscopy. This higher elasticity of NM1 knock-out cells leads to 25% higher resistance to short-term hypotonic environment and rapid cell swelling. In contrast, overexpression of NM1 in wild type cells leads to an additional 30% reduction of their survival. We have shown that NM1 has a direct functional role in the cytoplasm as a dynamic linker between the cell membrane and the underlying cytoskeleton, regulating the degree of effective plasma membrane tension. PMID:27480647

  15. Nuclear myosin I regulates cell membrane tension.

    PubMed

    Venit, Tomáš; Kalendová, Alžběta; Petr, Martin; Dzijak, Rastislav; Pastorek, Lukáš; Rohožková, Jana; Malohlava, Jakub; Hozák, Pavel

    2016-01-01

    Plasma membrane tension is an important feature that determines the cell shape and influences processes such as cell motility, spreading, endocytosis and exocytosis. Unconventional class 1 myosins are potent regulators of plasma membrane tension because they physically link the plasma membrane with adjacent cytoskeleton. We identified nuclear myosin 1 (NM1) - a putative nuclear isoform of myosin 1c (Myo1c) - as a new player in the field. Although having specific nuclear functions, NM1 localizes predominantly to the plasma membrane. Deletion of NM1 causes more than a 50% increase in the elasticity of the plasma membrane around the actin cytoskeleton as measured by atomic force microscopy. This higher elasticity of NM1 knock-out cells leads to 25% higher resistance to short-term hypotonic environment and rapid cell swelling. In contrast, overexpression of NM1 in wild type cells leads to an additional 30% reduction of their survival. We have shown that NM1 has a direct functional role in the cytoplasm as a dynamic linker between the cell membrane and the underlying cytoskeleton, regulating the degree of effective plasma membrane tension. PMID:27480647

  16. Reversible electron-hole separation in a hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    Linke, Heiner

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron-hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron-hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. To achieve this, we consider a highly selective energy filter such as a quantum dot embedded into a one-dimensional conductor. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. In addition this theoretical analysis, I will also report on first experimental results in a nanowire-based energy filter device. Ref: S Limpert, S Bremner, and H Linke, New J. Phys 17, 095004 (2015)

  17. Tandem-structured, hot electron based photovoltaic cell with double Schottky barriers

    PubMed Central

    Lee, Young Keun; Lee, Hyosun; Park, Jeong Young

    2014-01-01

    We demonstrate a tandem-structured, hot electron based photovoltaic cell with double Schottky barriers. The tandem-structured, hot electron based photovoltaic cell is composed of two metal/semiconductor interfaces. Two types of tandem cells were fabricated using TiO2/Au/Si and TiO2/Au/TiO2, and photocurrent enhancement was detected. The double Schottky barriers lead to an additional pathway for harvesting hot electrons, which is enhanced through multiple reflections between the two barriers with different energy ranges. In addition, light absorption is improved by the band-to-band excitation of both semiconductors with different band gaps. Short-circuit current and energy conversion efficiency of the tandem-structured TiO2/Au/Si increased by 86% and 70%, respectively, compared with Au/Si metal/semiconductor nanodiodes, showing an overall solar energy conversion efficiency of 5.3%. PMID:24694838

  18. Remote maintenance for a new generation of hot cells

    SciTech Connect

    Feldman, M.J.; Grant, N.R.

    1987-01-01

    For several years the Consolidated Fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) has been developing facility concepts, designing specialized equipment, and testing prototypical hardware for reprocessing spent fuel from fast breeder reactors. The major facility conceptual design, the Hot Experimental Facility, was based on total remote maintenance to increase plant availability and to reduce radiation exposure. This thrust included designing modular equipment to facilitate maintenance and the manipulation necessary to accomplish maintenance. Included in the design repetoire was the development effort in advanced servomanipulator systems, a remote sampling system, television viewing, and a transporter for manipulator positioning. Demonstration of these developed items is currently ongoing, and the technology is available for applications where production operations in highly radioactive environments are required.

  19. Proliferating cell nuclear antigen in neutrophil fate.

    PubMed

    Witko-Sarsat, Véronique; Ohayon, Delphine

    2016-09-01

    The life span of a neutrophil is a tightly regulated process as extended survival is beneficial for pathogen elimination and cell death necessary to prevent cytotoxic content release from activated neutrophils at the inflammatory site. Therefore, the control between survival and death must be a dynamic process. We have previously described that proliferating cell nuclear antigen (PCNA) which is known as a nuclear protein pivotal in DNA synthesis, is a key element in controlling neutrophil survival through its association with procaspases. Contrary to the dogma which asserted that PCNA has a strictly nuclear function, in mature neutrophils, PCNA is present exclusively within the cytosol due to its nuclear export at the end of the granulocytic differentiation. More recent studies are consistent with the notion that the cytosolic scaffold of PCNA is aimed at modulating neutrophil fate rather than simply preventing death. Ultimately, targeting neutrophil survival might have important applications not just in the field of immunology and inflammation, but also in hematology and transfusion. The neutrophil emerges as a unique and powerful cellular model to unravel the basic mechanisms governing the cell cycle-independent functions of PCNA and should be considered as a leader of the pack. PMID:27558345

  20. Spin-polarized lithium diffusion in a glass hot-vapor cell

    NASA Astrophysics Data System (ADS)

    Ishikawa, Kiyoshi

    2016-08-01

    We report diffusion coefficients of optically pumped lithium atoms in helium buffer gas. The free-induction decay and the spin-echo signals of ground-state atoms were optically detected in an external magnetic field with the addition of field gradient. Lithium hot vapor was produced in a borosilicate-glass cell at a temperature between 290 and 360°C. The simple setup using the glass cells enabled lithium atomic spectroscopy in a similar way to other alkali-metal atoms and study of the collisional properties of lithium atoms in a hot-vapor phase.

  1. HOT CELL BUILDING, TRA632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA ...

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

    HOT CELL BUILDING, TRA-632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA FACING EASTERLY. HOT CELL BUILDING IS AT CENTER LEFT OF VIEW; THE LOW-BAY PROJECTION WITH LADDER IS THE TEST TRAIN ASSEMBLY FACILITY, ADDED IN 1968. MTR BUILDING IS IN LEFT OF VIEW. HIGH-BAY BUILDING AT RIGHT IS THE ENGINEERING TEST REACTOR BUILDING, TRA-642. INL NEGATIVE NO. HD46-32-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. Multiphysics Thermal-Fluid Design Analysis of a Non-Nuclear Tester for Hot-Hydrogen Materials and Component Development

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Foote, John; Litchford, Ron

    2006-01-01

    The objective of this effort is to perform design analyses for a non-nuclear hot-hydrogen materials tester, as a first step towards developing efficient and accurate multiphysics, thermo-fluid computational methodology to predict environments for hypothetical solid-core, nuclear thermal engine thrust chamber design and analysis. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, thermally radiating, unstructured-grid, and pressure-based formulation. The multiphysics invoked in this study include hydrogen dissociation kinetics and thermodynamics, turbulent flow, convective, and thermal radiative heat transfers. The goals of the design analyses are to maintain maximum hot-hydrogen jet impingement energy and to minimize chamber wall heating. The results of analyses on three test fixture configurations and the rationale for final selection are presented. The interrogation of physics revealed that reactions of hydrogen dissociation and recombination are highly correlated with local temperature and are necessary for accurate prediction of the hot-hydrogen jet temperature.

  3. Multiphysics Thermal-Fluid Design Analysis of a Non-Nuclear Tester for Hot-Hydrogen Materials and Component Development

    SciTech Connect

    Wang, T.-S.; Foote, John; Litchford, Ron

    2006-01-20

    The objective of this effort is to perform design analyses for a non-nuclear hot-hydrogen materials tester, as a first step towards developing efficient and accurate multiphysics, thermo-fluid computational methodology to predict environments for hypothetical solid-core, nuclear thermal engine thrust chamber design and analysis. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, thermally radiating, unstructured-grid, and pressure-based formulation. The multiphysics invoked in this study include hydrogen dissociation kinetics and thermodynamics, turbulent flow, convective, and thermal radiative heat transfers. The goals of the design analyses are to maintain maximum hot-hydrogen jet impingement energy and to minimize chamber wall heating. The results of analyses on three test fixture configurations and the rationale for final selection are presented. The interrogation of physics revealed that reactions of hydrogen dissociation and recombination are highly correlated with local temperature and are necessary for accurate prediction of the hot-hydrogen jet temperature.

  4. Nuclear asynchrony in multinucleate rat kangaroo cells.

    PubMed

    Ghosh, S; Paweletz, N

    1984-11-01

    Multinucleate (MN) cells were induced in PtK1 cells by colcemid treatment. A large percentage of cells developed nuclear asynchrony both in relation to DNA synthesis and mitosis within one cell cycle. Asynchrony could be traced even in metaphase and anaphase cells in which interphase nuclei, PCC of S-phase nuclei and less condensed prophase-like chromosomes could be observed along with normally condensed chromosomes. The occurrence of such abnormalities in these large MN cells may be explained on the basis of an uneven distribution of inducer molecules of DNA synthesis and mitosis due to cytoplasmic compartmentation. The less condensed form of all the chromosomes except chromosome 4 could be traced in asynchronous metaphase. The failure of the less condensed chromosomes to undergo complete condensation does not always appear to result from late entry of nuclei containing these chromosomes into G2 phase. It is likely that chromosome 4 carries gene(s) for chromosome condensation, as this chromosome itself never appears in a less condensed form. The inducers for chromosome condensation may not always be available at equal concentrations to all chromosomes located in separate nuclei, thus they may sometimes fail to undergo complete condensation before other nuclei reach the end of prophase, when the nuclear envelopes of all nuclei present in the cell break down simultaneously.

  5. All-Hot-Wire Chemical Vapor Deposition a-Si:H Solar Cells

    SciTech Connect

    Iwaniczko, E.; Wang, Q.; Xu, Y.; Nelson, B. P.; Mahan, A. H.; Crandall, R. S.; Branz, H. M.

    2000-01-01

    Efficient hydrogenated amorphous silicon (a-Si:H) nip solar cells have been fabricated with all doped and undoped a-Si:H layers deposited by hot-wire chemical vapor deposition (HWCVD). The total deposition time of all layers, except the top ITO-contact, is less than 4 minutes.

  6. 111. ARAI Hot cell (ARA626) Building elevations of north, south, ...

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

    111. ARA-I Hot cell (ARA-626) Building elevations of north, south, east, and west sides. Includes details of personnel decontamination area, dark room, and other features. Norman Engineering Company: 961-area/SF-626-A-3. Date: January 1959. Ineel index code no. 068-0626-00-613-102723. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  7. HOT CELL BUILDING, TRA632. ELEVATIONS FOR SOUTH, NORTH AND WEST ...

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

    HOT CELL BUILDING, TRA-632. ELEVATIONS FOR SOUTH, NORTH AND WEST SIDES OF 1958 EXTENSION. H.K. FERGUSON CO. 895-MTR-ETR-632-A3, 12/1958. INL INDEX NO. 531-0632-00-279-101926, REV. 3. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. A&M. TAN607. Special service cubicle (hot cell). Details include Zpipe ...

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

    A&M. TAN-607. Special service cubicle (hot cell). Details include Z-pipe and stepped plug penetrations through shielding wall. Ralph M. Parsons 902-3-ANP-607-A116. Date: December 1952. Approved by INEEL Classification Office for public release. INEEL index code no. 034-0607-693-106767 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  9. VIEW OF FECF HOT CELL OF FUEL STORAGE BUILDING (CPP603). ...

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

    VIEW OF FECF HOT CELL OF FUEL STORAGE BUILDING (CPP-603). PHOTO TAKEN LOOKING NORHTWEST. INL PHOTO NUMBER HD-54-18-3. Mike Crane, Photographer, 8/2005 - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

  10. 114. ARAI Hot cell (ARA626) Building details of fuel storage ...

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

    114. ARA-I Hot cell (ARA-626) Building details of fuel storage pit in plan and section. Spaces shown for 20 elements. Norman Engineering Company: 961-area/SF-626-S-4. Date: January 1959. Ineel index code no. 068-0626-60-613-102752. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  11. A&M. Hot cell annex (TAN633). Camera facing east. Construction view ...

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

    A&M. Hot cell annex (TAN-633). Camera facing east. Construction view of north and west walls. Photographer: Jack L. Anderson. Date: October 23, 1957. INEEL negative no. 57-5336 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  12. A&M. Hot cell annex (TAN633) contextual view also showing east ...

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

    A&M. Hot cell annex (TAN-633) contextual view also showing east facade. Camera facing west. Note corridor connecting annex to pool area of TAN-607. Pumice block walls. Date: March 2004. INEEL negative no. HD-39-2-2 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  13. HOT CELL BUILDING, TRA632. ELEVATIONS. PUMICE BLOCK WALLS. BLOWER AND ...

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

    HOT CELL BUILDING, TRA-632. ELEVATIONS. PUMICE BLOCK WALLS. BLOWER AND FILTER LOFT PLATFORM AND LADDER ON EAST SIDE. IDAHO OPERATIONS OFFICE MTR-632-IDO-4, 11/1952. INL INDEX NO. 531-0632-00-396-110563, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  14. 112. ARAI Hot cell (ARA626) Building roof plan and details ...

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

    112. ARA-I Hot cell (ARA-626) Building roof plan and details of roof ventilating equipment and parapet. Norman Engineering Company: 961-area/SF-626-A-2. Date: January 1959. Ineel index code no. 068-0626-00-613-102722. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  15. 115. ARAI Details of hot cell section of building ARA626. ...

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

    115. ARA-I Details of hot cell section of building ARA-626. Shows location of high density concrete, viewing windows, filters, monorail crane, bridge crane, and other details. Norman Engineering Company 961-area/SF-626-MS-1. Date: January 1959. Ineel index code no. 068-0626-40-613-102737. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  16. HOT CELL BUILDING, TRA632. SOUTH FACADE. CAMERA FACING NORTHWEST AND ...

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

    HOT CELL BUILDING, TRA-632. SOUTH FACADE. CAMERA FACING NORTHWEST AND DETAIL OF 1986 ADDITION OF TRUCK ENCLOSURE TO SERVICE UTILITY DOOR IN EAST END. INL NEGATIVE NO. HD46-32-3. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. HOT CELL BUILDING, TRA632. INSTRUMENT FITTINGS, MASTER/SLAVE MANIPULATOR, "POT LID ...

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

    HOT CELL BUILDING, TRA-632. INSTRUMENT FITTINGS, MASTER/SLAVE MANIPULATOR, "POT LID CRANE." IDAHO OPERATIONS OFFICE MTR-632-IDO-16, 11/1952. INL INDEX NO. 531-0632-40-396-110574, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  18. HOT CELL BUILDING, TRA632. SHIELDED WINDOWS HAVE BEEN INSTALLED. MANIPULATORS ...

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

    HOT CELL BUILDING, TRA-632. SHIELDED WINDOWS HAVE BEEN INSTALLED. MANIPULATORS AWAIT ATTACHMENT TO HAND CONTROLS. INL NEGATIVE NO. 9001. Unknown Photographer, photo is identified as taken 10/28/1953, but it may be an error as it shows progress since ID-33-G-266 of same date. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  19. Cloning by somatic cell nuclear transfer.

    PubMed

    Fulka, J; First, N L; Loi, P; Moor, R M

    1998-10-01

    The birth of the first cloned mammals, produced by the introduction of somatic cell nuclei into enucleated oocytes, was an impressive and surprising development. Although the ethical debate has been intense, the important scientific questions raised by this work have been inadequately discussed and are still unresolved. In this essay we address three questions about nuclear transplantation in the eggs of mice and domestic animals. First, why were the recent experiments on somatic cell cloning successful, when so many others have failed? Second, were these exceptional cases, or is somatic cloning now open to all? Third, what are the future possibilities for increasing the efficiency and wider applicability of the cloning process?

  20. Plant cell nucleolus as a hot spot for iron.

    PubMed

    Roschzttardtz, Hannetz; Grillet, Louis; Isaure, Marie-Pierre; Conéjéro, Geneviève; Ortega, Richard; Curie, Catherine; Mari, Stéphane

    2011-08-12

    Many central metabolic processes require iron as a cofactor and take place in specific subcellular compartments such as the mitochondrion or the chloroplast. Proper iron allocation in the different organelles is thus critical to maintain cell function and integrity. To study the dynamics of iron distribution in plant cells, we have sought to identify the different intracellular iron pools by combining three complementary imaging approaches, histochemistry, micro particle-induced x-ray emission, and synchrotron radiation micro X-ray fluorescence. Pea (Pisum sativum) embryo was used as a model in this study because of its large cell size and high iron content. Histochemical staining with ferrocyanide and diaminobenzidine (Perls/diaminobenzidine) strongly labeled a unique structure in each cell, which co-labeled with the DNA fluorescent stain DAPI, thus corresponding to the nucleus. The unexpected presence of iron in the nucleus was confirmed by elemental imaging using micro particle-induced x-ray emission. X-ray fluorescence on cryo-sectioned embryos further established that, quantitatively, the iron concentration found in the nucleus was higher than in the expected iron-rich organelles such as plastids or vacuoles. Moreover, within the nucleus, iron was particularly accumulated in a subcompartment that was identified as the nucleolus as it was shown to transiently disassemble during cell division. Taken together, our data uncover an as yet unidentified although abundant iron pool in the cell, which is located in the nuclei of healthy, actively dividing plant tissues. This result paves the way for the discovery of a novel cellular function for iron related to nucleus/nucleolus-associated processes.

  1. Los Alamos Hot-Cell-Facility modifications for examining FFTF fuel pins

    SciTech Connect

    Campbell, B.M.; Ledbetter, J.M.

    1982-01-01

    Commissioned in 1960, the Wing 9 Hot Cell Facility at Los Alamos was recently modified to meet the needs of the 1980s. Because fuel pins from the Fast Flux Test Facility (FFTF) at the Hanford Engineering Development Laboratory (HEDL) are too long for examination in the original hot cells, we modified cells to accommodate longer fuel pins and to provide other capabilities as well. For instance, the T-3 shipping cask now can be opened in an inert atmosphere that can be maintained for all nondestructive and destructive examinations of the fuel pins. The full-length pins are visually examined and photographed, the wire wrap is removed, and fission gas is sampled. After the fuel pin is cropped, a cap is seal-welded on the section containing the fuel column. This section is then transferred to other cells for gamma-scanning, radiography, profilometry, sectioning for metallography, and chemical analysis.

  2. Modification of hot cells for general purpose heat source assembly at the Radioisotope Power Systems Facility

    NASA Astrophysics Data System (ADS)

    Carteret, B. A.

    1991-09-01

    Eight existing, unused hot cells currently are being modified for use in the Radioisotope Power Systems Facility (RPSF) to assemble Pu-238 fueled heat sources for radioisotope thermoelectric generators (RTGs). Four air atmosphere cells will be used for storage, decanning, and decontamination of the iridium-clad radioisotope fuel. The remaining four argon atmosphere cells will be used to assemble fuel and graphite components for production and packaging of general purpose heat source (GPHS) assembly modules, which provide heat to drive the thermoelectric conversion process in the generators. The hot cells will be equipped to perform remote and glovebox-type operations. They will provide shielding and contamination control measures to reduce worker radiation exposure to levels within current U.S. Department of Energy (DOE) guidelines. Designs emphasize the Westinghouse Hanford Company (Westinghouse Hanford) as low as reasonably achievable (ALARA) radiation protection policy.

  3. Modification of hot cells for general purpose heat source assembly at the radioisotope power systems facility

    NASA Astrophysics Data System (ADS)

    Carteret, Betty A.

    1992-01-01

    Eight existing, unused hot cells currently are being modified for use in the Radioisotope Power Systems Facility (RPSF) to assemble 238Pu-fueled heat sources for Radioisotope Thermoelectric Generators (RTGs). Four air atmosphere cells will be used for storage, decanning, and decontamination of the iridium-clad radioisotope fuel. The remaining four argon atmosphere cells will be used to assemble fuel and graphite components for production and packaging of general purpose heat source (GPHS) assembly modules, which provide heat to drive the thermoelectric conversion process in the generators. The hot cells will be equipped to perform remote and glovebox-type operations. They will provide shielding and contamination control measures to reduce worker radiation exposure to levels within current U.S. Department of Energy (DOE) guidelines. Designs emphasize the Westinghouse Hanford Company (Westinghouse Hanford) as low as reasonably achievable (ALARA) radiation protection policy.

  4. Optoelectronic characterization of carrier extraction in a hot carrier photovoltaic cell structure

    NASA Astrophysics Data System (ADS)

    Dimmock, James A. R.; Kauer, Matthias; Smith, Katherine; Liu, Huiyun; Stavrinou, Paul N.; Ekins-Daukes, Nicholas J.

    2016-07-01

    A hot carrier photovoltaic cell requires extraction of electrons on a timescale faster than they can lose energy to the lattice. We optically and optoelectronically characterize two resonant tunneling structures, showing their compatability with hot carrier photovoltaic operation, demonstrating structural and carrier extraction properties necessary for such a device. In particular we use time resolved and temperature dependent photoluminescence to determine extraction timescales and energy levels in the structures and demonstrate fast carrier extraction by tunneling. We also show that such devices are capable of extracting photo-generated electrons at high carrier densities, with an open circuit voltage in excess of 1 V.

  5. A&M. TAN633. Sections show view of hot cell caskentry doors, ...

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

    A&M. TAN-633. Sections show view of hot cell cask-entry doors, manipulators in each cell, drainage trenches, door and room details. Ralph M. Parsons 1229-13-ANP/GE-3-633-A-2. Date: December 1956. Approved by INEEL Classification Office for public release. INNEL index code no. 034-0633-00-693-107316 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  6. New electron beam facility for irradiated plasma facing materials testing in hot cell

    SciTech Connect

    Sakamoto, N.; Kawamura, H.; Akiba, M.

    1995-09-01

    Since plasma facing components such as the first wall and the divertor for the next step fusion reactors are exposed to high heat loads and high energy neutron flux generated by the plasma, it is urgent to develop of plasma facing components which can resist these. Then, we have established electron beam heat facility ({open_quotes}OHBIS{close_quotes}, Oarai Hot-cell electron Beam Irradiating System) at a hot cell in JMTR (Japan Materials Testing Reactor) hot laboratory in order to estimate thermal shock resistivity of plasma facing materials and heat removal capabilities of divertor elements under steady state heating. In this facility, irradiated plasma facing materials (beryllium, carbon based materials and so on) and divertor elements can be treated. This facility consists of an electron beam unit with the maximum beam power of 50kW and the vacuum vessel. The acceleration voltage and the maximum beam current are 30kV (constant) and 1.7A, respectively. The loading time of electron beam is more than 0.1ms. The shape of vacuum vessel is cylindrical, and the mainly dimensions are 500mm in inner diameter, 1000mm in height. The ultimate vacuum of this vessel is 1 x 10{sup -4}Pa. At present, the facility for thermal shock test has been established in a hot cell. And performance estimation on the electron beam is being conducted. Presently, the devices for heat loading tests under steady state will be added to this facility.

  7. Nuclear microscopy of rat colon epithelial cells

    NASA Astrophysics Data System (ADS)

    Ren, M.; Rajendran, Reshmi; Ng, Mary; Udalagama, Chammika; Rodrigues, Anna E.; Watt, Frank; Jenner, Andrew Michael

    2011-10-01

    Using Nuclear microscopy, we have investigated iron distributions in the colons of Sprague Dawley rats, in order to elucidate heme uptake. Four groups of five Sprague Dawley rats (mean weight 180 g) were fed different purified diets containing either heme diet (2.5% w/w hemoglobin), high fat diet (HFD) (18% w/w fat, 1% w/w cholesterol), 'western' diet (combination of hemoglobin 2.5% and 18% fat, 1% cholesterol) or control diet (7% w/w fat). After 4 weeks, animals were sacrificed by exsanguination after anaesthesia. Thin sections of frozen colon tissue were taken, freeze dried and scanned using nuclear microscopy utilising the techniques PIXE, RBS and STIM. The new data acquisition system (IonDaq) developed in CIBA was used to obtain high resolution images and line scans were used to map the iron distributions across the colon boundaries. The nuclear microscope results indicate that when HFD is given in addition to heme, the iron content of the epithelial cells that line the colon decreases, and the zinc in the smooth muscle wall increases. This implies that the level of heme and fat in diet has an important role in colon health, possibly by influencing epithelial cells directly or changing luminal composition such as bacterial flora or levels of metabolites and cytotoxins.

  8. The impact of hot charge carrier mobility on photocurrent losses in polymer-based solar cells.

    PubMed

    Philippa, Bronson; Stolterfoht, Martin; Burn, Paul L; Juška, Gytis; Meredith, Paul; White, Ronald D; Pivrikas, Almantas

    2014-07-22

    A typical signature of charge extraction in disordered organic systems is dispersive transport, which implies a distribution of charge carrier mobilities that negatively impact on device performance. Dispersive transport has been commonly understood to originate from a time-dependent mobility of hot charge carriers that reduces as excess energy is lost during relaxation in the density of states. In contrast, we show via photon energy, electric field and film thickness independence of carrier mobilities that the dispersive photocurrent in organic solar cells originates not from the loss of excess energy during hot carrier thermalization, but rather from the loss of carrier density to trap states during transport. Our results emphasize that further efforts should be directed to minimizing the density of trap states, rather than controlling energetic relaxation of hot carriers within the density of states.

  9. Study of LO-phonon decay in semiconductors for hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    Levard, Hugo; Vidal, Julien; Laribi, Sana; Guillemoles, Jean-François

    2014-03-01

    Knowledge of phonon decay is of crucial importance when studying basic properties of semiconductors, since they are closely related to Raman linewidth and non-equilibrium-hot-carriers cooling. The latter indeed cools down to the bottom of the conduction band within a picosecond range because of electron-phonon interaction. The eventual emitted hot phonons then decay in few picoseconds. The hot carriers cooling can be slowed down by considering the decay rate dependence of phonon on conservation rules, whose tuning may reduce the allowed two-phonon final states density. This is of direct interest for the third generation photovoltaic devices that are Hot Carrier Solar Cells (HCSC), in which the photoexcited carriers are extracted at an energy higher than thermal equilibrium. One of the HCSC main challenges then is to find an absorber material in which the hot phonons has a relaxation time longer than the carriers cooling time, so that we can expect the electron to ``reabsorb'' a phonon, slowing down the electronic cooling. HCSC yield is ultimately limited by LO phonon decay, though. In this work, we present theoretical results obtained from ab initio calculations of phonon lifetime in III-V and IV-IV semiconductors through a three-phonon process. Common approximations in the literature are questioned. In particular, we show that the usual ``zone-center approximation'' is not valid in some specific semiconductors. The analysis allows to correctly investigate phonon decay mechanisms in bulk and nanostructured materials.

  10. The feasibility study of hot cell decontamination by the PFC spray method

    SciTech Connect

    Hui-Jun Won; Chong-Hun Jung; Jei-Kwon Moon

    2008-01-15

    module. A performance test on each module was executed and the results have been reported. A combined test of the four modules, however, has not been performed as yet. The main objective of the present study is to demonstrate the feasibility of the full PFC spray decontamination process. Decontamination of the inside of the IMEF hot cell by the PFC spray method was also performed. PFC spray decontamination process was demonstrated by using a surrogate wall contaminated with Eu{sub 2}O{sub 3} powder. The spray pressure was 41 kgf/cm{sup 2}, the orifice diameter was 0.2 mm and the spray velocity was 0.2 L/min. And, the decontaminated area was 100 cm{sup 2}. From previous test results, we found that the decontamination factor of the PFC spray method was in the range from 9.6 to 62.4. When the decontamination efficiency of Co-60 was high, then the decontamination efficiency of Cs-137 was also high. As the surface roughness of the specimen increased, the PFC spray decontamination efficiency decreased. Inferring from the previous results, the surface of the surrogate wall was cleaned by the PFC spray method. The vacuum cup of the collection module operated well and gathered more than 99 % of the PFC solution. Also, filtration and distillation modules operated well. All the filtered PFC solution flowed to the storage chamber where some of the PFC solution was distilled. The coolant of the distillation module was a dry ice. And, the recycled solution was transferred to the spray module by a high pressure pump. To evaluate the PFC spray decontamination efficiency, a smear device was fabricated and operated by a manipulator. Before and after decontamination, a smear test was performed. The tested area was 100 cm{sup 2} and the radioactivity was estimated indirectly by measuring the radioactivity of the filter paper. The average decontamination factor was in the range between 10 and 15. One application time was 2 minutes. The sprayed PFC solution was collected by the vacuum cup and

  11. Dirac-Hartree-Bogoliubov calculation for spherical and deformed hot nuclei: Temperature dependence of the pairing energy and gaps, nuclear deformation, nuclear radii, excitation energy, and entropy

    NASA Astrophysics Data System (ADS)

    Lisboa, R.; Malheiro, M.; Carlson, B. V.

    2016-02-01

    Background: Unbound single-particle states become important in determining the properties of a hot nucleus as its temperature increases. We present relativistic mean field (RMF) for hot nuclei considering not only the self-consistent temperature and density dependence of the self-consistent relativistic mean fields but also the vapor phase that takes into account the unbound nucleon states. Purpose: The temperature dependence of the pairing gaps, nuclear deformation, radii, binding energies, entropy, and caloric curves of spherical and deformed nuclei are obtained in self-consistent RMF calculations up to the limit of existence of the nucleus. Method: We perform Dirac-Hartree-Bogoliubov (DHB) calculations for hot nuclei using a zero-range approximation to the relativistic pairing interaction to calculate proton-proton and neutron-neutron pairing energies and gaps. A vapor subtraction procedure is used to account for unbound states and to remove long range Coulomb repulsion between the hot nucleus and the gas as well as the contribution of the external nucleon gas. Results: We show that p -p and n -n pairing gaps in the S10 channel vanish for low critical temperatures in the range Tcp≈0.6 -1.1 MeV for spherical nuclei such as 90Zr, 124Sn, and 140Ce and for both deformed nuclei 150Sm and 168Er. We found that superconducting phase transition occurs at Tcp=1.03 Δp p(0 ) for 90Zr, Tcp=1.16 Δp p(0 ) for 140Ce, Tcp=0.92 Δp p(0 ) for 150Sm, and Tcp=0.97 Δp p(0 ) for 168Er. The superfluidity phase transition occurs at Tcp=0.72 Δn n(0 ) for 124Sn, Tcp=1.22 Δn n(0 ) for 150Sm, and Tcp=1.13 Δn n(0 ) for 168Er. Thus, the nuclear superfluidity phase—at least for this channel—can only survive at very low nuclear temperatures and this phase transition (when the neutron gap vanishes) always occurs before the superconducting one, where the proton gap is zero. For deformed nuclei the nuclear deformation disappear at temperatures of about Tcs=2.0 -4.0 MeV , well above the

  12. Hot-wall corrosion testing of simulated high level nuclear waste

    SciTech Connect

    Chandler, G.T.; Zapp, P.E.; Mickalonis, J.I.

    1995-01-01

    Three materials of construction for steam tubes used in the evaporation of high level radioactive waste were tested under heat flux conditions, referred to as hot-wall tests. The materials were type 304L stainless steel alloy C276, and alloy G3. Non-radioactive acidic and alkaline salt solutions containing halides and mercury simulated different high level waste solutions stored or processed at the United States Department of Energy`s Savannah River Site. Alloy C276 was also tested for corrosion susceptibility under steady-state conditions. The nickel-based alloys C276 and G3 exhibited excellent corrosion resistance under the conditions studied. Alloy C276 was not susceptible to localized corrosion and had a corrosion rate of 0.01 mpy (0.25 {mu}m/y) when exposed to acidic waste sludge and precipitate slurry at a hot-wall temperature of 150{degrees}C. Type 304L was susceptible to localized corrosion under the same conditions. Alloy G3 had a corrosion rate of 0.1 mpy (2.5 {mu}m/y) when exposed to caustic high level waste evaporator solution at a hot-wall temperature of 220{degrees}C compared to 1.1 mpy (28.0 {mu}/y) for type 304L. Under extreme caustic conditions (45 weight percent sodium hydroxide) G3 had a corrosion rate of 0.1 mpy (2.5 {mu}m/y) at a hot-wall temperature of 180{degrees}C while type 304L had a high corrosion rate of 69.4 mpy (1.8 mm/y).

  13. Hot-Wire CVD Amorphous Si Materials for Solar Cell Application

    SciTech Connect

    Wang, Q.

    2009-01-01

    Hydrogenated amorphous silicon (a-Si:H) thin films and their application to solar cells fabricated using the hot-wire chemical vapor deposition (HWCVD) or (CAT)-CVD will be reviewed. This review will focus on the comparison to the standard plasma enhance (PE) CVD in the terms of deposition technique, film properties, and solar cell performance. The advantages of using HWCVD for a-Si:H solar cell research as well as the criteria for industry's adaptation of this technique for mass production will be addressed.

  14. Global enhancement of nuclear localization-dependent nuclear transport in transformed cells.

    PubMed

    Kuusisto, Henna V; Wagstaff, Kylie M; Alvisi, Gualtiero; Roth, Daniela M; Jans, David A

    2012-03-01

    Fundamental to eukaryotic cell function, nucleocytoplasmic transport can be regulated at many levels, including through modulation of the importin/exportin (Imp/Exp) nuclear transport machinery itself. Although Imps/Exps are overexpressed in a number of transformed cell lines and patient tumor tissues, the efficiency of nucleocytoplasmic transport in transformed cell types compared with nontransformed cells has not been investigated. Here we use quantitative live cell imaging of 3 isogenic nontransformed/transformed cell pairs to show that nuclear accumulation of nuclear localization signal (NLS)-containing proteins, but not their NLS-mutated derivatives, is increased up to 7-fold in MCF10CA1h human epithelial breast carcinoma cells and in simian virus 40 (SV40)-transformed fibroblasts of human and monkey origin, compared with their nontransformed counterparts. The basis for this appears to be a significantly faster rate of nuclear import in transformed cell types, as revealed by analysis using fluorescence recovery after photobleaching for the human MCF10A/MCF10CA1h cell pair. Nuclear accumulation of NLS/nuclear export signal-containing (shuttling) proteins was also enhanced in transformed cell types, experiments using the nuclear export inhibitor leptomycin B demonstrating that efficient Exp-1-mediated nuclear export was not impaired in transformed compared with nontransformed cells. Enhanced nuclear import and export efficiencies were found to correlate with 2- to 4-fold higher expression of specific Imps/Exps in transformed cells, as indicated by quantitative Western blot analysis, with ectopic expression of Imps able to enhance NLS nuclear accumulation levels up to 5-fold in nontransformed MCF10A cells. The findings indicate that transformed cells possess altered nuclear transport properties, most likely due to the overexpression of Imps/Exps. The findings have important implications for the development of tumor-specific drug nanocarriers in anticancer therapy.

  15. A&M. TAN633. Hot cell floor plans, elevations, sections. Hole schedule ...

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

    A&M. TAN-633. Hot cell floor plans, elevations, sections. Hole schedule (penetrations through concrete). Swing-door details. Ralph M. Parsons 1229-13-ANP/GE-3-633-A-3. Date: December 1956. Approved by INEEL Classification Office for public release. INNEL index code no. 034-0633-00-693-107317 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

  16. HOT CELL BUILDING, TRA632, INTERIOR. WINDOWED ROOM IS OFFICE; NEXT ...

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

    HOT CELL BUILDING, TRA-632, INTERIOR. WINDOWED ROOM IS OFFICE; NEXT DOOR WAS DARKROOM, AND THIRD DOOR LED TO ANOTHER OFFICE. ALL ARE ALONG NORTH WALL OF BUILDING (ETR EXTENSION OF 1958). CAMERA FACES NORTHEAST. PUMICE BLOCK WALLS. INL NEGATIVE NO. HD46-29-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. CSER 97-008: 327 Building hot cell and SERF one-gallon can criticality analysis

    SciTech Connect

    Erickson, D.G.

    1997-10-22

    This CSER gives the limits for the storage of one-gallon cans in the hot cells and the SERF in the 327 Building. The 327 Building is used to perform post irradiation testing of fissionable materials in remotely manipulated hot cells. Historically, scrap pieces of fuel cladding, cleanup materials, and other items have been placed into one-gallon paint cans for storage and ultimately disposal. These cans of materials had been assumed to contain no (or essentially no) fissionable materials, and therefore were not specifically controlled for material accountability. Recently, eight cans with high radiation levels were selected to be assayed for content. These cans contained from 0 to 2.5 grams of fissionable material, with an average of 1 gram per can. Since several of the hot cells contained a significant quantity of the cans, concerns were raised as to whether a CPS nonconformance had occurred, and should the cans have some limits for operation placed on them. This analysis is a response to the concerns raised, and gives guidance for incorporating operating limits for the one-gallon waste cans.

  18. Evaluation of Tritium Behavior in the Epoxy Painted Concrete Wall of ITER Hot Cell

    SciTech Connect

    Nakamura, Hirofumi; Hayashi, Takumi; Kobayashi, Kazuhiro; Nishi, Masataka

    2005-07-15

    Tritium behavior released in the ITER hot cell has been investigated numerically using a combined analytical methods of a tritium transport analysis in the multi-layer wall (concrete and epoxy paint) with the one dimensional diffusion model and a tritium concentration analysis in the hot cell with the complete mixing model by the ventilation. As the results, it is revealed that tritium concentration decay and permeation issues are not serious problem in a viewpoint of safety, since it is expected that tritium concentration in the hot cell decrease rapidly within several days just after removing the tritium release source, and tritium permeation through the epoxy painted concrete wall will be negligible as long as the averaged realistic diffusion coefficient is ensured in the concrete wall. It is also revealed that the epoxy paint on the concrete wall prevents the tritium inventory increase in the concrete wall greatly (two orders of magnitudes), but still, the inventory in the wall is estimated to reach about 0.1 PBq for 20 years operation.

  19. Somatic Cell Nuclear Transfer in the Mouse

    NASA Astrophysics Data System (ADS)

    Kishigami, Satoshi; Wakayama, Teruhiko

    Somatic cell nuclear transfer (SCNT) has become a unique and powerful tool for epigenetic reprogramming research and gene manipulation in animals since “Dolly,” the first animal cloned from an adult cell was reported in 1997. Although the success rates of somatic cloning have been inefficient and the mechanism of reprogramming is still largely unknown, this technique has been proven to work in more than 10 mammalian species. Among them, the mouse provides the best model for both basic and applied research of somatic cloning because of its abounding genetic resources, rapid sexual maturity and propagation, minimal requirements for housing, etc. This chapter describes a basic protocol for mouse cloning using cumulus cells, the most popular cell type for NT, in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. In particular, we focus on a new, more efficient mouse cloning protocol using trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, which increases both in vitro and in vivo developmental rates from twofold to fivefold. This new method including TSA will be helpful to establish mouse cloning in many laboratories.

  20. Experimental demonstration of hot-carrier photo-current in an InGaAs quantum well solar cell

    SciTech Connect

    Hirst, L. C.; Walters, R. J.; Führer, M. F.; Ekins-Daukes, N. J.

    2014-06-09

    An unambiguous observation of hot-carrier photocurrent from an InGaAs single quantum well solar cell is reported. Simultaneous photo-current and photoluminescence measurements were performed for incident power density 0.04–3 kW cm{sup −2}, lattice temperature 10 K, and forward bias 1.2 V. An order of magnitude photocurrent increase was observed for non-equilibrium hot-carrier temperatures >35 K. This photocurrent activation temperature is consistent with that of equilibrium carriers in a lattice at elevated temperature. The observed hot-carrier photo-current is extracted from the well over an energy selective GaAs barrier, thus integrating two essential components of a hot-carrier solar cell: a hot-carrier absorber and an energy selective contact.

  1. Hot Hydrogen Testing of Tungsten-Uranium Dioxide (W-UO2) CERMET Fuel Materials for Nuclear Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Hickman, Robert; Broadway, Jeramie

    2014-01-01

    CERMET fuel materials are being developed at the NASA Marshall Space Flight Center for a Nuclear Cryogenic Propulsion Stage. Recent work has resulted in the development and demonstration of a Compact Fuel Element Environmental Test (CFEET) System that is capable of subjecting depleted uranium fuel material samples to hot hydrogen. A critical obstacle to the development of an NCPS engine is the high-cost and safety concerns associated with developmental testing in nuclear environments. The purpose of this testing capability is to enable low-cost screening of candidate materials, fabrication processes, and further validation of concepts. The CERMET samples consist of depleted uranium dioxide (UO2) fuel particles in a tungsten metal matrix, which has been demonstrated on previous programs to provide improved performance and retention of fission products1. Numerous past programs have utilized hot hydrogen furnace testing to develop and evaluate fuel materials. The testing provides a reasonable simulation of temperature and thermal stress effects in a flowing hydrogen environment. Though no information is gained about radiation damage, the furnace testing is extremely valuable for development and verification of fuel element materials and processes. The current work includes testing of subscale W-UO2 slugs to evaluate fuel loss and stability. The materials are then fabricated into samples with seven cooling channels to test a more representative section of a fuel element. Several iterations of testing are being performed to evaluate fuel mass loss impacts from density, microstructure, fuel particle size and shape, chemistry, claddings, particle coatings, and stabilizers. The fuel materials and forms being evaluated on this effort have all been demonstrated to control fuel migration and loss. The objective is to verify performance improvements of the various materials and process options prior to expensive full scale fabrication and testing. Post test analysis will

  2. Nuclear microscopy of sperm cell elemental structure

    SciTech Connect

    Bench, G.S.

    1994-12-31

    Theories have suggested that there is a link between protamine concentrations in individual sperm and sperm fertility. At present, biochemical analyses have only been performed on bulk populations and existing methods have not been able to determine what percentage of morphologically normal sperm are biochemically defective and potentially infertile. As part of an investigation into male sperm fertility, nuclear microscopy has been utilized to measure elemental profiles at the single sperm level. By measuring the ratio of Phosphorus to Sulfur the authors have been able to determine the amount of protamine 1 and protamine 2 in individual cells from bulk fertile samples of bull and mouse sperm. Preliminary results show that, for each species, the relative amounts of protamine 1 and protamine 2 in morphologically normal sperm agree well with expected values.

  3. Phonon lifetime in SiSn and its suitability for hot-carrier solar cells

    SciTech Connect

    Levard, Hugo; Laribi, Sana; Guillemoles, Jean-François

    2014-06-02

    We present a phononic and electronic study of SiSn in the zinc-blende phase. A detailed description of the longitudinal optical (LO) phonon decay in a three-phonon process is presented together with the corresponding lifetime. The necessity to go beyond the zone center phonon approximation in this case is highlighted as it reveals a steep dependence of the lifetime on the initial phonon wavenumber, which differs from usual semiconductors. The electronic band structure is calculated within the GW formalism and shows a small direct band gap. It is shown that the LO-phonon resulting from electron cooling has a lifetime four to eight orders of magnitude above all the known value in semiconductors for this process. We finally show the suitability of SiSn for hot-carrier solar cells, as it is endowed with ultra-slow cooling of hot carriers.

  4. Nuclear Star Formation in the Hot-Spot Galaxy NGC 2903

    NASA Technical Reports Server (NTRS)

    Alonso-Herrero, A.; Ryder, S. D.; Knapen, J. H.

    1994-01-01

    We present high-resolution near-infrared imaging obtained using adaptive optics and HST/NICMOS and ground-based spectroscopy of the hot-spot galaxy NGC 2903. Our near-infrared resolution imaging enables us to resolve the infrared hot spots into individual young stellar clusters or groups of these. The spatial distribution of the stellar clusters is not coincident with that of the bright H II regions, as revealed by the HST/NICMOS Pace image. Overall, the circumnuclear star formation in NGC 2903 shows a ring-like morphology with an approximate diameter of 625 pc. The SF properties of the stellar clusters and H II regions have been studied using the photometric and spectroscopic information in conjunction with evolutionary synthesis models. The population of bright stellar clusters shows a very narrow range of ages, 4 to 7 x 10(exp 6) yr after the peak of star formation, or absolute ages 6.5 to 9.5 x 10(exp 6) yr (for the assumed short-duration Gaussian bursts), and luminosities similar to the clusters found in the Antennae interacting galaxy. This population of young stellar clusters accounts for some 7 - 12% of the total stellar mass in the central 625 pc of NGC 2903. The H II regions in the ring of star formation have luminosities close to that of the super-giant H II region 30 Doradus, they are younger than the stellar clusters, and will probably evolve into bright infrared stellar clusters similar to those observed today. We find that the star formation efficiency in the central regions of NGC 2903 is higher than in normal galaxies, approaching the lower end of infrared luminous galaxies.

  5. Assays to measure nuclear mechanics in interphase cells.

    PubMed

    Isermann, Philipp; Davidson, Patricia M; Sliz, Josiah D; Lammerding, Jan

    2012-09-01

    The nucleus is the characteristic hallmark of all eukaryotic cells. The physical properties of the nucleus reflect important biological characteristics, such as chromatin organization or nuclear envelope composition; they can also directly affect cellular function, e.g., when cells pass through narrow constrictions, where the stiff nucleus may present a limiting factor. We present two complementary techniques to probe the mechanical properties of the nucleus. In the first, nuclear stiffness relative to the surrounding cytoskeleton is inferred from induced nuclear deformations during strain application to cells on an elastic substrate. In the second approach, nuclear deformability is deduced from the transit time through a perfusion-based microfabricated device with constrictions smaller than the size of the nucleus. These complementary methods, which can be applied to measure nuclear stiffness in large numbers of living adherent or suspended cells, can help identify important changes in nuclear mechanics associated with disease or development.

  6. Assays to measure nuclear mechanics in interphase cells

    PubMed Central

    Isermann, Philipp; Davidson, Patricia M.; Sliz, Josiah D.

    2012-01-01

    The nucleus is the characteristic hallmark of all eukaryotic cells. The physical properties of the nucleus reflect important biological characteristics, such as chromatin organization or nuclear envelope composition; they can also directly affect cellular function, for example, when cells pass through narrow constrictions, where the stiff nucleus may present a limiting factor. We present two complementary techniques to probe the mechanical properties of the nucleus. In the first, nuclear stiffness relative to the surrounding cytoskeleton is inferred from induced nuclear deformations during strain application to cells on an elastic substrate. In the second approach, nuclear deformability is deduced from the transit time through a perfusion-based microfabricated device with constrictions smaller than the size of the nucleus. These complementary methods, which can be applied to measure nuclear stiffness in large numbers of living adherent or suspended cells, can help identify important changes in nuclear mechanics associated with disease or development. PMID:22968843

  7. A hot water extract of Curcuma longa inhibits adhesion molecule protein expression and monocyte adhesion to TNF-α-stimulated human endothelial cells.

    PubMed

    Kawasaki, Kengo; Muroyama, Koutarou; Yamamoto, Norio; Murosaki, Shinji

    2015-01-01

    The recruitment of arterial leukocytes to endothelial cells is an important step in the progression of various inflammatory diseases. Therefore, its modulation is thought to be a prospective target for the prevention or treatment of such diseases. Adhesion molecules on endothelial cells are induced by proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), and contribute to the recruitment of leukocytes. In the present study, we investigated the effect of hot water extract of Curcuma longa (WEC) on the protein expression of adhesion molecules, monocyte adhesion induced by TNF-α in human umbilical vascular endothelial cells (HUVECs). Treatment of HUVECs with WEC significantly suppressed both TNF-α-induced protein expression of adhesion molecules and monocyte adhesion. WEC also suppressed phosphorylation and degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) induced by TNF-α in HUVECs, suggesting that WEC inhibits the NF-κB signaling pathway.

  8. Tumor cell growth inhibition is correlated with levels of capsaicin present in hot peppers.

    PubMed

    Dou, Dan; Ahmad, Aamir; Yang, Huanjie; Sarkar, Fazlul H

    2011-01-01

    There are conflicting reports with regard to the value of hot peppers and their primary active component compound, capsaicin, as an anticancer agent. We tested extracts from a number of peppers and found them to induce significant growth arrest and apoptosis in human breast and leukemia cancer cell lines in vitro with no significant effect on normal breast epithelial cells. Further, cell growth inhibition and cell death induction were positively correlated with the capsaicin content (based on the Scoville scale) of the peppers, and the hydroxyl radical scavenger thiourea significantly inhibited the activity of pepper extracts, suggesting the involvement of free radicals in mediating the biological activity of the pepper extracts. These results suggest a potential use of pepper extracts as anticancer agents.

  9. Development of Hot Pressing as a Low Cost Processing Technique for Fuel Cell Fabrication

    SciTech Connect

    Sarin, V

    2003-01-14

    Dependable, plentiful, and economical energy has been the driving force for financial, industrial, and political growth in the US since the mid 19th century. For a country whose progress is so deeply rooted in abundant energy and whose current political agenda involves stabilizing world fossil fuel prices, the development of a reliable, efficient and environmentally friendly power generating source seems compulsory. The maturing of high technology fuel cells may be the panacea the country will find indispensable to free itself from foreign dependence. Fuel cells offer an efficient, combustion-less, virtually pollution-free power source, capable of being sited in downtown urban areas or in remote regions. Fuel cells have few moving parts and run almost silently. Fuel cells are electrochemical devices that convert the chemical energy of a fuel directly to electrical energy. Unlike batteries, which store a finite amount of energy, fuel cells will generate electricity continuously, as long as fuel and oxidant are available to the electrodes. Additionally, fuel cells offer clean, efficient, and reliable power and they can be operated using a variety of fuels. Hence, the fuel cell is an extremely promising technology. Over the course of this research, the fundamental knowledge related to ceramic processing, sintering, and hot pressing to successfully hot press a single operational SOFC in one step has been developed. Ceramic powder processing for each of the components of an SOFC has bene tailored towards this goal. Processing parameter for the electrolyte and cathode have been studied and developed until they converted. Several anode fabrication techniques have been developed. Additionally, a novel anode structured has been developed and refined. These individual processes have been cultivated until a single cell SOFC has been fabricated in one step.

  10. Cloning mice and ES cells by nuclear transfer from somatic stem cells and fully differentiated cells.

    PubMed

    Wang, Zhongde

    2011-01-01

    Cloning animals by nuclear transfer (NT) has been successful in several mammalian species. In addition to cloning live animals (reproductive cloning), this technique has also been used in several species to establish cloned embryonic stem (ntES) cell lines from somatic cells. It is the latter application of this technique that has been heralded as being the potential means to produce isogenic embryonic stem cells from patients for cell therapy (therapeutic cloning). These two types of cloning differ only in the steps after cloned embryos are produced: for reproductive cloning the cloned embryos are transferred to surrogate mothers to allow them to develop to full term and for therapeutic cloning the cloned embryos are used to derive ntES cells. In this chapter, a detailed NT protocol in mouse by using somatic stem cells (neuron and skin stem cells) and fully differentiated somatic cells (cumulus cells and fibroblast cells) as nuclear donors is described.

  11. Reactions of a prototype nuclear-waste ceramic with a hot magnesium-rich brine

    NASA Astrophysics Data System (ADS)

    Komarneni, S.; Scheetz, B. E.; Freeborn, W. P.; McCarthy, G. J.; White, W. B.

    1982-10-01

    Prototype ceramic nuclear waste forms were experimentally reacted with a high calcium and magnesium brine under hydrothermal conditions. The said reaction products and fluid were analyzed at the end of the experiment. Alteration of the waste forms was observed and the reaction products identified. Uptake of cesium, rubidium, strontium, barium, lanthanum and neodymium into the brine was measured with a strong temperature dependence, i.e., increased concentrations with increased temperature. The concentrations of the six elements also increased with time, and imply that dissolution of the ceramic is controlled by diffusion and/or crystalline dissolution mechanism.

  12. Large scale densification of a nuclear waste ceramic by hot isostatic pressing

    SciTech Connect

    Hoenig, C.L.; Larker, H.T.

    1983-12-01

    Experimental results show that loaded bellows steel canisters, evacuated and sealed, can be cold-isostatically pressed before HIP from an initial density of 26 to 46% theoretical. Calcined powders are hygroscopic and may require degassing at 600 degrees C under vaccum, and residual gas, unless removed, is an impediment to HIP densification. Results also show that degassed synroc D powder in 50 kg quantities can be HIP densified to greater than 97% theoretical density at 1100 degrees C, 150 MPa, for 5h in a bellows canister without radial buckling. The authors believe that on the basis of this preliminary study, full-scale nuclear waste monoliths can be produced by HIP.

  13. Particle-in-cell simulations of hot electron generation using defocused laser light in cone targets

    NASA Astrophysics Data System (ADS)

    Yang, Lei; Pasley, John

    2016-08-01

    The effects of defocusing a high intensity pulse of laser light on the generation of hot electrons in a cone are investigated using particle-in-cell simulations. The results indicate that defocused laser light can soften the electron energy spectrum and increase the coupling efficiency compared to the use of a laser in tight focus. It is shown that this is a consequence of the density profile of plasma produced by the laser prepulse, which is less dense in the case of the defocused laser. The relevance of this result to fast ignition inertial confinement fusion is discussed.

  14. Thermal and stress analysis of hot isostatically pressed, alumina ceramic, nuclear waste containers

    SciTech Connect

    Chang, Yun; Hoenig, C.L.

    1990-03-01

    The Yucca Mountain Project is studying design and fabrication options for a safe durable container in which to store nuclear waste underground at Yucca Mountain, Nevada. The ceramic container discussed here is an alternative to using a metal container. This ceramic alternative would be selected if site conditions prove too corrosive to use metals for nuclear waste storage. Some of the engineering problems addressed in this study were: the stress generated in the alumina container by compressive loads when 4000 to 40,000 psi of external pressure is applied; the thermal stress in the container during the heating and cooling processes; the temperature histories of the container in various production scenarios and the power required for typical heaters; the fastest possible turnaround time to heat, seal, and cool the container commensurate with preserving the structural integrity of the ceramic and the closure; the testing of some commercial heating elements to determine the maximum available heat output; and the trade-offs between the minimization in thermal stress and cycle time for closure. 2 refs., 23 figs., 2 tabs.

  15. Investigation of the basic physics of high efficiency semiconductor hot carrier solar cell

    NASA Technical Reports Server (NTRS)

    Alfano, R. R.; Wang, W. B.; Mohaidat, J. M.; Cavicchia, M. A.; Raisky, O. Y.

    1995-01-01

    The main purpose of this research program is to investigate potential semiconductor materials and their multi-band-gap MQW (multiple quantum wells) structures for high efficiency solar cells for aerospace and commercial applications. The absorption and PL (photoluminescence) spectra, the carrier dynamics, and band structures have been investigated for semiconductors of InP, GaP, GaInP, and InGaAsP/InP MQW structures, and for semiconductors of GaAs and AlGaAs by previous measurements. The barrier potential design criteria for achieving maximum energy conversion efficiency, and the resonant tunneling time as a function of barrier width in high efficiency MQW solar cell structures have also been investigated in the first two years. Based on previous carrier dynamics measurements and the time-dependent short circuit current density calculations, an InAs/InGaAs - InGaAs/GaAs - GaAs/AlGaAs MQW solar cell structure with 15 bandgaps has been designed. The absorption and PL spectra in InGaAsP/InP bulk and MQW structures were measured at room temperature and 77 K with different pump wavelength and intensity, to search for resonant states that may affect the solar cell activities. Time-resolved IR absorption for InGaAsP/InP bulk and MQW structures has been measured by femtosecond visible-pump and IR-probe absorption spectroscopy. This, with the absorption and PL measurements, will be helpful to understand the basic physics and device performance in multi-bandgap InAs/InGaAs - InGaAs/InP - InP/InGaP MQW solar cells. In particular, the lifetime of the photoexcited hot electrons is an important parameter for the device operation of InGaAsP/InP MQW solar cells working in the resonant tunneling conditions. Lastly, time evolution of the hot electron relaxation in GaAs has been measured in the temperature range of 4 K through 288 K using femtosecond pump-IR-probe absorption technique. The temperature dependence of the hot electron relaxation time in the X valley has been measured.

  16. TERT promoter hot spot mutations are frequent in Indian cervical and oral squamous cell carcinomas.

    PubMed

    Vinothkumar, Vilvanathan; Arunkumar, Ganesan; Revathidevi, Sundaramoorthy; Arun, Kanagaraj; Manikandan, Mayakannan; Rao, Arunagiri Kuha Deva Magendhra; Rajkumar, Kottayasamy Seenivasagam; Ajay, Chandrasekar; Rajaraman, Ramamurthy; Ramani, Rajendren; Murugan, Avaniyapuram Kannan; Munirajan, Arasambattu Kannan

    2016-06-01

    Squamous cell carcinoma (SCC) of the uterine cervix and oral cavity are most common cancers in India. Telomerase reverse transcriptase (TERT) overexpression is one of the hallmarks for cancer, and activation through promoter mutation C228T and C250T has been reported in variety of tumors and often shown to be associated with aggressive tumors. In the present study, we analyzed these two hot spot mutations in 181 primary tumors of the uterine cervix and oral cavity by direct DNA sequencing and correlated with patient's clinicopathological characteristics. We found relatively high frequency of TERT hot spot mutations in both cervical [21.4 % (30/140)] and oral [31.7 % (13/41)] squamous cell carcinomas. In cervical cancer, TERT promoter mutations were more prevalent (25 %) in human papilloma virus (HPV)-negative cases compared to HPV-positive cases (20.6 %), and both TERT promoter mutation and HPV infection were more commonly observed in advanced stage tumors (77 %). Similarly, the poor and moderately differentiated tumors of the uterine cervix had both the TERT hot spot mutations and HPV (16 and 18) at higher frequency (95.7 %). Interestingly, we observed eight homozygous mutations (six 228TT and two 250TT) only in cervical tumors, and all of them were found to be positive for high-risk HPV. To the best of our knowledge, this is the first study from India reporting high prevalence of TERT promoter mutations in primary tumors of the uterine cervix and oral cavity. Our results suggest that TERT reactivation through promoter mutation either alone or in association with the HPV oncogenes (E6 and E7) could play an important role in the carcinogenesis of cervical and oral cancers. PMID:26700669

  17. Methods for Assessing Nuclear Rotation and Nuclear Positioning in Developing Skeletal Muscle Cells.

    PubMed

    Wilson, Meredith H; Bray, Matthew G; Holzbaur, Erika L F

    2016-01-01

    Skeletal muscle cells are large syncytia, containing hundreds of nuclei positioned regularly along the length of the fiber. During development, nuclei are actively distributed throughout the myotube by the microtubule motor proteins, kinesin-1, and cytoplasmic dynein. Nuclear movement consists of translocation along the long axis of the cell concurrent with three-dimensional rotation of nuclei. In this chapter we describe methods for quantitatively assessing the speed of nuclear rotation in cultured myotubes using live-cell imaging techniques coupled with rigid body kinematic analyses. Additionally, we provide protocols for analyzing nuclear distribution in myotubes. PMID:27147049

  18. The nuclear pore complex acts as a master switch for nuclear and cell differentiation.

    PubMed

    Iwamoto, Masaaki; Hiraoka, Yasushi; Haraguchi, Tokuko

    2015-01-01

    Cell differentiation is associated with the functional differentiation of the nucleus, in which alteration of the expression profiles of transcription factors occurs to destine cell fate. Nuclear transport machineries, such as importin-α, have also been reported as critical factors that induce cell differentiation. Using various fluorescence live cell imaging methods, including time-lapse imaging, FRAP analysis and live-cell imaging associated correlative light and electron microscopy (Live CLEM) of Tetrahymena, a unicellular ciliated protozoan, we have recently discovered that type switching of the NPC is the earliest detectable event of nuclear differentiation. Our studies suggest that this type switching of the NPC directs the fate of the nucleus to differentiate into either a macronucleus or a micronucleus. Our findings in this organism may provide new insights into the role of the NPC in controlling nuclear functions in general in eukaryotes, including controlling cell fate leading to cell differentiation in multicellular metazoa. PMID:26479399

  19. Subnatural-linewidth biphotons from a Doppler-broadened hot atomic vapour cell

    PubMed Central

    Shu, Chi; Chen, Peng; Chow, Tsz Kiu Aaron; Zhu, Lingbang; Xiao, Yanhong; Loy, M.M.T.; Du, Shengwang

    2016-01-01

    Entangled photon pairs, termed as biphotons, have been the benchmark tool for experimental quantum optics. The quantum-network protocols based on photon–atom interfaces have stimulated a great demand for single photons with bandwidth comparable to or narrower than the atomic natural linewidth. In the past decade, laser-cooled atoms have often been used for producing such biphotons, but the apparatus is too large and complicated for engineering. Here we report the generation of subnatural-linewidth (<6 MHz) biphotons from a Doppler-broadened (530 MHz) hot atomic vapour cell. We use on-resonance spontaneous four-wave mixing in a hot paraffin-coated 87Rb vapour cell at 63 °C to produce biphotons with controllable bandwidth (1.9–3.2 MHz) and coherence time (47–94 ns). Our backward phase-matching scheme with spatially separated optical pumping is the key to suppress uncorrelated photons from resonance fluorescence. The result may lead towards miniature narrowband biphoton sources. PMID:27658721

  20. Observation of the critical end point in the phase diagram for hot and dense nuclear matter

    NASA Astrophysics Data System (ADS)

    Lacey, Roy

    2015-10-01

    Excitation functions for the Gaussian emission source radii difference (Rout2 -Rside2) obtained from two-pion interferometry measurements in Au+Au (√{sNN} = 7 . 7 - 200 GeV) and Pb+Pb (√{sNN} = 2 . 76 TeV) collisions, are studied for a broad range of collision centralities. The observed non-monotonic excitation functions validate the finite-size scaling patterns expected for the deconfinement phase transition and the critical end point (CEP), in the temperature vs. baryon chemical potential (T ,μB) plane of the nuclear matter phase diagram. A Dynamic Finite-Size Scaling (DFSS) analysis of these data suggests a second order phase transition with the estimates Tcep 165 MeV and μBcep 95 MeV for the location of the critical end point. The critical exponents (ν 0 . 66 and γ 1 . 2) extracted via the same DFSS analysis, places this CEP in the 3D Ising model universality class. This research is supported by the US DOE under Contract DE-FG02-87ER40331.A008.

  1. Extreme nuclear shapes examined via giant dipole resonance lineshapes in hot light-mass systems

    SciTech Connect

    Pandit, Deepak; Mukhopadhyay, S.; Pal, Surajit; Bhattacharya, S.; Bhattacharya, C.; Banerjee, K.; Kundu, S.; Rana, T. K.; Dey, A.; Mukherjee, G.; Ghosh, T.; Banerjee, S. R.; De, A.; Gupta, D.

    2010-06-15

    The influence of alpha clustering on nuclear reaction dynamics is investigated using the giant dipole resonance (GDR) lineshape studies in the reactions {sup 20}Ne (E{sub lab}=145,160 MeV) + {sup 12}C and {sup 20}Ne (E{sub lab}=160 MeV) + {sup 27}Al, populating {sup 32}S and {sup 47}V, respectively. The GDR lineshapes from the two systems are remarkably different from each other. Whereas, the non-alpha-like {sup 47}V undergoes Jacobi shape transition and matches exceptionally well with the theoretical GDR lineshape estimated under the framework rotating liquid drop model (RLDM) and thermal shape fluctuation model (TSFM) signifying shape equilibration, for the alpha cluster {sup 32}S an extended prolate kind of shape is observed. This unusual deformation, seen directly via gamma decay for the first time, is predicted to be due to the formation of orbiting dinuclear configuration or molecular structure of {sup 16}O + {sup 16}O in the {sup 32}S superdeformed band.

  2. Cell wall and lipid composition of Isosphaera pallida, a budding eubacterium from hot springs.

    PubMed Central

    Giovannoni, S J; Godchaux, W; Schabtach, E; Castenholz, R W

    1987-01-01

    Isosphaera pallida is an unusual gliding, budding eubacterium recently isolated from North American hot springs. Electron micrographs of ultrathin sections revealed a cell wall atypical of eubacteria: two electrondense layers separated by an electron-transparent layer, with no evident peptidoglycan layer. Growth was not inhibited by penicillin. Cell walls were isolated from sheared cells by velocity sedimentation. The rigid-layer fraction, prepared from cell walls by treatment with boiling 10% sodium dodecyl sulfate, was hydrolyzed and chemically analyzed for muramic acid. This essential component of peptidoglycan was absent. Amino acid analysis demonstrated a proteinaceous wall structure. Pitlike surface structures seen in negatively stained whole cells and thin sections were correlated with periodically spaced perforations of the rigid sacculus. An analysis of the lipid composition of I. pallida revealed typical ester-linked lipids with unbranched fatty acids, in contrast to the isoprenyl ether-linked lipids of archaebacteria, which also have proteinaceous cell walls. Capnoids, unusual sulfonolipids which are present in gliding bacteria of the Cytophaga-Flexibacter group, were absent. Images PMID:3584067

  3. Cell wall and lipid composition of Isosphaera pallida, a budding eubacterium from hot springs.

    PubMed

    Giovannoni, S J; Godchaux, W; Schabtach, E; Castenholz, R W

    1987-06-01

    Isosphaera pallida is an unusual gliding, budding eubacterium recently isolated from North American hot springs. Electron micrographs of ultrathin sections revealed a cell wall atypical of eubacteria: two electrondense layers separated by an electron-transparent layer, with no evident peptidoglycan layer. Growth was not inhibited by penicillin. Cell walls were isolated from sheared cells by velocity sedimentation. The rigid-layer fraction, prepared from cell walls by treatment with boiling 10% sodium dodecyl sulfate, was hydrolyzed and chemically analyzed for muramic acid. This essential component of peptidoglycan was absent. Amino acid analysis demonstrated a proteinaceous wall structure. Pitlike surface structures seen in negatively stained whole cells and thin sections were correlated with periodically spaced perforations of the rigid sacculus. An analysis of the lipid composition of I. pallida revealed typical ester-linked lipids with unbranched fatty acids, in contrast to the isoprenyl ether-linked lipids of archaebacteria, which also have proteinaceous cell walls. Capnoids, unusual sulfonolipids which are present in gliding bacteria of the Cytophaga-Flexibacter group, were absent. PMID:3584067

  4. Practical concept of an all-optical hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    König, Dirk; Yao, Yao

    2015-08-01

    The all-optical hot carrier solar cell (aoHCSC) is an intriguing device concept which circumvents HC thermalization by feeding HCs into local radiative recombination centers. These have transition energies above the HC absorber (HCA) bandgap and are located within the HCA to match the HC ballistic mean free path, suppressing HC cooling as major loss mechanism. HC energy extraction proceeds by photon emission. We propose a technologically feasible concept of the aoHC energy converter (aoHCEC) which feeds into a conventional solar cell with its bandgap matching the emitted photons. Using real materials, the concept builds upon waveguides within a HCA which consist of highly polar direct bandgap material to promote radiative carrier recombination.

  5. Nuclear protein import is reduced in cells expressing nuclear envelopathy-causing lamin A mutants

    SciTech Connect

    Busch, Albert; Kiel, Tilman; Heupel, Wolfgang-M.; Wehnert, Manfred; Huebner, Stefan

    2009-08-15

    Lamins, which form the nuclear lamina, not only constitute an important determinant of nuclear architecture, but additionally play essential roles in many nuclear functions. Mutations in A-type lamins cause a wide range of human genetic disorders (laminopathies). The importance of lamin A (LaA) in the spatial arrangement of nuclear pore complexes (NPCs) prompted us to study the role of LaA mutants in nuclear protein transport. Two mutants, causing prenatal skin disease restrictive dermopathy (RD) and the premature aging disease Hutchinson Gilford progeria syndrome, were used for expression in HeLa cells to investigate their impact on the subcellular localization of NPC-associated proteins and nuclear protein import. Furthermore, dynamics of the LaA mutants within the nuclear lamina were studied. We observed affected localization of NPC-associated proteins, diminished lamina dynamics for both LaA mutants and reduced nuclear import of representative cargo molecules. Intriguingly, both LaA mutants displayed similar effects on nuclear morphology and functions, despite their differences in disease severity. Reduced nuclear protein import was also seen in RD fibroblasts and impaired lamina dynamics for the nucleoporin Nup153. Our data thus represent the first study of a direct link between LaA mutant expression and reduced nuclear protein import.

  6. Joint modeling of cell and nuclear shape variation.

    PubMed

    Johnson, Gregory R; Buck, Taraz E; Sullivan, Devin P; Rohde, Gustavo K; Murphy, Robert F

    2015-11-01

    Modeling cell shape variation is critical to our understanding of cell biology. Previous work has demonstrated the utility of nonrigid image registration methods for the construction of nonparametric nuclear shape models in which pairwise deformation distances are measured between all shapes and are embedded into a low-dimensional shape space. Using these methods, we explore the relationship between cell shape and nuclear shape. We find that these are frequently dependent on each other and use this as the motivation for the development of combined cell and nuclear shape space models, extending nonparametric cell representations to multiple-component three-dimensional cellular shapes and identifying modes of joint shape variation. We learn a first-order dynamics model to predict cell and nuclear shapes, given shapes at a previous time point. We use this to determine the effects of endogenous protein tags or drugs on the shape dynamics of cell lines and show that tagged C1QBP reduces the correlation between cell and nuclear shape. To reduce the computational cost of learning these models, we demonstrate the ability to reconstruct shape spaces using a fraction of computed pairwise distances. The open-source tools provide a powerful basis for future studies of the molecular basis of cell organization. PMID:26354424

  7. Probing charge transfer and hot carrier dynamics in organic solar cells with terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Cunningham, Paul D.; Lane, Paul A.; Melinger, Joseph S.; Esenturk, Okan; Heilweil, Edwin J.

    2016-04-01

    Time-resolved terahertz spectroscopy (TRTS) was used to explore charge generation, transfer, and the role of hot carriers in organic solar cell materials. Two model molecular photovoltaic systems were investigated: with zinc phthalocyanine (ZnPc) or alpha-sexathiophene (α-6T) as the electron donors and buckminsterfullerene (C60) as the electron acceptor. TRTS provides charge carrier conductivity dynamics comprised of changes in both population and mobility. By using time-resolved optical spectroscopy in conjunction with TRTS, these two contributions can be disentangled. The sub-picosecond photo-induced conductivity decay dynamics of C60 were revealed to be caused by auto-ionization: the intrinsic process by which charge is generated in molecular solids. In donor-acceptor blends, the long-lived photo-induced conductivity is used for weight fraction optimization of the constituents. In nanoscale multilayer films, the photo-induced conductivity identifies optimal layer thicknesses. In films of ZnPc/C60, electron transfer from ZnPc yields hot charges that localize and become less mobile as they thermalize. Excitation of high-lying Franck Condon states in C60 followed by hole-transfer to ZnPc similarly produces hot charge carriers that self-localize; charge transfer clearly precedes carrier cooling. This picture is contrasted to charge transfer in α-6T/C60, where hole transfer takes place from a thermalized state and produces equilibrium carriers that do not show characteristic signs of cooling and self-localization. These results illustrate the value of terahertz spectroscopic methods for probing charge transfer reactions.

  8. Crystal Silicon Heterojunction Solar Cells by Hot-Wire CVD: Preprint

    SciTech Connect

    Wang, Q.; Page, M. R.; Iwaniczko, E.; Xu, Y. Q.; Roybal, L.; Bauer, R.; To, B.; Yuan, H. C.; Duda, A.; Yan, Y. F.

    2008-05-01

    Hot-wire chemical vapor deposition (HWCVD) is a promising technique for fabricating Silicon heterojunction (SHJ) solar cells. In this paper we describe our efforts to increase the open circuit voltage (Voc) while improving the efficiency of these devices. On p-type c-Si float-zone wafers, we used a double heterojunction structure with an amorphous n/i contact to the top surface and an i/p contact to the back surface to obtain an open circuit voltage (Voc) of 679 mV in a 0.9 cm2 cell with an independently confirmed efficiency of 19.1%. This is the best reported performance for a cell of this configuration. We also made progress on p-type CZ wafers and achieved 18.7% independently confirmed efficiency with little degradation under prolong illumination. Our best Voc for a p-type SHJ cell is 0.688 V, which is close to the 691 mV we achieved for SHJ cells on n type c-Si wafers.

  9. Nuclear envelope rupture and repair during cancer cell migration

    PubMed Central

    Denais, Celine M.; Gilbert, Rachel M.; Isermann, Philipp; McGregor, Alexandra L.; te Lindert, Mariska; Weigelin, Bettina; Davidson, Patricia M.; Friedl, Peter; Wolf, Katarina; Lammerding, Jan

    2016-01-01

    During cancer metastasis, tumor cells penetrate tissues through tight interstitial spaces, requiring extensive deformation of the cell and its nucleus. Here, we investigated tumor cell migration in confining microenvironments in vitro and in vivo. Nuclear deformation caused localized loss of nuclear envelope (NE) integrity, which led to the uncontrolled exchange of nucleo-cytoplasmic content, herniation of chromatin across the NE, and DNA damage. The incidence of NE rupture increased with cell confinement and with depletion of nuclear lamins, NE proteins that structurally support the nucleus. Cells restored NE integrity using components of the endosomal sorting complexes required for transport-III (ESCRT-III) machinery. Our findings indicate that cell migration incurs substantial physical stress on the NE and its content, requiring efficient NE and DNA damage repair for survival. PMID:27013428

  10. Cell fusion through a microslit between adhered cells and observation of their nuclear behavior.

    PubMed

    Wada, Ken-Ichi; Hosokawa, Kazuo; Kondo, Eitaro; Ito, Yoshihiro; Maeda, Mizuo

    2014-07-01

    This paper describes a novel cell fusion method which induces cell fusion between adhered cells through a microslit for preventing nuclear mixing. For this purpose, a microfluidic device which had ∼ 100 cell pairing structures (CPSs) making cell pairs through microslits with 2.1 ± 0.3 µm width was fabricated. After trapping NIH3T3 cells with hydrodynamic forces at the CPSs, the cells were fused through the microslit by the Sendai virus envelope method. With following timelapse observation, we discovered that the spread cells were much less susceptible to nuclear migration passing through the microslit compared with round cells, and that cytoplasmic fraction containing mitochondria was transferred through the microslit without nuclear mixing. These findings will provide an effective method for cell fusion without nuclear mixing, and will lead to an efficient method for reprograming and transdifferentiation of target cells toward regenerative medicine.

  11. Intermediate filaments promote nuclear mechanical constraints during somatic cell nuclear transfer in the mouse.

    PubMed

    Gall, Laurence; Brochard, Vincent; Ruffini, Sylvie; Laffont, Ludivine; Fleurot, Renaud; Lavin, Tiphaine Aguirre; Jouneau, Alice; Beaujean, Nathalie

    2012-12-01

    The somatic cell nuclear transfer (SCNT) procedure requires nuclear remodeling to return differentiated somatic nuclei to the totipotent undifferentiated stage. We hypothesize that mechanical constraints might occur upon SCNT and thereby affect nuclear remodeling. Therefore, we analyzed the nuclear structures upon SCNT using as donors either wild-type fibroblasts with a dense vimentin network or vimentin-deprived cells [embryonic stem cells (ESCs) and fibroblasts invalidated for vimetin]. We demonstrated that following nuclear transfer of wild-type fibroblasts, vimentin intermediate filaments (IFs) persisted around the transplanted nuclei and 88% of them presented severe distortions. We also showed that the presence of vimentin filaments in the reconstructed embryos was correlated with DNA damage, as evidenced by γH2A.X foci. On the other hand, when ESCs or vimentin-null (Vim(-/-)) fibroblasts devoid of IFs were used as nuclear donors, no nuclear distortion and less DNA damage were observed. Altogether we believe that the introduction of vimentin into recipient oocytes during SCNT induces a mechanical constraint on the transplanted nucleus that is responsible for nuclear distortions and DNA damage. This could lead to incomplete reprogramming that would be detrimental to further embryonic development.

  12. Differentiated cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer.

    PubMed

    Sung, Li-Ying; Gao, Shaorong; Shen, Hongmei; Yu, Hui; Song, Yifang; Smith, Sadie L; Chang, Ching-Chien; Inoue, Kimiko; Kuo, Lynn; Lian, Jin; Li, Ao; Tian, X Cindy; Tuck, David P; Weissman, Sherman M; Yang, Xiangzhong; Cheng, Tao

    2006-11-01

    Since the creation of Dolly via somatic cell nuclear transfer (SCNT), more than a dozen species of mammals have been cloned using this technology. One hypothesis for the limited success of cloning via SCNT (1%-5%) is that the clones are likely to be derived from adult stem cells. Support for this hypothesis comes from the findings that the reproductive cloning efficiency for embryonic stem cells is five to ten times higher than that for somatic cells as donors and that cloned pups cannot be produced directly from cloned embryos derived from differentiated B and T cells or neuronal cells. The question remains as to whether SCNT-derived animal clones can be derived from truly differentiated somatic cells. We tested this hypothesis with mouse hematopoietic cells at different differentiation stages: hematopoietic stem cells, progenitor cells and granulocytes. We found that cloning efficiency increases over the differentiation hierarchy, and terminally differentiated postmitotic granulocytes yield cloned pups with the greatest cloning efficiency.

  13. Nanotopographical Modulation of Cell Function through Nuclear Deformation

    PubMed Central

    Wang, Kai; Bruce, Allison; Mezan, Ryan; Kadiyala, Anand; Wang, Liying; Dawson, Jeremy; Rojanasakul, Yon; Yang, Yong

    2016-01-01

    Although nanotopography has been shown to be a potent modulator of cell behavior, it is unclear how the nanotopographical cue, through focal adhesions, affects the nucleus, eventually influencing cell phenotype and function. Thus, current methods to apply nanotopography to regulate cell behavior are basically empirical. We, herein, engineered nanotopographies of various shapes (gratings and pillars) and dimensions (feature size, spacing and height), and thoroughly investigated cell spreading, focal adhesion organization and nuclear deformation of human primary fibroblasts as the model cell grown on the nanotopographies. We examined the correlation between nuclear deformation and cell functions such as cell proliferation, transfection and extracellular matrix protein type I collagen production. It was found that the nanoscale gratings and pillars could facilitate focal adhesion elongation by providing anchoring sites, and the nanogratings could orient focal adhesions and nuclei along the nanograting direction, depending on not only the feature size but also the spacing of the nanogratings. Compared with continuous nanogratings, discrete nanopillars tended to disrupt the formation and growth of focal adhesions and thus had less profound effects on nuclear deformation. Notably, nuclear volume could be effectively modulated by the height of nanotopography. Further, we demonstrated that cell proliferation, transfection, and type I collagen production were strongly associated with the nuclear volume, indicating that the nucleus serves as a critical mechanosensor for cell regulation. Our study delineated the relationships between focal adhesions, nucleus and cell function and highlighted that the nanotopography could regulate cell phenotype and function by modulating nuclear deformation. This study provides insight into the rational design of nanotopography for new biomaterials and the cell–substrate interfaces of implants and medical devices. PMID:26844365

  14. Fascin Regulates Nuclear Movement and Deformation in Migrating Cells.

    PubMed

    Jayo, Asier; Malboubi, Majid; Antoku, Susumu; Chang, Wakam; Ortiz-Zapater, Elena; Groen, Christopher; Pfisterer, Karin; Tootle, Tina; Charras, Guillaume; Gundersen, Gregg G; Parsons, Maddy

    2016-08-22

    Fascin is an F-actin-bundling protein shown to stabilize filopodia and regulate adhesion dynamics in migrating cells, and its expression is correlated with poor prognosis and increased metastatic potential in a number of cancers. Here, we identified the nuclear envelope protein nesprin-2 as a binding partner for fascin in a range of cell types in vitro and in vivo. Nesprin-2 interacts with fascin through a direct, F-actin-independent interaction, and this binding is distinct and separable from a role for fascin within filopodia at the cell periphery. Moreover, disrupting the interaction between fascin and nesprin-2 C-terminal domain leads to specific defects in F-actin coupling to the nuclear envelope, nuclear movement, and the ability of cells to deform their nucleus to invade through confined spaces. Together, our results uncover a role for fascin that operates independently of filopodia assembly to promote efficient cell migration and invasion. PMID:27554857

  15. Hot-carrier solar cells using low-dimensional quantum structures

    SciTech Connect

    Watanabe, Daiki; Kasamatsu, Naofumi; Harada, Yukihiro; Kita, Takashi

    2014-10-27

    We propose a high-conversion-efficiency solar cell (SC) utilizing the hot carrier (HC) population in an intermediate-band (IB) of a quantum dot superlattice (QDSL) structure. The bandgap of the host semiconductor in this device plays an important role as an energy-selective barrier for HCs in the QDSLs. According to theoretical calculation using the detailed balance model with an air mass 1.5 spectrum, the optimum IB energy is determined by a trade-off relation between the number of HCs with energy exceeding the conduction-band edge and the number of photons absorbed by the valence band−IB transition. Utilizing experimental data of HC temperature in InAs/GaAs QDSLs, the maximum conversion efficiency under maximum concentration (45 900 suns) has been demonstrated to increase by 12.6% as compared with that for a single-junction GaAs SC.

  16. Experimental evidence of hot carriers solar cell operation in multi-quantum wells heterostructures

    SciTech Connect

    Rodière, Jean; Lombez, Laurent; Le Corre, Alain; Durand, Olivier; Guillemoles, Jean-François

    2015-05-04

    We investigated a semiconductor heterostructure based on InGaAsP multi quantum wells (QWs) using optical characterizations and demonstrate its potential to work as a hot carrier cell absorber. By analyzing photoluminescence spectra, the quasi Fermi level splitting Δμ and the carrier temperature are quantitatively measured as a function of the excitation power. Moreover, both thermodynamics values are measured at the QWs and the barrier emission energy. High values of Δμ are found for both transition, and high carrier temperature values in the QWs. Remarkably, the quasi Fermi level splitting measured at the barrier energy exceeds the absorption threshold of the QWs. This indicates a working condition beyond the classical Shockley-Queisser limit.

  17. A simple polymeric model describes cell nuclear mechanical response

    NASA Astrophysics Data System (ADS)

    Banigan, Edward; Stephens, Andrew; Marko, John

    The cell nucleus must continually resist inter- and intracellular mechanical forces, and proper mechanical response is essential to basic cell biological functions as diverse as migration, differentiation, and gene regulation. Experiments probing nuclear mechanics reveal that the nucleus stiffens under strain, leading to two characteristic regimes of force response. This behavior depends sensitively on the intermediate filament protein lamin A, which comprises the outer layer of the nucleus, and the properties of the chromatin interior. To understand these mechanics, we study a simulation model of a polymeric shell encapsulating a semiflexible polymer. This minimalistic model qualitatively captures the typical experimental nuclear force-extension relation and observed nuclear morphologies. Using a Flory-like theory, we explain the simulation results and mathematically estimate the force-extension relation. The model and experiments suggest that chromatin organization is a dominant contributor to nuclear mechanics, while the lamina protects cell nuclei from large deformations.

  18. The Mammalian Cell Cycle Regulates Parvovirus Nuclear Capsid Assembly

    PubMed Central

    Riolobos, Laura; Domínguez, Carlos; Kann, Michael; Almendral, José M.

    2015-01-01

    It is unknown whether the mammalian cell cycle could impact the assembly of viruses maturing in the nucleus. We addressed this question using MVM, a reference member of the icosahedral ssDNA nuclear parvoviruses, which requires cell proliferation to infect by mechanisms partly understood. Constitutively expressed MVM capsid subunits (VPs) accumulated in the cytoplasm of mouse and human fibroblasts synchronized at G0, G1, and G1/S transition. Upon arrest release, VPs translocated to the nucleus as cells entered S phase, at efficiencies relying on cell origin and arrest method, and immediately assembled into capsids. In synchronously infected cells, the consecutive virus life cycle steps (gene expression, proteins nuclear translocation, capsid assembly, genome replication and encapsidation) proceeded tightly coupled to cell cycle progression from G0/G1 through S into G2 phase. However, a DNA synthesis stress caused by thymidine irreversibly disrupted virus life cycle, as VPs became increasingly retained in the cytoplasm hours post-stress, forming empty capsids in mouse fibroblasts, thereby impairing encapsidation of the nuclear viral DNA replicative intermediates. Synchronously infected cells subjected to density-arrest signals while traversing early S phase also blocked VPs transport, resulting in a similar misplaced cytoplasmic capsid assembly in mouse fibroblasts. In contrast, thymidine and density arrest signals deregulating virus assembly neither perturbed nuclear translocation of the NS1 protein nor viral genome replication occurring under S/G2 cycle arrest. An underlying mechanism of cell cycle control was identified in the nuclear translocation of phosphorylated VPs trimeric assembly intermediates, which accessed a non-conserved route distinct from the importin α2/β1 and transportin pathways. The exquisite cell cycle-dependence of parvovirus nuclear capsid assembly conforms a novel paradigm of time and functional coupling between cellular and virus life

  19. Nuclear localization of Merkel cell polyomavirus large T antigen in Merkel cell carcinoma

    SciTech Connect

    Nakamura, Tomoyuki; Sato, Yuko; Watanabe, Daisuke; Ito, Hideki; Shimonohara, Nozomi; Tsuji, Takahiro; Nakajima, Noriko; Suzuki, Yoshio; Matsuo, Koma; Nakagawa, Hidemi; Sata, Tetsutaro; Katano, Harutaka

    2010-03-15

    To clarify whether mutations in the large T gene encoded by Merkel cell polyomavirus affect the expression and function of large T antigen in Merkel cell carcinoma cases, we investigated the expression of large T antigen in vitro and in vivo. Immunohistochemistry using a rabbit polyclonal antibody revealed that large T antigen was expressed in the nuclei of Merkel cell carcinoma cells with Merkel cell polyomavirus infection. Deletion mutant analyses identified an Arg-Lys-Arg-Lys sequence (amino acids 277-280) as a nuclear localization signal in large T antigen. Sequence analyses revealed that there were no mutations in the nuclear localization signal in any of the eleven Merkel cell polyomavirus strains examined. Furthermore, stop codons were not observed in the upstream of the nuclear localization signal in any of the Merkel cell carcinoma cases examined. These data suggest that the nuclear localization signal is highly conserved and functional in Merkel cell carcinoma cases.

  20. Epitaxial Thin Film Silicon Solar Cells Fabricated by Hot Wire Chemical Vapor Deposition Below 750 ..deg..C: Preprint

    SciTech Connect

    Alberi, K.; Martin, I. T.; Shub, M.; Teplin, C. W.; Iwaniczko, E.; Xu, Y.; duda, A.; Stradin, P.; Johnston, S. W.; Romero, M. J.; Branz, H. M.; Young, D. L.

    2009-06-01

    We report on fabricating film c-Si solar cells on Si wafer templates by hot-wire chemical vapor deposition. These devices, grown at glass-compatible temperatures < 750..deg..C, demonstrate open-circuit voltages > 500 mV and efficiencies > 5%.

  1. Hot nuclear matter

    SciTech Connect

    Chapman, S.

    1992-11-01

    The goal in this thesis is thus twofold: The first is to investigate the feasibility of using heavy ion collisions to create conditions in the laboratory which are ripe for the formation of a quark-gluon plasma. The second is to develop a technique for studying some of the many non-perturbative features of this novel phase of matter.

  2. Cloning animals by somatic cell nuclear transfer--biological factors.

    PubMed

    Tian, X Cindy; Kubota, Chikara; Enright, Brian; Yang, Xiangzhong

    2003-11-13

    Cloning by nuclear transfer using mammalian somatic cells has enormous potential application. However, somatic cloning has been inefficient in all species in which live clones have been produced. High abortion and fetal mortality rates are commonly observed. These developmental defects have been attributed to incomplete reprogramming of the somatic nuclei by the cloning process. Various strategies have been used to improve the efficiency of nuclear transfer, however, significant breakthroughs are yet to happen. In this review we will discuss studies conducted, in our laboratories and those of others, to gain a better understanding of nuclear reprogramming. Because cattle are a species widely used for nuclear transfer studies, and more laboratories have succeeded in cloning cattle than any other species, this review will be focused on somatic cell cloning of cattle.

  3. PARP activation promotes nuclear AID accumulation in lymphoma cells.

    PubMed

    Tepper, Sandra; Jeschke, Julia; Böttcher, Katrin; Schmidt, Angelika; Davari, Kathrin; Müller, Peter; Kremmer, Elisabeth; Hemmerich, Peter; Pfeil, Ines; Jungnickel, Berit

    2016-03-15

    Activation-induced cytidine deaminase (AID) initiates immunoglobulin diversification in germinal center B cells by targeted introduction of DNA damage. As aberrant nuclear AID action contributes to the generation of B cell lymphoma, the protein's activity is tightly regulated, e.g. by nuclear/cytoplasmic shuttling and nuclear degradation. In the present study, we asked whether DNA damage may affect regulation of the AID protein. We show that exogenous DNA damage that mainly activates base excision repair leads to prevention of proteasomal degradation of AID and hence its nuclear accumulation. Inhibitor as well as knockout studies indicate that activation of poly (ADP-ribose) polymerase (PARP) by DNA damaging agents promotes both phenomena. These findings suggest that PARP inhibitors influence DNA damage dependent AID regulation, with interesting implications for the regulation of AID function and chemotherapy of lymphoma.

  4. PARP activation promotes nuclear AID accumulation in lymphoma cells

    PubMed Central

    Böttcher, Katrin; Schmidt, Angelika; Davari, Kathrin; Müller, Peter; Kremmer, Elisabeth; Hemmerich, Peter; Pfeil, Ines; Jungnickel, Berit

    2016-01-01

    Activation-induced cytidine deaminase (AID) initiates immunoglobulin diversification in germinal center B cells by targeted introduction of DNA damage. As aberrant nuclear AID action contributes to the generation of B cell lymphoma, the protein's activity is tightly regulated, e.g. by nuclear/cytoplasmic shuttling and nuclear degradation. In the present study, we asked whether DNA damage may affect regulation of the AID protein. We show that exogenous DNA damage that mainly activates base excision repair leads to prevention of proteasomal degradation of AID and hence its nuclear accumulation. Inhibitor as well as knockout studies indicate that activation of poly (ADP-ribose) polymerase (PARP) by DNA damaging agents promotes both phenomena. These findings suggest that PARP inhibitors influence DNA damage dependent AID regulation, with interesting implications for the regulation of AID function and chemotherapy of lymphoma. PMID:26921193

  5. Nuclear microscopy of sperm cell elemental structure

    NASA Astrophysics Data System (ADS)

    Bench, Graham S.; Balhorn, Rod; Friz, Alexander M.

    1995-05-01

    Theories suggest there is a link between protamine concentrations in individual sperm and male fertility. Previously, biochemical analyses have used pooled samples containing millions of sperm to determine protamine concentrations. These methods have not been able to determine what percentage of morphologically normal sperm are biochemically defective and potentially infertile. Nuclear microscopy has been utilized to measure elemental profiles at the single sperm level. By measuring the amount of phosphorus and sulfur, the total DNA and protamine content in individual sperm from fertile bull and mouse semen have been determined. These values agree with results obtained from other biochemical analyses. Nuclear microscopy shows promise for measuring elemental profiles in the chromatin of individual sperm. The technique may be able to resolve theories regarding the importance of protamines to male fertility and identify biochemical defects responsible for certain types of male infertility.

  6. Nuclear microscopy of sperm cell elemental structure

    SciTech Connect

    Bench, G.S.; Balhorn, R.; Friz, A.M.; Freeman, S.P.H.T.

    1994-09-28

    Theories suggest there is a link between protamine concentrations in individual sperm and male fertility. Previously, biochemical analyses have used pooled samples containing millions of sperm to determine protamine concentrations. These methods have not been able to determine what percentage of morphologically normal sperm are biochemically defective and potentially infertile. Nuclear microscopy has been utilized to measure elemental profiles at the single sperm level. By measuring the amount of phosphorus and sulfur, the total DNA and protamine content in individual sperm from fertile bull and mouse semen have been determined. These values agree with results obtained from other biochemical analyses. Nuclear microscopy shows promise for measuring elemental profiles in the chromatin of individual sperm. The technique may be able to resolve theories regarding the importance of protamines to male fertility and identify biochemical defects responsible for certain types of male infertility.

  7. Very thin and stable thin-film silicon alloy triple junction solar cells by hot wire chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Veldhuizen, L. W.; Schropp, R. E. I.

    2016-08-01

    We present a silicon-based triple junction solar cell that requires a deposition time of less than 15 min for all photoactive layers. As a low-bandgap material, we used thin layers of hydrogenated amorphous silicon germanium with lower band gap than commonly used, which is possible due to the application of hot wire chemical vapor deposition. The triple junction cell shows an initial energy conversion efficiency exceeding 10%, and with a relative performance stability within 6%, the cell shows a high tolerance to light-induced degradation. With these results, we help to demonstrate that hot wire chemical vapor deposition is a viable deposition method for the fabrication of low-cost solar cells.

  8. Nuclear distribution of claudin-2 increases cell proliferation in human lung adenocarcinoma cells.

    PubMed

    Ikari, Akira; Watanabe, Ryo; Sato, Tomonari; Taga, Saeko; Shimobaba, Shun; Yamaguchi, Masahiko; Yamazaki, Yasuhiro; Endo, Satoshi; Matsunaga, Toshiyuki; Sugatani, Junko

    2014-09-01

    Claudin-2 is expressed in human lung adenocarcinoma tissue and cell lines, although it is absent in normal lung tissue. However, the role of claudin-2 in cell proliferation and the regulatory mechanism of intracellular distribution remain undefined. Proliferation of human adenocarcinoma A549 cells was decreased by claudin-2 knockdown together with a decrease in the percentage of S phase cells. This knockdown decreased the expression levels of ZONAB and cell cycle regulators. Claudin-2 was distributed in the nucleus in human adenocarcinoma tissues and proliferating A549 cells. The nuclear distribution of ZONAB and percentage of S phase cells were higher in cells exogenously expressing claudin-2 with a nuclear localization signal than in cells expressing claudin-2 with a nuclear export signal. Nuclear claudin-2 formed a complex with ZO-1, ZONAB, and cyclin D1. Nuclear distribution of S208A mutant, a dephosphorylated form of claudin-2, was higher than that of wild type. We suggest that nuclear distribution of claudin-2 is up-regulated by dephosphorylation and claudin-2 serves to retain ZONAB and cyclin D1 in the nucleus, resulting in the enhancement of cell proliferation in lung adenocarcinoma cells.

  9. Nuclear stiffening inhibits migration of invasive melanoma cells

    PubMed Central

    Ribeiro, Alexandre J.S.; Khanna, Payal; Sukumar, Aishwarya; Dong, Cheng; Dahl, Kris Noel

    2014-01-01

    During metastasis, melanoma cells must be sufficiently deformable to squeeze through extracellular barriers with small pore sizes. We visualize and quantify deformability of single cells using micropipette aspiration and examine the migration potential of a population of melanoma cells using a flow migration apparatus. We artificially stiffen the nucleus with recombinant overexpression of Δ50 lamin A, which is found in patients with Hutchison Gilford progeria syndrome and in aged individuals. Melanoma cells, both WM35 and Lu1205, both show reduced nuclear deformability and reduced cell invasion with the expression of Δ50 lamin A. These studies suggest that cellular aging including expression of Δ50 lamin A and nuclear stiffening may reduce the potential for metastatic cancer migration. Thus, the pathway of cancer metastasis may be kept in check by mechanical factors in addition to known chemical pathway regulation. PMID:25544862

  10. Analyzing Cell Death by Nuclear Staining with Hoechst 33342.

    PubMed

    Crowley, Lisa C; Marfell, Brooke J; Waterhouse, Nigel J

    2016-01-01

    The nuclei of healthy cells are generally spherical, and the DNA is evenly distributed. During apoptosis the DNA becomes condensed, but this process does not occur during necrosis. Nuclear condensation can therefore be used to distinguish apoptotic cells from healthy cells or necrotic cells. Dyes that bind to DNA, such as Hoechst 33342 or 4',6-diamidino-2-phenylindole (DAPI), can be used to observe nuclear condensation. These dyes fluoresce at 461 nm when excited by ultraviolet light and can therefore be visualized using conventional fluorescent microscopes equipped with light sources that emit light at ∼350 nm and filter sets that permit the transmission of light at ∼460 nm. This protocol describes staining and visualization of cells stained with Hoechst 33342, but it can be adapted for staining with DAPI or other dyes. PMID:27587774

  11. Method and apparatus for fabricating a thin-film solar cell utilizing a hot wire chemical vapor deposition technique

    DOEpatents

    Wang, Qi; Iwaniczko, Eugene

    2006-10-17

    A thin-film solar cell is provided. The thin-film solar cell comprises an a-SiGe:H (1.6 eV) n-i-p solar cell having a deposition rate of at least ten (10) .ANG./second for the a-SiGe:H intrinsic layer by hot wire chemical vapor deposition. A method for fabricating a thin film solar cell is also provided. The method comprises depositing a n-i-p layer at a deposition rate of at least ten (10) .ANG./second for the a-SiGe:H intrinsic layer.

  12. Nuclear tristetraprolin acts as a corepressor of multiple steroid nuclear receptors in breast cancer cells.

    PubMed

    Barrios-García, Tonatiuh; Gómez-Romero, Vania; Tecalco-Cruz, Ángeles; Valadéz-Graham, Viviana; León-Del-Río, Alfonso

    2016-06-01

    Tristetraprolin (TTP) is a 34-kDa, zinc finger-containing factor that in mammalian cells acts as a tumor suppressor protein through two different mechanisms. In the cytoplasm TTP promotes the decay of hundreds of mRNAs encoding cell factors involved in inflammation, tissue invasion, and metastasis. In the cell nucleus TTP has been identified as a transcriptional corepressor of the estrogen receptor alpha (ERα), which has been associated to the development and progression of the majority of breast cancer tumors. In this work we report that nuclear TTP modulates the transactivation activity of progesterone receptor (PR), glucocorticoid receptor (GR) and androgen receptor (AR). In recent years these steroid nuclear receptors have been shown to be of clinical and therapeutical relevance in breast cancer. The functional association between TTP and steroid nuclear receptors is supported by the finding that TTP physically interacts with ERα, PR, GR and AR in vivo. We also show that TTP overexpression attenuates the transactivation of all the steroid nuclear receptors tested. In contrast, siRNA-mediated reduction of endogenous TTP expression in MCF-7 cells produced an increase in the transcriptional activities of ERα, PR, GR and AR. Taken together, these results suggest that the function of nuclear TTP in breast cancer cells is to act as a corepressor of ERα, PR, GR and AR. We propose that the reduction of TTP expression observed in different types of breast cancer tumors may contribute to the development of this disease by producing a dysregulation of the transactivation activity of multiple steroid nuclear receptors. PMID:27114912

  13. Nuclear tristetraprolin acts as a corepressor of multiple steroid nuclear receptors in breast cancer cells.

    PubMed

    Barrios-García, Tonatiuh; Gómez-Romero, Vania; Tecalco-Cruz, Ángeles; Valadéz-Graham, Viviana; León-Del-Río, Alfonso

    2016-06-01

    Tristetraprolin (TTP) is a 34-kDa, zinc finger-containing factor that in mammalian cells acts as a tumor suppressor protein through two different mechanisms. In the cytoplasm TTP promotes the decay of hundreds of mRNAs encoding cell factors involved in inflammation, tissue invasion, and metastasis. In the cell nucleus TTP has been identified as a transcriptional corepressor of the estrogen receptor alpha (ERα), which has been associated to the development and progression of the majority of breast cancer tumors. In this work we report that nuclear TTP modulates the transactivation activity of progesterone receptor (PR), glucocorticoid receptor (GR) and androgen receptor (AR). In recent years these steroid nuclear receptors have been shown to be of clinical and therapeutical relevance in breast cancer. The functional association between TTP and steroid nuclear receptors is supported by the finding that TTP physically interacts with ERα, PR, GR and AR in vivo. We also show that TTP overexpression attenuates the transactivation of all the steroid nuclear receptors tested. In contrast, siRNA-mediated reduction of endogenous TTP expression in MCF-7 cells produced an increase in the transcriptional activities of ERα, PR, GR and AR. Taken together, these results suggest that the function of nuclear TTP in breast cancer cells is to act as a corepressor of ERα, PR, GR and AR. We propose that the reduction of TTP expression observed in different types of breast cancer tumors may contribute to the development of this disease by producing a dysregulation of the transactivation activity of multiple steroid nuclear receptors.

  14. Robust nuclear lamina-based cell classification of aging and senescent cells

    PubMed Central

    Righolt, Christiaan H.; van 't Hoff, Merel L.R.; Vermolen, Bart J.; Young, Ian T.; Raz, Vered

    2011-01-01

    Changes in the shape of the nuclear lamina are exhibited in senescent cells, as well as in cells expressing mutations in lamina genes. To identify cells with defects in the nuclear lamina we developed an imaging method that quantifies the intensity and curvature of the nuclear lamina. We show that this method accurately describes changes in the nuclear lamina. Spatial changes in nuclear lamina coincide with redistribution of lamin A proteins and local reduction in protein mobility in senescent cell. We suggest that local accumulation of lamin A in the nuclear envelope leads to bending of the structure. A quantitative distinction of the nuclear lamina shape in cell populations was found between fresh and senescent cells, and between primary myoblasts from young and old donors. Moreover, with this method mutations in lamina genes were significantly distinct from cells with wild-type genes. We suggest that this method can be applied to identify abnormal cells during aging, in in vitro propagation, and in lamina disorders. PMID:22199022

  15. Cell fusion to study nuclear-cytoplasmic interactions in endothelial cell apoptosis.

    PubMed Central

    Polunovsky, V. A.; Ingbar, D. H.; Peterson, M.; Bitterman, P. B.

    1996-01-01

    Studies examining the regulation of nuclear rearrangements during apoptosis have led to conflicting results. Cytoplasmic control of nuclear events has been strongly suggested by cell-free experimental systems. In contrast, strict cytoplasmic control cannot account for the results of fibroblast-thymocyte fusion experiments in which dexamethasone induction of polykaryons led only to thymocyte nuclear apoptosis. Unresolved by these fusion studies was whether fibroblast nuclei were indifferent to heterologous cytoplasmic signals. Our objective was to resolve this discrepancy using cell fusion in a homologous system. Our strategy was to fuse endothelial cells with high levels of susceptibility to the induction of apoptosis (log phase cells arrested in G1 for 48 hours by isoleucine deprivation) with those manifesting low levels of susceptibility (serum-deprived, G0). Resultant fused and unfused cells were induced to undergo apoptosis by incubation with tumor necrosis factor-alpha and cycloheximide. Depending on the parental cell of origin, between 14 and 30% of dikaryons contained one apoptotic and one intact nucleus, indicating that strict cytoplasmic control was not occurring. In accord with this, the total frequency of nuclear apoptosis was unchanged after fusion. However, the distribution of apoptotic nuclei revealed a pronounced cytoplasmic influence, with a two- to fivefold increase in coordinate nuclear behavior. This pattern of nuclear apoptosis was consistent with a model of control in which both the state of nuclear susceptibility to apoptosis and expression of cytoplasmic pro-apoptotic regulators determined whether nuclear apoptosis would eventuate. Images Figure 3 Figure 4 PMID:8686735

  16. Hot Cell Liners Category of Transuranic Waste Stored Below Ground within Area G

    SciTech Connect

    Jones, Robert Wesley; Hargis, Kenneth Marshall

    2014-09-01

    A large wildfire called the Las Conchas Fire burned large areas near Los Alamos National Laboratory (LANL) in 2011 and heightened public concern and news media attention over transuranic (TRU) waste stored at LANL’s Technical Area 54 (TA-54) Area G waste management facility. The removal of TRU waste from Area G had been placed at a lower priority in budget decisions for environmental cleanup at LANL because TRU waste removal is not included in the March 2005 Compliance Order on Consent (Reference 1) that is the primary regulatory driver for environmental cleanup at LANL. The Consent Order is an agreement between LANL and the New Mexico Environment Department (NMED) that contains specific requirements and schedules for cleaning up historical contamination at the LANL site. After the Las Conchas Fire, discussions were held by the U.S. Department of Energy (DOE) with the NMED on accelerating TRU waste removal from LANL and disposing it at the Waste Isolation Pilot Plant (WIPP). This report summarizes available information on the origin, configuration, and composition of the waste containers within the Hot Cell Liners category; their physical and radiological characteristics; the results of the radioassays; and the justification to reclassify the five containers as LLW rather than TRU waste.

  17. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    SciTech Connect

    Takeda, Yasuhiko Sugimoto, Noriaki; Ichiki, Akihisa; Kusano, Yuya; Motohiro, Tomoyoshi

    2015-09-28

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs.

  18. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    NASA Astrophysics Data System (ADS)

    Takeda, Yasuhiko; Ichiki, Akihisa; Kusano, Yuya; Sugimoto, Noriaki; Motohiro, Tomoyoshi

    2015-09-01

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs.

  19. Hot-gas cleanup for molten carbonate fuel cells-dechlorination and soot formation

    NASA Astrophysics Data System (ADS)

    Ham, D.; Gelb, A.; Lord, G.; Simons, G.

    1984-01-01

    Two separate aspects of hot-gas conditioning for molten carbonate fuel cells (MCFC) were investigated: potential high temperature chloride sorbent materials were screened and tested and carbon deposition on MCFC components was studied experimentally to determine guidelines for maximizing MCFC efficiency while avoiding carbon fouling. Natural minerals containing sodium carbonate were identified as the most promising candidates for economical removal of chlorides from coal gasifier effluents at temperatures of about 800 K (980 F). The mineral Shortite was tested in a fixed bed and found to perform remarkably well with no calcination. Measurements showed that carbon deposition can occur in the equilibrium carbon free region because of the relative rates of the relevant reactions. On all surfaces tested, the Boudouard carbon formation reaction is much faster than the water-gas shift reaction which is much faster than the methanation reaction. This means that the normal practice of adding steam to prevent carbon formation will only succeed if flows are slow enough for the water shift reaction to go substantially to completion. More direct suppression of carbon formation can be achieved by CO2 addition through anode recycle to force the Boudouard reaction backward.

  20. Development of remote crane system for use inside small argon hot-cell

    SciTech Connect

    Lee, Jong Kwang; Park, Byung Suk; Yu, Seung-Nam; Kim, Kiho; Cho, Ilje

    2013-07-01

    In this paper, we describe the design of a novel crane system for the use in a small argon hot-cell where only a pair of master-slave manipulators (MSM) is available for the remote maintenance of the crane. To increase the remote maintainability in the space-limited environment, we devised a remote actuation mechanism in which electrical parts consisting of a servo-motor, a position sensor, and two limit switches located inside the workspace of the MSM transmit power to the mechanical parts located in the ceiling. Even though the design concept does not provide thoroughly sufficient solution because the mechanical parts are placed out of the MSM's workspace, the durability of mechanical parts can be easily increased if they have a high safety margin. Therefore, the concept may be one of the best solutions for our special crane system. In addition, we developed a servo-control system based on absolute positioning technology; therefore, it is possible for us to perform the given tasks more safely through an automatic operation. (authors)

  1. Murine somatic cell nuclear transfer using reprogrammed donor cells expressing male germ cell-specific genes.

    PubMed

    Kang, Hoin; Park, Jong Im; Roh, Sangho

    2016-01-01

    In vivo-matured mouse oocytes were enucleated, and a single murine embryonic fibroblast (control or reprogrammed by introducing extracts from murine testis tissue, which showed expression of male germ cell-specific genes) was injected into the cytoplasm of the oocytes. The rate of blastocyst development and expression levels of Oct-4, Eomes and Cdx-2 were not significantly different in both experimental groups. However, the expression levels of Nanog, Sox9 and Glut-1 were significantly increased when reprogrammed cells were used as donor nuclei. Increased expression of Nanog can be supportive of complete reprogramming of somatic cell nuclear transfer murine embryos. The present study suggested that donor cells expressing male germ cell-specific genes can be reconstructed and can develop into embryos with normal high expression of developmentally essential genes. PMID:26369430

  2. Exosomes surf on filopodia to enter cells at endocytic hot spots, traffic within endosomes, and are targeted to the ER.

    PubMed

    Heusermann, Wolf; Hean, Justin; Trojer, Dominic; Steib, Emmanuelle; von Bueren, Stefan; Graff-Meyer, Alexandra; Genoud, Christel; Martin, Katrin; Pizzato, Nicolas; Voshol, Johannes; Morrissey, David V; Andaloussi, Samir E L; Wood, Matthew J; Meisner-Kober, Nicole C

    2016-04-25

    Exosomes are nanovesicles released by virtually all cells, which act as intercellular messengers by transfer of protein, lipid, and RNA cargo. Their quantitative efficiency, routes of cell uptake, and subcellular fate within recipient cells remain elusive. We quantitatively characterize exosome cell uptake, which saturates with dose and time and reaches near 100% transduction efficiency at picomolar concentrations. Highly reminiscent of pathogenic bacteria and viruses, exosomes are recruited as single vesicles to the cell body by surfing on filopodia as well as filopodia grabbing and pulling motions to reach endocytic hot spots at the filopodial base. After internalization, exosomes shuttle within endocytic vesicles to scan the endoplasmic reticulum before being sorted into the lysosome as their final intracellular destination. Our data quantify and explain the efficiency of exosome internalization by recipient cells, establish a new parallel between exosome and virus host cell interaction, and suggest unanticipated routes of subcellular cargo delivery. PMID:27114500

  3. Exosomes surf on filopodia to enter cells at endocytic hot spots, traffic within endosomes, and are targeted to the ER

    PubMed Central

    Hean, Justin; Trojer, Dominic; Steib, Emmanuelle; von Bueren, Stefan; Graff-Meyer, Alexandra; Genoud, Christel; Martin, Katrin; Pizzato, Nicolas; Voshol, Johannes; Morrissey, David V.; Andaloussi, Samir E.L.; Wood, Matthew J.

    2016-01-01

    Exosomes are nanovesicles released by virtually all cells, which act as intercellular messengers by transfer of protein, lipid, and RNA cargo. Their quantitative efficiency, routes of cell uptake, and subcellular fate within recipient cells remain elusive. We quantitatively characterize exosome cell uptake, which saturates with dose and time and reaches near 100% transduction efficiency at picomolar concentrations. Highly reminiscent of pathogenic bacteria and viruses, exosomes are recruited as single vesicles to the cell body by surfing on filopodia as well as filopodia grabbing and pulling motions to reach endocytic hot spots at the filopodial base. After internalization, exosomes shuttle within endocytic vesicles to scan the endoplasmic reticulum before being sorted into the lysosome as their final intracellular destination. Our data quantify and explain the efficiency of exosome internalization by recipient cells, establish a new parallel between exosome and virus host cell interaction, and suggest unanticipated routes of subcellular cargo delivery. PMID:27114500

  4. Somatic cell nuclear transfer in mammals: progress and applications.

    PubMed

    Colman, A

    Somatic nuclear transfer has been performed with frogs since the early 1960s, yet it has proved impossible to generate an adult frog using an adult cell as nuclear donor. After some initial skepticism, the birth of sheep, cows, goats, and mice using this technique with fetal or adult cell donors is now established fact. The success with adult mammalian cell donors extends the historic work in frogs by attesting to the totipotency of nuclei in at least some adult, differentiated cell types. Because the technique offers a developmental read out of the totality of genetic and molecular lifetime changes accumulated by the nucleus of a single somatic cell, basic research applications are seen in the fields of ageing, cancer, X chromosome inactivation, and imprinting. The prospect of a method for gene targeting in livestock holds particular promise for commercial applications; whilst for humans, the use of nuclear transfer to provide diverse populations of customized stem cells for therapeutic purposes presents a tantalizing future goal.

  5. Cell-fusion method to visualize interphase nuclear pore formation.

    PubMed

    Maeshima, Kazuhiro; Funakoshi, Tomoko; Imamoto, Naoko

    2014-01-01

    In eukaryotic cells, the nucleus is a complex and sophisticated organelle that organizes genomic DNA to support essential cellular functions. The nuclear surface contains many nuclear pore complexes (NPCs), channels for macromolecular transport between the cytoplasm and nucleus. It is well known that the number of NPCs almost doubles during interphase in cycling cells. However, the mechanism of NPC formation is poorly understood, presumably because a practical system for analysis does not exist. The most difficult obstacle in the visualization of interphase NPC formation is that NPCs already exist after nuclear envelope formation, and these existing NPCs interfere with the observation of nascent NPCs. To overcome this obstacle, we developed a novel system using the cell-fusion technique (heterokaryon method), previously also used to analyze the shuttling of macromolecules between the cytoplasm and the nucleus, to visualize the newly synthesized interphase NPCs. In addition, we used a photobleaching approach that validated the cell-fusion method. We recently used these methods to demonstrate the role of cyclin-dependent protein kinases and of Pom121 in interphase NPC formation in cycling human cells. Here, we describe the details of the cell-fusion approach and compare the system with other NPC formation visualization methods.

  6. Somatic cell nuclear transfer: pros and cons.

    PubMed

    Sumer, Huseyin; Liu, Jun; Tat, Pollyanna; Heffernan, Corey; Jones, Karen L; Verma, Paul J

    2009-01-01

    Even though the technique of mammalian SCNT is just over a decade old it has already resulted in numerous significant advances. Despite the recent advances in the reprogramming field, SCNT remains the bench-mark for the generation of both genetically unmodified autologous pluripotent stem cells for transplantation and for the production of cloned animals. In this review we will discuss the pros and cons of SCNT, drawing comparisons with other reprogramming methods. PMID:20232594

  7. Somatic cell nuclear transfer: pros and cons.

    PubMed

    Sumer, Huseyin; Liu, Jun; Tat, Pollyanna; Heffernan, Corey; Jones, Karen L; Verma, Paul J

    2009-01-01

    Even though the technique of mammalian SCNT is just over a decade old it has already resulted in numerous significant advances. Despite the recent advances in the reprogramming field, SCNT remains the bench-mark for the generation of both genetically unmodified autologous pluripotent stem cells for transplantation and for the production of cloned animals. In this review we will discuss the pros and cons of SCNT, drawing comparisons with other reprogramming methods.

  8. Preliminary development of thermal nuclear cell homogenization code

    NASA Astrophysics Data System (ADS)

    Su'ud, Z.; Shafii, M. A.; Yudha, S. P.; Waris, A.; Rijal, K.

    2012-06-01

    Nuclear fuel cell homogenization for thermal reactors usually include three main parts, i.e., fast energy resonance part which usually adopt narrow resonance approximation to treat the resonance, low (intermediate) energy region in which the resonance can not be treated accurately using NR approximation and therefore we should use intermediate resonance treatment, and thermal energy region (very low) in which the effect of thermal must be treated properly. In n this study the application of the intermediate resonance approximation treatment for low energy nuclear resonance is discussed. The method is iterative based. As a sample the method is applied in U-235 low lying resonance and the result is presented and discussed.

  9. Variational Theory of Hot Dense Matter

    ERIC Educational Resources Information Center

    Mukherjee, Abhishek

    2009-01-01

    We develop a variational theory of hot nuclear matter in neutron stars and supernovae. It can also be used to study charged, hot nuclear matter which may be produced in heavy-ion collisions. This theory is a generalization of the variational theory of cold nuclear and neutron star matter based on realistic models of nuclear forces and pair…

  10. Rabbit embryonic stem cell lines derived from fertilized, parthenogenetic or somatic cell nuclear transfer embryos

    SciTech Connect

    Fang, Zhen F.; Gai, Hui; Huang, You Z.; Li, Shan G.; Chen, Xue J.; Shi, Jian J.; Wu, Li; Liu, Ailian; Xu, Ping; Sheng, Hui Z. . E-mail: hzsheng2003@yahoo.com

    2006-11-01

    Embryonic stem cells were isolated from rabbit blastocysts derived from fertilization (conventional rbES cells), parthenogenesis (pES cells) and nuclear transfer (ntES cells), and propagated in a serum-free culture system. Rabbit ES (rbES) cells proliferated for a prolonged time in an undifferentiated state and maintained a normal karyotype. These cells grew in a monolayer with a high nuclear/cytoplasm ratio and contained a high level of alkaline phosphate activity. In addition, rbES cells expressed the pluripotent marker Oct-4, as well as EBAF2, FGF4, TDGF1, but not antigens recognized by antibodies against SSEA-1, SSEA-3, SSEA-4, TRA-1-10 and TRA-1-81. All 3 types of ES cells formed embryoid bodies and generated teratoma that contained tissue types of all three germ layers. rbES cells exhibited a high cloning efficiency, were genetically modified readily and were used as nuclear donors to generate a viable rabbit through somatic cell nuclear transfer. In combination with genetic engineering, the ES cell technology should facilitate the creation of new rabbit lines.

  11. A combined gas cooled nuclear reactor and fuel cell cycle

    NASA Astrophysics Data System (ADS)

    Palmer, David J.

    Rising oil costs, global warming, national security concerns, economic concerns and escalating energy demands are forcing the engineering communities to explore methods to address these concerns. It is the intention of this thesis to offer a proposal for a novel design of a combined cycle, an advanced nuclear helium reactor/solid oxide fuel cell (SOFC) plant that will help to mitigate some of the above concerns. Moreover, the adoption of this proposal may help to reinvigorate the Nuclear Power industry while providing a practical method to foster the development of a hydrogen economy. Specifically, this thesis concentrates on the importance of the U.S. Nuclear Navy adopting this novel design for its nuclear electric vessels of the future with discussion on efficiency and thermodynamic performance characteristics related to the combined cycle. Thus, the goals and objectives are to develop an innovative combined cycle that provides a solution to the stated concerns and show that it provides superior performance. In order to show performance, it is necessary to develop a rigorous thermodynamic model and computer program to analyze the SOFC in relation with the overall cycle. A large increase in efficiency over the conventional pressurized water reactor cycle is realized. Both sides of the cycle achieve higher efficiencies at partial loads which is extremely important as most naval vessels operate at partial loads as well as the fact that traditional gas turbines operating alone have poor performance at reduced speeds. Furthermore, each side of the cycle provides important benefits to the other side. The high temperature exhaust from the overall exothermic reaction of the fuel cell provides heat for the reheater allowing for an overall increase in power on the nuclear side of the cycle. Likewise, the high temperature helium exiting the nuclear reactor provides a controllable method to stabilize the fuel cell at an optimal temperature band even during transients helping

  12. Somatic cell nuclear transfer in horses.

    PubMed

    Galli, Cesare; Lagutina, Irina; Duchi, Roberto; Colleoni, Silvia; Lazzari, Giovanna

    2008-07-01

    The cloning of equids was achieved in 2003, several years after the birth of Dolly the sheep and also after the cloning of numerous other laboratory and farm animal species. The delay was because of the limited development in the horse of more classical-assisted reproductive techniques required for successful cloning, such as oocyte maturation and in vitro embryo production. When these technologies were developed, the application of cloning also became possible and cloned horse offspring were obtained. This review summarizes the main technical procedures that are required for cloning equids and the present status of this technique. The first step is competent oocyte maturation, this is followed by oocyte enucleation and reconstruction, using either zona-enclosed or zona-free oocytes, by efficient activation to allow high cleavage rates and finally by a suitable in vitro embryo culture technique. Cloning of the first equid, a mule, was achieved using an in vivo-matured oocytes and immediate transfer of the reconstructed embryo, i.e. at the one cell stage, to the recipient oviduct. In contrast, the first horse offspring was obtained using a complete in vitro procedure from oocyte maturation to embryo culture to the blastocyst stage, followed by non-surgical transfer. Later studies on equine cloning report high efficiency relative to that for other species. Cloned equid offspring reported to date appear to be normal and those that have reached puberty have been confirmed to be fertile. In summary, horse cloning is now a reproducible technique that offers the opportunity to preserve valuable genetics and notably to generate copies of castrated champions and therefore, offspring from those champions that would be impossible to obtain otherwise. PMID:18638143

  13. Recent advancements in cloning by somatic cell nuclear transfer

    PubMed Central

    Ogura, Atsuo; Inoue, Kimiko; Wakayama, Teruhiko

    2013-01-01

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

  14. Cloning of ES cells and mice by nuclear transfer.

    PubMed

    Wakayama, Sayaka; Kishigami, Satoshi; Wakayama, Teruhiko

    2009-01-01

    We have been able to develop a stable nuclear transfer (NT) method in the mouse, in which donor nuclei are directly injected into the oocyte using a piezo-actuated micromanipulator. Although the piezo unit is a complex tool, once mastered it is of great help not only in NT experiments, but also in almost all other forms of micromanipulation. Using this technique, embryonic stem (ntES) cell lines established from somatic cell nuclei can be generated relatively easily from a variety of mouse genotypes and cell types. Such ntES cells can be used not only for experimental models of human therapeutic cloning but also as a means of preserving mouse genomes instead of preserving germ cells. Here, we describe our most recent protocols for mouse cloning.

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

    PubMed

    Ogura, Atsuo; Inoue, Kimiko; Wakayama, Teruhiko

    2013-01-01

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

  16. Nuclear envelope and genome interactions in cell fate

    PubMed Central

    Talamas, Jessica A.; Capelson, Maya

    2015-01-01

    The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate. PMID:25852741

  17. Hot gas cleanup for molten carbonate fuel cells. A zinc oxide reactor model, Final report

    SciTech Connect

    Steinfeld, G.

    1980-09-16

    Utilization of coal gasifiers to power MCFC requires a cleanup system to remove sulfur and particulates. Of the two near term options available for desulfurization of gasifier effluent, namely low temperature cleanup utilizing absorber/stripper technology, and hot gas cleanup utilizing metal oxides, there is a clear advantage to using hot gas cleanup. Since the MCFC will operate at 1200/sup 0/F, and the gasifier effluent could be between 1200 to 1900/sup 0/F, a hot gas cleanup system will require little or no change in process gas temperature, thereby contributing to a high overall system efficiency. A hot gas cleanup system will consist of FeO for bulk H/sub 2/S removal and ZnO for reduction of H/sub 2/S to sub ppM levels. Hot gas cleanup systems at present are not available commercially, and therefore it is the objective of this project to model the components of the system in order to help bring this technology closer to commercialization, by providing simulated operating characteristics to aid in system design, and system simulations of gasifier/MCFC systems. The modeling of the ZnO reactor is presented.

  18. Nuclear phosphoinositides and their roles in cell biology and disease.

    PubMed

    Martelli, Alberto M; Ognibene, Andrea; Buontempo, Francesca; Fini, Milena; Bressanin, Daniela; Goto, Kaoru; McCubrey, James A; Cocco, Lucio; Evangelisti, Camilla

    2011-10-01

    Since the late 1980s, a growing body of evidence has documented that phosphoinositides and their metabolizing enzymes, which regulate a large variety of cellular functions both in the cytoplasm and at the plasma membrane, are present also within the nucleus, where they are involved in processes such as cell proliferation, differentiation, and survival. Remarkably, nuclear phosphoinositide metabolism operates independently from that present elsewhere in the cell. Although nuclear phosphoinositides generate second messengers such as diacylglycerol and inositol 1,4,5 trisphosphate, it is becoming increasingly clear that they may act by themselves to influence chromatin structure, gene expression, DNA repair, and mRNA export. The understanding of the biological roles played by phosphoinositides is supported by the recent acquisitions demonstrating the presence in the nuclear compartment of several proteins harboring phosphoinositide-binding domains. Some of these proteins have functional roles in RNA splicing/processing and chromatin assembly. Moreover, recent evidence shows that nuclear phospholipase Cβ1 (a key phosphoinositide metabolizing enzyme) could somehow be involved in the myelodysplastic syndrome, i.e. a hematopoietic disorder that frequently evolves into an acute leukemia. This review aims to highlight the most significant and updated findings about phosphoinositide metabolism in the nucleus under both physiological and pathological conditions.

  19. Germ Cell Nuclear Factor Regulates Gametogenesis in Developing Gonads

    PubMed Central

    Sabour, Davood; Xu, Xueping; Chung, Arthur C. K.; Le Menuet, Damien; Ko, Kinarm; Tapia, Natalia; Araúzo-Bravo, Marcos J.; Gentile, Luca; Greber, Boris; Hübner, Karin; Sebastiano, Vittorio; Wu, Guangming; Schöler, Hans R.; Cooney, Austin J.

    2014-01-01

    Expression of germ cell nuclear factor (GCNF; Nr6a1), an orphan member of the nuclear receptor gene family of transcription factors, during gastrulation and neurulation is critical for normal embryogenesis in mice. Gcnf represses the expression of the POU-domain transcription factor Oct4 (Pou5f1) during mouse post-implantation development. Although Gcnf expression is not critical for the embryonic segregation of the germ cell lineage, we found that sexually dimorphic expression of Gcnf in germ cells correlates with the expression of pluripotency-associated genes, such as Oct4, Sox2, and Nanog, as well as the early meiotic marker gene Stra8. To elucidate the role of Gcnf during mouse germ cell differentiation, we generated an ex vivo Gcnf-knockdown model in combination with a regulated CreLox mutation of Gcnf. Lack of Gcnf impairs normal spermatogenesis and oogenesis in vivo, as well as the derivation of germ cells from embryonic stem cells (ESCs) in vitro. Inactivation of the Gcnf gene in vivo leads to loss of repression of Oct4 expression in both male and female gonads. PMID:25140725

  20. Preferential Binding of Hot Spot Mutant p53 Proteins to Supercoiled DNA In Vitro and in Cells

    PubMed Central

    Brázdová, Marie; Navrátilová, Lucie; Tichý, Vlastimil; Němcová, Kateřina; Lexa, Matej; Hrstka, Roman; Pečinka, Petr; Adámik, Matej; Vojtesek, Borivoj; Paleček, Emil; Deppert, Wolfgang; Fojta, Miroslav

    2013-01-01

    Hot spot mutant p53 (mutp53) proteins exert oncogenic gain-of-function activities. Binding of mutp53 to DNA is assumed to be involved in mutp53-mediated repression or activation of several mutp53 target genes. To investigate the importance of DNA topology on mutp53-DNA recognition in vitro and in cells, we analyzed the interaction of seven hot spot mutp53 proteins with topologically different DNA substrates (supercoiled, linear and relaxed) containing and/or lacking mutp53 binding sites (mutp53BS) using a variety of electrophoresis and immunoprecipitation based techniques. All seven hot spot mutp53 proteins (R175H, G245S, R248W, R249S, R273C, R273H and R282W) were found to have retained the ability of wild-type p53 to preferentially bind circular DNA at native negative superhelix density, while linear or relaxed circular DNA was a poor substrate. The preference of mutp53 proteins for supercoiled DNA (supercoil-selective binding) was further substantiated by competition experiments with linear DNA or relaxed DNA in vitro and ex vivo. Using chromatin immunoprecipitation, the preferential binding of mutp53 to a sc mutp53BS was detected also in cells. Furthermore, we have shown by luciferase reporter assay that the DNA topology influences p53 regulation of BAX and MSP/MST1 promoters. Possible modes of mutp53 binding to topologically constrained DNA substrates and their biological consequences are discussed. PMID:23555710

  1. Single and multijunction silicon based thin film solar cells on a flexible substrate with absorber layers made by hot-wire CVD

    NASA Astrophysics Data System (ADS)

    Li, Hongbo

    2007-09-01

    With the worldwide growing concern about reliable energy supply and the environmental problems of fossil and nuclear energy production, the need for clean and sustainable energy sources is evident. Solar energy conversion, such as in photovoltaic systems, can play a major role in the urgently needed energy transition in electricity production. Solar cells based on thin film silicon and its alloys are a promising candidate that is capable of fulfilling the fast increasing demand of a reliable solar cell supply. The conventional method to deposit silicon thin films is based on plasma enhanced chemical vapour deposition (PECVD) techniques, which have the disadvantage of increasing film inhomogeneity at a high deposition rate when scaling up for the industrial production. In this thesis, we study the possibility of making high efficiency single and multijunction thin film silicon solar cells with the so-called hot-wire CVD technique, in which no strong electromagnetic field is involved in the deposition. Therefore, the up-scaling for industrial production is straightforward. We report and discuss our findings on the correlation of substrate surface rms roughness and the main output parameter of a solar cell, the open circuit voltage Voc of c-Si:H n i p cells. By considering all the possible reasons that could influence the Voc of such cells, we conclude that the near linear correlation of Voc and substrate surface rms roughness is the result the two most probable reasons: the unintentional doping through the cracks originated near the valleys of the substrate surface due to the in-diffusion of impurities, and the high density electrical defects formed by the collision of columnar silicon structures. Both of them relate to the morphology of substrate surface. Therefore, to have the best cell performance on a rough substrate surface, a good control on the substrate surface morphology is necessary. Another issue influencing the performance of c-Si:H solar cells is the

  2. Generation of cloned mice and nuclear transfer embryonic stem cell lines from urine-derived cells

    PubMed Central

    Mizutani, Eiji; Torikai, Kohei; Wakayama, Sayaka; Nagatomo, Hiroaki; Ohinata, Yasuhide; Kishigami, Satoshi; Wakayama, Teruhiko

    2016-01-01

    Cloning animals by nuclear transfer provides the opportunity to preserve endangered mammalian species. However, there are risks associated with the collection of donor cells from the body such as accidental injury to or death of the animal. Here, we report the production of cloned mice from urine-derived cells collected noninvasively. Most of the urine-derived cells survived and were available as donors for nuclear transfer without any pretreatment. After nuclear transfer, 38–77% of the reconstructed embryos developed to the morula/blastocyst, in which the cell numbers in the inner cell mass and trophectoderm were similar to those of controls. Male and female cloned mice were delivered from cloned embryos transferred to recipient females, and these cloned animals grew to adulthood and delivered pups naturally when mated with each other. The results suggest that these cloned mice had normal fertility. In additional experiments, 26 nuclear transfer embryonic stem cell lines were established from 108 cloned blastocysts derived from four mouse strains including inbreds and F1 hybrids with relatively high success rates. Thus, cells derived from urine, which can be collected noninvasively, may be used in the rescue of endangered mammalian species by using nuclear transfer without causing injury to the animal. PMID:27033801

  3. Generation of cloned mice and nuclear transfer embryonic stem cell lines from urine-derived cells.

    PubMed

    Mizutani, Eiji; Torikai, Kohei; Wakayama, Sayaka; Nagatomo, Hiroaki; Ohinata, Yasuhide; Kishigami, Satoshi; Wakayama, Teruhiko

    2016-01-01

    Cloning animals by nuclear transfer provides the opportunity to preserve endangered mammalian species. However, there are risks associated with the collection of donor cells from the body such as accidental injury to or death of the animal. Here, we report the production of cloned mice from urine-derived cells collected noninvasively. Most of the urine-derived cells survived and were available as donors for nuclear transfer without any pretreatment. After nuclear transfer, 38-77% of the reconstructed embryos developed to the morula/blastocyst, in which the cell numbers in the inner cell mass and trophectoderm were similar to those of controls. Male and female cloned mice were delivered from cloned embryos transferred to recipient females, and these cloned animals grew to adulthood and delivered pups naturally when mated with each other. The results suggest that these cloned mice had normal fertility. In additional experiments, 26 nuclear transfer embryonic stem cell lines were established from 108 cloned blastocysts derived from four mouse strains including inbreds and F1 hybrids with relatively high success rates. Thus, cells derived from urine, which can be collected noninvasively, may be used in the rescue of endangered mammalian species by using nuclear transfer without causing injury to the animal. PMID:27033801

  4. State of Washington Department of Health radioactive air emission notice of construction phase 1 for spent nuclear fuel project - hot conditioning system annex, project W-484

    SciTech Connect

    Turnbaugh, J.E.

    1996-08-15

    This notice of construction (NOC) provides information regarding the source and the estimated annual possession quantity resulting from the operation of the Hot Conditioning System Annex (HCSA). This information will be discussed again in the Phase II NOC, providing additional details on emissions generated by the operation of the HCSA. This Phase I NOC is defined as construct in the substructure, including but limited to, pouring the concrete for the floor; construction of the process pits and exterior walls; making necessary interface connections to the Canister Storage Building (CSB) ventilation and utility systems for personnel comfort; and extending the multi-canister over-pack (MCO) handling machine rails into the HCSA. A Phase II NOC will be submitted for approval prior to installation and is defined as the completion of the HCSA, which will consist of installation of Hot Conditioning System Equipment (HCSA), air emissions control equipment, and emission monitoring equipment. About 80 percent of the U.S. Department of Energy`s spent nuclear fuel (SNF) inventory is stored under water in the Hanford Site K Basins. Spent nuclear fuel in the K West Basin is contained in closed canisters, while the SNF in the K East Basin is contained in open canisters, which allow free release of corrosion products to the K East Basin water. Storage in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PUREX Plant left approximately 2,300 MT (2,530 tons) of N Reactor SNF in the K Basins with no means for near-term removal and processing. The HCSA will be constructed as an addition to the CSB and will contain the HCSA. The hot conditioning system (HCS) will remove chemically-bound water and will passivate the exposed uranium surfaces associated,with the SNF. The HCSA will house seven hot

  5. U.S. Environmental Protection Agency Clean Air Act notice of construction for spent nuclear fuel project - hot conditioning system annex, project W-484

    SciTech Connect

    Baker, S.K., Westinghouse Hanford

    1996-12-10

    This notice of construction (NOC) provides information regarding the source and the estimated quantity of potential airborne radionuclide emissions resulting from the operation of the Hot Conditioning System (HCS) Annex. The construction of the HCS Annex is scheduled to conunence on or about December 1996, and will be completed when the process equipment begins operations. This document serves as a NOC pursuant to the requirements of 40 Code of Federal Regulations (CFR) 61 for the HCS Annex. About 80 percent of the U.S. Department of Energy`s spent nuclear fuel (SNF) inventory is stored under water in the Hanford Site K Basins. Spent nuclear fuel in the K West Basin is contained in closed canisters, while the SNF in the K East Basin is contained in open canisters, which allows release of corrosion products to the K East Basin water. Storage of the current inventory in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PUREX Plant left approximately 2, 1 00 MT (2,300 tons) of uranium, as part of 1133 N Reactor SNF in the K Basins with no means for near-term removal and processing. The HCS Annex will be constructed as an annex to the Canister Storage Building (CSB) and will contain the hot conditioning equipment. The hot conditioning system (HCS) will release chemically-bound water and will condition (process of using a controlled amount of oxygen to destroy uranium hydride) the exposed uranium surfaces associated with the SNF through oxidation. The HCS Annex will house seven hot conditioning process stations, six operational and one auxiliary, which could be used as a welding area for final closure of the vessel containing the SNF. The auxiliary pit is being evaluated at this time for its usefulness to support other operations that may be needed to ensure proper conditioning of the SNF

  6. Photo-Injected Hot-Electron Damage at the Silicon/silicon Dioxide Interface in Point-Contact Solar Cells.

    NASA Astrophysics Data System (ADS)

    Gruenbaum, Peter E.

    1990-01-01

    Point-contact solar cells currently hold the record for the most efficient silicon solar cell, reaching 28.5% under concentrated sunlight. These cells have both p and n contacts on the back, eliminating the losses due to grid shadowing found in a conventional cell. However, this means that the electron-hole pairs created near the front of the cell during illumination must diffuse all the way to the back of the cell without recombining. Therefore, point-contact solar cells have been processed to have the minimum number of recombination centers possible. Unfortunately, a decrease in the efficiency of these highly efficient cells can be measured after exposure to concentrated sunlight for just a few hours. The degradation was found to be due to an increase in the surface recombination velocity at the front surface of the cell. Experimental evidence suggests that what is occurring is an effect called "hot electron photoinjection", where electrons can absorb enough energy from an ultraviolet photon that they can overcome the 3.1 eV barrier between the silicon conduction band and the oxide conduction band, and be injected from the silicon into the oxide. This injection has been reported to create interface states, although the mechanism is not well understood. By utilizing literature results about hot electron injection, we were able to slow the degradation rate considerably by altering oxidation conditions to reduce water and mechanical stress at the interface. The stability of the cells also can be increased greatly by putting a light phosphorus diffusion at the interface. This creates an electric field near the surface that will keep holes away from the interface; since both electrons and holes are needed for recombination, the carrier recombination at the surface will be reduced, even though the surface recombination velocity itself can be very high. We have also been able to utilize the hot -electron resistance of ultrathin oxides by putting them on the front of

  7. Nuclear lamins and oxidative stress in cell proliferation and longevity.

    PubMed

    Shimi, Takeshi; Goldman, Robert D

    2014-01-01

    In mammalian cells, the nuclear lamina is composed of a complex fibrillar network associated with the inner membrane of the nuclear envelope. The lamina provides mechanical support for the nucleus and functions as the major determinant of its size and shape. At its innermost aspect it associates with peripheral components of chromatin and thereby contributes to the organization of interphase chromosomes. The A- and B-type lamins are the major structural components of the lamina, and numerous mutations in the A-type lamin gene have been shown to cause many types of human diseases collectively known as the laminopathies. These mutations have also been shown to cause a disruption in the normal interactions between the A and B lamin networks. The impact of these mutations on nuclear functions is related to the roles of lamins in regulating various essential processes including DNA synthesis and damage repair, transcription and the regulation of genes involved in the response to oxidative stress. The major cause of oxidative stress is the production of reactive oxygen species (ROS), which is critically important for cell proliferation and longevity. Moderate increases in ROS act to initiate signaling pathways involved in cell proliferation and differentiation, whereas excessive increases in ROS cause oxidative stress, which in turn induces cell death and/or senescence. In this review, we cover current findings about the role of lamins in regulating cell proliferation and longevity through oxidative stress responses and ROS signaling pathways. We also speculate on the involvement of lamins in tumor cell proliferation through the control of ROS metabolism.

  8. Nuclear Lamins and Oxidative Stress in Cell Proliferation and Longevity

    PubMed Central

    Shimi, Takeshi

    2014-01-01

    In mammalian cells, the nuclear lamina is composed of a complex fibrillar network associated with the inner membrane of the nuclear envelope. The lamina provides mechanical support for the nucleus and functions as the major determinant of its size and shape. At its innermost aspect it associates with peripheral components of chromatin and thereby contributes to the organization of interphase chromosomes. The A- and B-type lamins are the major structural components of the lamina, and numerous mutations in the A-type lamin gene have been shown to cause many types of human diseases collectively known as the laminopathies. These mutations have also been shown to cause a disruption in the normal interactions between the A and B lamin networks. The impact of these mutations on nuclear functions is related to the roles of lamins in regulating various essential processes including DNA synthesis and damage repair, transcription and the regulation of genes involved in the response to oxidative stress. The major cause of oxidative stress is the production of reactive oxygen species (ROS), which is critically important for cell proliferation and longevity. Moderate increases in ROS act to initiate signaling pathways involved in cell proliferation and differentiation, whereas excessive increases in ROS cause oxidative stress, which in turn induces cell death and/or senescence. In this review, we cover current findings about the role of lamins in regulating cell proliferation and longevity through oxidative stress responses and ROS signaling pathways. We also speculate on the involvement of lamins in tumor cell proliferation through the control of ROS metabolism. PMID:24563359

  9. Nuclear PI3K signaling in cell growth and tumorigenesis

    PubMed Central

    Davis, William J.; Lehmann, Peter Z.; Li, Weimin

    2015-01-01

    The PI3K/Akt signaling pathway is a major driving force in a variety of cellular functions. Dysregulation of this pathway has been implicated in many human diseases including cancer. While the activity of the cytoplasmic PI3K/Akt pathway has been extensively studied, the functions of these molecules and their effector proteins within the nucleus are poorly understood. Harboring key cellular processes such as DNA replication and repair as well as nascent messenger RNA transcription, the nucleus provides a unique compartmental environment for protein–protein and protein–DNA/RNA interactions required for cell survival, growth, and proliferation. Here we summarize recent advances made toward elucidating the nuclear PI3K/Akt signaling cascade and its key components within the nucleus as they pertain to cell growth and tumorigenesis. This review covers the spatial and temporal localization of the major nuclear kinases having PI3K activities and the counteracting phosphatases as well as the role of nuclear PI3K/Akt signaling in mRNA processing and exportation, DNA replication and repair, ribosome biogenesis, cell survival, and tumorigenesis. PMID:25918701

  10. Cloning Endangered Felids by Interspecies Somatic Cell Nuclear Transfer.

    PubMed

    Gómez, Martha C; Pope, C Earle

    2015-01-01

    In 2003, the first wild felid was produced by interspecies somatic cell nuclear transfer. Since then other wild felid clone offspring have been produced by using the same technique with minor modifications. This chapter describes detailed protocols used in our laboratory for (1) the isolation, culture, and preparation of fibroblast cells as donor nucleus, and (2) embryo reconstruction with domestic cat enucleated oocytes to produce cloned embryos that develop to the blastocyst stage in vitro and, after transfer into synchronized recipients, establish successful pregnancies.

  11. ERK5 and Cell Proliferation: Nuclear Localization Is What Matters

    PubMed Central

    Gomez, Nestor; Erazo, Tatiana; Lizcano, Jose M.

    2016-01-01

    ERK5, the last MAP kinase family member discovered, is activated by the upstream kinase MEK5 in response to growth factors and stress stimulation. MEK5-ERK5 pathway has been associated to different cellular processes, playing a crucial role in cell proliferation in normal and cancer cells by mechanisms that are both dependent and independent of its kinase activity. Thus, nuclear ERK5 activates transcription factors by either direct phosphorylation or acting as co-activator thanks to a unique transcriptional activation TAD domain located at its C-terminal tail. Consequently, ERK5 has been proposed as an interesting target to tackle different cancers, and either inhibitors of ERK5 activity or silencing the protein have shown antiproliferative activity in cancer cells and to block tumor growth in animal models. Here, we review the different mechanisms involved in ERK5 nuclear translocation and their consequences. Inactive ERK5 resides in the cytosol, forming a complex with Hsp90-Cdc37 superchaperone. In a canonical mechanism, MEK5-dependent activation results in ERK5 C-terminal autophosphorylation, Hsp90 dissociation, and nuclear translocation. This mechanism integrates signals such as growth factors and stresses that activate the MEK5-ERK5 pathway. Importantly, two other mechanisms, MEK5-independent, have been recently described. These mechanisms allow nuclear shuttling of kinase-inactive forms of ERK5. Although lacking kinase activity, these forms activate transcription by interacting with transcription factors through the TAD domain. Both mechanisms also require Hsp90 dissociation previous to nuclear translocation. One mechanism involves phosphorylation of the C-terminal tail of ERK5 by kinases that are activated during mitosis, such as Cyclin-dependent kinase-1. The second mechanism involves overexpression of chaperone Cdc37, an oncogene that is overexpressed in cancers such as prostate adenocarcinoma, where it collaborates with ERK5 to promote cell proliferation

  12. Reshaping the Transcriptional Frontier: Epigenetics and Somatic Cell Nuclear Transfer

    PubMed Central

    LONG, CHARLES R.; WESTHUSIN, MARK E.; GOLDING, MICHAEL C.

    2014-01-01

    SUMMARY Somatic-cell nuclear transfer (SCNT) experiments have paved the way to the field of cellular reprogramming. The demonstrated ability to clone over 20 different species to date has proven that the technology is robust but very inefficient, and is prone to developmental anomalies. Yet, the offspring from cloned animals exhibit none of the abnormalities of their parents, suggesting the low efficiency and high developmental mortality are epigenetic in origin. The epigenetic barriers to reprogramming somatic cells into a totipotent embryo capable of developing into a viable offspring are significant and varied. Despite their intimate relationship, chromatin structure and transcription are often not uniformly reprogramed after nuclear transfer, and many cloned embryos develop gene expression profiles that are hybrids between the donor cell and an embryonic blastomere. Recent advances in cellular reprogramming suggest that alteration of donor-cell chromatin structure towards that found in an normal embryo is actually the rate-limiting step in successful development of SCNT embryos. Here we review the literature relevant to the transformation of a somatic-cell nucleus into an embryo capable of full-term development. Interestingly, while resetting somatic transcription and associated epigenetic marks are absolutely required for development of SCNT embryos, life does not demand perfection. PMID:24167064

  13. Using somatic-cell nuclear transfer to study aging.

    PubMed

    Kishigami, Satoshi; Lee, Ah Reum; Wakayama, Teruhiko

    2013-01-01

    In mammals, a diploid genome following fertilization of haploid cells, an egg, and a spermatozoon is unique and irreproducible. This implies that the generated unique diploid genome is doomed with the individual's inevitable demise. Since it was first reported in 1997 that Dolly the sheep had been cloned, many mammalian species have been cloned successfully using somatic-cell nuclear transfer (SCNT). The success of SCNT in mammals enables us not only to reproduce offspring without germ cells, that is, to "passage" a unique diploid genome, but also to address valuable biological questions on development, nuclear reprogramming, and epigenetic memory. Successful cloning can also support epigenetic reprogramming where the aging clock is reset or reversed. Recent work using iPS cell technology has explored the practicality and led to the recapitulation of premature aging with iPSCs from progeroid laminopathies. As a result, reprogramming tools are also expected to contribute to studying biological age. However, the efficiency of animal cloning is still low in most cases and the mechanism of reprogramming in cloned embryos is still largely unclear. Here, based on recent advances, we describe an improved, more efficient mouse cloning protocol using histone deacetylase inhibitors (HDACis) and latrunculin A, which increases the success rates of producing cloned mice or establishing ES cells fivefold. This improved method of cloning will provide a strong tool to address many issues including biological aging more easily and with lower cost.

  14. Using somatic-cell nuclear transfer to study aging.

    PubMed

    Kishigami, Satoshi; Lee, Ah Reum; Wakayama, Teruhiko

    2013-01-01

    In mammals, a diploid genome following fertilization of haploid cells, an egg, and a spermatozoon is unique and irreproducible. This implies that the generated unique diploid genome is doomed with the individual's inevitable demise. Since it was first reported in 1997 that Dolly the sheep had been cloned, many mammalian species have been cloned successfully using somatic-cell nuclear transfer (SCNT). The success of SCNT in mammals enables us not only to reproduce offspring without germ cells, that is, to "passage" a unique diploid genome, but also to address valuable biological questions on development, nuclear reprogramming, and epigenetic memory. Successful cloning can also support epigenetic reprogramming where the aging clock is reset or reversed. Recent work using iPS cell technology has explored the practicality and led to the recapitulation of premature aging with iPSCs from progeroid laminopathies. As a result, reprogramming tools are also expected to contribute to studying biological age. However, the efficiency of animal cloning is still low in most cases and the mechanism of reprogramming in cloned embryos is still largely unclear. Here, based on recent advances, we describe an improved, more efficient mouse cloning protocol using histone deacetylase inhibitors (HDACis) and latrunculin A, which increases the success rates of producing cloned mice or establishing ES cells fivefold. This improved method of cloning will provide a strong tool to address many issues including biological aging more easily and with lower cost. PMID:23929101

  15. Nuclear microprobe imaging of gallium nitrate in cancer cells

    NASA Astrophysics Data System (ADS)

    Ortega, Richard; Suda, Asami; Devès, Guillaume

    2003-09-01

    Gallium nitrate is used in clinical oncology as treatment for hypercalcemia and for cancer that has spread to the bone. Its mechanism of antitumor action has not been fully elucidated yet. The knowledge of the intracellular distribution of anticancer drugs is of particular interest in oncology to better understand their cellular pharmacology. In addition, most metal-based anticancer compounds interact with endogenous trace elements in cells, altering their metabolism. The purpose of this experiment was to examine, by use of nuclear microprobe analysis, the cellular distribution of gallium and endogenous trace elements within cancer cells exposed to gallium nitrate. In a majority of cellular analyses, gallium was found homogeneously distributed in cells following the distribution of carbon. In a smaller number of cells, however, gallium appeared concentrated together with P, Ca and Fe within round structures of about 2-5 μm diameter located in the perinuclear region. These intracellular structures are typical of lysosomial material.

  16. BLACK HOLE-NEUTRON STAR MERGERS WITH A HOT NUCLEAR EQUATION OF STATE: OUTFLOW AND NEUTRINO-COOLED DISK FOR A LOW-MASS, HIGH-SPIN CASE

    SciTech Connect

    Deaton, M. Brett; Duez, Matthew D.; Foucart, Francois; O'Connor, Evan; Ott, Christian D.; Scheel, Mark A.; Szilagyi, Bela; Kidder, Lawrence E.; Muhlberger, Curran D. E-mail: m.duez@wsu.edu

    2013-10-10

    Neutrino emission significantly affects the evolution of the accretion tori formed in black hole-neutron star mergers. It removes energy from the disk, alters its composition, and provides a potential power source for a gamma-ray burst. To study these effects, simulations in general relativity with a hot microphysical equation of state (EOS) and neutrino feedback are needed. We present the first such simulation, using a neutrino leakage scheme for cooling to capture the most essential effects and considering a moderate mass (1.4 M{sub ☉} neutron star, 5.6 M{sub ☉} black hole), high-spin (black hole J/M {sup 2} = 0.9) system with the K{sub 0} = 220 MeV Lattimer-Swesty EOS. We find that about 0.08 M{sub ☉} of nuclear matter is ejected from the system, while another 0.3 M{sub ☉} forms a hot, compact accretion disk. The primary effects of the escaping neutrinos are (1) to make the disk much denser and more compact, (2) to cause the average electron fraction Y{sub e} of the disk to rise to about 0.2 and then gradually decrease again, and (3) to gradually cool the disk. The disk is initially hot (T ∼ 6 MeV) and luminous in neutrinos (L{sub ν} ∼ 10{sup 54} erg s{sup –1}), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution.

  17. Micronuclei Frequencies and Nuclear Abnormalities in Oral Exfoliated Cells of Nuclear Power Plant Workers

    PubMed Central

    Babannavar, Roopa; Lohra, Abhishek; Kodgi, Ashwin; Bapure, Sunil; Rao, Yogesh; J., Arun; Malghan, Manjunath

    2014-01-01

    Aim: Biomonitoring provides a useful tool to estimate the genetic risk from exposure to genotoxic agents. The aim of this study was to evaluate the frequencies of Micronuclei (MN) and other Nuclear abnormalities (NA) from exfoliated oral mucosal cells in Nuclear Power Station (NPS) workers. Materials and Methods: Micronucleus frequencies in oral exfoliated cells were done from individuals not known to be exposed to either environmental or occupational carcinogens (Group I). Similarly samples were obtained from full-time Nuclear Power Station (NPS) workers with absence of Leukemia and any malignancy (Group II) and workers diagnosed as leukemic patients and undergoing treatment (Group III). Results: There was statistically significant difference between Group I, Group II & Group III. MN and NA frequencies in Leukemic Patients were significantly higher than those in exposed workers &control groups (p < 0.05). Conclusion: MN and other NA reflect genetic changes, events associated with malignancies. Therefore, there is a need to educate those who work in NPS about the potential hazard of occupational exposure and the importance of using protective measures. PMID:25654022

  18. Somatic cell nuclear transfer: Past, present and future perspectives.

    PubMed

    Campbell, K H S; Fisher, P; Chen, W C; Choi, I; Kelly, R D W; Lee, J-H; Xhu, J

    2007-09-01

    It is now over a decade since the birth, in 1996, of Dolly the first animal to be produced by nuclear transfer using an adult derived somatic cell as nuclear donor. Since this time similar techniques have been successfully applied to a range of species producing live offspring and allowing the development of transgenic technologies for agricultural, biotechnological and medical uses. However, though applicable to a range of species, overall, the efficiencies of development of healthy offspring remain low. The low frequency of successful development has been attributed to incomplete or inappropriate reprogramming of the transferred nuclear genome. Many studies have demonstrated that such reprogramming occurs by epigenetic mechanisms not involving alterations in DNA sequence, however, at present the molecular mechanisms underlying reprogramming are poorly defined. Since the birth of Dolly many studies have attempted to improve the frequency of development, this review will discuss the process of animal production by nuclear transfer and in particular changes in the methodology which have increased development and survival, simplified or increased robustness of the technique. Although much of the discussion is applicable across species, for simplicity we will concentrate primarily on published data for cattle, sheep, pigs and mice. PMID:17610946

  19. Coordination between donor cell type and cell cycle stage improves nuclear cloning efficiency in cattle.

    PubMed

    Wells, D N; Laible, G; Tucker, F C; Miller, A L; Oliver, J E; Xiang, T; Forsyth, J T; Berg, M C; Cockrem, K; L'Huillier, P J; Tervit, H R; Oback, B

    2003-01-01

    Several studies have shown that both quiescent and proliferating somatic donor cells can be fully reprogrammed after nuclear transfer (NT) and result in viable offspring. So far, however, no comparative study has conclusively demonstrated the relative importance of donor cell cycle stage on nuclear cloning efficiency. Here, we compare two different types of bovine fetal fibroblasts (BFFs) that were synchronized in G(0), G(1), and different phases within G(1). We show that for non-transgenic (non-TG) fibroblasts, serum starvation into G(0) results in a significantly higher percentage of viable calves at term than synchronization in early G(1) or late G(1). For transgenic fibroblasts, however, cells selected in G(1) show significantly higher development to calves at term and higher post-natal survival to weaning than cells in G(0). This suggests that it may be necessary to coordinate donor cell type and cell cycle stage to maximize overall cloning efficiency.

  20. Production of Cloned Mice by Nuclear Transfer of Cumulus Cells

    PubMed Central

    Kurd, Soleiman; Zarei, Mohammad Ali; Fathi, Fardin; Ghadimi, Tayyeb; Hakhamaneshi, Mohammad Saeed; Jalili, Ali

    2013-01-01

    Background Over the past several years, mammals have been successfully cloned by either the splitting of an early stage embryo or nuclear transfer of adult somatic cells (NT) into oocytes. Although it has been 15 years since the generation of the first cloned mammals from somatic cells by NT, the success rate for producing live offspring by this technique is low regardless of the cell type and animal species used. However, these techniques have the potential to be important tools for future research in basic biology. In the present study, we described our experiences in producing successfully cloned mouse using NT method and piezo-actuated micromanipulator. Methods B6D2F1 mice, 8-12 weeks old, were superovulated with injections of 5 IU of pregnant mare serum gonadotropin and 5 IU of human chorionic gonadotropin administered 48 hr apart. Enucleation and donor nuclei cumulus cell injection were performed with a piezo-actuated micromanipulator after which activation and trichostatin A treatment were used for reconstructed oocytes. Two-cell stage cloned embryos that developed in the mWM medium were transferred into the oviducts of pseudopregnant NMRI mice. Results Of 367 oocytes collected, 131 (69%) developed into 2-cell stage embryos. Of these, 5 (1%) live pups were successfully delivered. We used NMRI foster mother to raise the pups by lactation. One adult cloned mouse was mated, after which she delivered and raised normal offspring. Conclusion For mouse cloning, the present study also successfully tested the capability of somatic cell nuclear transfer SCNT using a piezo unit. PMID:23919122

  1. Nuclear anomalies in the buccal cells of calcite factory workers

    PubMed Central

    2010-01-01

    The micronucleus (MN) assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers) calcite factory workers and 50 (25 smokers and 25 non-smokers) age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA) other than micronuclei, such as binucleates, karyorrhexis, karyolysis and ‘broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05). The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage. PMID:21637497

  2. Multiphysics Thermal-Fluid Analysis of a Non-Nuclear Tester for Hot-Hydrogen Materials Development

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Foote, John; Litchford, Ron

    2006-01-01

    The objective of this effort is to analyze the thermal field of a non-nuclear tester, as a first step towards developing efficient and accurate multiphysics, thermo-fluid computational methodology to predict environments for hypothetical solid-core, nuclear thermal engine thrust chamber design and analysis. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, radiating, unstructured-grid, and pressure-based formulation. The multiphysics invoked in this study include hydrogen dissociation kinetics and thermodynamics, turbulent flow, convective, radiative and conjugate heat transfers.

  3. Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells.

    PubMed

    Ju, Young Seok; Tubio, Jose M C; Mifsud, William; Fu, Beiyuan; Davies, Helen R; Ramakrishna, Manasa; Li, Yilong; Yates, Lucy; Gundem, Gunes; Tarpey, Patrick S; Behjati, Sam; Papaemmanuil, Elli; Martin, Sancha; Fullam, Anthony; Gerstung, Moritz; Nangalia, Jyoti; Green, Anthony R; Caldas, Carlos; Borg, Åke; Tutt, Andrew; Lee, Ming Ta Michael; van't Veer, Laura J; Tan, Benita K T; Aparicio, Samuel; Span, Paul N; Martens, John W M; Knappskog, Stian; Vincent-Salomon, Anne; Børresen-Dale, Anne-Lise; Eyfjörd, Jórunn Erla; Flanagan, Adrienne M; Foster, Christopher; Neal, David E; Cooper, Colin; Eeles, Rosalind; Lakhani, Sunil R; Desmedt, Christine; Thomas, Gilles; Richardson, Andrea L; Purdie, Colin A; Thompson, Alastair M; McDermott, Ultan; Yang, Fengtang; Nik-Zainal, Serena; Campbell, Peter J; Stratton, Michael R

    2015-06-01

    Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm, and the mitochondrial double membrane. Despite these physical barriers, we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements, and the features of the fusion fragments indicate that nonhomologous end joining and/or replication-dependent DNA double-strand break repair are the dominant mechanisms involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells. PMID:25963125

  4. Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells

    PubMed Central

    Ju, Young Seok; Tubio, Jose M.C.; Mifsud, William; Fu, Beiyuan; Davies, Helen R.; Ramakrishna, Manasa; Li, Yilong; Yates, Lucy; Gundem, Gunes; Tarpey, Patrick S.; Behjati, Sam; Papaemmanuil, Elli; Martin, Sancha; Fullam, Anthony; Gerstung, Moritz; Nangalia, Jyoti; Green, Anthony R.; Caldas, Carlos; Borg, Åke; Tutt, Andrew; Lee, Ming Ta Michael; van't Veer, Laura J.; Tan, Benita K.T.; Aparicio, Samuel; Span, Paul N.; Martens, John W.M.; Knappskog, Stian; Vincent-Salomon, Anne; Børresen-Dale, Anne-Lise; Eyfjörd, Jórunn Erla; Flanagan, Adrienne M.; Foster, Christopher; Neal, David E.; Cooper, Colin; Eeles, Rosalind; Lakhani, Sunil R.; Desmedt, Christine; Thomas, Gilles; Richardson, Andrea L.; Purdie, Colin A.; Thompson, Alastair M.; McDermott, Ultan; Yang, Fengtang; Nik-Zainal, Serena; Campbell, Peter J.; Stratton, Michael R.

    2015-01-01

    Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm, and the mitochondrial double membrane. Despite these physical barriers, we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements, and the features of the fusion fragments indicate that nonhomologous end joining and/or replication-dependent DNA double-strand break repair are the dominant mechanisms involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells. PMID:25963125

  5. Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells.

    PubMed

    Ju, Young Seok; Tubio, Jose M C; Mifsud, William; Fu, Beiyuan; Davies, Helen R; Ramakrishna, Manasa; Li, Yilong; Yates, Lucy; Gundem, Gunes; Tarpey, Patrick S; Behjati, Sam; Papaemmanuil, Elli; Martin, Sancha; Fullam, Anthony; Gerstung, Moritz; Nangalia, Jyoti; Green, Anthony R; Caldas, Carlos; Borg, Åke; Tutt, Andrew; Lee, Ming Ta Michael; van't Veer, Laura J; Tan, Benita K T; Aparicio, Samuel; Span, Paul N; Martens, John W M; Knappskog, Stian; Vincent-Salomon, Anne; Børresen-Dale, Anne-Lise; Eyfjörd, Jórunn Erla; Flanagan, Adrienne M; Foster, Christopher; Neal, David E; Cooper, Colin; Eeles, Rosalind; Lakhani, Sunil R; Desmedt, Christine; Thomas, Gilles; Richardson, Andrea L; Purdie, Colin A; Thompson, Alastair M; McDermott, Ultan; Yang, Fengtang; Nik-Zainal, Serena; Campbell, Peter J; Stratton, Michael R

    2015-06-01

    Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm, and the mitochondrial double membrane. Despite these physical barriers, we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements, and the features of the fusion fragments indicate that nonhomologous end joining and/or replication-dependent DNA double-strand break repair are the dominant mechanisms involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells.

  6. Changes in plant cell-wall structure of corn stover due to hot compressed water pretreatment and enhanced enzymatic hydrolysis.

    PubMed

    Zhou, Wei; Yang, Maohua; Wang, Caixia; Liu, Jianfei; Xing, Jianmin

    2014-08-01

    Corn stover is a potential feedstock for biofuel production. This work investigated physical and chemical changes in plant cell-wall structure of corn stover due to hot compressed water (HCW) pretreatment at 170-190 °C in a tube reactor. Chemical composition analysis showed the soluble hemicellulose content increased with pretreatment temperature, whereas the hemicellulose content decreased from 29 to 7 % in pretreated solids. Scanning electron microscopy revealed the parenchyma-type second cell-wall structure of the plant was almost completely removed at 185 °C, and the sclerenchyma-type second cell wall was greatly damaged upon addition of 5 mmol/L ammonium sulfate during HCW pretreatment. These changes favored accessibility for enzymatic action. Enzyme saccharification of solids by optimized pretreatment with HCW at 185 °C resulted in an enzymatic hydrolysis yield of 87 %, an enhancement of 77 % compared to the yield from untreated corn stover.

  7. Factors affecting the development of somatic cell nuclear transfer embryos in Cattle.

    PubMed

    Akagi, Satoshi; Matsukawa, Kazutsugu; Takahashi, Seiya

    2014-01-01

    Nuclear transfer is a complex multistep procedure that includes oocyte maturation, cell cycle synchronization of donor cells, enucleation, cell fusion, oocyte activation and embryo culture. Therefore, many factors are believed to contribute to the success of embryo development following nuclear transfer. Numerous attempts to improve cloning efficiency have been conducted since the birth of the first sheep by somatic cell nuclear transfer. However, the efficiency of somatic cell cloning has remained low, and applications have been limited. In this review, we discuss some of the factors that affect the developmental ability of somatic cell nuclear transfer embryos in cattle.

  8. A New, Dynamic Era for Somatic Cell Nuclear Transfer?

    PubMed

    Loi, Pasqualino; Iuso, Domenico; Czernik, Marta; Ogura, Atsuo

    2016-10-01

    Cloning animals by somatic cell nuclear transfer (SCNT) has remained an uncontrollable process for many years. High rates of embryonic losses, stillbirths, and postnatal mortality have been typical outcomes. These developmental problems arise from abnormal genomic reprogramming: the capacity of the oocyte to reset the differentiated memory of a somatic cell. However, effective reprogramming strategies are now available. These target the whole genome or single domains such as the Xist gene, and their effectiveness has been validated with the ability of experimental animals to develop to term. Thus, SCNT has become a controllable process that can be used to 'rescue' endangered species, and for biomedical research such as therapeutic cloning and the isolation of induced pluripotent stem cells (iPSCs). PMID:27118511

  9. Cloned ferrets produced by somatic cell nuclear transfer

    PubMed Central

    Li, Ziyi; Sun, Xingshen; Chen, Juan; Liu, Xiaoming; Wisely, Samantha M.; Zhou, Qi; Renard, Jean-Paul; Leno, Gregory H.; Engelhardt, John F.

    2007-01-01

    Somatic cell nuclear transfer (SCNT) offers great potential for developing better animal models of human disease. The domestic ferret (Mustela putorius furo) is an ideal animal model for influenza infections and potentially other human respiratory diseases such as cystic fibrosis, where mouse models have failed to reproduce the human disease phenotype. Here, we report the successful production of live cloned, reproductively competent, ferrets using species-specific SCNT methodologies. Critical to developing a successful SCNT protocol for the ferret was the finding that hormonal treatment, normally used for superovulation, adversely affected the developmental potential of recipient oocytes. The onset of Oct4 expression was delayed and incomplete in parthenogenetically activated oocytes collected from hormone-treated females relative to oocytes collected from females naturally mated with vasectomized males. Stimulation induced by mating and in vitro oocyte maturation produced the optimal oocyte recipient for SCNT. Although nuclear injection and cell fusion produced mid-term fetuses at equivalent rates (~3–4%), only cell fusion gave rise to healthy surviving clones. Single cell fusion rates and the efficiency of SCNT were also enhanced by placing two somatic cells into the perivitelline space. These species-specific modifications facilitated the birth of live, healthy, and fertile cloned ferrets. The development of microsatellite genotyping for domestic ferrets confirmed that ferret clones were genetically derived from their respective somatic cells and unrelated to their surrogate mother. With this technology, it is now feasible to begin generating genetically defined ferrets for studying transmissible and inherited human lung diseases. Cloning of the domestic ferret may also aid in recovery and conservation of the endangered black-footed ferret and European mink. PMID:16584722

  10. Somatic cell nuclear transfer-derived embryonic stem cell lines in humans: pros and cons.

    PubMed

    Langerova, Alena; Fulka, Helena; Fulka, Josef

    2013-12-01

    The recent paper, published by Mitalipov's group in Cell (Tachibana et al., 2013 ), reporting the production of human somatic cell nuclear transfer (SCNT) embryonic stem cells (ESCs), opens again the debate if, in the era of induced pluripotent stem cells (iPSCs), the production of these cells is indeed necessary and, if so, whether they are different from ESCs produced from spare embryos and iPSCs. It is our opinion that these questions are very difficult to answer because it is still unclear whether and how normal ESCs differ from iPSCs. PMID:24180743

  11. Somatic cell nuclear transfer-derived embryonic stem cell lines in humans: pros and cons.

    PubMed

    Langerova, Alena; Fulka, Helena; Fulka, Josef

    2013-12-01

    The recent paper, published by Mitalipov's group in Cell (Tachibana et al., 2013 ), reporting the production of human somatic cell nuclear transfer (SCNT) embryonic stem cells (ESCs), opens again the debate if, in the era of induced pluripotent stem cells (iPSCs), the production of these cells is indeed necessary and, if so, whether they are different from ESCs produced from spare embryos and iPSCs. It is our opinion that these questions are very difficult to answer because it is still unclear whether and how normal ESCs differ from iPSCs.

  12. Effect of microstructure of carbon steel on magnetite formation in simulated Hot Conditioning environment of nuclear reactors

    NASA Astrophysics Data System (ADS)

    Sinha, Prafful Kumar; Kiran Kumar, M.; Kain, Vivekanand

    2015-09-01

    The objective of present investigation is to establish the role of starting microstructure of carbon steel on the magnetite formation behaviour in Hot Conditioning simulated environment. Two grades of carbon steel (low and high carbon) were subjected to selective heat-treatments to generate different microstructures: martensite, tempered martensite and modified ferrite-pearlite. Oxidation was carried out in lithiated water of pH 10-10.2 in a static autoclave at 270 °C. The results of the investigation clearly establish that: (a) high carbon steel (0.63% C) showed a relatively higher rate of oxidation over the low carbon (0.08% C) grade at all the test durations and (b) the oxidation rates for both the grades were sensitive to microstructural differences at initial stages of oxidation while the differences narrowed down after 72 h of exposure. The oxide formed was established to be magnetite on all the specimens.

  13. Role of nuclear receptors in breast cancer stem cells

    PubMed Central

    Papi, Alessio; Orlandi, Marina

    2016-01-01

    The recapitulation of primary tumour heterogenity and the existence of a minor sub-population of cancer cells, capable of initiating tumour growth in xenografts on serial passages, led to the hypothesis that cancer stem cells (CSCs) exist. CSCs are present in many tumours, among which is breast cancer. Breast CSCs (BCSCs) are likely to sustain the growth of the primary tumour mass, as well as to be responsible for disease relapse and metastatic spreading. Consequently, BCSCs represent the most significant target for new drugs in breast cancer therapy. Both the hypoxic condition in BCSCs biology and pro-inflammatory cytokine network has gained increasing importance in the recent past. Breast stromal cells are crucial components of the tumours milieu and are a major source of inflammatory mediators. Recently, the anti-inflammatory role of some nuclear receptors ligands has emerged in several diseases, including breast cancer. Therefore, the use of nuclear receptors ligands may be a valid strategy to inhibit BCSCs viability and consequently breast cancer growth and disease relapse. PMID:27022437

  14. Cytoplasmic proliferating cell nuclear antigen connects glycolysis and cell survival in acute myeloid leukemia

    PubMed Central

    Ohayon, Delphine; De Chiara, Alessia; Chapuis, Nicolas; Candalh, Céline; Mocek, Julie; Ribeil, Jean-Antoine; Haddaoui, Lamya; Ifrah, Norbert; Hermine, Olivier; Bouillaud, Frédéric; Frachet, Philippe; Bouscary, Didier; Witko-Sarsat, Véronique

    2016-01-01

    Cytosolic proliferating cell nuclear antigen (PCNA), a scaffolding protein involved in DNA replication, has been described as a key element in survival of mature neutrophil granulocytes, which are non-proliferating cells. Herein, we demonstrated an active export of PCNA involved in cell survival and chemotherapy resistance. Notably, daunorubicin-resistant HL-60 cells (HL-60R) have a prominent cytosolic PCNA localization due to increased nuclear export compared to daunorubicin-sensitive HL-60 cells (HL-60S). By interacting with nicotinamide phosphoribosyltransferase (NAMPT), a protein involved in NAD biosynthesis, PCNA coordinates glycolysis and survival, especially in HL-60R cells. These cells showed a dramatic increase in intracellular NAD+ concentration as well as glycolysis including increased expression and activity of hexokinase 1 and increased lactate production. Furthermore, this functional activity of cytoplasmic PCNA was also demonstrated in patients with acute myeloid leukemia (AML). Our data uncover a novel pathway of nuclear export of PCNA that drives cell survival by increasing metabolism flux. PMID:27759041

  15. Gnotobiotic Miniature Pig Interbreed Somatic Cell Nuclear Transfer for Xenotransplantation.

    PubMed

    Hwang, Jeong Ho; Kim, Sang Eun; Gupta, Mukesh Kumar; Lee, HoonTaek

    2016-08-01

    Transgenic animal producing technology has improved consistently over the last couple of decades. Among the available methods, somatic cell nuclear transfer (SCNT) technology was officially the most popular. However, SCNT has low efficiency and requires a highly skilled individual. Additionally, the allo-SCNT nuclear reprogramming mechanism is poorly understood in the gnotobiotic miniature pig, which is a candidate for xenotransplantation, making sampling in oocytes very difficult compared to commercial hybrid pigs. Therefore, interbreed SCNT (ibSCNT), which is a combination of miniature pig and commercial pig (Landrace based), was analyzed and was found to be similar to SCNT in terms of the rate of blastocyst formation (12.6% ± 2.9% vs. 15.5% ± 2.2%; p > 0.05). However, a significantly lower fusion rate was observed in the ibSCNT compared to normal SCNT with Landrace pig somatic cells (29.6% ± 0.8% vs. 65.0% ± 4.9%). Thus, the optimization of fusion parameters was necessary for efficient SCNT. Our results further revealed that ibSCNT by the whole-cell intracytoplasmic injection (WCICI) method had a significantly higher blastocyst forming efficiency than the electrofusion method (31.1 ± 8.5 vs. 15.5% ± 2.2%). The nuclear remodeling and the pattern of changes in acetylation at H3K9 residue were similar in both SCNT and ibSCNT embryos. PMID:27459580

  16. Cdk1 Activates Pre-mitotic Nuclear Envelope Dynein Recruitment and Apical Nuclear Migration in Neural Stem Cells.

    PubMed

    Baffet, Alexandre D; Hu, Daniel J; Vallee, Richard B

    2015-06-22

    Dynein recruitment to the nuclear envelope is required for pre-mitotic nucleus-centrosome interactions in nonneuronal cells and for apical nuclear migration in neural stem cells. In each case, dynein is recruited to the nuclear envelope (NE) specifically during G2 via two nuclear pore-mediated mechanisms involving RanBP2-BicD2 and Nup133-CENP-F. The mechanisms responsible for cell-cycle control of this behavior are unknown. We now find that Cdk1 serves as a direct master controller for NE dynein recruitment in neural stem cells and HeLa cells. Cdk1 phosphorylates conserved sites within RanBP2 and activates BicD2 binding and early dynein recruitment. Late recruitment is triggered by a Cdk1-induced export of CENP-F from the nucleus. Forced NE targeting of BicD2 overrides Cdk1 inhibition, fully rescuing dynein recruitment and nuclear migration in neural stem cells. These results reveal how NE dynein recruitment is cell-cycle regulated and identify the trigger mechanism for apical nuclear migration in the brain.

  17. A hot-electron thermophotonic solar cell demonstrated by thermal up-conversion of sub-bandgap photons

    PubMed Central

    Farrell, Daniel J.; Sodabanlu, Hassanet; Wang, Yunpeng; Sugiyama, Masakazu; Okada, Yoshitaka

    2015-01-01

    The direct conversion of solar energy to electricity can be broadly separated into two main categories: photovoltaics and thermal photovoltaics, where the former utilizes gradients in electrical potential and the latter thermal gradients. Conventional thermal photovoltaics has a high theoretical efficiency limit (84%) but in practice cannot be easily miniaturized and is limited by the engineering challenges of sustaining large (>1,000 K) temperature gradients. Here we show a hot-carrier-based thermophotonic solar cell, which combines the compact nature of photovoltaic devices with the potential to reach the high-efficiency regime of thermal photovoltaics. In the device, a thermal gradient of 500 K is established by hot electrons, under Stokes illumination, rather than by raising the temperature of the material itself. Under anti-Stokes (sub-bandgap) illumination we observe a thermal gradient of ∼20 K, which is maintained by steady-state Auger heating of carriers and corresponds to a internal thermal up-conversion efficiency of 30% between the collector and solar cell. PMID:26541415

  18. A hot-electron thermophotonic solar cell demonstrated by thermal up-conversion of sub-bandgap photons.

    PubMed

    Farrell, Daniel J; Sodabanlu, Hassanet; Wang, Yunpeng; Sugiyama, Masakazu; Okada, Yoshitaka

    2015-11-06

    The direct conversion of solar energy to electricity can be broadly separated into two main categories: photovoltaics and thermal photovoltaics, where the former utilizes gradients in electrical potential and the latter thermal gradients. Conventional thermal photovoltaics has a high theoretical efficiency limit (84%) but in practice cannot be easily miniaturized and is limited by the engineering challenges of sustaining large (>1,000 K) temperature gradients. Here we show a hot-carrier-based thermophotonic solar cell, which combines the compact nature of photovoltaic devices with the potential to reach the high-efficiency regime of thermal photovoltaics. In the device, a thermal gradient of 500 K is established by hot electrons, under Stokes illumination, rather than by raising the temperature of the material itself. Under anti-Stokes (sub-bandgap) illumination we observe a thermal gradient of ∼20 K, which is maintained by steady-state Auger heating of carriers and corresponds to a internal thermal up-conversion efficiency of 30% between the collector and solar cell.

  19. Nuclear removal during terminal lens fiber cell differentiation requires CDK1 activity: appropriating mitosis-related nuclear disassembly

    PubMed Central

    Chaffee, Blake R.; Shang, Fu; Chang, Min-Lee; Clement, Tracy M.; Eddy, Edward M.; Wagner, Brad D.; Nakahara, Masaki; Nagata, Shigekazu; Robinson, Michael L.; Taylor, Allen

    2014-01-01

    Lens epithelial cells and early lens fiber cells contain the typical complement of intracellular organelles. However, as lens fiber cells mature they must destroy their organelles, including nuclei, in a process that has remained enigmatic for over a century, but which is crucial for the formation of the organelle-free zone in the center of the lens that assures clarity and function to transmit light. Nuclear degradation in lens fiber cells requires the nuclease DNase IIβ (DLAD) but the mechanism by which DLAD gains access to nuclear DNA remains unknown. In eukaryotic cells, cyclin-dependent kinase 1 (CDK1), in combination with either activator cyclins A or B, stimulates mitotic entry, in part, by phosphorylating the nuclear lamin proteins leading to the disassembly of the nuclear lamina and subsequent nuclear envelope breakdown. Although most post-mitotic cells lack CDK1 and cyclins, lens fiber cells maintain these proteins. Here, we show that loss of CDK1 from the lens inhibited the phosphorylation of nuclear lamins A and C, prevented the entry of DLAD into the nucleus, and resulted in abnormal retention of nuclei. In the presence of CDK1, a single focus of the phosphonuclear mitotic apparatus is observed, but it is not focused in CDK1-deficient lenses. CDK1 deficiency inhibited mitosis, but did not prevent DNA replication, resulting in an overall reduction of lens epithelial cells, with the remaining cells possessing an abnormally large nucleus. These observations suggest that CDK1-dependent phosphorylations required for the initiation of nuclear membrane disassembly during mitosis are adapted for removal of nuclei during fiber cell differentiation. PMID:25139855

  20. Characterization of Aes nuclear foci in colorectal cancer cells.

    PubMed

    Itatani, Yoshiro; Sonoshita, Masahiro; Kakizaki, Fumihiko; Okawa, Katsuya; Stifani, Stefano; Itoh, Hideaki; Sakai, Yoshiharu; Taketo, M Mark

    2016-01-01

    Amino-terminal enhancer of split (Aes) is a member of Groucho/Transducin-like enhancer (TLE) family. Aes is a recently found metastasis suppressor of colorectal cancer (CRC) that inhibits Notch signalling, and forms nuclear foci together with TLE1. Although some Notch-associated proteins are known to form subnuclear bodies, little is known regarding the dynamics or functions of these structures. Here, we show that Aes nuclear foci in CRC observed under an electron microscope are in a rather amorphous structure, lacking surrounding membrane. Investigation of their behaviour during the cell cycle by time-lapse cinematography showed that Aes nuclear foci dissolve during mitosis and reassemble after completion of cytokinesis. We have also found that heat shock cognate 70 (HSC70) is an essential component of Aes foci. Pharmacological inhibition of the HSC70 ATPase activity with VER155008 reduces Aes focus formation. These results provide insight into the understanding of Aes-mediated inhibition of Notch signalling. PMID:26229111

  1. Decontamination of hot cells K-1, K-3, M-1, M-3, and A-1, M-Wing, Building 200: Project final report Argonne National Laboratory-East

    SciTech Connect

    Cheever, C.L.; Rose, R.W.

    1996-09-01

    The purpose of this project was to remove radioactively contaminated materials and equipment from the hot cells, to decontaminate the hot cells, and to dispose of the radioactive waste. The goal was to reduce stack releases of Rn-220 and to place the hot cells in an emptied, decontaminated condition with less than 10 {micro}Sv/h (1 mrem/h) general radiation background. The following actions were needed: organize and mobilize a decontamination team; prepare decontamination plans and procedures; perform safety analyses to ensure protection of the workers, public, and environment; remotely size-reduce, package, and remove radioactive materials and equipment for waste disposal; remotely decontaminate surfaces to reduce hot cell radiation background levels to allow personnel entries using supplied air and full protective suits; disassemble and package the remaining radioactive materials and equipment using hands-on techniques; decontaminate hot cell surfaces to remove loose radioactive contaminants and to attain a less than 10 {micro}Sv/h (1 mrem/h) general background level; document and dispose of the radioactive and mixed waste; and conduct a final radiological survey.

  2. Nuclear microscopy of single whole cultured cells: Preparation and analysis of human Chang liver cells

    NASA Astrophysics Data System (ADS)

    Thong, P. S. P.; Watt, F.; Paramanantham, R.; Bay, B. H.; Sit, K. H.

    1997-07-01

    Nuclear microscopy is a powerful tool for the measurement of elemental concentrations in single cells. Six methods involving the use of various fixing agents, rinsing agents and drying methods were tried in the preparation of cultured human Chang liver cells for nuclear microscopy and the suitability of each method was evaluated by monitoring the {K}/{Na} ratios and shapes of individual cells. The {K}/{Na} ratio is a commonly used criteria for the ionic integrity of cells; {K}/{Na} ratios well above 1 indicates minimal perturbation of the intracellular ionic composition. Non-stimulated human Chang liver cells in a resting state are usually polygonal in shape and flattened in firm anchorage to the substrate, while dividing or stimulated cells appear rounded. Therefore the shapes of the cells can be used as an indicator of whether the cells are in a resting or stimulated state. It is not desirable for cells to be in a stimulated state since then the effects of other external stimuli cannot be observed independently. Of the six methods tested, chemical fixation, as expected, was considered non-ideal for the preparation of human cultured Chang liver cells. Ice-cold 150 mM sucrose was found to be the most suitable rinsing solution for the preparation of cultured human Chang liver cells. Both freeze-drying and air-drying were used as drying methods and cells processed by either method were found to have {K}/{Na} ratios well above 1. Hence both drying methods were found to be suitable although membrane blotting followed by air-drying was preferred as excess rinsing solution can be very quickly removed during the blotting process. The {K}/{Na} ratios of cells on the same target holder but from different regions were found to be dependent on the local cell density. Cells which are locally dense-packed were found to have a much higher {K}/{Na} ratio than cells in a less dense region.

  3. Interspecies Somatic Cell Nuclear Transfer: Advancements and Problems

    PubMed Central

    Lagutina, Irina; Fulka, Helena; Lazzari, Giovanna

    2013-01-01

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

  4. Ras-mediated cell cycle arrest is altered by nuclear oncogenes to induce Schwann cell transformation.

    PubMed Central

    Ridley, A J; Paterson, H F; Noble, M; Land, H

    1988-01-01

    The cellular responses to ras and nuclear oncogenes were investigated in purified populations of rat Schwann cells. v-Ha-ras and SV40 large T cooperate to transform Schwann cells, inducing growth in soft agar and allowing proliferation in the absence of added mitogens. Expression of large T alone reduces their growth factor requirements but is insufficient to induce full transformation. In contrast, expression of v-Ha-ras leads to proliferation arrest in Schwann cells expressing a temperature-sensitive mutant of large T at the restrictive temperature. Cells arrest in either the G1 or G2/M phases of the cell cycle, and can re-enter cell division at the permissive temperature even after prolonged periods at the restrictive conditions. Oncogenic ras proteins also inhibit DNA synthesis when microinjected into Schwann cells. Adenovirus E1a and c-myc oncogenes behave similarly to SV40 large T. They cooperate with Ha-ras oncogenes to transform Schwann cells, and prevent ras-induced growth arrest. Thus nuclear oncogenes fundamentally alter the response of Schwann cells to a ras oncogene from cell cycle arrest to transformation. Images PMID:3049071

  5. Method for somatic cell nuclear transfer in zebrafish.

    PubMed

    Siripattarapravat, K; Prukudom, S; Cibelli, J

    2016-01-01

    This chapter presents a detailed methodology for somatic cell nuclear transfer-cloning of zebrafish. We aim to place the reader in a virtual lab experience to assist acquisition of the technical skills required for reproducing the published protocol. All materials, including catalog numbers for reagents and techniques for their preparation, are provided. Our protocols describe laser inactivation of egg chromosomes, the transfer of a cell through the oocyte micropyle, and spontaneous activation of the reconstructed embryo. High-quality eggs are the key to cloning success, and Chinook salmon ovarian fluid is indispensable for keeping eggs arrested at the metaphase of meiosis II. This protocol continues to be refined by our laboratory. However, naive investigators should be able to apply it in its present form to generate cloned zebrafish. PMID:27443929

  6. Nuclear Localization of Flavivirus RNA Synthesis in Infected Cells

    PubMed Central

    Uchil, Pradeep Devappa; Kumar, Anil V. A.; Satchidanandam, Vijaya

    2006-01-01

    Flaviviral replication is believed to be exclusively cytoplasmic, occurring within virus-induced membrane-bound replication complexes in the host cytoplasm. Here we show that a significant proportion (20%) of the total RNA-dependent RNA polymerase (RdRp) activity from cells infected with West Nile virus, Japanese encephalitis virus (JEV), and dengue virus is resident within the nucleus. Consistent with this, the major replicase proteins NS3 and NS5 of JEV also localized within the nucleus. NS5 was found distributed throughout the nucleoplasm, but NS3 was present at sites of active flaviviral RNA synthesis, colocalizing with NS5, and visible as distinct foci along the inner periphery of the nucleus by confocal and immunoelectron microscopy. Both these viral replicase proteins were also present in the nuclear matrix, colocalizing with the peripheral lamina, and revealed a well-entrenched nuclear location for the viral replication complex. In keeping with this observation, antibodies to either NS3 or NS5 coimmunoprecipitated the other protein from isolated nuclei along with newly synthesized viral RNA. Taken together these data suggest an absolute requirement for both of the replicase proteins for nucleus-localized synthesis of flavivirus RNA. Thus, we conclusively demonstrate for the first time that the host cell nucleus functions as an additional site for the presence of functionally active flaviviral replicase complex. PMID:16699025

  7. Vertical nanopillars for in situ probing of nuclear mechanics in adherent cells.

    PubMed

    Hanson, Lindsey; Zhao, Wenting; Lou, Hsin-Ya; Lin, Ziliang Carter; Lee, Seok Woo; Chowdary, Praveen; Cui, Yi; Cui, Bianxiao

    2015-06-01

    The mechanical stability and deformability of the cell nucleus are crucial to many biological processes, including migration, proliferation and polarization. In vivo, the cell nucleus is frequently subjected to deformation on a variety of length and time scales, but current techniques for studying nuclear mechanics do not provide access to subnuclear deformation in live functioning cells. Here we introduce arrays of vertical nanopillars as a new method for the in situ study of nuclear deformability and the mechanical coupling between the cell membrane and the nucleus in live cells. Our measurements show that nanopillar-induced nuclear deformation is determined by nuclear stiffness, as well as opposing effects from actin and intermediate filaments. Furthermore, the depth, width and curvature of nuclear deformation can be controlled by varying the geometry of the nanopillar array. Overall, vertical nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and mechanotransduction in live cells. PMID:25984833

  8. Vertical nanopillars for in situ probing of nuclear mechanics in adherent cells

    NASA Astrophysics Data System (ADS)

    Hanson, Lindsey; Zhao, Wenting; Lou, Hsin-Ya; Lin, Ziliang Carter; Lee, Seok Woo; Chowdary, Praveen; Cui, Yi; Cui, Bianxiao

    2015-06-01

    The mechanical stability and deformability of the cell nucleus are crucial to many biological processes, including migration, proliferation and polarization. In vivo, the cell nucleus is frequently subjected to deformation on a variety of length and time scales, but current techniques for studying nuclear mechanics do not provide access to subnuclear deformation in live functioning cells. Here we introduce arrays of vertical nanopillars as a new method for the in situ study of nuclear deformability and the mechanical coupling between the cell membrane and the nucleus in live cells. Our measurements show that nanopillar-induced nuclear deformation is determined by nuclear stiffness, as well as opposing effects from actin and intermediate filaments. Furthermore, the depth, width and curvature of nuclear deformation can be controlled by varying the geometry of the nanopillar array. Overall, vertical nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and mechanotransduction in live cells.

  9. Vertical nanopillars for in situ probing of nuclear mechanics in adherent cells.

    PubMed

    Hanson, Lindsey; Zhao, Wenting; Lou, Hsin-Ya; Lin, Ziliang Carter; Lee, Seok Woo; Chowdary, Praveen; Cui, Yi; Cui, Bianxiao

    2015-06-01

    The mechanical stability and deformability of the cell nucleus are crucial to many biological processes, including migration, proliferation and polarization. In vivo, the cell nucleus is frequently subjected to deformation on a variety of length and time scales, but current techniques for studying nuclear mechanics do not provide access to subnuclear deformation in live functioning cells. Here we introduce arrays of vertical nanopillars as a new method for the in situ study of nuclear deformability and the mechanical coupling between the cell membrane and the nucleus in live cells. Our measurements show that nanopillar-induced nuclear deformation is determined by nuclear stiffness, as well as opposing effects from actin and intermediate filaments. Furthermore, the depth, width and curvature of nuclear deformation can be controlled by varying the geometry of the nanopillar array. Overall, vertical nanopillar arrays constitute a novel approach for non-invasive, subcellular perturbation of nuclear mechanics and mechanotransduction in live cells.

  10. Development of buffalo (Bubalus bubalis) embryonic stem cell lines from somatic cell nuclear transferred blastocysts.

    PubMed

    Shah, Syed Mohmad; Saini, Neha; Ashraf, Syma; Singh, Manoj K; Manik, Radheysham; Singla, Suresh K; Palta, Prabhat; Chauhan, Manmohan Singh

    2015-11-01

    We developed buffalo embryonic stem cell lines from somatic cell nuclear transfer derived blastocysts, produced by hand-guided cloning technique. The inner cell mass of the blastocyst was cut mechanically using a Microblade and cultured onto feeder cells in buffalo embryonic stem (ES) cell culture medium at 38 °C in a 5% CO2 incubator. The stem cell colonies were characterized for alkaline phosphatase activity, karyotype, pluripotency and self-renewal markers like OCT4, NANOG, SOX2, c-Myc, FOXD3, SSEA-1, SSEA-4, TRA-1-60, TRA-1-81 and CD90. The cell lines also possessed the capability to differentiate across all the three germ layers under spontaneous differentiation conditions. PMID:26987926

  11. Murine leukemia virus vector integration favors promoter regions and regional hot spots in a human T-cell line

    SciTech Connect

    Tsukahara, Tomonori; Agawa, Hideyuki; Matsumoto, Sayori; Matsuda, Mizuho; Ueno, Shuichi; Yamashita, Yuki; Yamada, Koichiro; Tanaka, Nobuyuki; Kojima, Katsuhiko; Takeshita, Toshikazu . E-mail: takesit@sch.md.shinshu-u.ac.jp

    2006-07-07

    Genomic analysis of integration will be important in evaluating the safety of human gene therapy with retroviral vectors. Here, we investigated MLV vector integration sites in human T-cells, since they are amenable to gene transfer studies, and have been used therapeutically in clinical trials. We mapped 340 MLV vector integration sites in the infected human T-cell clones we established. The data showed that MLV preferred integration near the transcription start sites ({+-}5 kb), near CpG islands ({+-}1 kb), and within the first intron of RefSeq genes. We also identified MLV integration hot spots that contained three or more integrations within a 100 kb region. RT-PCR revealed that mRNA-levels of T-cell clones that contained MLV integrations near transcription start sites or introns were dysregulated compared to the uninfected cells. These studies help define the profile of MLV integration in T-cells and the risks associated with MLV-based gene therapy.

  12. The nuclear microprobe: An insight of applications in cell biology

    NASA Astrophysics Data System (ADS)

    Moretto, Ph.; Llabador, Y.

    1997-07-01

    During the last five years, the evolution of biomedical research based upon nuclear microprobe analysis has followed the development of experimental models of cultured or isolated cells. Fundamental studies of cellular mechanisms have been approached by means of in vitro assays associated with single cell analysis. Within those groups which are involved in such programs, special emphasis has been placed on cell culture and processing techniques which fulfill the methodological requirements for intracellular ion beam analysis. Great efforts have been orientated towards the improvement of normalization procedures. It is now possible to provide reliable quantitative results expressed in such units that they can be easily cross-checked using conventional methods. Imaging techniques have been also developed for the identification of the analyzed structures. In this paper, different domains of cell biology which have been addressed during the last years are reviewed. Studies dealing with cellular physiology and pharmacology are briefly presented as are also those related to the role of trace elements. Topics under development in our group as well as ongoing investigations will be also evoked.

  13. Hot conditioning equipment conceptual design report

    SciTech Connect

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

  14. ASSESSMENT OF THE RADIONUCLIDE COMPOSITION OF "HOT PARTICLES" SAMPLED IN THE CHERNOBYL NUCLEAR POWER PLANT FOURTH REACTOR UNIT

    SciTech Connect

    Farfan, E.; Jannik, T.; Marra, J.

    2011-10-01

    Fuel-containing materials sampled from within the Chernobyl Nuclear Power Plant (ChNPP) 4th Reactor Unit Confinement Shelter were spectroscopically studied for gamma and alpha content. Isotopic ratios for cesium, europium, plutonium, americium, and curium were identified and the fuel burnup in these samples was determined. A systematic deviation in the burnup values based on the cesium isotopes, in comparison with other radionuclides, was observed. The conducted studies were the first ever performed to demonstrate the presence of significant quantities of {sup 242}Cm and {sup 243}Cm. It was determined that there was a systematic underestimation of activities of transuranic radionuclides in fuel samples from inside of the ChNPP Confinement Shelter, starting from {sup 241}Am (and going higher), in comparison with the theoretical calculations.

  15. Assessment of the radionuclide composition of "hot particles" sampled in the Chernobyl nuclear power plant fourth reactor unit.

    PubMed

    Bondarkov, Mikhail D; Zheltonozhsky, Viktor A; Zheltonozhskaya, Maryna V; Kulich, Nadezhda V; Maksimenko, Andrey M; Farfán, Eduardo B; Jannik, G Timothy; Marra, James C

    2011-10-01

    Fuel-containing materials sampled from within the Chernobyl Nuclear Power Plant (ChNPP) Unit 4 Confinement Shelter were spectroscopically studied for gamma and alpha content. Isotopic ratios for cesium, europium, plutonium, americium, and curium were identified, and the fuel burn-up in these samples was determined. A systematic deviation in the burn-up values based on the cesium isotopes in comparison with other radionuclides was observed. The studies conducted were the first ever performed to demonstrate the presence of significant quantities of 242Cm and 243Cm. It was determined that there was a systematic underestimation of activities of transuranic radionuclides in fuel samples from inside of the ChNPP Confinement Shelter, starting from 241Am (and going higher) in comparison with the theoretical calculations.

  16. Nuclear orphan receptor TLX affects gene expression, proliferation and cell apoptosis in beta cells.

    PubMed

    Shi, Xiaoli; Xiong, Xiaokan; Dai, Zhe; Deng, Haohua; Sun, Li; Hu, Xuemei; Zhou, Feng; Xu, Yancheng

    Nuclear orphan receptor TLX is an essential regulator of the growth of neural stem cells. However, its exact function in pancreatic islet cells is still unknown. In the present study, gene expression profiling analysis revealed that overexpression of TLX in beta cell line MIN6 causes suppression of 176 genes and upregulation of 49 genes, including a cadre of cell cycle, cell proliferation and cell death control genes, such as Btg2, Ddit3 and Gadd45a. We next examined the effects of TLX overexpression on proliferation, apoptosis and insulin secretion in MIN6 cells. Proliferation analysis using EdU assay showed that overexpression of TLX increased percentage of EdU-positive cells. Cell cycle and apoptosis analysis revealed that overexpression of TLX in MIN6 cells resulted in higher percentage of cells exiting G1 into S-phase, and a 58.8% decrease of cell apoptosis induced by 0.5 mM palmitate. Moreover, TLX overexpression did not cause impairment of insulin secretion. Together, we conclude that TLX is among factors capable of controlling beta cell proliferation and survival, which may serve as a target for the development of novel therapies for diabetes.

  17. Las1 Is an Essential Nuclear Protein Involved in Cell Morphogenesis and Cell Surface Growth

    PubMed Central

    Doseff, A. I.; Arndt, K. T.

    1995-01-01

    Saccharomyces cerevisiae mutations that cause a requirement for SSD1-v for viability were isolated, yielding one new gene, LAS1, and three previously identified genes, SIT4, BCK1/SLK1, and SMP3. Three of these genes, LAS1, SIT4, and BCK1/SLK1, encode proteins that have roles in bud formation or morphogenesis. LAS1 is essential and loss of LAS1 function causes the cells to arrest as 80% unbudded cells and 20% large budded cells that accumulate many vesicles at the mother-daughter neck. Overexpression of LAS1 results in extra cell surface projections in the mother cell, alterations in actin and SPA2 localization, and the accumulation of electron-dense structures along the periphery of both the mother cell and the bud. The nuclear localization of LAS1 suggests a role of LAS1 for regulating bud formation and morphogenesis via the expression of components that function directly in these processes. PMID:8582632

  18. Homocysteine-induced apoptosis in endothelial cells coincides with nuclear NOX2 and peri-nuclear NOX4 activity.

    PubMed

    Sipkens, Jessica A; Hahn, Nynke; van den Brand, Carlien S; Meischl, Christof; Cillessen, Saskia A G M; Smith, Desirée E C; Juffermans, Lynda J M; Musters, René J P; Roos, Dirk; Jakobs, Cornelis; Blom, Henk J; Smulders, Yvo M; Krijnen, Paul A J; Stehouwer, Coen D A; Rauwerda, Jan A; van Hinsbergh, Victor W M; Niessen, Hans W M

    2013-11-01

    Apoptosis of endothelial cells related to homocysteine (Hcy) has been reported in several studies. In this study, we evaluated whether reactive oxygen species (ROS)-producing signaling pathways contribute to Hcy-induced apoptosis induction, with specific emphasis on NADPH oxidases. Human umbilical vein endothelial cells were incubated with 0.01-2.5 mM Hcy. We determined the effect of Hcy on caspase-3 activity, annexin V positivity, intracellular NOX1, NOX2, NOX4, and p47(phox) expression and localization, nuclear nitrotyrosine accumulation, and mitochondrial membrane potential (ΔΨ m). Hcy induced caspase-3 activity and apoptosis; this effect was concentration dependent and maximal after 6-h exposure to 2.5 mM Hcy. It was accompanied by a significant increase in ΔΨ m. Cysteine was inactive on these parameters excluding a reactive thiol group effect. Hcy induced an increase in cellular NOX2, p47(phox), and NOX4, but not that of NOX1. 3D digital imaging microscopy followed by image deconvolution analysis showed nuclear accumulation of NOX2 and p47(phox) in endothelial cells exposed to Hcy, but not in control cells, which coincided with accumulation of nuclear nitrotyrosine residues. Furthermore, Hcy enhanced peri-nuclear localization of NOX4 coinciding with accumulation of peri-nuclear nitrotyrosine residues, a reflection of local ROS production. p47(phox) was also increased in the peri-nuclear region. The Hcy-induced increase in caspase-3 activity was prevented by DPI and apocynin, suggesting involvement of NOX activity. The data presented in this article reveal accumulation of nuclear NOX2 and peri-nuclear NOX4 accumulation as potential source of ROS production in Hcy-induced apoptosis in endothelial cells.

  19. [Inhibitory effects of a hot water extract from Japanese tea on the cell growth of mutans streptococci].

    PubMed

    Kitamura, K; Loyola, J P; Sobue, S

    1990-01-01

    This study was undertaken to examine the effect of a hot water extract from Japanese tea on the cellular growth of mutans streptococci in vitro. The extract contained polyphenol compounds, mainly catechin derivatives. Few fluoride components were contained in the extract. Streptococcus mutans MT8148R (serotype c) and S. sobrinus MT6715 (serotype g) strains were used in the present study. The organisms (10-10(7) CFU/ml) were cultured in brain heart infusion (BHI) and tryptose phosphate (TP) broths containing the tea extract (0-8 mg/ml). After incubation for 24-48 hours the cell numbers in the cultures were determined. Furthermore, cell growth of these strains on BHI agar plates containing the extract (0-2 mg/ml) were examined. The results obtained were as follows: 1. The tea extract (2-8 mg/ml) in BHI broth inhibited remarkably the growth of S. mutans and S. sobrinus (inoculum size; 10(6) CFU/ml). No difference in susceptibility to the tea extract between S. mutans and S. sobrinus was noted. 2. The cell growth of both strains in TP broth was inhibited by the tea extract. However S. sobrinus was found to be more sensitive to the extract than S. mutans. 3. Growth of S. sobrinus cells on the BHI agar plate was suppressed by the tea extract more effectively than that of S. mutans. These results suggest that the tea extract would be useful as an anti-cariogenic agent. PMID:2133962

  20. XPO1 Inhibition Preferentially Disrupts the 3D Nuclear Organization of Telomeres in Tumor Cells.

    PubMed

    Taylor-Kashton, Cheryl; Lichtensztejn, Daniel; Baloglu, Erkan; Senapedis, William; Shacham, Sharon; Kauffman, Michael G; Kotb, Rami; Mai, Sabine

    2016-12-01

    Previous work has shown that the three-dimensional (3D) nuclear organization of telomeres is altered in cancer cells and the degree of alterations coincides with aggressiveness of disease. Nuclear pores are essential for spatial genome organization and gene regulation and XPO1 (exportin 1/CRM1) is the key nuclear export protein. The Selective Inhibitor of Nuclear Export (SINE) compounds developed by Karyopharm Therapeutics (KPT-185, KPT-330/selinexor, and KPT-8602) inhibit XPO1 nuclear export function. In this study, we investigated whether XPO1 inhibition has downstream effects on the 3D nuclear organization of the genome. This was assessed by measuring the 3D telomeric architecture of normal and tumor cells in vitro and ex vivo. Our data demonstrate for the first time a rapid and preferential disruption of the 3D nuclear organization of telomeres in tumor cell lines and in primary cells ex vivo derived from treatment-naïve newly diagnosed multiple myeloma patients. Normal primary cells in culture as well as healthy lymphocyte control cells from the same patients were minimally affected. Using both lymphoid and non-lymphoid tumor cell lines, we found that the downstream effects on the 3D nuclear telomere structure are independent of tumor type. We conclude that the 3D nuclear organization of telomeres is a sensitive indicator of cellular response when treated with XPO1 inhibitors. J. Cell. Physiol. 231: 2711-2719, 2016. © 2016 Wiley Periodicals, Inc. PMID:26991404

  1. XPO1 Inhibition Preferentially Disrupts the 3D Nuclear Organization of Telomeres in Tumor Cells.

    PubMed

    Taylor-Kashton, Cheryl; Lichtensztejn, Daniel; Baloglu, Erkan; Senapedis, William; Shacham, Sharon; Kauffman, Michael G; Kotb, Rami; Mai, Sabine

    2016-12-01

    Previous work has shown that the three-dimensional (3D) nuclear organization of telomeres is altered in cancer cells and the degree of alterations coincides with aggressiveness of disease. Nuclear pores are essential for spatial genome organization and gene regulation and XPO1 (exportin 1/CRM1) is the key nuclear export protein. The Selective Inhibitor of Nuclear Export (SINE) compounds developed by Karyopharm Therapeutics (KPT-185, KPT-330/selinexor, and KPT-8602) inhibit XPO1 nuclear export function. In this study, we investigated whether XPO1 inhibition has downstream effects on the 3D nuclear organization of the genome. This was assessed by measuring the 3D telomeric architecture of normal and tumor cells in vitro and ex vivo. Our data demonstrate for the first time a rapid and preferential disruption of the 3D nuclear organization of telomeres in tumor cell lines and in primary cells ex vivo derived from treatment-naïve newly diagnosed multiple myeloma patients. Normal primary cells in culture as well as healthy lymphocyte control cells from the same patients were minimally affected. Using both lymphoid and non-lymphoid tumor cell lines, we found that the downstream effects on the 3D nuclear telomere structure are independent of tumor type. We conclude that the 3D nuclear organization of telomeres is a sensitive indicator of cellular response when treated with XPO1 inhibitors. J. Cell. Physiol. 231: 2711-2719, 2016. © 2016 Wiley Periodicals, Inc.

  2. Somatic cell nuclear transfer (cloning): implications for the medical practitioner.

    PubMed

    Tong, W F; Ng, Y F; Ng, S C

    2002-07-01

    The current century will bring tremendous changes to the science and the practice of medicine. This century will be acknowledged as the century of Biology as the fusion of molecular genetics and experimental embryology pushes the barriers of science beyond perimeters that we have thought existed, as much as the past century was the century of Physics, with all the exact scientific calculations and predictions, resulting in electricity, nuclear power and quantum physics. The first major breakthrough has been the pioneering work of Wilmut and Campbell, first with the birth of Megan and Moran in 1995 (1), followed by the birth of Dolly the sheep, the first reported mammalian clone from a fully differentiated adult cell, reported in July 1996 (2). However, current cloning techniques are an extension of over 40 years of research using nuclei derived from non-human embryonic and fetal cells. However, following the birth of Dolly, the prospects of cloning technology have extended to ethically hazier areas of human cloning and embryonic stem cell research. This review hopes to bring the reader closer to the science and the ethics of this new technology, and what the implications are for the medical practitioner.

  3. Somatic cell nuclear transfer (cloning): implications for the medical practitioner.

    PubMed

    Tong, W F; Ng, Y F; Ng, S C

    2002-07-01

    The current century will bring tremendous changes to the science and the practice of medicine. This century will be acknowledged as the century of Biology as the fusion of molecular genetics and experimental embryology pushes the barriers of science beyond perimeters that we have thought existed, as much as the past century was the century of Physics, with all the exact scientific calculations and predictions, resulting in electricity, nuclear power and quantum physics. The first major breakthrough has been the pioneering work of Wilmut and Campbell, first with the birth of Megan and Moran in 1995 (1), followed by the birth of Dolly the sheep, the first reported mammalian clone from a fully differentiated adult cell, reported in July 1996 (2). However, current cloning techniques are an extension of over 40 years of research using nuclei derived from non-human embryonic and fetal cells. However, following the birth of Dolly, the prospects of cloning technology have extended to ethically hazier areas of human cloning and embryonic stem cell research. This review hopes to bring the reader closer to the science and the ethics of this new technology, and what the implications are for the medical practitioner. PMID:12437047

  4. Quantification of nanoscale nuclear refractive index changes during the cell cycle

    NASA Astrophysics Data System (ADS)

    Bista, Rajan K.; Uttam, Shikhar; Wang, Pin; Staton, Kevin; Choi, Serah; Bakkenist, Christopher J.; Hartman, Douglas J.; Brand, Randall E.; Liu, Yang

    2011-07-01

    Intrigued by our recent finding that the nuclear refractive index is significantly increased in malignant cells and histologically normal cells in clinical histology specimens derived from cancer patients, we sought to identify potential biological mechanisms underlying the observed phenomena. The cell cycle is an ordered series of events that describes the intervals of cell growth, DNA replication, and mitosis that precede cell division. Since abnormal cell cycles and increased proliferation are characteristic of many human cancer cells, we hypothesized that the observed increase in nuclear refractive index could be related to an abundance or accumulation of cells derived from cancer patients at a specific point or phase(s) of the cell cycle. Here we show that changes in nuclear refractive index of fixed cells are seen as synchronized populations of cells that proceed through the cell cycle, and that increased nuclear refractive index is strongly correlated with increased DNA content. We therefore propose that an abundance of cells undergoing DNA replication and mitosis may explain the increase in nuclear refractive index observed in both malignant and histologically normal cells from cancer patients. Our findings suggest that nuclear refractive index may be a novel physical parameter for early cancer detection and risk stratification.

  5. Silicon quantum dots in SiO{sub x} dielectrics as energy selective contacts in hot carrier solar cells

    SciTech Connect

    Kar, Debjit; Das, Debajyoti

    2015-06-24

    Thin films of c-Si QDs embedded in a-SiO{sub x} dielectric matrix was achieved at a low temperature ∼400°C, from one step process by reactive rf magnetron co-sputtering of c-Si wafer and pure SiO{sub 2} targets, in the (H{sub 2}+Ar)- plasma. Formation of a double-barrier structure has been primarily identified from the SAX data and exclusively confirmed from the resonant tunneling current appearing in the J-E characteristic curve peaks, determined by the discrete energy levels of c-Si QDs, at which it could be used as energy selective contacts in hot carrier solar cells.

  6. Nuclear matrix and structural and functional compartmentalization of the eucaryotic cell nucleus.

    PubMed

    Razin, S V; Borunova, V V; Iarovaia, O V; Vassetzky, Y S

    2014-07-01

    Becoming popular at the end of the 20th century, the concept of the nuclear matrix implies the existence of a nuclear skeleton that organizes functional elements in the cell nucleus. This review presents a critical analysis of the results obtained in the study of nuclear matrix in the light of current views on the organization of the cell nucleus. Numerous studies of nuclear matrix have failed to provide evidence of the existence of such a structure. Moreover, the existence of a filamentous structure that supports the nuclear compartmentalization appears to be unnecessary, since this function is performed by the folded genome itself.

  7. New approaches for understanding the nuclear force balance in living, adherent cells.

    PubMed

    Neelam, Srujana; Dickinson, Richard B; Lele, Tanmay P

    2016-02-01

    Cytoskeletal forces are transmitted to the nucleus to position and shape it. Linkages mediated by the LINC (linker of nucleoskeleton and cytoskeleton) complex transfer these forces to the nuclear envelope. Nuclear position and shape can be thought to be determined by a balance of cytoskeletal forces generated by microtubule motors that shear the nuclear surface, actomyosin forces that can pull, push and shear the nucleus, and intermediate filaments that may passively resist nuclear decentering and deformation. Parsing contributions of these different forces to nuclear mechanics is a very challenging task. Here we review new approaches that can be used in living cells to probe and understand the nuclear force balance.

  8. Nuclear vasohibin-2 promotes cell proliferation by inducing G0/G1 to S phase progression.

    PubMed

    Ge, Qianqian; Zhou, Jia; Tu, Min; Xue, Xiaofeng; Li, Zhanjun; Lu, Zipeng; Wei, Jishu; Song, Guoxin; Chen, Jianmin; Guo, Feng; Jiang, Kuirong; Miao, Yi; Gao, Wentao

    2015-09-01

    As a member of the vasohibin (VASH2) family, VASH2 is localized intracellularly as a nuclear and cytoplasmic type. Cytoplasmic VASH2 is associated with carcinoma angiogenesis and malignant transformation and promotes cancer growth. However, the function of nuclear VASH2 has yet to be investigated. The aim of the present study was to detect the nuclear VASH2 expression profile in human organs and tissues by protein microarray technique. To examine the function of nuclear VASH2, we analyzed the relationship between nuclear VASH2 and Ki-67, and stably constructed VASH2 overexpression and knockdown in LO2 and HepG2 cell lines, based on a previous study in hepatic cells. The study was conducted using bromodeoxyuridine, immunofluorescent staining, western blot analysis and flow cytometry. Nuclear VASH2 was highly expressed in actively dividing cells in normal and cancer tissues. There was a significant positive correlation between nuclear VASH2 and Ki-67, indicating that nuclear VASH2 positively correlated with cell proliferation in normal and cancer tissues. The bromodeoxyuridine (BrdU) proliferation test showed that nuclear VASH2 increased the S-phase population and promoted cell proliferation, while VASH2 knockdown reduced BrdU absorbance. Cell cycle analysis revealed that nuclear VASH2 overexpression increased the S-phase population in LO2 and HepG2 cells, while nuclear VASH2 knockdown reduced the S-phase population and increased the G0/G1 population. The findings of this study challenge the classic view of VASH2, which was previously reported as an angiogenesis factor. Furthermore, to the best of our knowledge, these results are the first clinical data indicating that nuclear VASH2, but not cytoplasmic VASH2, promotes cell proliferation by driving the cell cycle from the G0/G1 to S phase.

  9. Nuclear transition between the conjunction cells of Phaeodactylum tricornutum Bohlin (Bacillariophyta)

    NASA Astrophysics Data System (ADS)

    Li, Si; Pan, Kehou; Zhu, Baohua; Zhang, Lin

    2012-09-01

    Phaeodactylum tricornutum is one of the important marine diatoms for oceanic primary production. Its reproduction has profound significance in the life cycle; however, the nuclear behavior during its sexual reproduction was not clear. In this study, we observed the nuclear transition and determined its correlation with cell conjunction. It was found that two cells jointed at their apices first and swung and aligned each other immediately, and nucleus from one cell was able to transfer into another one during cell conjugation. The cell pairs conjugated for nuclear transition were different from those formed in mitosis in hypovalve thickness and cellular arrangement. Our findings proved the existence of sexual reproduction in P. tricornutum.

  10. Nuclear receptors as regulators of stem cell and cancer stem cell metabolism.

    PubMed

    Simandi, Zoltan; Cuaranta-Monroy, Ixchelt; Nagy, Laszlo

    2013-12-01

    Cellular metabolism is underpinning physiological processes in all cells. These include housekeeping functions as well as specific activities unique to a particular cell type. A growing number of studies in various experimental models indicate that metabolism is tightly connected to embryonic development as well. It is also emerging that metabolic processes have regulatory roles and by changing metabolism, cellular processes and even fates can be influenced. Nuclear receptors (NRs) are transcription factors, responding to changes in metabolites and are implicated in diverse biological processes such as embryonic development, differentiation, metabolism and cancer. Therefore, NRs are key links between metabolism and cell fate decisions. In this review, we introduce ESRRβ, DAX-1 and LRH-1 as putative regulators of metabolism in pluripotent embryonic stem cells. We also discuss the role of TR4, NGF1β, LXRβ and RARs in stemness. In addition, we summarize our current understanding of the potential roles of NRs in cancer stem cells. PMID:24184382

  11. 3D nuclear architecture reveals coupled cell cycle dynamics of chromatin and nuclear pores in the malaria parasite Plasmodium falciparum.

    PubMed

    Weiner, Allon; Dahan-Pasternak, Noa; Shimoni, Eyal; Shinder, Vera; von Huth, Palle; Elbaum, Michael; Dzikowski, Ron

    2011-07-01

    The deadliest form of human malaria is caused by the protozoan parasite Plasmodium falciparum. The complex life cycle of this parasite is associated with tight transcriptional regulation of gene expression. Nuclear positioning and chromatin dynamics may play an important role in regulating P. falciparum virulence genes. We have applied an emerging technique of electron microscopy to construct a 3D model of the parasite nucleus at distinct stages of development within the infected red blood cell. We have followed the distribution of nuclear pores and chromatin throughout the intra-erythrocytic cycle, and have found a striking coupling between the distributions of nuclear pores and chromatin organization. Pore dynamics involve clustering, biogenesis, and division among daughter cells, while chromatin undergoes stage-dependent changes in packaging. Dramatic changes in heterochromatin distribution coincide with a previously identified transition in gene expression and nucleosome positioning during the mid-to-late schizont phase. We also found a correlation between euchromatin positioning at the nuclear envelope and the local distribution of nuclear pores, as well as a dynamic nuclear polarity during schizogony. These results suggest that cyclic patterns in gene expression during parasite development correlate with gross changes in cellular and nuclear architecture.

  12. Viscum Album Var Hot Water Extract Mediates Anti-cancer Effects through G1 Phase Cell Cycle Arrest in SK-Hep1 Human Hepatocarcinoma cells.

    PubMed

    dela Cruz, Joseph Flores; Kim, Yeon Soo; Lumbera, Wenchie Marie Lara; Hwang, Seong Gu

    2015-01-01

    Viscum album var (VAV) also known as mistletoe, has long been categorized as a traditional herbal medicine in Asia. In addition to its immunomodulating activities, mistletoe has also been used in the treatment of chronic hepatic disorders in China and Korea. There are numerous reports showing that VAV possesses anti-cancer effects, however influence on human hepatocarcinoma has never been elucidated. In the present study, hot water extracts of VAV was evaluated for its potential anti-cancer effect in vitro. SK-Hep1 cells were treated with VAV (50-400 ug/ml) for both 24 and 48 hours then cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry analysis was used to measure the proportion of SK-Hep1 in the different stages of cell cycle. RT-PCR and Western blot analysis were conducted to measure expression of cell cycle arrest related genes and proteins respectively. VAV dose dependently inhibited the proliferation of SK-Hep1 cells without any cytotoxicity with normal Chang liver cell (CCL-13). Flow cytometry analysis showed that VAV extract inhibited the cell cycle of SK-Hep1 cells via G1 phase arrest. RT-PCR and Western blot analysis both revealed that cyclin dependent kinase 2 (Cdk2) and cyclin D1 gene expression were significantly down regulated while p21 was upregulated dose dependently by VAV treatment. Combined down regulation of Cdk2, Cyclin D1 and up regulation of p21 can result in cell death. These results indicate that VAV showed evidence of anti-cancer activity through G1 phase cell cycle arrest in SK-Hep1 cells. PMID:26434853

  13. Atypical nuclear localization of VIP receptors in glioma cell lines and patients

    SciTech Connect

    Barbarin, Alice; Séité, Paule; Godet, Julie; Bensalma, Souheyla; Muller, Jean-Marc; Chadéneau, Corinne

    2014-11-28

    Highlights: • The VIP receptor VPAC1 contains a putative NLS signal. • VPAC1 is predominantly nuclear in GBM cell lines but not VPAC2. • Non-nuclear VPAC1/2 protein expression is correlated with glioma grade. • Nuclear VPAC1 is observed in 50% of stage IV glioma (GBM). - Abstract: An increasing number of G protein-coupled receptors, like receptors for vasoactive intestinal peptide (VIP), are found in cell nucleus. As VIP receptors are involved in the regulation of glioma cell proliferation and migration, we investigated the expression and the nuclear localization of the VIP receptors VPAC1 and VPAC2 in this cancer. First, by applying Western blot and immunofluorescence detection in three human glioblastoma (GBM) cell lines, we observed a strong nuclear staining for the VPAC1 receptor and a weak nuclear VPAC2 receptor staining. Second, immunohistochemical staining of VPAC1 and VPAC2 on tissue microarrays (TMA) showed that the two receptors were expressed in normal brain and glioma tissues. Expression in the non-nuclear compartment of the two receptors significantly increased with the grade of the tumors. Analysis of nuclear staining revealed a significant increase of VPAC1 staining with glioma grade, with up to 50% of GBM displaying strong VPAC1 nuclear staining, whereas nuclear VPAC2 staining remained marginal. The increase in VPAC receptor expression with glioma grades and the enhanced nuclear localization of the VPAC1 receptors in GBM might be of importance for glioma progression.

  14. Value of volume weighted mean nuclear volume in grading and prognosis of renal cell carcinoma.

    PubMed Central

    Artacho-Pérula, E; Roldán-Villalobos, R; Martínez-Cuevas, J F

    1994-01-01

    AIMS--To perform stereological quantitation of volume weighted mean nuclear volume in renal cell carcinomas; and to correlate the data obtained with recognised clinical and pathological variables and determine their prognostic value. METHODS--The point-sampled intercepts method was used to estimate mean nuclear volume in 63 cases of clear cell renal carcinoma diagnosed between 1980 and 1988. New paraffin wax embedded histological sections were analysed after systematic sampling and the test systems superimposed on a projected microscopic image to measure nuclear intercept lengths. After mathematical estimation of mean nuclear volume, statistical analyses of the data in relation to clinical and pathological variables as well as the prognostic impact were investigated. RESULTS--The mean nuclear volume was significantly associated with tumour dedifferentiation. However, mean nuclear volume showed no statistical differences with sex, age, and clinical stage. The prognostic value of mean nuclear volume, nuclear grading, and clinical stage in renal cell carcinomas was high: mean nuclear volume greater than 140 micron3 was associated with short term survival. CONCLUSIONS--Measurement of mean nuclear volume was useful as a guide to objective grading of renal cell carcinomas, though there was an overlap between tumour grades. Based on the limited number of cases analysed, the mean nuclear volume is proposed as an additional prognostic indicator. Images PMID:8027369

  15. Thin film solar cells with Si nanocrystallites embedded in amorphous intrinsic layers by hot-wire chemical vapor deposition.

    PubMed

    Park, Seungil; Parida, Bhaskar; Kim, Keunjoo

    2013-05-01

    We investigated the thin film growths of hydrogenated silicon by hot-wire chemical vapor deposition with different flow rates of SiH4 and H2 mixture ambient and fabricated thin film solar cells by implementing the intrinsic layers to SiC/Si heterojunction p-i-n structures. The film samples showed the different infrared absorption spectra of 2,000 and 2,100 cm(-1), which are corresponding to the chemical bonds of SiH and SiH2, respectively. The a-Si:H sample with the relatively high silane concentration provides the absorption peak of SiH bond, but the microc-Si:H sample with the relatively low silane concentration provides the absorption peak of SiH2 bond as well as SiH bond. Furthermore, the microc-Si:H sample showed the Raman spectral shift of 520 cm(-1) for crystalline phase Si bonds as well as the 480 cm(-1) for the amorphous phase Si bonds. These bonding structures are very consistent with the further analysis of the long-wavelength photoconduction tail and the formation of nanocrystalline Si structures. The microc-Si:H thin film solar cell has the photovoltaic behavior of open circuit voltage similar to crystalline silicon thin film solar cell, indicating that microc-Si:H thin film with the mixed phase of amorphous and nanocrystalline structures show the carrier transportation through the channel of nanocrystallites.

  16. Wide-Gap Thin Film Si n-i-p Solar Cells Deposited by Hot-Wire CVD: Preprint

    SciTech Connect

    Wang, Q.; Iwaniczko, E.; Yang, J.; Lord, K.; Guha, S.; Wang, K.; Han, D.

    2002-05-01

    High-voltage wide bandgap thin-film Si n-i-p solar cells have been made using the hot-wire chemical vapor deposition (HWCVD) technique. The best open-circuit voltage (Voc) has exceeded 0.94 V in solar cells using HWCVD in the entire n-i-p structure. A Voc of 0.97V has been achieved using HWCVD in the n and i layers and plasma-enhanced (PE) CVD for the p layer. The high voltages are attributed to the wide-gap i layer and an improved p/i interface. The wide-gap i layer is obtained by using low substrate temperatures and sufficient hydrogen dilution during the growth of the i layer to arrive at the amorphous-to-microcrystalline phase transition region. The optical band gap (E04) of the i layer is found to be 1.90 eV. These high-voltage cells also exhibit good fill factors exceeding 0.7 with short-circuit-current densities of 8 to 10 mA/cm2 on bare stainless steel substrates. We have also carried out photoluminescence (PL) spectroscopy studies and found a correlation between Voc and the PL peak energy position.

  17. Generation of embryonic stem cells from mouse adipose-tissue derived cells via somatic cell nuclear transfer.

    PubMed

    Qin, Yiren; Qin, Jilong; Zhou, Chikai; Li, Jinsong; Gao, Wei-Qiang

    2015-01-01

    Somatic cells can be reprogrammed into embryonic stem cells (ESCs) by nuclear transfer (NT-ESCs), or into induced pluripotent stem cells (iPSCs) by the "Yamanaka method." However, recent studies have indicated that mouse and human iPSCs are prone to epigenetic and transcriptional aberrations, and that NT-ESCs correspond more closely to ESCs derived from in vitro fertilized embryos than iPSCs. In addition, the procedure of NT-ESCs does not involve gene modification. Demonstration of generation of NT-ESCs using an easily-accessible source of adult cell types would be very important. Adipose tissue is a source of readily accessible donor cells and can be isolated from both males and females at different ages. Here we report that NT-ESCs can be generated from adipose tissue-derived cells (ADCs). At morphological, mRNA and protein levels, these NT-ESCs show classic ESC colonies, exhibit alkaline phosphatase (AP) activity, and display normal diploid karyotypes. Importantly, these cells express pluripotent markers including Oct4, Sox2, Nanog and SSEA-1. Furthermore, they can differentiate in vivo into various types of cells from 3 germinal layers by teratoma formation assays. This study demonstrates for the first time that ESCs can be generated from the adipose tissue by somatic cell nuclear transfer (SCNT) and suggests that ADCs can be a new donor-cell type for potential therapeutic cloning.

  18. Generation of embryonic stem cells from mouse adipose-tissue derived cells via somatic cell nuclear transfer

    PubMed Central

    Qin, Yiren; Qin, Jilong; Zhou, Chikai; Li, Jinsong; Gao, Wei-Qiang

    2015-01-01

    Somatic cells can be reprogrammed into embryonic stem cells (ESCs) by nuclear transfer (NT-ESCs), or into induced pluripotent stem cells (iPSCs) by the “Yamanaka method.” However, recent studies have indicated that mouse and human iPSCs are prone to epigenetic and transcriptional aberrations, and that NT-ESCs correspond more closely to ESCs derived from in vitro fertilized embryos than iPSCs. In addition, the procedure of NT-ESCs does not involve gene modification. Demonstration of generation of NT-ESCs using an easily-accessible source of adult cell types would be very important. Adipose tissue is a source of readily accessible donor cells and can be isolated from both males and females at different ages. Here we report that NT-ESCs can be generated from adipose tissue-derived cells (ADCs). At morphological, mRNA and protein levels, these NT-ESCs show classic ESC colonies, exhibit alkaline phosphatase (AP) activity, and display normal diploid karyotypes. Importantly, these cells express pluripotent markers including Oct4, Sox2, Nanog and SSEA-1. Furthermore, they can differentiate in vivo into various types of cells from 3 germinal layers by teratoma formation assays. This study demonstrates for the first time that ESCs can be generated from the adipose tissue by somatic cell nuclear transfer (SCNT) and suggests that ADCs can be a new donor-cell type for potential therapeutic cloning. PMID:25692793

  19. In Vivo “Hot Spot” MR Imaging of Neural Stem Cells using Fluorinated Nanoparticles

    PubMed Central

    Ruiz-Cabello, Jesús; Walczak, Piotr; Kedziorek, Dorota A.; Chacko, Vadappuram P.; Schmieder, Anna H.; Wickline, Samuel A.; Lanza, Gregory M.; Bulte., Jeff W.M.

    2008-01-01

    To optimize 19F MR tracking of stem cells, we compared cellular internalization of cationic and anionic perfluoro-15-crown-5-ether (PFCE) nanoparticles using cell culture plates with different surface coatings. The viability and proliferation of anionic and cationic PFCE-labeled neural stem cells (NSCs) did not differ from unlabeled cells. Cationic PFCE nanoparticles (19F T1/T2= 580/536 ms at 9.4T) were superior to anionic particles for intracellular fluorination. Best results were obtained with modified polystyrene culture dishes coated with both carboxylic and amino groups rather than conventional carboxyl-coated dishes. After injecting PFCE-labeled NSCs into the striatum of mouse brain, cells were readily identified in vivo by 19F MRI without changes in signal or viability over a 2-week period post-grafting. These results demonstrate that neural stem cells can be efficiently fluorinated with cationic PFCE nanoparticles without using transfection agents and visualized in vivo over prolonged periods with an MR sensitivity of approximately 140 pmol of PFCE/cell. PMID:19025893

  20. Silencing by nuclear matrix attachment distinguishes cell-type specificity: association with increased proliferation capacity

    PubMed Central

    Linnemann, Amelia K.; Krawetz, Stephen A.

    2009-01-01

    DNA loop organization by nuclear scaffold/matrix attachment is a key regulator of gene expression that may provide a means to modulate phenotype. We have previously shown that attachment of genes to the NaCl-isolated nuclear matrix correlates with their silencing in HeLa cells. In contrast, expressed genes were associated with the lithium 3,5-diiodosalicylate (LIS)-isolated nuclear scaffold. To define their role in determining phenotype matrix attached regions (MARs) on human chromosomes 14–18 were identified as a function of expression in a primary cell line. The locations of MARs in aortic adventitial fibroblast (AoAF) cells were very stable (r = 0.909) and 96% of genes attached at MARs are silent (P < 0.001). Approximately one-third of the genes uniquely expressed in AoAF cells were associated with the HeLa cell nuclear matrix and silenced. Comparatively, 81% were associated with the AoAF cell nuclear scaffold (P < 0.001) and expressed. This suggests that nuclear scaffold/matrix association mediates a portion of cell type-specific gene expression thereby modulating phenotype. Interestingly, nuclear matrix attachment and thus silencing of specific genes that regulate proliferation and maintain the integrity of the HeLa cell genome suggests that transformation may at least in part be achieved through aberrant nuclear matrix attachment. PMID:19276204

  1. Hot Groups.

    ERIC Educational Resources Information Center

    Vail, Kathleen

    1996-01-01

    Collaborators sparked by creative ideas and obsessed by a common task may not realize they're part of a "hot group"--a term coined by business professors Harold J. Leavitt and Jean Lipman-Blumen. Spawned by group decision making and employee empowerment, hot groups can flourish in education settings. They're typically small, short lived, and goal…

  2. Nuclear Atrophy of Retinal Ganglion Cells Precedes the Bax-Dependent Stage of Apoptosis

    PubMed Central

    Janssen, Katherine T.; Mac Nair, Caitlin E.; Dietz, Joel A.; Schlamp, Cassandra L.; Nickells, Robert W.

    2013-01-01

    Purpose. Retinal ganglion cells atrophy during the execution of the intrinsic apoptotic program. This process, which has been termed the apoptotic volume decrease (AVD) in other cell types, has not been well-characterized in ganglion cells. Methods. Acute optic nerve crush was used to examine neuronal atrophy in the ganglion cell layer in wild-type and Bax-deficient mice. Nuclear size was measured from retinal wholemounts. Heterochromatin formation was assessed using transmission electron microscopy, whereas histone H4 acetylation was monitored using immunofluoresence. Ganglion cell and retinal transcript abundance was measured using quantitative PCR. Results. Nuclear and soma sizes linearly correlated in both control and damaged retinas. Cells in wild-type mice exhibited nuclear atrophy within 1 day after optic nerve damage. Three days after crush, nuclear atrophy was restricted to ganglion cells identified by retrograde labeling, while amacrine cells also exhibited some atrophy by 5 days. Similar kinetics of nuclear atrophy were observed in cells deficient for the essential proapoptotic gene Bax. Bax-deficient cells also exhibited other nuclear changes common in wild-type cells, including the deacetylation of histones, formation of heterochromatin, and the silencing of ganglion cell–specific gene expression. Conclusions. Retinal ganglion cell somas and nuclei undergo the AVD in response to optic nerve damage. Atrophy is rapid and precedes the Bax-dependent committed step of the intrinsic apoptotic pathway. PMID:23422829

  3. Somatic cell nuclear transfer cloning: practical applications and current legislation.

    PubMed

    Niemann, H; Lucas-Hahn, A

    2012-08-01

    Somatic cloning is emerging as a new biotechnology by which the opportunities arising from the advances in molecular genetics and genome analysis can be implemented in animal breeding. Significant improvements have been made in SCNT protocols in the past years which now allow to embarking on practical applications. The main areas of application of SCNT are: Reproductive cloning, therapeutic cloning and basic research. A great application potential of SCNT based cloning is the production of genetically modified (transgenic) animals. Somatic cell nuclear transfer based transgenic animal production has significant advances over the previously employed microinjection of foreign DNA into pronuclei of zygotes. This cell based transgenesis is compatible with gene targeting and allows both, the addition of a specific gene and the deletion of an endogenous gene. Efficient transgenic animal production provides numerous opportunities for agriculture and biomedicine. Regulatory agencies around the world have agreed that food derived from cloned animals and their offspring is safe and there is no scientific basis for questioning this. Commercial application of somatic cloning within the EU is via the Novel Food regulation EC No. 258/97. Somatic cloning raises novel questions regarding the ethical and moral status of animals and their welfare which has prompted a controversial discussion in Europe which has not yet been resolved.

  4. Water Permeability of Chlorella Cell Membranes by Nuclear Magnetic Resonance

    PubMed Central

    Stout, Darryl G.; Steponkus, Peter L.; Bustard, Larry D.; Cotts, Robert M.

    1978-01-01

    Measurement by two nuclear magnetic resonance (NMR) techniques of the mean residence time τa of water molecules inside Chlorella vulgaris (Beijerinck) var. “viridis” (Chodot) is reported. The first is the Conlon and Outhred (1972 Biochim Biophys Acta 288: 354-361) technique in which extracellular water is doped with paramagnetic Mn2+ ions. Some complications in application of this technique are identified as being caused by the affinity of Chlorella cell walls for Mn2+ ions which shortens the NMR relaxation times of intra- and extracellular water. The second is based upon observations of effects of diffusion on the spin echo of intra- and extracellular water. Echo attenuation of intracellular water is distinguished from that of extracellular water by the extent to which diffusive motion is restricted. Intracellular water, being restricted to the cell volume, suffers less echo attenuation. From the dependence of echo amplitude upon gradient strength at several values of echo time, the mean residence time of intracellular water can be determined. From the mean residence time of intracellular water, the diffusional water permeability coefficient of the Chlorella membrane is calculated to be 2.1 ± 0.4 × 10−3 cm sec−1. PMID:16660456

  5. Characterization of tumor cells and stem cells by differential nuclear methylation imaging

    NASA Astrophysics Data System (ADS)

    Tajbakhsh, Jian; Wawrowsky, Kolja A.; Gertych, Arkadiusz; Bar-Nur, Ori; Vishnevsky, Eugene; Lindsley, Erik H.; Farkas, Daniel L.

    2008-02-01

    DNA methylation plays a key role in cellular differentiation. Aberrant global methylation patterns are associated with several cancer types, as a result of changes in long-term activation status of up to 50% of genes, including oncogenes and tumor-suppressor genes, which are regulated by methylation and demethylation of promoter region CpG dinucleotides (CpG islands). Furthermore, DNA methylation also occurs in nonisland CpG sites (> 95% of the genome), present once per 80 dinucleotides on average. Nuclear DNA methylation increases during the course of cellular differentiation while cancer cells usually show a net loss in methylation. Given the large dynamic range in DNA methylation load, the methylation pattern of a cell can provide a valuable distinction as to its status during differentiation versus the disease state. By applying immunofluorescence, confocal microscopy and 3D image analysis we assessed the potential of differential nuclear distribution of methylated DNA to be utilized as a biomarker to characterize cells during development and when diseased. There are two major fields that may immediately benefit from this development: (1) the search for factors that contribute to pluripotency and cell fate in human embryonic stem cell expansion and differentiation, and (2) the characterization of tumor cells with regard to their heterogeneity in molecular composition and behavior. We performed topological analysis of the distribution of methylated CpG-sites (MeC) versus heterochromatin. This innovative approach revealed significant differences in colocalization patterns of MeC and heterochromatin-derived signals between undifferentiated and differentiated human embryonic stem cells, as well as untreated AtT20 mouse pituitary tumor cells compared to a subpopulation of these cells treated with 5-azacytidine for 48 hours.

  6. D&D of a reactor, hot cells and gloveboxes - an integrated experience

    SciTech Connect

    Yule, T.J.; Fellhauer, C.R.; Rose, R.W.; Bhattacharyya, S.K.

    1997-08-01

    Performing Decontamination and Decommissioning (D&D) operations at a multi-use laboratory containing small sites which run the gamut of nuclear facility types within the DOE Complex provides engaging challenges, as well as many unique opportunities. While the relatively small scale of the D&D work performed at Argonne National Laboratory (ANL-E) does not present the significant environmental, safety and health risks which might be encountered at large production sites, the types of issues are representative of the most significant problems. Being a small site with relatively low risks and an exceptional rapport with local stakeholders provides for the development and demonstration of technologies and methodologies which could be utilized at the larger sites.

  7. Fission yeast Lem2 and Man1 perform fundamental functions of the animal cell nuclear lamina.

    PubMed

    Gonzalez, Yanira; Saito, Akira; Sazer, Shelley

    2012-01-01

    In animal cells the nuclear lamina, which consists of lamins and lamin-associated proteins, serves several functions: it provides a structural scaffold for the nuclear envelope and tethers proteins and heterochromatin to the nuclear periphery. In yeast, proteins and large heterochromatic domains including telomeres are also peripherally localized, but there is no evidence that yeast have lamins or a fibrous nuclear envelope scaffold. Nonetheless, we found that the Lem2 and Man1 proteins of the fission yeast Schizosaccharomyces pombe, evolutionarily distant relatives of the Lap2/Emerin/Man1 (LEM) sub-family of animal cell lamin-associated proteins, perform fundamental functions of the animal cell lamina. These integral inner nuclear membrane localized proteins, with nuclear localized DNA binding Helix-Extension-Helix (HEH) domains, impact nuclear envelope structure and integrity, are essential for the enrichment of telomeres at the nuclear periphery and by means of their HEH domains anchor chromatin, most likely transcriptionally repressed heterochromatin, to the nuclear periphery. These data indicate that the core functions of the nuclear lamina are conserved between fungi and animal cells and can be performed in fission yeast, without lamins or other intermediate filament proteins.

  8. An open-end burst test method to obtain uniaxial hoop tensile properties of fuel cladding in a hot cell

    NASA Astrophysics Data System (ADS)

    Nakatsuka, Masafumi; Aita, Makoto; Sakamoto, Kan; Higuchi, Toru

    2013-03-01

    The hoop stress-hoop strain relationship of fuel cladding is one of the essential input parameters for safety analysis of fuel rods. The three objectives of this paper were: to propose a burst test method for open-end tube specimens with the uniaxial hoop stress condition; to develop the necessary in-cell high temperature open-end burst (OEB) techniques to implement the method; and to determine the optimum specimen length for the proposed OEB test method. Silicone oil was selected as the pressurization medium, and it was sealed inside the specimens not by welding but by O-rings so that no axial tensile stress was induced in the specimens. The specimens with combined end plugs and O-rings were successfully assembled by manipulators in a hot cell, and a high temperature (⩽350 °C), high pressure (⩽100 MPa) seal was achieved. The optimum specimen length was determined by using ductile and embrittled tubes with various lengths of 30-60 mm and was found to be around 45 mm for typical BWR fuel rods. During the OEB test, internal pressure and diametral expansion were monitored to obtain the basic mechanical performance properties of the fuel cladding such as yield stress, ultimate strength, as well as the true hoop stress-hoop strain curve.

  9. The nuclear periphery of embryonic stem cells is a transcriptionally permissive and repressive compartment

    PubMed Central

    Luo, Li; Gassman, Katherine L.; Petell, Lydia M.; Wilson, Christian L.; Bewersdorf, Joerg; Shopland, Lindsay S.

    2009-01-01

    Summary Chromatin adapts a distinct structure and epigenetic state in embryonic stem cells (ESCs), but how chromatin is three-dimensionally organized within the ESC nucleus is poorly understood. Because nuclear location can influence gene expression, we examined the nuclear distributions of chromatin with key epigenetic marks in ESC nuclei. We focused on chromatin at the nuclear periphery, a compartment that represses some but not all associated genes and accumulates facultative heterochromatin in differentiated cells. Using a quantitative, cytological approach, we measured the nuclear distributions of genes in undifferentiated mouse ESCs according to epigenetic state and transcriptional activity. We found that trimethyl histone H3 lysine 27 (H3K27-Me3), which marks repressed gene promoters, is enriched at the ESC nuclear periphery. In addition, this compartment contains 10-15% of chromatin with active epigenetic marks and hundreds of transcription sites. Surprisingly, comparisons with differentiated cell types revealed similar nuclear distributions of active chromatin. By contrast, H3K27-Me3 was less concentrated at the nuclear peripheries of differentiated cells. These findings demonstrate that the nuclear periphery is an epigenetically dynamic compartment that might be distinctly marked in pluripotent ESCs. In addition, our data indicate that the nuclear peripheries of multiple cell types can contain a significant fraction of both active and repressed genes. PMID:19773359

  10. Targeting Proliferating Cell Nuclear Antigen and Its Protein Interactions Induces Apoptosis in Multiple Myeloma Cells

    PubMed Central

    Müller, Rebekka; Bachke, Siri; Gilljam, Karin M.; Våtsveen, Thea K.; Rø, Torstein B.; Bellacchio, Emanuele; Sundan, Anders; Otterlei, Marit

    2013-01-01

    Multiple myeloma is a hematological cancer that is considered incurable despite advances in treatment strategy during the last decade. Therapies targeting single pathways are unlikely to succeed due to the heterogeneous nature of the malignancy. Proliferating cell nuclear antigen (PCNA) is a multifunctional protein essential for DNA replication and repair that is often overexpressed in cancer cells. Many proteins involved in the cellular stress response interact with PCNA through the five amino acid sequence AlkB homologue 2 PCNA-interacting motif (APIM). Thus inhibiting PCNA’s protein interactions may be a good strategy to target multiple pathways simultaneously. We initially found that overexpression of peptides containing the APIM sequence increases the sensitivity of cancer cells to contemporary therapeutics. Here we have designed a cell-penetrating APIM-containing peptide, ATX-101, that targets PCNA and show that it has anti-myeloma activity. We found that ATX-101 induced apoptosis in multiple myeloma cell lines and primary cancer cells, while bone marrow stromal cells and primary healthy lymphocytes were much less sensitive. ATX-101-induced apoptosis was caspase-dependent and cell cycle phase-independent. ATX-101 also increased multiple myeloma cells’ sensitivity against melphalan, a DNA damaging agent commonly used for treatment of multiple myeloma. In a xenograft mouse model, ATX-101 was well tolerated and increased the anti-tumor activity of melphalan. Therefore, targeting PCNA by ATX-101 may be a novel strategy in multiple myeloma treatment. PMID:23936203

  11. Inhibition of thromboxane synthase induces lung cancer cell death via increasing the nuclear p27

    SciTech Connect

    Leung, Kin Chung; Hsin, Michael K.Y.; Chan, Joey S.Y.; Yip, Johnson H.Y.; Li, Mingyue; Leung, Billy C.S.; Mok, Tony S.K.; Warner, Timothy D.; Underwood, Malcolm J.; Chen, George G.

    2009-10-15

    The role of thromboxane in lung carcinogenesis is not clearly known, though thromboxane B2 (TXB{sub 2}) level is increased and antagonists of thromboxane receptors or TXA2 can induce apoptosis of lung cancer cells. p27, an atypical tumor suppressor, is normally sequestered in the nucleus. The increased nuclear p27 may result in apoptosis of tumor cells. We hypothesize that the inhibition of thromboxane synthase (TXS) induces the death of lung cancer cells and that such inhibition is associated with the nuclear p27 level. Our experiment showed that the inhibition of TXS significantly induced the death or apoptosis in lung cancer cells. The activity of TXS was increased in lung cancer. The nuclear p27 was remarkably reduced in lung cancer tissues. The inhibition of TXS caused the cell death and apoptosis of lung cancer cells, likely via the elevation of the nuclear p27 since the TXS inhibition promoted the nuclear p27 level and the inhibition of p27 by its siRNA recovered the cell death induced by TXS inhibition. Collectively, lung cancer cells produce high levels of TXB{sub 2} but their nuclear p27 is markedly reduced. The inhibition of TXS results in the p27-related induction of cell death in lung cancer cells.

  12. Literature review of metal corrosion sensitivity in high temperature, high impurity hot cell atmospheres

    SciTech Connect

    Eberle, C.S.

    1997-09-01

    The pyrochemical conditions of spent nuclear fuel for the purpose of final disposal is being demonstrated at Argonne National Laboratory (ANL). One aspect of this program is to develop a lithium preprocessing stage for the Fuel Conditioning Facility (FCF). One of the design considerations under investigation in this program is the system`s corrosion response in the presence of irradiated commercial fuel as well as atmospheric impurities. Static corrosion coupon tests have been completed which demonstrate the potential corrosivity of the salt matrix in a worse case environment as well as provide a boundary for allowable impurities in the system during operation. The literature concerning corrosion of either fused salts or molten metals consistently emphasizes three similar features which are common to both systems: (1) the overall corrosion rate is strongly dependent on temperature, impurity concentration and flow velocity; (2) many different mechanisms can be involved in a specific corrosion process; and (3) corrosion rates will significantly increase as all three of these independent variables are increased. The qualitative and quantitative understanding of these corrosion results is important for this spent fuel program since all of these variables will increase as the process scale increases. The purpose of this work was to determine if any data existed which could provide a quantitative expectation for corrosion rates of refractory metals in a lithium chloride salt bath.

  13. Improving the Presage® polymer radiosensitivity for hot cell and glovebox 3D characterization.

    PubMed

    Adamovics, John; Farfán, Eduardo B; Coleman, J Rusty

    2013-01-01

    RadBall is a novel, passive, radiation detection device that provides 3D mapping of radiation from areas where measurements have not been possible previously due to lack of access or extremely high radiation doses. This kind of technology is beneficial when decommissioning and decontamination of nuclear facilities occur. The key components of the RadBall technology include a tungsten outer shell that houses a radiosensitive PRESAGE polymer. The 1.0-cm-thick tungsten shell has a number of holes that allow photons to reach the polymer, thus generating radiation tracks that are analyzed to characterize the radiation sources within the contaminated area being considered. Facilities being mapped frequently have to be shut down to minimize radiation exposures to workers; therefore, reducing the mapping or characterization time is significant. The objective of this study was to reduce the RadBall deployment time by increasing the radiosensitivity of the PRESAGE formulation. The new formulation is four times more radiosensitive than the original formulation. Consequently, RadBall deployment times can be reduced fourfold, which is a considerable improvement.

  14. Improving the Presage® polymer radiosensitivity for hot cell and glovebox 3D characterization.

    PubMed

    Adamovics, John; Farfán, Eduardo B; Coleman, J Rusty

    2013-01-01

    RadBall is a novel, passive, radiation detection device that provides 3D mapping of radiation from areas where measurements have not been possible previously due to lack of access or extremely high radiation doses. This kind of technology is beneficial when decommissioning and decontamination of nuclear facilities occur. The key components of the RadBall technology include a tungsten outer shell that houses a radiosensitive PRESAGE polymer. The 1.0-cm-thick tungsten shell has a number of holes that allow photons to reach the polymer, thus generating radiation tracks that are analyzed to characterize the radiation sources within the contaminated area being considered. Facilities being mapped frequently have to be shut down to minimize radiation exposures to workers; therefore, reducing the mapping or characterization time is significant. The objective of this study was to reduce the RadBall deployment time by increasing the radiosensitivity of the PRESAGE formulation. The new formulation is four times more radiosensitive than the original formulation. Consequently, RadBall deployment times can be reduced fourfold, which is a considerable improvement. PMID:23192088

  15. Photoinjected hot-electron damage in silicon point-contact solar cells

    NASA Astrophysics Data System (ADS)

    Gruenbaum, P. E.; King, R. R.; Swanson, R. M.

    1989-12-01

    Initial designs of single-crystal silicon point-contact solar cells have shown a degradation in their efficiency after being exposed to concentrated sunlight. The main mechanism appears to be an increase in recombination centers at the Si/SiO2 interface due to ultraviolet light photoinjecting electrons from the silicon conduction band into the silicon dioxide that passivates the cell's front surface. The instability of the interface is significantly worse if the oxide is grown in the presence of trichloroethane. Texturization of the surface also leads to more instability. A reasonably good resistance to ultraviolet can be created by putting a phosphorus diffusion at the surface, and can be improved further by stripping off the deposited oxide after the diffusion and regrowing a dry thermal oxide.

  16. Nuclear receptors and microRNAs: Who regulates the regulators in neural stem cells?

    PubMed

    Eendebak, Robert J A H; Lucassen, Paul J; Fitzsimons, Carlos P

    2011-03-01

    In this mini-review, we focus on regulatory loops between nuclear receptors and microRNAs, an emerging class of small RNA regulators of gene expression. Evidence supporting interactions between microRNAs and nuclear receptors in the regulation of gene expression networks is discussed in relation to its possible role in neural stem cell self renewal and differentiation. Furthermore, we discuss possible disturbances of the regulatory loops between microRNAs and nuclear receptors in human neurodegenerative disease. Finally, we discuss the possible use of nuclear receptors as pharmacological entry points to regulate neural stem cell self-renewal and differentiation.

  17. Potential of primary kidney cells for somatic cell nuclear transfer mediated transgenesis in pig

    PubMed Central

    2012-01-01

    Background Somatic cell nuclear transfer (SCNT) is currently the most efficient and precise method to generate genetically tailored pig models for biomedical research. However, the efficiency of this approach is crucially dependent on the source of nuclear donor cells. In this study, we evaluate the potential of primary porcine kidney cells (PKCs) as cell source for SCNT, including their proliferation capacity, transfection efficiency, and capacity to support full term development of SCNT embryos after additive gene transfer or homologous recombination. Results PKCs could be maintained in culture with stable karyotype for up to 71 passages, whereas porcine fetal fibroblasts (PFFs) and porcine ear fibroblasts (PEFs) could be hardly passaged more than 20 times. Compared with PFFs and PEFs, PKCs exhibited a higher proliferation rate and resulted in a 2-fold higher blastocyst rate after SCNT and in vitro cultivation. Among the four transfection methods tested with a GFP expression plasmid, best results were obtained with the NucleofectorTM technology, resulting in transfection efficiencies of 70% to 89% with high fluorescence intensity, low cytotoxicity, good cell proliferation, and almost no morphological signs of cell stress. Usage of genetically modified PKCs in SCNT resulted in approximately 150 piglets carrying at least one of 18 different transgenes. Several of those pigs originated from PKCs that underwent homologous recombination and antibiotic selection before SCNT. Conclusion The high proliferation capacity of PKCs facilitates the introduction of precise and complex genetic modifications in vitro. PKCs are thus a valuable cell source for the generation of porcine biomedical models by SCNT. PMID:23140586

  18. Nuclear Membrane Dynamics and Reassembly in Living Cells: Targeting of an Inner Nuclear Membrane Protein in Interphase and Mitosis

    PubMed Central

    Ellenberg, Jan; Siggia, Eric D.; Moreira, Jorge E.; Smith, Carolyn L.; Presley, John F.; Worman, Howard J.; Lippincott-Schwartz, Jennifer

    1997-01-01

    The mechanisms of localization and retention of membrane proteins in the inner nuclear membrane and the fate of this membrane system during mitosis were studied in living cells using the inner nuclear membrane protein, lamin B receptor, fused to green fluorescent protein (LBR–GFP). Photobleaching techniques revealed the majority of LBR–GFP to be completely immobilized in the nuclear envelope (NE) of interphase cells, suggesting a tight binding to heterochromatin and/or lamins. A subpopulation of LBR–GFP within ER membranes, by contrast, was entirely mobile and diffused rapidly and freely (D = 0.41 ± 0.1 μm2/s). High resolution confocal time-lapse imaging in mitotic cells revealed LBR–GFP redistributing into the interconnected ER membrane system in prometaphase, exhibiting the same high mobility and diffusion constant as observed in interphase ER membranes. LBR–GFP rapidly diffused across the cell within the membrane network defined by the ER, suggesting the integrity of the ER was maintained in mitosis, with little or no fragmentation and vesiculation. At the end of mitosis, nuclear membrane reformation coincided with immobilization of LBR–GFP in ER elements at contact sites with chromatin. LBR–GFP–containing ER membranes then wrapped around chromatin over the course of 2–3 min, quickly and efficiently compartmentalizing nuclear material. Expansion of the NE followed over the course of 30–80 min. Thus, selective changes in lateral mobility of LBR–GFP within the ER/NE membrane system form the basis for its localization to the inner nuclear membrane during interphase. Such changes, rather than vesiculation mechanisms, also underlie the redistribution of this molecule during NE disassembly and reformation in mitosis. PMID:9298976

  19. Molecular Characterization and Functional Analysis of Annulate Lamellae Pore Complexes in Nuclear Transport in Mammalian Cells

    PubMed Central

    Raghunayakula, Sarita; Subramonian, Divya; Dasso, Mary; Kumar, Rita; Zhang, Xiang-Dong

    2015-01-01

    Annulate lamellae are cytoplasmic organelles containing stacked sheets of membranes embedded with pore complexes. These cytoplasmic pore complexes at annulate lamellae are morphologically similar to nuclear pore complexes at the nuclear envelope. Although annulate lamellae has been observed in nearly all types of cells, their biological functions are still largely unknown. Here we show that SUMO1-modification of the Ran GTPase-activating protein RanGAP1 not only target RanGAP1 to its known sites at nuclear pore complexes but also to annulate lamellae pore complexes through interactions with the Ran-binding protein RanBP2 and the SUMO-conjugating enzyme Ubc9 in mammalian cells. Furthermore, upregulation of annulate lamellae, which decreases the number of nuclear pore complexes and concurrently increases that of annulate lamellae pore complexes, causes a redistribution of nuclear transport receptors including importin α/β and the exportin CRM1 from nuclear pore complexes to annulate lamellae pore complexes and also reduces the rates of nuclear import and export. Moreover, our results reveal that importin α/β-mediated import complexes initially accumulate at annulate lamellae pore complexes upon the activation of nuclear import and subsequently disassociate for nuclear import through nuclear pore complexes in cells with upregulation of annulate lamellae. Lastly, CRM1-mediated export complexes are concentrated at both nuclear pore complexes and annulate lamellae pore complexes when the disassembly of these export complexes is inhibited by transient expression of a Ran GTPase mutant arrested in its GTP-bound form, suggesting that RanGAP1/RanBP2-activated RanGTP hydrolysis at these pore complexes is required for the dissociation of the export complexes. Hence, our findings provide a foundation for further investigation of how upregulation of annulate lamellae decreases the rates of nuclear transport and also for elucidation of the biological significance of the

  20. Molecular Characterization and Functional Analysis of Annulate Lamellae Pore Complexes in Nuclear Transport in Mammalian Cells.

    PubMed

    Raghunayakula, Sarita; Subramonian, Divya; Dasso, Mary; Kumar, Rita; Zhang, Xiang-Dong

    2015-01-01

    Annulate lamellae are cytoplasmic organelles containing stacked sheets of membranes embedded with pore complexes. These cytoplasmic pore complexes at annulate lamellae are morphologically similar to nuclear pore complexes at the nuclear envelope. Although annulate lamellae has been observed in nearly all types of cells, their biological functions are still largely unknown. Here we show that SUMO1-modification of the Ran GTPase-activating protein RanGAP1 not only target RanGAP1 to its known sites at nuclear pore complexes but also to annulate lamellae pore complexes through interactions with the Ran-binding protein RanBP2 and the SUMO-conjugating enzyme Ubc9 in mammalian cells. Furthermore, upregulation of annulate lamellae, which decreases the number of nuclear pore complexes and concurrently increases that of annulate lamellae pore complexes, causes a redistribution of nuclear transport receptors including importin α/β and the exportin CRM1 from nuclear pore complexes to annulate lamellae pore complexes and also reduces the rates of nuclear import and export. Moreover, our results reveal that importin α/β-mediated import complexes initially accumulate at annulate lamellae pore complexes upon the activation of nuclear import and subsequently disassociate for nuclear import through nuclear pore complexes in cells with upregulation of annulate lamellae. Lastly, CRM1-mediated export complexes are concentrated at both nuclear pore complexes and annulate lamellae pore complexes when the disassembly of these export complexes is inhibited by transient expression of a Ran GTPase mutant arrested in its GTP-bound form, suggesting that RanGAP1/RanBP2-activated RanGTP hydrolysis at these pore complexes is required for the dissociation of the export complexes. Hence, our findings provide a foundation for further investigation of how upregulation of annulate lamellae decreases the rates of nuclear transport and also for elucidation of the biological significance of the

  1. Mitotic chromosome length scales in response to both cell and nuclear size

    PubMed Central

    Ladouceur, Anne-Marie; Dorn, Jonas F.

    2015-01-01

    Multicellular development requires that cells reduce in size as a result of consecutive cell divisions without increase in embryo volume. To maintain cellular integrity, organelle size adapts to cell size throughout development. During mitosis, the longest chromosome arm must be shorter than half of the mitotic spindle for proper chromosome segregation. Using high-resolution time-lapse microscopy of living Caenorhabditis elegans embryos, we have quantified the relation between cell size and chromosome length. In control embryos, chromosome length scaled to cell size. Artificial reduction of cell size resulted in a shortening of chromosome length, following a trend predicted by measurements from control embryos. Disturbing the RAN (Ras-related nuclear protein)-GTP gradient decoupled nuclear size from cell size and resulted in chromosome scaling to nuclear size rather than cell size; smaller nuclei contained shorter chromosomes independent of cell size. In sum, quantitative analysis relating cell, nuclear, and chromosome size predicts two levels of chromosome length regulation: one through cell size and a second in response to nuclear size. PMID:26033258

  2. Pig transgenesis by piggyBac transposition in combination with somatic cell nuclear transfer.

    PubMed

    Wu, Zhenfang; Xu, Zhiqian; Zou, Xian; Zeng, Fang; Shi, Junsong; Liu, Dewu; Urschitz, Johann; Moisyadi, Stefan; Li, Zicong

    2013-12-01

    The production of animals by somatic cell nuclear transfer (SCNT) is inefficient, with approximately 2% of micromanipulated oocytes going to term and resulting in live births. However, it is the most commonly used method for the generation of cloned transgenic livestock as it facilitates the attainment of transgenic animals once the nuclear donor cells are stably transfected and more importantly as alternatives methods of transgenesis in farm animals have proven even less efficient. Here we describe piggyBac-mediated transposition of a transgene into porcine primary cells and use of these genetically modified cells as nuclear donors for the generation of transgenic pigs by SCNT. Gene transfer by piggyBac transposition serves to provide an alternative approach for the transfection of nuclear donor cells used in SCNT.

  3. Localization of P-glycoprotein at the nuclear envelope of rat brain cells

    SciTech Connect

    Babakhanian, Karlo; Bendayan, Moise; Bendayan, Reina . E-mail: r.bendayan@utoronto.ca

    2007-09-21

    P-Glycoprotein is a plasma membrane drug efflux protein implicated in extrusion of cytotoxic compounds out of a cell. There is now evidence that suggests expression of this transporter at several subcellular sites, including the nucleus, mitochondria, and Golgi apparatus. This study investigated the localization and expression of P-glycoprotein at the nuclear membrane of rat brain microvessel endothelial (RBE4) and microglial (MLS-9) cell lines. Immunocytochemistry at the light and electron microscope levels using P-glycoprotein monoclonals antibodies demonstrated the localization of the protein at the nuclear envelope of RBE4 and MLS-9 cells. Western blot analysis revealed a single band of 170-kDa in purified nuclear membranes prepared from isolated nuclei of RBE4 and MLS-9 cells. These findings indicate that P-glycoprotein is expressed at the nuclear envelope of rat brain cells and suggest a role in multidrug resistance at this subcellular site.

  4. Identification of a novel RNA giant nuclear body in cancer cells.

    PubMed

    Zhou, Hong; Zhang, Jiawei; Gu, Ying; Gan, Xiaoxian; Gan, Yichao; Zheng, Weiwei; Kim, Byung-Wook; Xu, Xiaohua; Lu, Xiaoya; Dong, Qi; Zheng, Shu; Huang, Wendong; Xu, Rongzhen

    2016-01-26

    Constitutive synthesis of oncogenic mRNAs is essential for maintaining the uncontrolled growth of cancer cells. However, little is known about how these mRNAs are exported from the nucleus to the cytoplasm. Here, we report the identification of a RNA giant nuclear body (RNA-GNB) that is abundant in cancer cells but rare in normal cells. The RNA-GNB contains a RNA core surrounded by a protein shell. We identify 782 proteins from cancer-associated RNA-GNBs, 40% of which are involved in the nuclear mRNA trafficking. RNA-GNB is required for cell proliferation, and its abundance is positively associated with tumor burden and outcome of therapies. Our findings suggest that the RNA-GNB is a novel nuclear RNA trafficking organelle that may contribute to the nuclear mRNA exporting and proliferation of cancer cells. PMID:26678034

  5. Identification of a novel RNA giant nuclear body in cancer cells.

    PubMed

    Zhou, Hong; Zhang, Jiawei; Gu, Ying; Gan, Xiaoxian; Gan, Yichao; Zheng, Weiwei; Kim, Byung-Wook; Xu, Xiaohua; Lu, Xiaoya; Dong, Qi; Zheng, Shu; Huang, Wendong; Xu, Rongzhen

    2016-01-26

    Constitutive synthesis of oncogenic mRNAs is essential for maintaining the uncontrolled growth of cancer cells. However, little is known about how these mRNAs are exported from the nucleus to the cytoplasm. Here, we report the identification of a RNA giant nuclear body (RNA-GNB) that is abundant in cancer cells but rare in normal cells. The RNA-GNB contains a RNA core surrounded by a protein shell. We identify 782 proteins from cancer-associated RNA-GNBs, 40% of which are involved in the nuclear mRNA trafficking. RNA-GNB is required for cell proliferation, and its abundance is positively associated with tumor burden and outcome of therapies. Our findings suggest that the RNA-GNB is a novel nuclear RNA trafficking organelle that may contribute to the nuclear mRNA exporting and proliferation of cancer cells.

  6. GHz Rabi Flopping to Rydberg States in Hot Atomic Vapor Cells

    SciTech Connect

    Huber, B.; Baluktsian, T.; Schlagmueller, M.; Koelle, A.; Kuebler, H.; Loew, R.; Pfau, T.

    2011-12-09

    We report on the observation of Rabi oscillations to a Rydberg state on a time scale below 1 ns in thermal rubidium vapor. We use a bandwidth-limited pulsed excitation and observe up to 6 full Rabi cycles within a pulse duration of {approx}4 ns. We find good agreement between the experiment and numerical simulations based on a surprisingly simple model. This result shows that fully coherent dynamics with Rydberg states can be achieved even in thermal atomic vapor, thus suggesting small vapor cells as a platform for room-temperature quantum devices. Furthermore, the result implies that previous coherent dynamics in single-atom Rydberg gates can be accelerated by 3 orders of magnitude.

  7. Nuclear location-dependent role of peripheral benzodiazepine receptor (PBR) in hepatic tumoral cell lines proliferation.

    PubMed

    Corsi, L; Geminiani, E; Avallone, R; Baraldi, M

    2005-04-15

    PBR is involved in numerous biological functions, including steroid biosynthesis, mitochondrial oxidative phosphorylation and cell proliferation. The presence of PBR at the perinuclear/nuclear subcellular level has been demonstrated in aggressive breast cancer cell lines and human glioma cells where it seems to be involved in cell proliferation. In our study we investigated the presence of perinuclear/nuclear PBR in different hepatic tumor cell lines with regard to binding to [3H] PK 11195 and protein analysis. The results obtained by saturation binding experiments and scatchard analysis of perinuclear/nuclear PBR density in parallel with the results on the growth curves of the cell lines tested, indicate that the perinuclear/nuclear PBR density correlates inversely with cell doubling time. Moreover, the cell line with high perinuclear/nuclear PBR proliferated in response to PBR ligand, whereas that with low perinuclear/nuclear PBR did not. Our results reinforce the idea that the subcellular localisation of PBR defines its function and that this receptor could be a possible target for new strategies against cancer.

  8. Role of Actin Filaments in Correlating Nuclear Shape and Cell Spreading

    PubMed Central

    Vishavkarma, Renu; Raghavan, Swetavalli; Kuyyamudi, Chandrashekar; Majumder, Abhijit; Dhawan, Jyotsna; Pullarkat, Pramod A.

    2014-01-01

    It is well known that substrate properties like stiffness and adhesivity influence stem cell morphology and differentiation. Recent experiments show that cell morphology influences nuclear geometry and hence gene expression profile. The mechanism by which surface properties regulate cell and nuclear properties is only beginning to be understood. Direct transmission of forces as well as chemical signalling are involved in this process. Here, we investigate the formal aspect by studying the correlation between cell spreading and nuclear deformation using Mesenchymal stem cells under a wide variety of conditions. It is observed that a robust quantitative relation holds between the cell and nuclear projected areas, irrespective of how the cell area is modified or when various cytoskeletal or nuclear components are perturbed. By studying the role of actin stress fibers in compressing the nucleus we propose that nuclear compression by stress fibers can lead to enhanced cell spreading due to an interplay between elastic and adhesion factors. The significance of myosin-II in regulating this process is also explored. We demonstrate this effect using a simple technique to apply external compressive loads on the nucleus. PMID:25251154

  9. SUMOylation regulates the nuclear mobility of CREB binding protein and its association with nuclear bodies in live cells

    SciTech Connect

    Ryan, Colm M.; Kindle, Karin B.; Collins, Hilary M.; Heery, David M.

    2010-01-01

    The lysine acetyltransferase CREB binding protein (CBP) is required for chromatin modification and transcription at many gene promoters. In fixed cells, a large proportion of CBP colocalises to PML or nuclear bodies. Using live cell imaging, we show here that YFP-tagged CBP expressed in HEK293 cells undergoes gradual accumulation in nuclear bodies, some of which are mobile and migrate towards the nuclear envelope. Deletion of a short lysine-rich domain that contains the major SUMO acceptor sites of CBP abrogated its ability to be SUMO modified, and prevented its association with endogenous SUMO-1/PML speckles in vivo. This SUMO-defective CBP showed enhanced ability to co-activate AML1-mediated transcription. Deletion mapping revealed that the SUMO-modified region was not sufficient for targeting CBP to PML bodies, as C-terminally truncated mutants containing this domain showed a strong reduction in accumulation at PML bodies. Fluorescence recovery after photo-bleaching (FRAP) experiments revealed that YFP-CBP{Delta}998-1087 had a retarded recovery time in the nucleus, as compared to YFP-CBP. These results indicate that SUMOylation regulates CBP function by influencing its shuttling between nuclear bodies and chromatin microenvironments.

  10. Nuclear-mitochondrial incompatibility in interorder rhesus monkey-cow embryos derived from somatic cell nuclear transfer.

    PubMed

    Kwon, Daekee; Koo, Ok-Jae; Kim, Min-Jung; Jang, Goo; Lee, Byeong Chun

    2016-10-01

    Monkey interorder somatic cell nuclear transfer (iSCNT) using enucleated cow oocytes yielded poor blastocysts development and contradictory results among research groups. Determining the reason for this low blastocyst development is a prerequisite for optimizing iSCNT in rhesus monkeys. The aim of this study was to elucidate nuclear-mitochondrial incompatibility of rhesus monkey-cow iSCNT embryos and its relationship to low blastocyst development. Cytochrome b is a protein of complex III of the electron transport chain (ETC). According to meta-analysis of amino acid sequences, the homology of cytochrome b is 75 % between rhesus monkeys and cattle. To maintain the function of ETC after iSCNT, 4n iSCNT embryos were produced by fusion of non-enucleated cow oocytes and rhesus monkey somatic cells. The blastocyst development rate of 4n iSCNT embryos was higher than that of 2n embryos (P < 0.01). Formation of reactive oxygen species (ROS) is an indirect indicator of ETC activity of cells. The ROS levels of 4n iSCNT embryos was higher than that of 2n embryos (P < 0.01). Collectively, rhesus monkey iSCNT embryos reconstructed with cow oocytes have nuclear-mitochondrial incompatibility due to fundamental species differences between rhesus monkeys and cattle. Nuclear-mitochondrial incompatibility seems to correlate with low ETC activity and extremely low blastocyst development of rhesus monkey-cow iSCNT embryos.

  11. Passive permeability and effective pore size of HeLa cell nuclear membranes.

    PubMed

    Samudram, Arunkarthick; Mangalassery, Bijeesh M; Kowshik, Meenal; Patincharath, Nandakumar; Varier, Geetha K

    2016-09-01

    Nuclear pore complexes in the nuclear membrane act as the sole gateway of transport of molecules from the cytoplasm to the nucleus and vice versa. Studies on biomolecular transport through nuclear membranes provide vital data on the nuclear pore complexes. In this work, we use fluorescein isothiocyanate-labeled dextran molecules as a model system and study the passive nuclear import of biomolecules through nuclear pore complexes in digitonin-permeabilized HeLa cells. Experiments are carried out under transient conditions in the time lapse imaging scheme using an in-house constructed confocal laser scanning microscope. Transport rates of dextran molecules having molecular weights of 4-70 kDa corresponding to Stokes radius of 1.4-6 nm are determined. Analyzing the permeability of the nuclear membrane for different sizes the effective pore radius of HeLa cell nuclear membrane is determined to be 5.3 nm, much larger than the value reported earlier using proteins as probe molecules. The range of values reported for the nuclear pore radius suggest that they may not be rigid structures and it is quite probable that the effective pore size of nuclear pore complexes is critically dependent on the probe molecules and on the environmental factors.

  12. Total and Viable Legionella pneumophila Cells in Hot and Natural Waters as Measured by Immunofluorescence-Based Assays and Solid-Phase Cytometry ▿†

    PubMed Central

    Parthuisot, N.; Binet, M.; Touron-Bodilis, A.; Pougnard, C.; Lebaron, P.; Baudart, J.

    2011-01-01

    A new method was developed for the rapid and sensitive detection of viable Legionella pneumophila. The method combines specific immunofluorescence (IF) staining using monoclonal antibodies with a bacterial viability marker (ChemChrome V6 cellular esterase activity marker) by means of solid-phase cytometry (SPC). IF methods were applied to the detection and enumeration of both the total and viable L. pneumophila cells in water samples. The sensitivity of the IF methods coupled to SPC was 34 cells liter−1, and the reproducibility was good, with the coefficient of variation generally falling below 30%. IF methods were applied to the enumeration of total and viable L. pneumophila cells in 46 domestic hot water samples as well as in cooling tower water and natural water samples, such as thermal spring water and freshwater samples. Comparison with standard plate counts showed that (i) the total direct counts were always higher than the plate counts and (ii) the viable counts were higher than or close to the plate counts. With domestic hot waters, when the IF assay was combined with the viability test, SPC detected up to 3.4 × 103 viable but nonculturable L. pneumophila cells per liter. These direct IF methods could be a powerful tool for high-frequency monitoring of domestic hot waters or for investigating the occurrence of viable L. pneumophila in both man-made water systems and environmental water samples. PMID:21742913

  13. Total and viable Legionella pneumophila cells in hot and natural waters as measured by immunofluorescence-based assays and solid-phase cytometry.

    PubMed

    Parthuisot, N; Binet, M; Touron-Bodilis, A; Pougnard, C; Lebaron, P; Baudart, J

    2011-09-01

    A new method was developed for the rapid and sensitive detection of viable Legionella pneumophila. The method combines specific immunofluorescence (IF) staining using monoclonal antibodies with a bacterial viability marker (ChemChrome V6 cellular esterase activity marker) by means of solid-phase cytometry (SPC). IF methods were applied to the detection and enumeration of both the total and viable L. pneumophila cells in water samples. The sensitivity of the IF methods coupled to SPC was 34 cells liter(-1), and the reproducibility was good, with the coefficient of variation generally falling below 30%. IF methods were applied to the enumeration of total and viable L. pneumophila cells in 46 domestic hot water samples as well as in cooling tower water and natural water samples, such as thermal spring water and freshwater samples. Comparison with standard plate counts showed that (i) the total direct counts were always higher than the plate counts and (ii) the viable counts were higher than or close to the plate counts. With domestic hot waters, when the IF assay was combined with the viability test, SPC detected up to 3.4 × 10(3) viable but nonculturable L. pneumophila cells per liter. These direct IF methods could be a powerful tool for high-frequency monitoring of domestic hot waters or for investigating the occurrence of viable L. pneumophila in both man-made water systems and environmental water samples. PMID:21742913

  14. Nuclear thioredoxin-1 is required to suppress cisplatin-mediated apoptosis of MCF-7 cells

    SciTech Connect

    Chen, Xiao-Ping; Liu, Shou; Tang, Wen-Xin; Chen, Zheng-Wang . E-mail: zwchen@mail.hust.edu.cn

    2007-09-21

    Different cell line with increased thioredoxin-1 (Trx-1) showed a decreased or increased sensitivity to cell killing by cisplatin. Recently, several studies found that the subcellular localization of Trx-1 is closely associated with its functions. In this study, we explored the association of the nuclear Trx-1 with the cisplatin-mediated apoptosis of breast cancer cells MCF-7. Firstly, we found that higher total Trx-1 accompanied by no change of nuclear Trx-1 can not influence apoptosis induced by cisplatin in MCF-7 cells transferred with Trx-1 cDNA. Secondly, higher nuclear Trx-1 accompanied by no change of total Trx-1 can protect cells from apoptosis induced by cisplatin. Thirdly, high nuclear Trx-1 involves in the cisplatin-resistance in cisplatin-resistive cells. Meanwhile, we found that the mRNA level of p53 is closely correlated with the level of nuclear Trx-1. In summary, we concluded that the nuclear Trx-1 is required to resist apoptosis of MCF-7 cells induced by cisplatin, probably through up-regulating the anti-apoptotic gene, p53.

  15. Nuclear export in plants. Use of geminivirus movement proteins for a cell-based export assay.

    PubMed Central

    Ward, B M; Lazarowitz, S G

    1999-01-01

    The nuclear export of proteins and RNAs has been studied in heterokaryons or by microinjecting test substrates into nuclei of HeLa cells or Xenopus oocytes. We have previously shown that the two movement proteins BR1 and BL1 encoded by the plant pathogenic squash leaf curl virus act in a coordinated manner to facilitate virus cell-to-cell movement and that one of these (BR1) is a nuclear shuttle protein. By using a novel in vivo cell-based assay for nuclear export in which nuclear-localized BR1 is trapped by BL1 and redirected to the cortical cytoplasm, we demonstrate that residues 177 to 198 of BR1 contain a leucine-rich nuclear export signal (NES) of the type found in the Rev protein encoded by the human immunodeficiency virus and in Xenopus TFIIIA. We further show that the TFIIIA NES can functionally replace the NES of BR1 in both nuclear export and viral infectivity. These findings suggest that this basic pathway for nuclear export is highly conserved among plant and animal cells and in yeast. PMID:10402428

  16. Expression of nuclear membrane proteins in normal, hyperplastic, and neoplastic thyroid epithelial cells.

    PubMed

    Wang, Jieying; Kondo, Tetsuo; Yamane, Tetsu; Nakazawa, Tadao; Oish, Naoki; Mochizuki, Kunio; Katoh, Ryohei

    2015-10-01

    Emerin, lamin A/C, lamin B, and lamin-associated polypeptide 2 (LAP2) are nuclear membrane proteins that play an important role in maintaining nuclear structure and coordinating cell activity. We studied the expression and significance of nuclear membrane proteins in neoplastic thyroid cells by immunohistochemistry, RT-PCR, and real-time PCR. In papillary carcinomas (PCs), the nuclear proteins most frequently expressed at high levels were emerin (82 % positive), lamin A/C (64 %), and LAP2 (82 %). Follicular carcinomas (FCs) most frequently expressed lamin B, while none of the undifferentiated carcinomas (UCs) showed strong expression of emerin or lamin A/C. In all medullary carcinomas (MCs), intermediate to high levels of expression of lamin A/C and LAP2 were found. By RT-PCR analysis, messenger RNA (mRNA) expression of all nuclear membrane proteins except emerin was higher in PC than in normal tissue. Real-time PCR analysis showed that mRNA expression of nuclear membrane protein varied between cell lines. Our findings suggest that expression of nuclear membrane proteins may be related to follicular function in normal and hyperplastic follicles, and we hypothesize that they are also involved in the proliferation and differentiation of neoplastic thyroid cells. We suggest that they reflect the biological nature and/or function of normal, hyperplastic, and neoplastic thyroid cells and may have some value in diagnosing thyroid tumors.

  17. Human somatic cell nuclear transfer and reproductive cloning: an Ethics Committee opinion.

    PubMed

    2016-04-01

    This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer and cloning," last published in Fertil Steril 2012;98:804-7. PMID:26746137

  18. Intracellular lysyl oxidase: Effect of a specific inhibitor on nuclear mass in proliferating cells

    SciTech Connect

    Saad, Fawzy A.; Torres, Marie; Wang, Hao; Graham, Lila

    2010-06-11

    LOX, the principal enzyme involved in crosslinking of collagen, was the first of several lysyl oxidase isotypes to be characterized. Its active form was believed to be exclusively extracellular. Active LOX was later reported to be present in cell nuclei; its function there is unknown. LOX expression opposes the effect of mutationally activated Ras, which is present in about 30% of human cancers. The mechanism of LOX in countering the action of Ras is also unknown. In the present work, assessment of nuclear protein for possible effects of lysyl oxidase activity led to the discovery that proliferating cells dramatically increase their nuclear protein content when exposed to BAPN ({beta}-aminopropionitrile), a highly specific lysyl oxidase inhibitor that reportedly blocks LOX inhibition of Ras-induced oocyte maturation. In three cell types (PC12 cells, A7r5 smooth muscle cells, and NIH 3T3 fibroblasts), BAPN caused a 1.8-, 1.7-, and 2.1-fold increase in total nuclear protein per cell, respectively, affecting all major components in both nuclear matrix and chromatin fractions. Since nuclear size is correlated with proliferative status, enzyme activity restricting nuclear growth may be involved in the lysyl oxidase tumor suppressive effect. Evidence is also presented for the presence of apparent lysyl oxidase isotype(s) containing a highly conserved LOX active site sequence in the nuclei of PC12 cells, which do not manufacture extracellular lysyl oxidase substrates. Results reported here support the hypothesis that nuclear lysyl oxidase regulates nuclear growth, and thereby modulates cell proliferation.

  19. Human somatic cell nuclear transfer and reproductive cloning: an Ethics Committee opinion.

    PubMed

    2016-04-01

    This document presents arguments that conclude that it is unethical to use somatic cell nuclear transfer (SCNT) for infertility treatment due to concerns about safety; the unknown impact of SCNT on children, families, and society; and the availability of other ethically acceptable means of assisted reproduction. This document replaces the ASRM Ethics Committee report titled, "Human somatic cell nuclear transfer and cloning," last published in Fertil Steril 2012;98:804-7.

  20. Analysis of cell growth and gene expression of porcine adipose tissue-derived mesenchymal stem cells as nuclear donor cell.

    PubMed

    Oh, Hyun Ju; Park, Jung Eun; Park, Eun Jung; Kim, Min Jung; Kim, Geon A; Rhee, Sang Ho; Lim, Sang Hyun; Kang, Sung Keun; Lee, Byeong Chun

    2014-12-01

    In several laboratory animals and humans, adipose tissue-derived mesenchymal stem cells (ASC) are of considerable interest because they are easy to harvest and can generate a huge proliferation of cells from a small quantity of fat. In this study, we investigated: (i) the expression patterns of reprogramming-related genes in porcine ASC; and (ii) whether ASC can be a suitable donor cell type for generating cloned pigs. For these experiments, ASC, adult skin fibroblasts (AF) and fetal fibroblasts (FF) were derived from a 4-year-old female miniature pig. The ASC expressed cell-surface markers characteristic of stem cells, and underwent in vitro differentiation when exposed to specific differentiation-inducing conditions. Expression of DNA methyltransferase (DNMT)1 in ASC was similar to that in AF, but the highest expression of the DNMT3B gene was observed in ASC. The expression of OCT4 was significantly higher in FF and ASC than in AF (P < 0.05), and SOX2 showed significantly higher expression in ASC than in the other two cell types (P < 0.05). After somatic cell nuclear transfer (SCNT), the development rate of cloned embryos derived from ASC was comparable to the development of those derived using FF. Total cell numbers of blastocysts derived using ASC and FF were significantly higher than in embryos made with AF. The results demonstrated that ASC used for SCNT have a potential comparable to those of AF and FF in terms of embryo in vitro development and blastocyst formation.

  1. CacyBP/SIP nuclear translocation induced by gastrin promotes gastric cancer cell proliferation

    PubMed Central

    Zhai, Hui-Hong; Meng, Juan; Wang, Jing-Bo; Liu, Zhen-Xiong; Li, Yuan-Fei; Feng, Shan-Shan

    2014-01-01

    AIM: To investigate the role of nuclear translocation of calcyclin binding protein, also called Siah-1 interacting protein (CacyBP/SIP), in gastric carcinogenesis. METHODS: The expression of CacyBP/SIP protein in gastric cancer cell lines was detected by Western blot. Immunofluorescence experiments were performed on gastric cancer cell lines that had been either unstimulated or stimulated with gastrin. To confirm the immunofluorescence findings, the relative abundance of CacyBP/SIP in nuclear and cytoplasmic compartments was assessed by Western blot. The effect of nuclear translocation of CacyBP/SIP on cell proliferation was examined using MTT assay. The colony formation assay was used to measure clonogenic cell survival. The effect of CacyBP/SIP nuclear translocation on cell cycle progression was investigated. Two CacyBP/SIP-specific siRNA vectors were designed and constructed to inhibit CacyBP/SIP expression in order to reduce the nuclear translocation of CacyBP/SIP, and the expression of CacyBP/SIP in stably transfected cells was determined by Western blot. The effect of inhibiting CacyBP/SIP nuclear translocation on cell proliferation was then assessed. RESULTS: CacyBP/SIP protein was present in most of gastric cancer cell lines. In unstimulated cells, CacyBP/SIP was distributed throughout the cytoplasm; while in stimulated cells, CacyBP/SIP was found mainly in the perinuclear region. CacyBP/SIP nuclear translocation generated a growth-stimulatory effect on cells. The number of colonies in the CacyBP/SIP nuclear translocation group was significantly higher than that in the control group. The percentage of stimulated cells in G1 phase was significantly lower than that of control cells (69.70% ± 0.46% and 65.80% ± 0.60%, control cells and gastrin-treated SGC7901 cells, P = 0.008; 72.99% ± 0.46% and 69.36% ± 0.51%, control cells and gastrin-treated MKN45 cells, P = 0.022). CacyBP/SIPsi1 effectively down-regulated the expression of CacyBP/SIP, and cells stably

  2. Impairment of nuclear pores in bovine herpesvirus 1-infected MDBK cells.

    PubMed

    Wild, Peter; Engels, Monika; Senn, Claudia; Tobler, Kurt; Ziegler, Urs; Schraner, Elisabeth M; Loepfe, Eva; Ackermann, Mathias; Mueller, Martin; Walther, Paul

    2005-01-01

    Herpesvirus capsids originating in the nucleus overcome the nucleocytoplasmic barrier by budding at the inner nuclear membrane. The fate of the resulting virions is still under debate. The fact that capsids approach Golgi membranes from the cytoplasmic side led to the theory of fusion between the viral envelope and the outer nuclear membrane, resulting in the release of capsids into the cytoplasm. We recently discovered a continuum from the perinuclear space to the Golgi complex implying (i) intracisternal viral transportation from the perinuclear space directly into Golgi cisternae and (ii) the existence of an alternative pathway of capsids from the nucleus to the cytoplasm. Here, we analyzed the nuclear surface by high-resolution microscopy. Confocal microscopy of MDBK cells infected with recombinant bovine herpesvirus 1 expressing green fluorescent protein fused to VP26 (a minor capsid protein) revealed distortions of the nuclear surface in the course of viral multiplication. High-resolution scanning and transmission electron microscopy proved the distortions to be related to enlargement of nuclear pores through which nuclear content including capsids protrudes into the cytoplasm, suggesting that capsids use impaired nuclear pores as gateways to gain access to the cytoplasmic matrix. Close examination of Golgi membranes, rough endoplasmic reticulum, and outer nuclear membrane yielded capsid-membrane interaction of high identity to the budding process at the inner nuclear membrane. These observations signify the ability of capsids to induce budding at any cell membrane, provided the fusion machinery is present and/or budding is not suppressed by viral proteins.

  3. Alterations in the nuclear proteome of HIV-1 infected T-cells

    SciTech Connect

    DeBoer, Jason; Jagadish, Teena; Haverland, Nicole A.; Madson, Christian J.; Ciborowski, Pawel; Belshan, Michael

    2014-11-15

    Virus infection of a cell involves the appropriation of host factors and the innate defensive response of the cell. The identification of proteins critical for virus replication may lead to the development of novel, cell-based inhibitors. In this study we mapped the changes in T-cell nuclei during human immunodeficiency virus type 1 (HIV-1) at 20 hpi. Using a stringent data threshold, a total of 13 and 38 unique proteins were identified in infected and uninfected cells, respectively, across all biological replicates. An additional 15 proteins were found to be differentially regulated between infected and control nuclei. STRING analysis identified four clusters of protein–protein interactions in the data set related to nuclear architecture, RNA regulation, cell division, and cell homeostasis. Immunoblot analysis confirmed the differential expression of several proteins in both C8166-45 and Jurkat E6-1 T-cells. These data provide a map of the response in host cell nuclei upon HIV-1 infection. - Highlights: • We identify changes in the expression of nuclear proteins during HIV-1 infection. • 163 nuclear proteins were found differentially regulated during HIV-1 infection. • Bioinformatic analysis identified several nuclear pathways altered by HIV infection. • Candidate factors were validated in two independent cell lines.

  4. Hot Canyon

    ScienceCinema

    None

    2016-07-12

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  5. Hot Canyon

    SciTech Connect

    2012-01-01

    This historical film footage, originally produced in the early 1950s as part of a series by WOI-TV, shows atomic research at Ames Laboratory. The work was conducted in a special area of the Laboratory known as the "Hot Canyon."

  6. Hot Tickets

    ERIC Educational Resources Information Center

    Fox, Bette-Lee; Hoffert, Barbara; Kuzyk, Raya; McCormack, Heather; Williams, Wilda

    2008-01-01

    This article describes the highlights of this year's BookExpo America (BEA) held at the Los Angeles Convention Center. The attendees at BEA had not minded that the air was recycled, the lighting was fluorescent, and the food was bad. The first hot book sighting came courtesy of Anne Rice. Michelle Moran, author of newly published novel, "The…

  7. Angiomotin promotes renal epithelial and carcinoma cell proliferation by retaining the nuclear YAP.

    PubMed

    Lv, Meng; Li, Shuting; Luo, Changqin; Zhang, Xiaoman; Shen, Yanwei; Sui, Yan Xia; Wang, Fan; Wang, Xin; Yang, Jiao; Liu, Peijun; Yang, Jin

    2016-03-15

    Renal cell carcinoma (RCC) is one of the common tumors in the urinary system without effective therapies. Angiomotin (Amot) can interact with Yes-associated protein (YAP) to either stimulate or inhibit YAP activity, playing a potential role in cell proliferation. However, the role of Amot in regulating the proliferation of renal epithelial and RCC cells is unknown. Here, we show that Amot is expressed predominantly in the nucleus of RCC cells and tissues, and in the cytoplasm and nucleus of renal epithelial cells and paracancerous tissues. Furthermore, Amot silencing inhibited proliferation of HK-2 and 786-O cells while Amot upregulation promoted proliferation of ACHN cells. Interestingly, the location of Amot and YAP in RCC clinical samples and cells was similar. Amot interacted with YAP in HK-2 and 786-O cells, particularly in the nucleus. Moreover, Amot silencing mitigated the levels of nuclear YAP in HK-2 and 786-O cells and reduced YAP-related CTGF and Cyr61 expression in 786-O cells. Amot upregulation slightly increased the nuclear YAP and YAP-related gene expression in ACHN cells. Finally, enhanced YAP expression restored proliferation of Amot-silencing 786-O cells. Together, these data indicate that Amot is crucial for the maintenance of nuclear YAP to promote renal epithelial and RCC proliferation.

  8. Longitudinal tracking of single live cancer cells to understand cell cycle effects of the nuclear export inhibitor, selinexor

    PubMed Central

    Marcus, Joshua M.; Burke, Russell T.; DeSisto, John A.; Landesman, Yosef; Orth, James D.

    2015-01-01

    Longitudinal tracking is a powerful approach to understand the biology of single cells. In cancer therapy, outcome is determined at the molecular and cellular scale, yet relationships between cellular response and cell fate are often unknown. The selective inhibitor of nuclear export, selinexor, is in development for the treatment of various cancers. Selinexor covalently binds exportin-1, causing nuclear sequestration of cargo proteins, including key regulators of the cell cycle and apoptosis. The cell cycle effects of selinexor and the relationships between cell cycle effects and cell fates, has not been described for individual cells. Using fluorescent cell cycle indicators we report the majority of cell death after selinexor treatment occurs from a protracted G1-phase and early S-phase. G1- or early S-phase treated cells show the strongest response and either die or arrest, while those treated in late S- or G2-phase progress to mitosis and divide. Importantly, the progeny of cell divisions also die or arrest, mostly in the next G1-phase. Cells that survive selinexor are negative for multiple proliferation biomarkers, indicating a penetrant, arrested state. Selinexor acts quickly, shows strong cell cycle selectivity, and is highly effective at arresting cell growth and inducing death in cancer-derived cells. PMID:26399741

  9. Nuclear translocation of nuclear factor of activated T cells (NFAT) as a quantitative pharmacodynamic parameter for tacrolimus.

    PubMed

    Maguire, Orla; Tornatore, Kathleen M; O'Loughlin, Kieran L; Venuto, Rocco C; Minderman, Hans

    2013-12-01

    Nuclear factor of activated T cells (NFAT) is a family of transcription factors involved in regulating the immune response. The canonical NFAT pathway is calcium-dependent and upon activation, NFAT is dephosphorylated by the phosphatase, calcineurin. This results in its translocation from the cytoplasm to the nucleus and transcription of downstream target genes that include the cytokines IL-2, IL-10, and IFNγ. Calcineurin inhibitors including tacrolimus inhibit the NFAT pathway and are used as immunosuppressants in transplant settings to prevent graft rejection. There is, as yet, no direct means to monitor tacrolimus pharmacodynamics. In this study, a rapid, quantitative, image cytometry-based measurement of nuclear translocation of NFAT1 is used to evaluate NFAT activation in T cells and its tacrolimus-induced inhibition. A strong dose-dependent correlation between NFAT1 inhibition and tacrolimus dose is demonstrated in vitro. Time kinetic analysis of NFAT1 inhibition in plasma from stable renal transplant recipients before and after an in vivo dose with tacrolimus correlated with the expected pharmacokinetic profile of tacrolimus. This was further corroborated by analysis of patients' autologous CD4 and CD8 T cells. This is the first report to show that the measurement of NFAT1 activation potential by nuclear translocation can be used as a direct, sensitive, reproducible and quantitative pharmacodynamic readout for tacrolimus action. These results, and the rapid turnaround time for this assay, warrant its evaluation in a larger clinical setting to assess its role in therapeutic drug monitoring of calcineurin inhibitors.

  10. Cell-mediated transgenesis in rabbits: chimeric and nuclear transfer animals.

    PubMed

    Zakhartchenko, V; Flisikowska, T; Li, S; Richter, T; Wieland, H; Durkovic, M; Rottmann, O; Kessler, B; Gungor, T; Brem, G; Kind, A; Wolf, E; Schnieke, A

    2011-02-01

    The ability to perform precise genetic engineering such as gene targeting in rabbits would benefit biomedical research by enabling, for example, the generation of genetically defined rabbit models of human diseases. This has so far not been possible because of the lack of functional rabbit embryonic stem cells and the high fetal and perinatal mortality associated with rabbit somatic cell nuclear transfer. We examined cultured pluripotent and multipotent cells for their ability to support the production of viable animals. Rabbit putative embryonic stem (ES) cells were derived and shown capable of in vitro and in vivo pluripotent differentiation. We report the first live born ES-derived rabbit chimera. Rabbit mesenchymal stem cells (MSCs) were derived from bone marrow, and multipotent differentiation was demonstrated in vitro. Nuclear transfer was carried out with both cell types, and embryo development was assessed in vitro and in vivo. Rabbit MSCs were markedly more successful than ES cells as nuclear donors. MSCs were transfected with fluorescent reporter gene constructs and assessed for nuclear transfer competence. Transfected MSCs supported development with similar efficiency as normal MSCs and resulted in the first live cloned rabbits from genetically manipulated MSCs. Reactivation of fluorescence reporter gene expression in reconstructed embryos was investigated as a means of identifying viable embryos in vitro but was not a reliable predictor. We also examined serial nuclear transfer as a means of rescuing dead animals.

  11. Cell cycle-dependent alteration in NAC1 nuclear body dynamics and morphology

    NASA Astrophysics Data System (ADS)

    Wu, Pei-Hsun; Hung, Shen-Hsiu; Ren, Tina; Shih, Ie-Ming; Tseng, Yiider

    2011-02-01

    NAC1, a BTB/POZ family member, has been suggested to participate in maintaining the stemness of embryonic stem cells and has been implicated in the pathogenesis of human cancer. In ovarian cancer, NAC1 upregulation is associated with disease aggressiveness and with the development of chemoresistance. Like other BTB/POZ proteins, NAC1 forms discrete nuclear bodies in non-dividing cells. To investigate the biological role of NAC1 nuclear bodies, we characterized the expression dynamics of NAC1 nuclear bodies during different phases of the cell cycle. Fluorescence recovery after photobleaching assays revealed that NAC1 was rapidly exchanged between the nucleoplasm and NAC1 nuclear bodies in interphase cells. The number of NAC1 bodies significantly increased and their size decreased in the S phase as compared to the G0/G1 and G2 phases. NAC1 nuclear bodies disappeared and NAC1 became diffuse during mitosis. NAC1 nuclear bodies reappeared immediately after completion of mitosis. These results indicate that a cell cycle-dependent regulatory mechanism controls NAC1 body formation in the nucleus and suggest that NAC1 body dynamics are associated with mitosis or cytokinesis.

  12. Granulocytic nuclear differentiation of lamin B receptor-deficient mouse EPRO cells

    PubMed Central

    Zwerger, Monika; Herrmann, Harald; Gaines, Peter; Olins, Ada L.; Olins, Donald E.

    2008-01-01

    Objective Lamin B receptor (LBR) is an integral protein of the inner nuclear membrane. Recent studies have demonstrated that genetic deficiency of LBR during granulopoiesis results in hypolobulation of the mature neutrophil nucleus, as observed in human Pelger-Huët anomaly (PHA) and mouse ichthyosis (ic). In this study we have utilized differentiated promyelocytes (EPRO cells) that were derived from the bone marrow of homozygous and heterozygous ichthyosis mice to examine changes to the expression of nuclear envelope proteins and heterochromatin structure that result from deficient LBR expression. Materials and Methods Wildtype (+/+), heterozygous (+/ic) and homozygous (ic/ic) granulocytic forms of EPRO cells were analyzed for the expression of multiple lamins and inner nuclear envelope proteins by immunostaining and immunoblotting techniques. The heterochromatin architecture was also examined by immunostaining for histone lysine methylation. Results Wildtype (+/+) and heterozygous (+/ic) granulocytic forms revealed ring-shaped nuclei and contained LBR within the nuclear envelope; ic/ic granulocytes exhibited smaller ovoid nuclei devoid of LBR. The pericentric heterochromatin of undifferentiated and granulocytic ic/ic cells was condensed into larger spots and shifted away from the nuclear envelope, compared to +/+ and +/ic cell forms. Lamin A/C, which is normally not present in mature granulocytes, was significantly elevated in LBR-deficient EPRO cells. Conclusions Our observations suggest roles for LBR during granulopoiesis which may involve augmenting nuclear membrane growth, facilitating compartmentalization of heterochromatin and promoting down-regulation of lamin A/C expression. PMID:18495328

  13. Cell cycle-dependent alteration in NAC1 nuclear body dynamics and morphology.

    PubMed

    Wu, Pei-Hsun; Hung, Shen-Hsiu; Ren, Tina; Shih, Ie-Ming; Tseng, Yiider

    2011-02-01

    NAC1, a BTB/POZ family member, has been suggested to participate in maintaining the stemness of embryonic stem cells and has been implicated in the pathogenesis of human cancer. In ovarian cancer, NAC1 upregulation is associated with disease aggressiveness and with the development of chemoresistance. Like other BTB/POZ proteins, NAC1 forms discrete nuclear bodies in non-dividing cells. To investigate the biological role of NAC1 nuclear bodies, we characterized the expression dynamics of NAC1 nuclear bodies during different phases of the cell cycle. Fluorescence recovery after photobleaching assays revealed that NAC1 was rapidly exchanged between the nucleoplasm and NAC1 nuclear bodies in interphase cells. The number of NAC1 bodies significantly increased and their size decreased in the S phase as compared to the G₀/G₁ and G₂ phases. NAC1 nuclear bodies disappeared and NAC1 became diffuse during mitosis. NAC1 nuclear bodies reappeared immediately after completion of mitosis. These results indicate that a cell cycle-dependent regulatory mechanism controls NAC1 body formation in the nucleus and suggest that NAC1 body dynamics are associated with mitosis or cytokinesis.

  14. Nuclear deformability constitutes a rate-limiting step during cell migration in 3-D environments

    PubMed Central

    Davidson, Patricia M.; Denais, Celine; Bakshi, Maya C.; Lammerding, Jan

    2014-01-01

    Cell motility plays a critical role in many physiological and pathological settings, ranging from wound healing to cancer metastasis. While cell migration on 2-dimensional (2-D) substrates has been studied for decades, the physical challenges cells face when moving in 3-D environments are only now emerging. In particular, the cell nucleus, which occupies a large fraction of the cell volume and is normally substantially stiffer than the surrounding cytoplasm, may impose a major obstacle when cells encounter narrow constrictions in the interstitial space, the extracellular matrix, or small capillaries. Using novel microfluidic devices that allow observation of cells moving through precisely defined geometries at high spatial and temporal resolution, we determined nuclear deformability as a critical factor in the cells’ ability to pass through constrictions smaller than the size of the nucleus. Furthermore, we found that cells with reduced levels of the nuclear envelope proteins lamins A/C, which are the main determinants of nuclear stiffness, passed significantly faster through narrow constrictions during active migration and passive perfusion. Given recent reports that many human cancers have altered lamin expression, our findings suggest a novel biophysical mechanism by which changes in nuclear structure and composition may promote cancer cell invasion and metastasis. PMID:25436017

  15. Identification and Ultrastructural Characterization of a Novel Nuclear Degradation Complex in Differentiating Lens Fiber Cells.

    PubMed

    Costello, M Joseph; Brennan, Lisa A; Mohamed, Ashik; Gilliland, Kurt O; Johnsen, Sönke; Kantorow, Marc

    2016-01-01

    An unresolved issue in structural biology is how the encapsulated lens removes membranous organelles to carry out its role as a transparent optical element. In this ultrastructural study, we establish a mechanism for nuclear elimination in the developing chick lens during the formation of the organelle-free zone. Day 12-15 chick embryo lenses were examined by high-resolution confocal light microscopy and thin section transmission electron microscopy (TEM) following fixation in 10% formalin and 4% paraformaldehyde, and then processing for confocal or TEM as described previously. Examination of developing fiber cells revealed normal nuclei with dispersed chromatin and clear nucleoli typical of cells in active ribosome production to support protein synthesis. Early signs of nuclear degradation were observed about 300 μm from the lens capsule in Day 15 lenses where the nuclei display irregular nuclear stain and prominent indentations that sometimes contained a previously undescribed macromolecular aggregate attached to the nuclear envelope. We have termed this novel structure the nuclear excisosome. This complex by confocal is closely adherent to the nuclear envelope and by TEM appears to degrade the outer leaflet of the nuclear envelope, then the inner leaflet up to 500 μm depth. The images suggest that the nuclear excisosome separates nuclear membrane proteins from lipids, which then form multilamellar assemblies that stain intensely in confocal and in TEM have 5 nm spacing consistent with pure lipid bilayers. The denuded nucleoplasm then degrades by condensation and loss of structure in the range 600 to 700 μm depth producing pyknotic nuclear remnants. None of these stages display any classic autophagic vesicles or lysosomes associated with nuclei. Uniquely, the origin of the nuclear excisosome is from filopodial-like projections of adjacent lens fiber cells that initially contact, and then appear to fuse with the outer nuclear membrane. These filopodial

  16. Identification and Ultrastructural Characterization of a Novel Nuclear Degradation Complex in Differentiating Lens Fiber Cells

    PubMed Central

    Costello, M. Joseph; Brennan, Lisa A.; Gilliland, Kurt O.; Johnsen, Sönke; Kantorow, Marc

    2016-01-01

    An unresolved issue in structural biology is how the encapsulated lens removes membranous organelles to carry out its role as a transparent optical element. In this ultrastructural study, we establish a mechanism for nuclear elimination in the developing chick lens during the formation of the organelle-free zone. Day 12–15 chick embryo lenses were examined by high-resolution confocal light microscopy and thin section transmission electron microscopy (TEM) following fixation in 10% formalin and 4% paraformaldehyde, and then processing for confocal or TEM as described previously. Examination of developing fiber cells revealed normal nuclei with dispersed chromatin and clear nucleoli typical of cells in active ribosome production to support protein synthesis. Early signs of nuclear degradation were observed about 300 μm from the lens capsule in Day 15 lenses where the nuclei display irregular nuclear stain and prominent indentations that sometimes contained a previously undescribed macromolecular aggregate attached to the nuclear envelope. We have termed this novel structure the nuclear excisosome. This complex by confocal is closely adherent to the nuclear envelope and by TEM appears to degrade the outer leaflet of the nuclear envelope, then the inner leaflet up to 500 μm depth. The images suggest that the nuclear excisosome separates nuclear membrane proteins from lipids, which then form multilamellar assemblies that stain intensely in confocal and in TEM have 5 nm spacing consistent with pure lipid bilayers. The denuded nucleoplasm then degrades by condensation and loss of structure in the range 600 to 700 μm depth producing pyknotic nuclear remnants. None of these stages display any classic autophagic vesicles or lysosomes associated with nuclei. Uniquely, the origin of the nuclear excisosome is from filopodial-like projections of adjacent lens fiber cells that initially contact, and then appear to fuse with the outer nuclear membrane. These filopodial

  17. Effects of donor cells' sex on nuclear transfer efficiency and telomere lengths of cloned goats.

    PubMed

    Liu, H-J; Peng, H; Hu, C-C; Li, X-Y; Zhang, J-L; Zheng, Z; Zhang, W-C

    2016-10-01

    The aim of this study was to investigate the effects of donor cells' sex on nuclear transfer efficiency and telomere length of cloned goats from adult skin fibroblast cells. The telomere length of somatic cell cloned goats and their offspring was determined by measuring their mean terminal restriction fragment (TRF) length. The result showed that (i) reconstructed embryos with fibroblast cells from males Boer goats obtained significantly higher kids rate and rate of live kids than those of female embryos and (ii) the telomere lengths of four female cloned goats were shorter compared to their donor cells, but five male cloned goats had the same telomere length with their donor cells, mainly due to great variation existed among them. The offspring from female cloned goats had the same telomere length with their age-matched counterparts. In conclusion, the donor cells' sex had significant effects on nuclear transfer efficiency and telomere lengths of cloned goats.

  18. Effects of donor cells' sex on nuclear transfer efficiency and telomere lengths of cloned goats.

    PubMed

    Liu, H-J; Peng, H; Hu, C-C; Li, X-Y; Zhang, J-L; Zheng, Z; Zhang, W-C

    2016-10-01

    The aim of this study was to investigate the effects of donor cells' sex on nuclear transfer efficiency and telomere length of cloned goats from adult skin fibroblast cells. The telomere length of somatic cell cloned goats and their offspring was determined by measuring their mean terminal restriction fragment (TRF) length. The result showed that (i) reconstructed embryos with fibroblast cells from males Boer goats obtained significantly higher kids rate and rate of live kids than those of female embryos and (ii) the telomere lengths of four female cloned goats were shorter compared to their donor cells, but five male cloned goats had the same telomere length with their donor cells, mainly due to great variation existed among them. The offspring from female cloned goats had the same telomere length with their age-matched counterparts. In conclusion, the donor cells' sex had significant effects on nuclear transfer efficiency and telomere lengths of cloned goats. PMID:27558653

  19. In silico synchronization reveals regulators of nuclear ruptures in lamin A/C deficient model cells.

    PubMed

    Robijns, J; Molenberghs, F; Sieprath, T; Corne, T D J; Verschuuren, M; De Vos, W H

    2016-01-01

    The nuclear lamina is a critical regulator of nuclear structure and function. Nuclei from laminopathy patient cells experience repetitive disruptions of the nuclear envelope, causing transient intermingling of nuclear and cytoplasmic components. The exact causes and consequences of these events are not fully understood, but their stochastic occurrence complicates in-depth analyses. To resolve this, we have established a method that enables quantitative investigation of spontaneous nuclear ruptures, based on co-expression of a firmly bound nuclear reference marker and a fluorescent protein that shuttles between the nucleus and cytoplasm during ruptures. Minimally invasive imaging of both reporters, combined with automated tracking and in silico synchronization of individual rupture events, allowed extracting information on rupture frequency and recovery kinetics. Using this approach, we found that rupture frequency correlates inversely with lamin A/C levels, and can be reduced in genome-edited LMNA knockout cells by blocking actomyosin contractility or inhibiting the acetyl-transferase protein NAT10. Nuclear signal recovery followed a kinetic that is co-determined by the severity of the rupture event, and could be prolonged by knockdown of the ESCRT-III complex component CHMP4B. In conclusion, our approach reveals regulators of nuclear rupture induction and repair, which may have critical roles in disease development.

  20. In silico synchronization reveals regulators of nuclear ruptures in lamin A/C deficient model cells

    PubMed Central

    Robijns, J.; Molenberghs, F.; Sieprath, T.; Corne, T. D. J.; Verschuuren, M.; De Vos, W. H.

    2016-01-01

    The nuclear lamina is a critical regulator of nuclear structure and function. Nuclei from laminopathy patient cells experience repetitive disruptions of the nuclear envelope, causing transient intermingling of nuclear and cytoplasmic components. The exact causes and consequences of these events are not fully understood, but their stochastic occurrence complicates in-depth analyses. To resolve this, we have established a method that enables quantitative investigation of spontaneous nuclear ruptures, based on co-expression of a firmly bound nuclear reference marker and a fluorescent protein that shuttles between the nucleus and cytoplasm during ruptures. Minimally invasive imaging of both reporters, combined with automated tracking and in silico synchronization of individual rupture events, allowed extracting information on rupture frequency and recovery kinetics. Using this approach, we found that rupture frequency correlates inversely with lamin A/C levels, and can be reduced in genome-edited LMNA knockout cells by blocking actomyosin contractility or inhibiting the acetyl-transferase protein NAT10. Nuclear signal recovery followed a kinetic that is co-determined by the severity of the rupture event, and could be prolonged by knockdown of the ESCRT-III complex component CHMP4B. In conclusion, our approach reveals regulators of nuclear rupture induction and repair, which may have critical roles in disease development. PMID:27461848

  1. In silico synchronization reveals regulators of nuclear ruptures in lamin A/C deficient model cells

    NASA Astrophysics Data System (ADS)

    Robijns, J.; Molenberghs, F.; Sieprath, T.; Corne, T. D. J.; Verschuuren, M.; de Vos, W. H.

    2016-07-01

    The nuclear lamina is a critical regulator of nuclear structure and function. Nuclei from laminopathy patient cells experience repetitive disruptions of the nuclear envelope, causing transient intermingling of nuclear and cytoplasmic components. The exact causes and consequences of these events are not fully understood, but their stochastic occurrence complicates in-depth analyses. To resolve this, we have established a method that enables quantitative investigation of spontaneous nuclear ruptures, based on co-expression of a firmly bound nuclear reference marker and a fluorescent protein that shuttles between the nucleus and cytoplasm during ruptures. Minimally invasive imaging of both reporters, combined with automated tracking and in silico synchronization of individual rupture events, allowed extracting information on rupture frequency and recovery kinetics. Using this approach, we found that rupture frequency correlates inversely with lamin A/C levels, and can be reduced in genome-edited LMNA knockout cells by blocking actomyosin contractility or inhibiting the acetyl-transferase protein NAT10. Nuclear signal recovery followed a kinetic that is co-determined by the severity of the rupture event, and could be prolonged by knockdown of the ESCRT-III complex component CHMP4B. In conclusion, our approach reveals regulators of nuclear rupture induction and repair, which may have critical roles in disease development.

  2. Changing nuclear landscape and unique PML structures during early epigenetic transitions of human embryonic stem cells.

    PubMed

    Butler, John T; Hall, Lisa L; Smith, Kelly P; Lawrence, Jeanne B

    2009-07-01

    The complex nuclear structure of somatic cells is important to epigenomic regulation, yet little is known about nuclear organization of human embryonic stem cells (hESC). Here we surveyed several nuclear structures in pluripotent and transitioning hESC. Observations of centromeres, telomeres, SC35 speckles, Cajal Bodies, lamin A/C and emerin, nuclear shape and size demonstrate a very different "nuclear landscape" in hESC. This landscape is remodeled during a brief transitional window, concomitant with or just prior to differentiation onset. Notably, hESC initially contain abundant signal for spliceosome assembly factor, SC35, but lack discrete SC35 domains; these form as cells begin to specialize, likely reflecting cell-type specific genomic organization. Concomitantly, nuclear size increases and shape changes as lamin A/C and emerin incorporate into the lamina. During this brief window, hESC exhibit dramatically different PML-defined structures, which in somatic cells are linked to gene regulation and cancer. Unlike the numerous, spherical somatic PML bodies, hES cells often display approximately 1-3 large PML structures of two morphological types: long linear "rods" or elaborate "rosettes", which lack substantial SUMO-1, Daxx, and Sp100. These occur primarily between Day 0-2 of differentiation and become rare thereafter. PML rods may be "taut" between other structures, such as centromeres, but clearly show some relationship with the lamina, where PML often abuts or fills a "gap" in early lamin A/C staining. Findings demonstrate that pluripotent hES cells have a markedly different overall nuclear architecture, remodeling of which is linked to early epigenomic programming and involves formation of unique PML-defined structures.

  3. Extracellular IL-33 cytokine, but not endogenous nuclear IL-33, regulates protein expression in endothelial cells

    PubMed Central

    Gautier, Violette; Cayrol, Corinne; Farache, Dorian; Roga, Stéphane; Monsarrat, Bernard; Burlet-Schiltz, Odile; Gonzalez de Peredo, Anne; Girard, Jean-Philippe

    2016-01-01

    IL-33 is a nuclear cytokine from the IL-1 family that plays important roles in health and disease. Extracellular IL-33 activates a growing number of target cells, including group 2 innate lymphoid cells, mast cells and regulatory T cells, but it remains unclear whether intracellular nuclear IL-33 has additional functions in the nucleus. Here, we used a global proteomic approach based on high-resolution mass spectrometry to compare the extracellular and intracellular roles of IL-33 in primary human endothelial cells, a major source of IL-33 protein in human tissues. We found that exogenous extracellular IL-33 cytokine induced expression of a distinct set of proteins associated with inflammatory responses in endothelial cells. In contrast, knockdown of endogenous nuclear IL-33 expression using two independent RNA silencing strategies had no reproducible effect on the endothelial cell proteome. These results suggest that IL-33 acts as a cytokine but not as a nuclear factor regulating gene expression in endothelial cells. PMID:27694941

  4. Vorinostat differentially alters 3D nuclear structure of cancer and non-cancerous esophageal cells.

    PubMed

    Nandakumar, Vivek; Hansen, Nanna; Glenn, Honor L; Han, Jessica H; Helland, Stephanie; Hernandez, Kathryn; Senechal, Patti; Johnson, Roger H; Bussey, Kimberly J; Meldrum, Deirdre R

    2016-01-01

    The histone deacetylase (HDAC) inhibitor vorinostat has received significant attention in recent years as an 'epigenetic' drug used to treat solid tumors. However, its mechanisms of action are not entirely understood, particularly with regard to its interaction with the aberrations in 3D nuclear structure that accompany neoplastic progression. We investigated the impact of vorinostat on human esophageal epithelial cell lines derived from normal, metaplastic (pre-cancerous), and malignant tissue. Using a combination of novel optical computed tomography (CT)-based quantitative 3D absorption microscopy and conventional confocal fluorescence microscopy, we show that subjecting malignant cells to vorinostat preferentially alters their 3D nuclear architecture relative to non-cancerous cells. Optical CT (cell CT) imaging of fixed single cells showed that drug-treated cancer cells exhibit significant alterations in nuclear morphometry. Confocal microscopy revealed that vorinostat caused changes in the distribution of H3K9ac-marked euchromatin and H3K9me3-marked constitutive heterochromatin. Additionally, 3D immuno-FISH showed that drug-induced expression of the DNA repair gene MGMT was accompanied by spatial relocation toward the center of the nucleus in the nuclei of metaplastic but not in non-neoplastic cells. Our data suggest that vorinostat's differential modulation of 3D nuclear architecture in normal and abnormal cells could play a functional role in its anti-cancer action. PMID:27503568

  5. Vorinostat differentially alters 3D nuclear structure of cancer and non-cancerous esophageal cells

    PubMed Central

    Nandakumar, Vivek; Hansen, Nanna; Glenn, Honor L.; Han, Jessica H.; Helland, Stephanie; Hernandez, Kathryn; Senechal, Patti; Johnson, Roger H.; Bussey, Kimberly J.; Meldrum, Deirdre R.

    2016-01-01

    The histone deacetylase (HDAC) inhibitor vorinostat has received significant attention in recent years as an ‘epigenetic’ drug used to treat solid tumors. However, its mechanisms of action are not entirely understood, particularly with regard to its interaction with the aberrations in 3D nuclear structure that accompany neoplastic progression. We investigated the impact of vorinostat on human esophageal epithelial cell lines derived from normal, metaplastic (pre-cancerous), and malignant tissue. Using a combination of novel optical computed tomography (CT)-based quantitative 3D absorption microscopy and conventional confocal fluorescence microscopy, we show that subjecting malignant cells to vorinostat preferentially alters their 3D nuclear architecture relative to non-cancerous cells. Optical CT (cell CT) imaging of fixed single cells showed that drug-treated cancer cells exhibit significant alterations in nuclear morphometry. Confocal microscopy revealed that vorinostat caused changes in the distribution of H3K9ac-marked euchromatin and H3K9me3-marked constitutive heterochromatin. Additionally, 3D immuno-FISH showed that drug-induced expression of the DNA repair gene MGMT was accompanied by spatial relocation toward the center of the nucleus in the nuclei of metaplastic but not in non-neoplastic cells. Our data suggest that vorinostat’s differential modulation of 3D nuclear architecture in normal and abnormal cells could play a functional role in its anti-cancer action. PMID:27503568

  6. Vorinostat differentially alters 3D nuclear structure of cancer and non-cancerous esophageal cells.

    PubMed

    Nandakumar, Vivek; Hansen, Nanna; Glenn, Honor L; Han, Jessica H; Helland, Stephanie; Hernandez, Kathryn; Senechal, Patti; Johnson, Roger H; Bussey, Kimberly J; Meldrum, Deirdre R

    2016-08-09

    The histone deacetylase (HDAC) inhibitor vorinostat has received significant attention in recent years as an 'epigenetic' drug used to treat solid tumors. However, its mechanisms of action are not entirely understood, particularly with regard to its interaction with the aberrations in 3D nuclear structure that accompany neoplastic progression. We investigated the impact of vorinostat on human esophageal epithelial cell lines derived from normal, metaplastic (pre-cancerous), and malignant tissue. Using a combination of novel optical computed tomography (CT)-based quantitative 3D absorption microscopy and conventional confocal fluorescence microscopy, we show that subjecting malignant cells to vorinostat preferentially alters their 3D nuclear architecture relative to non-cancerous cells. Optical CT (cell CT) imaging of fixed single cells showed that drug-treated cancer cells exhibit significant alterations in nuclear morphometry. Confocal microscopy revealed that vorinostat caused changes in the distribution of H3K9ac-marked euchromatin and H3K9me3-marked constitutive heterochromatin. Additionally, 3D immuno-FISH showed that drug-induced expression of the DNA repair gene MGMT was accompanied by spatial relocation toward the center of the nucleus in the nuclei of metaplastic but not in non-neoplastic cells. Our data suggest that vorinostat's differential modulation of 3D nuclear architecture in normal and abnormal cells could play a functional role in its anti-cancer action.

  7. Response of sheep lymphocytes to PHA: quantitation by nuclear volume measurement and cell counts (40764)

    SciTech Connect

    Chandra, P.; Chanana, A.D.; Joel, D.D.

    1980-03-01

    Phytohemagglutinin response of peripheral blood lymphocytes (PBL) of sheep was studied. Assessment of proliferative response was performed by determination of nuclear volumes and cell counts in cultures from 14 sheep and by incorporation of tritiated thymidine in cultures in four additional sheep. PBL of sheep were found to transform and proliferate with PHA similarly to human peripheral blood lymphocytes with minor differences. Quantitation of the proliferative response by determining the cell count and nuclear volumes provided more information on cell kinetics in culture than the commonly used isotope-labeled thymidine incorporation method.

  8. Nuclear size as a cell-kinetic marker for osteoblast differentiation

    NASA Technical Reports Server (NTRS)

    Roberts, W. E.; Mozsary, P. G.; Klingler, E.

    1982-01-01

    A nuclear morphometric assay for preosteoblasts is introduced as a cell-kinetic technique, applicable to routine histological preparations of mineralized tissue. Because this method is a morphological marker for osteoblast precursor cell differentiation, it provides a new dimension for determining the mechanism of osteoblast histogenesis. Osteoblast precursors of the periodontal ligament are a mixed population of progenitors, kinetically separable into two distinct groups according to nuclear size. Preosteoblasts, the immediate proliferating precursors of osteoblasts, have large nuclei (greater than 170 micrometers3) and are derived from relatively undifferentiated fibroblastlike cells, which have smaller nuclei (less than 80 micrometers3). Increase in nuclear volume, during G1 phase of the cell cycle, is apparently a morphological manifestation of change in genomic expression. This key event in preosteoblast differentiation is related to mechanical stress/strain and may be an important rate-limiting step in osteoblast histogenesis.

  9. Nuclear physics (of the cell, not the atom)

    PubMed Central

    Pederson, Thoru; Marko, John F.

    2014-01-01

    The nucleus is physically distinct from the cytoplasm in ways that suggest new ideas and approaches for interrogating the operation of this organelle. Chemical bond formation and breakage underlie the lives of cells, but as this special issue of Molecular Biology of the Cell attests, the nonchemical aspects of cell nuclei present a new frontier to biologists and biophysicists. PMID:25368422

  10. Multidimensional profiling of cell surface proteins and nuclear markers

    SciTech Connect

    Han, Ju; Chang, Hang; Andarawewa, Kumari; Yaswen, Paul; Helen Barcellos-Hoff, Mary; Parvin, Bahram

    2009-01-30

    Cell membrane proteins play an important role in tissue architecture and cell-cell communication. We hypothesize that segmentation and multidimensional characterization of the distribution of cell membrane proteins, on a cell-by-cell basis, enable improved classification of treatment groups and identify important characteristics that can otherwise be hidden. We have developed a series of computational steps to (i) delineate cell membrane protein signals and associate them with a specific nucleus; (ii) compute a coupled representation of the multiplexed DNA content with membrane proteins; (iii) rank computed features associated with such a multidimensional representation; (iv) visualize selected features for comparative evaluation through heatmaps; and (v) discriminate between treatment groups in an optimal fashion. The novelty of our method is in the segmentation of the membrane signal and the multidimensional representation of phenotypic signature on a cell-by-cell basis. To test the utility of this method, the proposed computational steps were applied to images of cells that have been irradiated with different radiation qualities in the presence and absence of other small molecules. These samples are labeled for their DNA content and E-cadherin membrane proteins. We demonstrate that multidimensional representations of cell-by-cell phenotypes improve predictive and visualization capabilities among different treatment groups, and identify hidden variables.

  11. Nuclear physics (of the cell, not the atom).

    PubMed

    Pederson, Thoru; Marko, John F

    2014-11-01

    The nucleus is physically distinct from the cytoplasm in ways that suggest new ideas and approaches for interrogating the operation of this organelle. Chemical bond formation and breakage underlie the lives of cells, but as this special issue of Molecular Biology of the Cell attests, the nonchemical aspects of cell nuclei present a new frontier to biologists and biophysicists.

  12. Nuclear Membranes ETB Receptors Mediate ET-1-induced Increase of Nuclear Calcium in Human Left Ventricular Endocardial Endothelial Cells.

    PubMed

    Jules, Farah; Avedanian, Levon; Al-Khoury, Johny; Keita, Ramatoulaye; Normand, Alexandre; Bkaily, Ghassan; Jacques, Danielle

    2015-07-01

    In fetal human left ventricular endocardial endothelial cells (EECLs), both plasma membrane (PM) ET(A)R and ET(B)R were reported to mediate ET-1-induced increase of intracellular calcium [Ca](i); however, this effect was mediated by ET(A)R in right EECs (EECRs). In this study, we verified whether, as for the PM, nuclear membranes (NMs) ET-1 receptors activation in EECLs and EECRs induce an increase of nuclear calcium ([Ca](n)) and if this effect is mediated through the same receptor type as in PM. Using a plasmalemma-perforated technique and 3D confocal microscopy, our results showed that, as in PM intact cells, superfusion of nuclei of both cell types with cytosolic ET-1 induced a concentration-dependent sustained increase of [Ca](n). In EECRs, the ET(A)R antagonist prevented the effect of ET-1 on [Ca](n) without affecting EECLs. However, in both cell types, the effect of cytosolic ET-1 on [Ca](n) was prevented by the ETBR antagonist. In conclusion, both NMs' ET(A)R and ET(B)R mediated the effect of cytosolic ET-1 on [Ca](n) in EECRs. In contrast, only NMs' ET(B)R activation mediated the effect of cytosolic ET-1 in EECLs. Hence, the type of NMs' receptors mediating the effect of ET-1 on [Ca](n) are different from those of PM mediating the increase in [Ca](i).

  13. Production of human CD59-transgenic pigs by embryonic germ cell nuclear transfer

    SciTech Connect

    Ahn, Kwang Sung; Won, Ji Young; Park, Jin-Ki; Sorrell, Alice M.; Heo, Soon Young; Kang, Jee Hyun; Woo, Jae-Seok; Choi, Bong-Hwan; Chang, Won-Kyong; Shim, Hosup

    2010-10-01

    Research highlights: {yields} Human CD59 (hCD59) gene was introduced into porcine embryonic germ (EG) cells. {yields} hCD59-transgenic EG cells were resistant to hyperacute rejection in cytolytic assay. {yields} hCD59-transgenic pigs were produced by EG cell nuclear transfer. -- Abstract: This study was performed to produce transgenic pigs expressing the human complement regulatory protein CD59 (hCD59) using the nuclear transfer (NT) of embryonic germ (EG) cells, which are undifferentiated stem cells derived from primordial germ cells. Because EG cells can be cultured indefinitely in an undifferentiated state, they may provide an inexhaustible source of nuclear donor cells for NT to produce transgenic pigs. A total of 1980 NT embryos derived from hCD59-transgenic EG cells were transferred to ten recipients, resulting in the birth of fifteen piglets from three pregnancies. Among these offspring, ten were alive without overt health problems. Based on PCR analysis, all fifteen piglets were confirmed as hCD59 transgenic. The expression of the hCD59 transgene in the ten living piglets was verified by RT-PCR. Western analysis showed the expression of the hCD59 protein in four of the ten RT-PCR-positive piglets. These results demonstrate that hCD59-transgenic pigs could effectively be produced by EG cell NT and that such transgenic pigs may be used as organ donors in pig-to-human xenotransplantation.

  14. Emp is a component of the nuclear matrix of mammalian cells and undergoes dynamic rearrangements during cell division

    SciTech Connect

    Bala, Shashi; Kumar, Ajay; Soni, Shivani; Sinha, Sudha; Hanspal, Manjit . E-mail: manjit.hanspal@tufts.edu

    2006-04-21

    Emp, originally detected in erythroblastic islands, is expressed in numerous cell types and tissues suggesting a functionality not limited to hematopoiesis. To study the function of Emp in non-hematopoietic cells, an epitope-tagged recombinant human Emp was expressed in HEK cells. Preliminary studies revealed that Emp partitioned into both the nuclear and Triton X-100-insoluble cytoskeletal fractions in approximately a 4:1 ratio. In this study, we report investigations of Emp in the nucleus. Sequential extractions of interphase nuclei showed that recombinant Emp was present predominantly in the nuclear matrix. Immunofluorescence microscopy showed that Emp was present in typical nuclear speckles enriched with the spliceosome assembly factor SC35 and partially co-localized with actin staining. Coimmunoprecipitation and GST-pull-down assays confirmed the apparent close association of Emp with nuclear actin. During mitosis, Emp was detected at the mitotic spindle/spindle poles, as well as in the contractile ring during cytokinesis. These results suggest that Emp undergoes dynamic rearrangements within the nuclear architecture that are correlated with cell division.

  15. Emp is a component of the nuclear matrix of mammalian cells and undergoes dynamic rearrangements during cell division.

    PubMed

    Bala, Shashi; Kumar, Ajay; Soni, Shivani; Sinha, Sudha; Hanspal, Manjit

    2006-04-21

    Emp, originally detected in erythroblastic islands, is expressed in numerous cell types and tissues suggesting a functionality not limited to hematopoiesis. To study the function of Emp in non-hematopoietic cells, an epitope-tagged recombinant human Emp was expressed in HEK cells. Preliminary studies revealed that Emp partitioned into both the nuclear and Triton X-100-insoluble cytoskeletal fractions in approximately a 4:1 ratio. In this study, we report investigations of Emp in the nucleus. Sequential extractions of interphase nuclei showed that recombinant Emp was present predominantly in the nuclear matrix. Immunofluorescence microscopy showed that Emp was present in typical nuclear speckles enriched with the spliceosome assembly factor SC35 and partially co-localized with actin staining. Coimmunoprecipitation and GST-pull-down assays confirmed the apparent close association of Emp with nuclear actin. During mitosis, Emp was detected at the mitotic spindle/spindle poles, as well as in the contractile ring during cytokinesis. These results suggest that Emp undergoes dynamic rearrangements within the nuclear architecture that are correlated with cell division.

  16. Visualizing the molecular sociology at the HeLa cell nuclear periphery.

    PubMed

    Mahamid, Julia; Pfeffer, Stefan; Schaffer, Miroslava; Villa, Elizabeth; Danev, Radostin; Cuellar, Luis Kuhn; Förster, Friedrich; Hyman, Anthony A; Plitzko, Jürgen M; Baumeister, Wolfgang

    2016-02-26

    The molecular organization of eukaryotic nuclear volumes remains largely unexplored. Here we combined recent developments in cryo-electron tomography (cryo-ET) to produce three-dimensional snapshots of the HeLa cell nuclear periphery. Subtomogram averaging and classification of ribosomes revealed the native structure and organization of the cytoplasmic translation machinery. Analysis of a large dynamic structure-the nuclear pore complex-revealed variations detectable at the level of individual complexes. Cryo-ET was used to visualize previously elusive structures, such as nucleosome chains and the filaments of the nuclear lamina, in situ. Elucidation of the lamina structure provides insight into its contribution to metazoan nuclear stiffness. PMID:26917770

  17. Isolation of chromatin DNA tightly bound to the nuclear envelope of HeLa cells.

    PubMed

    Kuvichkin, Vasily Vladimirovich

    2012-11-01

    Recent discovery of the role of nuclear pores in transcription, predicted by our early DNA-membrane complex (DMC) model, makes membrane-bound DNA (MBD) isolation from the cell nucleus and analysis of the MBD actual. The method of MBD isolation proposed by us retains DMC integrity during isolation. We used HeLa cells for DMC extraction. Changing the ionic composition of the isolation medium and replacing DNase I, used commonly for chromatin destruction, with a set of restriction enzymes allowed us to isolate the MBD. Treatment of a nuclear membrane with proteinase K and ultrasound has been used to increase the yield of MBD. Electron microscopic analysis of the purified fraction of isolated DMC supports our previous model of nuclear envelope lipid-chromatin interaction in the nuclear pore assembly.

  18. Cell Cycle Regulates Nuclear Stability of AID and Determines the Cellular Response to AID.

    PubMed

    Le, Quy; Maizels, Nancy

    2015-09-01

    AID (Activation Induced Deaminase) deaminates cytosines in DNA to initiate immunoglobulin gene diversification and to reprogram CpG methylation in early development. AID is potentially highly mutagenic, and it causes genomic instability evident as translocations in B cell malignancies. Here we show that AID is cell cycle regulated. By high content screening microscopy, we demonstrate that AID undergoes nuclear degradation more slowly in G1 phase than in S or G2-M phase, and that mutations that affect regulatory phosphorylation or catalytic activity can alter AID stability and abundance. We directly test the role of cell cycle regulation by fusing AID to tags that destabilize nuclear protein outside of G1 or S-G2/M phases. We show that enforced nuclear localization of AID in G1 phase accelerates somatic hypermutation and class switch recombination, and is well-tolerated; while nuclear AID compromises viability in S-G2/M phase cells. We identify AID derivatives that accelerate somatic hypermutation with minimal impact on viability, which will be useful tools for engineering genes and proteins by iterative mutagenesis and selection. Our results further suggest that use of cell cycle tags to regulate nuclear stability may be generally applicable to studying DNA repair and to engineering the genome.

  19. mReg2 inhibits nuclear entry of apoptosis-inducing factor in mouse insulinoma cells.

    PubMed

    Liu, Lu; Chowdhury, Subrata; Uppal, Sadaf; Fang, Xin; Liu, Jun-Li; Srikant, Coimbatore B

    2015-02-01

    We have reported earlier that murine-regenerating gene mReg2 protects MIN6 mouse insulinoma cells from ER stress and caspase-mediated apoptosis. In apoptotic cells, DNA damage is induced by the nuclear translocation of mitochondrial apoptosis-inducing factor (AIF). Here we tested the hypothesis that mReg2 may regulate Scythe and/or hsp70 which influence the nuclear import of AIF. Treatment with thapsigargin (Tg) or doxorubicin induced an increase in nuclear AIF in MIN6 cells carrying the empty transfection vector (MIN6-VC) but not in cells overexpressing mReg2 (MIN6-mReg2). On one hand, nuclear Scythe was higher in the nucleus of MIN6-mReg2 compared with that in MIN6-VC cells. mReg2 did not alter the expression of AIF or Scythe. On the other hand, mReg2 induced the expression of hsp70 which is known to promote cytosolic retention of AIF. We conclude that mReg2 inhibits AIF-mediated apoptosis by promoting the nuclear presence of Scythe and inducing hsp70.

  20. Nuclear receptors license phagocytosis by trem2+ myeloid cells in mouse models of Alzheimer's disease.

    PubMed

    Savage, Julie C; Jay, Taylor; Goduni, Elanda; Quigley, Caitlin; Mariani, Monica M; Malm, Tarja; Ransohoff, Richard M; Lamb, Bruce T; Landreth, Gary E

    2015-04-22

    Alzheimer's disease (AD) is characterized by a robust inflammatory response elicited by the accumulation and subsequent deposition of amyloid (Aβ) within the brain. The brain's immune cells migrate to and invest their processes within Aβ plaques but are unable to efficiently phagocytose and clear plaques from the brain. Previous studies have shown that treatment of myeloid cells with nuclear receptor agonists increases expression of phagocytosis-related genes. In this study, we elucidate a novel mechanism by which nuclear receptors act to enhance phagocytosis in the AD brain. Treatment of murine models of AD with agonists of the nuclear receptors PPARγ, PPARδ, LXR, and RXR stimulated microglial phagocytosis in vitro and rapidly induced the expression of the phagocytic receptors Axl and MerTK. In murine models of AD, we found that plaque-associated macrophages expressed Axl and MerTK and treatment of the cells with an RXR agonist further induced their expression, coincident with the rapid reduction in plaque burden. Further characterization of MerTK(+)/Axl(+) macrophages revealed that they also expressed the phagocytic receptor TREM2 and high levels of CD45, consistent with a peripheral origin of these cells. Importantly, in an ex vivo slice assay, nuclear receptor agonist treatment reversed the AD-related suppression of phagocytosis through a MerTK-dependent mechanism. Thus, nuclear receptor agonists increase MerTK and Axl expression on plaque-associated immune cells, consequently licensing their phagocytic activity and promoting plaque clearance.

  1. Fhit Nuclear Import Following EGF Stimulation Sustains Proliferation of Breast Cancer Cells.

    PubMed

    Bianchi, Francesca; Sasso, Marianna; Turdo, Federica; Beretta, Giovanni L; Casalini, Patrizia; Ghirelli, Cristina; Sfondrini, Lucia; Ménard, Sylvie; Tagliabue, Elda; Campiglio, Manuela

    2015-11-01

    The tumor-suppressor protein fragile histidine triad (Fhit) exerts its functions in the cytoplasm, although some reports suggest that it may also act in the nucleus. We previously showed that cytosolic Fhit protein levels in cancer cell lines stimulated to proliferate were reduced by proteasomal degradation. Here, we demonstrate that Fhit is physiologically present in the nucleus of breast cancer cell lines and tissues at a low level and that proliferative stimulation increases nuclear levels. Breast cancer cells expressing the FhitY114F mutant, which do not undergo proteasomal degradation, contained mutated Fhit in the nucleus, while cells treated with a proteasome inhibitor accumulated nuclear Fhit during proliferation. Thus, Fhit nuclear shuttling and proteasome degradation phenomena occur independently. When Fhit was coupled to a nuclear localization sequence, the proliferation rate of the transfected cells increased together with levels of proliferation pathway mediators cyclin D1, phospho-MAPK, and phospho-STAT3. Fhit nuclear translocation upon mitogenic stimulation may represent a new regulatory mechanism that allows rapid restoration of Fhit cytoplasmic levels and promotes the proliferation cascade activated by mitogenic stimulation.

  2. Universally Conserved Relationships between Nuclear Shape and Cytoplasmic Mechanical Properties in Human Stem Cells

    NASA Astrophysics Data System (ADS)

    Lozoya, Oswaldo A.; Gilchrist, Christopher L.; Guilak, Farshid

    2016-03-01

    The ability of cells to proliferate, differentiate, transduce extracellular signals and assemble tissues involves structural connections between nucleus and cytoskeleton. Yet, how the mechanics of these connections vary inside stem cells is not fully understood. To address those questions, we combined two-dimensional particle-tracking microrheology and morphological measures using variable reduction techniques to measure whether cytoplasmic mechanics allow for discrimination between different human adherent stem cell types and across different culture conditions. Here we show that nuclear shape is a quantifiable discriminant of mechanical properties in the perinuclear cytoskeleton (pnCSK) of various stem cell types. Also, we find the pnCSK is a region with different mechanical properties than elsewhere in the cytoskeleton, with heterogeneously distributed locations exhibiting subdiffusive features, and which obeys physical relations conserved among various stem cell types. Finally, we offer a prospective basis to discriminate between stem cell types by coupling perinuclear mechanical properties to nuclear shape.

  3. Universally Conserved Relationships between Nuclear Shape and Cytoplasmic Mechanical Properties in Human Stem Cells

    PubMed Central

    Lozoya, Oswaldo A.; Gilchrist, Christopher L.; Guilak, Farshid

    2016-01-01

    The ability of cells to proliferate, differentiate, transduce extracellular signals and assemble tissues involves structural connections between nucleus and cytoskeleton. Yet, how the mechanics of these connections vary inside stem cells is not fully understood. To address those questions, we combined two-dimensional particle-tracking microrheology and morphological measures using variable reduction techniques to measure whether cytoplasmic mechanics allow for discrimination between different human adherent stem cell types and across different culture conditions. Here we show that nuclear shape is a quantifiable discriminant of mechanical properties in the perinuclear cytoskeleton (pnCSK) of various stem cell types. Also, we find the pnCSK is a region with different mechanical properties than elsewhere in the cytoskeleton, with heterogeneously distributed locations exhibiting subdiffusive features, and which obeys physical relations conserved among various stem cell types. Finally, we offer a prospective basis to discriminate between stem cell types by coupling perinuclear mechanical properties to nuclear shape. PMID:26976044

  4. Bio-chemo-mechanical models for nuclear deformation in adherent eukaryotic cells.

    PubMed

    Nava, Michele M; Raimondi, Manuela T; Pietrabissa, Riccardo

    2014-10-01

    Adherent eukaryotic cells are subjected to a broad variety of extracellular and intracellular stimuli regulating their behaviour. These stimuli can be either purely chemical, for example soluble factors binding to the cell membrane, or mechano-chemical, for example integrin-based adhesion complexes stretching the cell cytoskeleton. Here, we focus on mechano-chemical stimuli such as extracellular forces (interstitial flow, pressurization) and intracellular forces (due to cell adhesion), which may combine generating stress-strain states in the cytoskeleton. These states are transferred to the nucleus to influence the transcription of specific genes, likely by changing the chromatin organization and by altering the permeability of the nuclear membrane. While there exists increasing experimental evidence of the mechanosensing role of the cell nucleus, both the underlying molecular mechanisms involved, and the nuclear structural behaviour in response to forces, are still poorly understood. Here, we review the existing literature on computational models developed to investigate the chemo-mechanical behaviour of adherent eukaryotic cells. We analyse two main classes of models of single-cell mechanics, based either on the discrete or on the continuum approaches. We focus on the bio-chemo-mechanical model and modelling techniques accounting for the nuclear body. The modelling techniques are discussed highlighting their ability in predicting cytoskeletal contractility states and nuclear stress-strain states.

  5. Evaluating cytoplasmic and nuclear levels of inflammatory cytokines in cancer cells by western blotting.

    PubMed

    Gatla, Himavanth R; Singha, Bipradeb; Persaud, Valerie; Vancurova, Ivana

    2014-01-01

    Increased expression and cellular release of inflammatory cytokines, interleukin-8 (IL-8; CXCL8), and high mobility group box-1 (HMGB1) are associated with increased cell proliferation, angiogenesis, and metastasis during cancer progression. In prostate and ovarian cancer cells, increased levels of IL-8 and HMGB1 correlate with poor prognosis. We have recently shown that proteasome inhibition by bortezomib (BZ) specifically increases IL-8 release from metastatic prostate and ovarian cancer cells. In this chapter, we describe a protocol to analyze the cytoplasmic and nuclear levels of IL-8 and HMGB1 in prostate and ovarian cancer cells by western blotting. IL-8 is localized in the cytoplasm in both cell types, and its protein levels are significantly increased by BZ. In contrast, HMGB1 is localized in the nucleus, and BZ increases its nuclear levels only in ovarian cancer cells. The protocol includes isolation of cytoplasmic and nuclear extracts, followed by SDS electrophoresis and western blotting, and can be easily modified to analyze the cytoplasmic and nuclear cytokine levels in other cell types. PMID:24908314

  6. Evaluating cytoplasmic and nuclear levels of inflammatory cytokines in cancer cells by western blotting.

    PubMed

    Gatla, Himavanth R; Singha, Bipradeb; Persaud, Valerie; Vancurova, Ivana

    2014-01-01

    Increased expression and cellular release of inflammatory cytokines, interleukin-8 (IL-8; CXCL8), and high mobility group box-1 (HMGB1) are associated with increased cell proliferation, angiogenesis, and metastasis during cancer progression. In prostate and ovarian cancer cells, increased levels of IL-8 and HMGB1 correlate with poor prognosis. We have recently shown that proteasome inhibition by bortezomib (BZ) specifically increases IL-8 release from metastatic prostate and ovarian cancer cells. In this chapter, we describe a protocol to analyze the cytoplasmic and nuclear levels of IL-8 and HMGB1 in prostate and ovarian cancer cells by western blotting. IL-8 is localized in the cytoplasm in both cell types, and its protein levels are significantly increased by BZ. In contrast, HMGB1 is localized in the nucleus, and BZ increases its nuclear levels only in ovarian cancer cells. The protocol includes isolation of cytoplasmic and nuclear extracts, followed by SDS electrophoresis and western blotting, and can be easily modified to analyze the cytoplasmic and nuclear cytokine levels in other cell types.

  7. Imaging Nuclear Morphology and Organization in Cleared Plant Tissues Treated with Cell Cycle Inhibitors.

    PubMed

    de Souza Junior, José Dijair Antonino; de Sa, Maria Fatima Grossi; Engler, Gilbert; Engler, Janice de Almeida

    2016-01-01

    Synchronization of root cells through chemical treatment can generate a large number of cells blocked in specific cell cycle phases. In plants, this approach can be employed for cell suspension cultures and plant seedlings. To identify plant cells in the course of the cell cycle, especially during mitosis in meristematic tissues, chemical inhibitors can be used to block cell cycle progression. Herein, we present a simplified and easy-to-apply protocol to visualize mitotic figures, nuclei morphology, and organization in whole Arabidopsis root apexes. The procedure is based on tissue clearing, and fluorescent staining of nuclear DNA with DAPI. The protocol allows carrying out bulk analysis of nuclei and cell cycle phases in root cells and will be valuable to investigate mutants like overexpressing lines of genes disturbing the plant cell cycle.

  8. Altering the cellular mechanical force balance results in integrated changes in cell, cytoskeletal and nuclear shape

    NASA Technical Reports Server (NTRS)

    Sims, J. R.; Karp, S.; Ingber, D. E.

    1992-01-01

    Studies were carried out with capillary endothelial cells cultured on fibronectin (FN)-coated dishes in order to analyze the mechanism of cell and nuclear shape control by extracellular matrix (ECM). To examine the role of the cytoskeleton in shape determination independent of changes in transmembrane osmotic pressure, membranes of adherent cells were permeabilized with saponin (25 micrograms/ml) using a buffer that maintains the functional integrity of contractile microfilaments. Real-time videomicroscopic studies revealed that addition of 250 microM ATP resulted in time-dependent retraction and rounding of permeabilized cells and nuclei in a manner similar to that observed in intact living cells following detachment using trypsin-EDTA. Computerized image analysis confirmed that permeabilized cells remained essentially rigid in the absence of ATP and that retraction was stimulated in a dose-dependent manner as the concentration of ATP was raised from 10 to 250 microM. Maximal rounding occurred by 30 min with projected cell and nuclear areas being reduced by 69 and 41%, respectively. ATP-induced rounding was also accompanied by a redistribution of microfilaments resulting in formation of a dense net of F-actin surrounding retracted nuclei. Importantly, ATP-stimulated changes in cell, cytoskeletal, and nuclear form were prevented in permeabilized cells using a synthetic myosin peptide (IRICRKG) that has been previously shown to inhibit actomyosin filament sliding in muscle. In contrast, both the rate and extent of cell and nuclear rounding were increased in permeabilized cells exposed to ATP when the soluble FN peptide, GRGDSP, was used to dislodge immobilized FN from cell surface integrin receptors.(ABSTRACT TRUNCATED AT 250 WORDS).

  9. Oral cancer/endothelial cell fusion experiences nuclear fusion and acquisition of enhanced survival potential

    SciTech Connect

    Song, Kai; Song, Yong; Zhao, Xiao-Ping; Shen, Hui; Wang, Meng; Yan, Ting-lin; Liu, Ke; Shang, Zheng-jun

    2014-10-15

    Most previous studies have linked cancer–macrophage fusion with tumor progression and metastasis. However, the characteristics of hybrid cells derived from oral cancer and endothelial cells and their involvement in cancer remained unknown. Double-immunofluorescent staining and fluorescent in situ hybridization (FISH) were performed to confirm spontaneous cell fusion between eGFP-labeled human umbilical vein endothelial cells (HUVECs) and RFP-labeled SCC9, and to detect the expression of vementin and cytokeratin 18 in the hybrids. The property of chemo-resistance of such hybrids was examined by TUNEL assay. The hybrid cells in xenografted tumor were identified by FISH and GFP/RFP dual-immunofluoresence staining. We showed that SCC9 cells spontaneously fused with cocultured endothelial cells, and the resultant hybrid cells maintained the division and proliferation activity after re-plating and thawing. Such hybrids expressed markers of both parental cells and became more resistant to chemotherapeutic drug cisplatin as compared to the parental SCC9 cells. Our in vivo data indicated that the hybrid cells contributed to tumor composition by using of immunostaining and FISH analysis, even though the hybrid cells and SCC9 cells were mixed with 1:10,000, according to the FACS data. Our study suggested that the fusion events between oral cancer and endothelial cells undergo nuclear fusion and acquire a new property of drug resistance and consequently enhanced survival potential. These experimental findings provide further supportive evidence for the theory that cell fusion is involved in cancer progression. - Highlights: • The fusion events between oral cancer and endothelial cells undergo nuclear fusion. • The resulting hybrid cells acquire a new property of drug resistance. • The resulting hybrid cells express the markers of both parental cells (i.e. vimentin and cytokeratin 18). • The hybrid cells contribute to tumor repopulation in vivo.

  10. Phenotype Clustering of Breast Epithelial Cells in Confocal Imagesbased on Nuclear Protein Distribution Analysis

    SciTech Connect

    Long, Fuhui; Peng, Hanchuan; Sudar, Damir; Levievre, Sophie A.; Knowles, David W.

    2006-09-05

    Background: The distribution of the chromatin-associatedproteins plays a key role in directing nuclear function. Previously, wedeveloped an image-based method to quantify the nuclear distributions ofproteins and showed that these distributions depended on the phenotype ofhuman mammary epithelial cells. Here we describe a method that creates ahierarchical tree of the given cell phenotypes and calculates thestatistical significance between them, based on the clustering analysisof nuclear protein distributions. Results: Nuclear distributions ofnuclear mitotic apparatus protein were previously obtained fornon-neoplastic S1 and malignant T4-2 human mammary epithelial cellscultured for up to 12 days. Cell phenotype was defined as S1 or T4-2 andthe number of days in cultured. A probabilistic ensemble approach wasused to define a set of consensus clusters from the results of multipletraditional cluster analysis techniques applied to the nucleardistribution data. Cluster histograms were constructed to show how cellsin any one phenotype were distributed across the consensus clusters.Grouping various phenotypes allowed us to build phenotype trees andcalculate the statistical difference between each group. The resultsshowed that non-neoplastic S1 cells could be distinguished from malignantT4-2 cells with 94.19 percent accuracy; that proliferating S1 cells couldbe distinguished from differentiated S1 cells with 92.86 percentaccuracy; and showed no significant difference between the variousphenotypes of T4-2 cells corresponding to increasing tumor sizes.Conclusion: This work presents a cluster analysis method that canidentify significant cell phenotypes, based on the nuclear distributionof specific proteins, with high accuracy.

  11. Nuclear localization of the tight junction protein ZO-2 in epithelial cells.

    PubMed

    Islas, Socorro; Vega, Jesús; Ponce, Lissette; González-Mariscal, Lorenza

    2002-03-10

    The tight junction constitutes the major barrier to solute and water flow through the paracellular space of epithelia and endothelia. It is formed by transmembrane proteins and submembranous molecules such as the MAGUKs ZOs. We have previously found that several MAGUKs, including those of the tight (ZO-1, ZO-2, and ZO-3) and septate junction (tamou and Dlg), contain one or two nuclear sorting signals located at their first PDZ and GK domains. Now we show that these proteins also contain a nuclear export signal and focus our study on the nuclear membrane shuttling of ZO-2. In sparse cultures this molecule concentrates at the nucleus in clusters, where it partially colocalizes with splicing factor SC35. Nuclear staining diminishes as the monolayer acquires confluence through a process sensitive to the nuclear export inhibitor leptomycin B. Nuclear localization can be induced by impairing cell-cell contacts, by mechanical injury. ZO-2 that shuttles from the cell periphery into the nucleus is not newly synthesized but originates from a preexistent pool. The movement of this protein is mediated by the actin cytoskeleton.

  12. Plasmonic Imaging of Human Oral Cancer Cell Communities During Programmed Cell Death by Nuclear Targeting Silver Nanoparticles

    PubMed Central

    Austin, Lauren A.; Kang, Bin; Yen, Chun-Wan; El-Sayed, Mostafa A.

    2016-01-01

    Plasmonic nanoparticles (NPs) have become a useful platform in the biomedical field due to their potential use in disease diagnosis and treatment. Recently, it has been reported that plasmonic NPs conjugated to nuclear-targeting peptides cause DNA damage and apoptotic populations in cancer cells. In the present work, we utilized the plasmonic scattering property and the ability of nuclear-targeted silver nanoparticles (NLS/RGD-AgNPs) to induce programmed cell death in order to image in real-time the behavior of human oral squamous carcinoma (HSC-3) cell communities during and after the induction of apoptosis. Plasmonic live-cell imaging (movie) revealed that HSC-3 cells behave as non-professional phagocytes. The induction of apoptosis in some cells led to the attraction and their subsequent engulfment by the neighboring cells. Attraction to apoptotic cells resulted in clustering of cellular community. The live-cell imaging movies also revealed that as the initial concentration of NLS/RGD-AgNPs increases, the rate of self-killing increases and the degree of attraction and clustering decreases. These results are discussed in terms of the proposed mechanism of cells undergoing programmed cell death. PMID:21981727

  13. Optimization of charge carrier transport balance for performance improvement of PDPP3T-based polymer solar cells prepared using a hot solution.

    PubMed

    Wang, Jian; Zhang, Fujun; Zhang, Miao; Wang, Wenbin; An, Qiaoshi; Li, Lingliang; Sun, Qianqian; Tang, Weihua; Zhang, Jian

    2015-04-21

    Polymer solar cells (PSCs), with poly(diketopyrrolopyrrole-terthiophene) (PDPP3T):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the active layers, were fabricated using solutions of different temperatures. The best power conversion efficiency (PCE) of the PSCs prepared using a hot solution was about 6.22%, which is better than 5.54% for PSCs prepared using cool (room temperature) solutions and 5.85% for PSCs prepared using cool solutions with a 1,8-diiodooctane (DIO) solvent additive. The underlying reasons for the improved PCE of the PSCs prepared using a hot solution could be attributed to the more dispersive donor and acceptor distribution in the active layer, resulting in a better bi-continuous interpenetrating network for exciton dissociation and charge carrier transport. An enhanced and more balanced charge carrier transport in the active layer is obtained for the PSCs prepared using a hot solution, which can be determined from the J-V curves of the related hole-only and electron-only devices.

  14. Recruitment to the Nuclear Periphery Can Alter Expression of Genes in Human Cells

    PubMed Central

    Finlan, Lee E.; Sproul, Duncan; Thomson, Inga; Boyle, Shelagh; Kerr, Elizabeth; Perry, Paul; Ylstra, Bauke; Chubb, Jonathan R.; Bickmore, Wendy A.

    2008-01-01

    The spatial organisation of the genome in the nucleus has a role in the regulation of gene expression. In vertebrates, chromosomal regions with low gene-density are located close to the nuclear periphery. Correlations have also been made between the transcriptional state of some genes and their location near the nuclear periphery. However, a crucial issue is whether this level of nuclear organisation directly affects gene function, rather than merely reflecting it. To directly investigate whether proximity to the nuclear periphery can influence gene expression in mammalian cells, here we relocate specific human chromosomes to the nuclear periphery by tethering them to a protein of the inner nuclear membrane. We show that this can reversibly suppress the expression of some endogenous human genes located near the tethering sites, and even genes further away. However, the expression of many other genes is not detectably reduced and we show that location at the nuclear periphery is not incompatible with active transcription. The dampening of gene expression around the nuclear periphery is dependent on the activity of histone deacetylases. Our data show that the radial position within the nucleus can influence the expression of some, but not all, genes. This is compatible with the suggestion that re-localisation of genes relative to the peripheral zone of the nucleus could be used by metazoans to modulate the expression of selected genes during development and differentiation. PMID:18369458

  15. Bipartite nuclear localization signal of matrin 3 is essential for vertebrate cells

    SciTech Connect

    Hisada-Ishii, Shoji; Ebihara, Mizuki; Kobayashi, Nao; Kitagawa, Yasuo . E-mail: yasuok@agr.nagoya-u.ac.jp

    2007-03-02

    Matrin 3, a nuclear matrix protein has potential (1) to withhold promiscuously edited RNAs within the nucleus in cooperation with p54{sup nrb} and PSF (2) to mediate NMDA-induced neuronal death, and (3) to modulate promoter activity of genes proximal to matrix/scaffold attachment region (MAR/SAR). We identified a bipartite nuclear localization signal (NLS) of chicken matrin 3 (cmatr3) at residues 583-602. By expressing green fluorescent protein (GFP) fused to the NLS mutant in chicken DT40 cells, we showed an essential role of the NLS for cell proliferation. Furthermore, we showed that both clusters of basic amino acids and a linker of the bipartite NLS were essential and sufficient for the nuclear import of GFP. Exogenous cmatr3 rescued the HeLa cells where human matrin 3 was suppressed by RNA interference, but cmatr3 containing deletions at either of the basic amino acid clusters or the linker could not.

  16. Cultivation and Differentiation Change Nuclear Localization of Chromosome Centromeres in Human Mesenchymal Stem Cells

    PubMed Central

    Voldgorn, Yana I.; Adilgereeva, Elmira P.; Nekrasov, Evgeny D.; Lavrov, Alexander V.

    2015-01-01

    Chromosome arrangement in the interphase nucleus is not accidental. Strong evidences support that nuclear localization is an important mechanism of epigenetic regulation of gene expression. The purpose of this research was to identify differences in the localization of centromeres of chromosomes 6, 12, 18 and X in human mesenchymal stem cells depending on differentiation and cultivating time. We analyzed centromere positions in more than 4000 nuclei in 19 mesenchymal stem cell cultures before and after prolonged cultivation and after differentiation into osteogenic and adipogenic directions. We found a centromere reposition of HSAX at late passages and after differentiation in osteogenic direction as well as of HSA12 and HSA18 after adipogenic differentiation. The observed changes of the nuclear structure are new nuclear characteristics of the studied cells which may reflect regulatory changes of gene expression during the studied processes. PMID:25775427

  17. The transmission of nuclear pore complexes to daughter cells requires a cytoplasmic pool of Nsp1.

    PubMed

    Colombi, Paolo; Webster, Brant M; Fröhlich, Florian; Lusk, C Patrick

    2013-10-28

    Nuclear pore complexes (NPCs) are essential protein assemblies that span the nuclear envelope and establish nuclear-cytoplasmic compartmentalization. We have investigated mechanisms that control NPC number in mother and daughter cells during the asymmetric division of budding yeast. By simultaneously tracking existing NPCs and newly synthesized NPC protomers (nups) through anaphase, we uncovered a pool of the central channel nup Nsp1 that is actively targeted to the bud in association with endoplasmic reticulum. Bud targeting required an intact actin cytoskeleton and the class V myosin, Myo2. Selective inhibition of cytoplasmic Nsp1 or inactivation of Myo2 reduced the inheritance of NPCs in daughter cells, leading to a daughter-specific loss of viability. Our data are consistent with a model in which Nsp1 releases a barrier that otherwise prevents NPC passage through the bud neck. It further supports the finding that NPC inheritance, not de novo NPC assembly, is primarily responsible for controlling NPC number in daughter cells.

  18. Nuclear Lamin A/C Deficiency Induces Defects in Cell Mechanics, Polarization, and Migration

    PubMed Central

    Lee, Jerry S. H.; Hale, Christopher M.; Panorchan, Porntula; Khatau, Shyam B.; George, Jerry P.; Tseng, Yiider; Stewart, Colin L.; Hodzic, Didier; Wirtz, Denis

    2007-01-01

    Lamin A/C is a major constituent of the nuclear lamina, a thin filamentous protein layer that lies beneath the nuclear envelope. Here we show that lamin A/C deficiency in mouse embryonic fibroblasts (Lmna−/− MEFs) diminishes the ability of these cells to polarize at the edge of a wound and significantly reduces cell migration speed into the wound. Moreover, lamin A/C deficiency induces significant separation of the microtubule organizing center (MTOC) from the nuclear envelope. Investigations using ballistic intracellular nanorheology reveal that lamin A/C deficiency also dramatically affects the micromechanical properties of the cytoplasm. Both the elasticity (stretchiness) and the viscosity (propensity of a material to flow) of the cytoplasm in Lmna−/− MEFs are significantly reduced. Disassembly of either the actin filament or microtubule networks in Lmna+/+ MEFs results in decrease of cytoplasmic elasticity and viscosity down to levels found in Lmna−/− MEFs. Together these results show that both the mechanical properties of the cytoskeleton and cytoskeleton-based processes, including cell motility, coupled MTOC and nucleus dynamics, and cell polarization, depend critically on the integrity of the nuclear lamina, which suggest the existence of a functional mechanical connection between the nucleus and the cytoskeleton. These results also suggest that cell polarization during cell migration requires tight mechanical coupling between MTOC and nucleus, which is mediated by lamin A/C. PMID:17631533

  19. [Nuclear spin catalysis in nanoreactors of living cells].

    PubMed

    Kol'tover, V K

    2013-01-01

    There is a great variety of chemical elements with magnetic and nonmagnetic isotopes in living cells. The question arises as to whether living cells can perceive the difference between magnetic and non-magnetic isotopes of chemical elements. It has been shown that bacteria Escherichia coli, which were previously enriched with the magnetic isotope of magnesium, 25Mg, essentially faster adapt to the new growth media in comparison with the cells, which were enriched with the nonmagnetic isotopes, 24Mg or 26Mg. In the experiments with another commonly accepted cell model, yeast Saccharomyces cerevisiae, it has been shown that the magnetic 25Mg, in comparison with the nonmagnetic 24Mg, essentially better stimulates recovery of the cells after short wave UV irradiation. Thus, for the first time, the magnetic isotope effects in vivo have been discovered. These findings reveal the novel, based on the stable magnetic isotopes, ways of control over efficiency and reliability of biological systems.

  20. Nuclear transfer with apoptotic bovine fibroblasts: can programmed cell death be reprogrammed?

    PubMed

    Miranda, Moyses dos Santos; Bressan, Fabiana Fernandes; De Bem, Tiago Henrique Camara; Merighe, Giovana Krempel Fonseca; Ohashi, Otávio Mitio; King, William Alan; Meirelles, Flavio Viera

    2012-06-01

    Cell death by apoptosis is considered to be irreversible. However, reports have indicated that its reversibility is possible if the cells have not yet reached the "point of no return." In order to add new information about this topic, we used cells at different moments of apoptotic process as nuclear donors in somatic cell nuclear transfer (SCNT) in order to test if programmed cell death can be reversed. Adult bovine fibroblasts were treated with 10 μM of staurosporine (STP) for 3 h and analyzed for phosphatidylserine externalization (Annexin assay) and presence of active caspase-9. Annexin-positive (Anx+) and Caspase-9-positive (Casp-9+) cells were isolated by FACS and immediately transferred into enucleated in vitro matured bovine oocytes. After STP treatment, 89.9% of cells were Anx+ (4.6% in control cells; p<0.01) and 24.9% were Casp-9+ (2.4% in control cells; p<0.01). Fusion and cleavage were not affected by the use apoptotic cells (p>0.05). Also, the use of Anx+ cells did not affect blastocyst production compared to control (26.4% vs. 22.9%, respectively; p>0.05). However, blastocyst formation was affected by the use of Casp-9+ cells (12.3%; p<0.05). These findings contribute to the idea of that apoptosis is reversible only at early stages. Additionally, we hypothesize that the "point of no return" for apoptosis may be located around activation of Caspase-9.

  1. Nuclear respiratory factor-1 and bioenergetics in tamoxifen-resistant breast cancer cells.

    PubMed

    Radde, Brandie N; Ivanova, Margarita M; Mai, Huy Xuan; Alizadeh-Rad, Negin; Piell, Kellianne; Van Hoose, Patrick; Cole, Marsha P; Muluhngwi, Penn; Kalbfleisch, Ted S; Rouchka, Eric C; Hill, Bradford G; Klinge, Carolyn M

    2016-09-10

    Acquired tamoxifen (TAM) resistance is a significant clinical problem in treating patients with estrogen receptor α (ERα)+ breast cancer. We reported that ERα increases nuclear respiratory factor-1 (NRF-1), which regulates nuclear-encoded mitochondrial gene transcription, in MCF-7 breast cancer cells and NRF-1 knockdown stimulates apoptosis. Whether NRF-1 and target gene expression is altered in endocrine resistant breast cancer cells is unknown. We measured NRF-1and metabolic features in a cell model of progressive TAM-resistance. NRF-1 and its target mitochondrial transcription factor A (TFAM) were higher in TAM-resistant LCC2 and LCC9 cells than TAM-sensitive MCF-7 cells. Using extracellular flux assays we observed that LCC1, LCC2, and LCC9 cells showed similar oxygen consumption rate (OCR), but lower mitochondrial reserve capacity which was correlated with lower Succinate Dehydrogenase Complex, Subunit B in LCC1 and LCC2 cells. Complex III activity was lower in LCC9 than MCF-7 cells. LCC1, LCC2, and LCC9 cells had higher basal extracellular acidification (ECAR), indicating higher aerobic glycolysis, relative to MCF-7 cells. Mitochondrial bioenergetic responses to estradiol and 4-hydroxytamoxifen were reduced in the endocrine-resistant cells compared to MCF-7 cells. These results suggest the acquisition of altered metabolic phenotypes in response to long term antiestrogen treatment may increase vulnerability to metabolic stress. PMID:27515002

  2. A novel single cell method to identify the genetic composition at a single nuclear body

    PubMed Central

    Anchel, David; Ching, Reagan W.; Cotton, Rachel; Li, Ren; Bazett-Jones, David P.

    2016-01-01

    Gene loci make specific associations with compartments of the nucleus (e.g. the nuclear envelope, nucleolus, and transcription factories) and this association may determine or reflect a mechanism of genetic control. With current methods, it is not possible to identify sets of genes that converge to form a “gene hub” as there is a reliance on loci-specific probes, or immunoprecipitation of a particular protein from bulk cells. We introduce a method that will allow for the identification of loci contained within the vicinity of a single nuclear body in a single cell. For the first time, we demonstrate that the DNA sequences originating from a single sub-nuclear structure in a single cell targeted by two-photon irradiation can be determined, and mapped to a particular locus. Its application to single PML nuclear bodies reveals ontologically related loci that frequently associate with each other and with PML bodies in a population of cells, and a possible nuclear body targeting role for specific transcription factor binding sites. PMID:27389808

  3. Analysis of Nuclear RNA Interference (RNAi) in Human Cells by Subcellular Fractionation and Argonaute Loading

    PubMed Central

    Gagnon, Keith T.; Li, Liande; Janowski, Bethany A.; Corey, David R.

    2014-01-01

    RNA interference (RNAi) is well known for its ability to regulate gene expression in the cytoplasm of mammalian cells. In mammalian cell nuclei, however, the impact of RNAi has remained more controversial. A key technical hurdle has been a lack of optimized protocols for the isolation and analysis of cell nuclei. Here we describe a simplified protocol for nuclei isolation from cultured cells that incorporates a method for obtaining nucleoplasmic and chromatin fractions and removing cytoplasmic contamination. Cell fractions can then be used to detect the presence and activity of RNAi factors in the nucleus. We present a protocol for investigating an early step in RNAi, Argonaute protein loading with small RNAs, which is enabled by our improved extract preparations. These protocols facilitate characterization of nuclear RNAi and can be applied to the analysis of other nuclear proteins and pathways. From cellular fractionation to analysis of Argonaute loading results, this protocol takes 4–6 d to complete. PMID:25079428

  4. Hot atom chemistry and radiopharmaceuticals

    SciTech Connect

    Krohn, Kenneth A.; Moerlein, Stephen M.; Link, Jeanne M.; Welch, Michael J.

    2012-12-19

    The chemical products made in a cyclotron target are a combined result of the chemical effects of the nuclear transformation that made the radioactive atom and the bulk radiolysis in the target. This review uses some well-known examples to understand how hot atom chemistry explains the primary products from a nuclear reaction and then how radiation chemistry is exploited to set up the optimal product for radiosynthesis. It also addresses the chemical effects of nuclear decay. There are important principles that are common to hot atom chemistry and radiopharmaceutical chemistry. Both emphasize short-lived radionuclides and manipulation of high specific activity nuclides. Furthermore, they both rely on radiochromatographic separation for identification of no-carrieradded products.

  5. Hot Meetings

    NASA Technical Reports Server (NTRS)

    Chiu, Mary

    2002-01-01

    A colleague walked by my office one time as I was conducting a meeting. There were about five or six members of my team present. The colleague, a man who had been with our institution (The Johns Hopkins Applied Physics Lab, a.k.a. APL) for many years, could not help eavesdropping. He said later it sounded like we we re having a raucous argument, and he wondered whether he should stand by the door in case things got out of hand and someone threw a punch. Our Advanced Composition Explorer (ACE) team was a hot group, to invoke the language that is fashionable today, although we never thought of ourselves in those terms. It was just our modus operandi. The tenor of the discussion got loud and volatile at times, but I prefer to think of it as animated, robust, or just plain collaborative. Mary Chiu and her "hot" team from the Johns Hopkins Applied Physics Laboratory built the Advanced Composition Explorer spacecraft for NASA. Instruments on the spacecraft continue to collect data that inform us about what's happening on our most important star, the Sun.

  6. Somatic cell nuclear transfer: origins, the present position and future opportunities.

    PubMed

    Wilmut, Ian; Bai, Yu; Taylor, Jane

    2015-10-19

    Nuclear transfer that involves the transfer of the nucleus from a donor cell into an oocyte or early embryo from which the chromosomes have been removed was considered first as a means of assessing changes during development in the ability of the nucleus to control development. In mammals, development of embryos produced by nuclear transfer depends upon coordination of the cell cycles of donor and recipient cells. Our analysis of nuclear potential was completed in 1996 when a nucleus from an adult ewe mammary gland cell controlled development to term of Dolly the sheep. The new procedure has been used to target the first precise genetic modification into livestock; however, the greatest inheritance of the Dolly experiment was to make biologists think differently. If unknown factors in the recipient oocyte could reprogramme the nucleus to a stage very early in development then there must be other ways of making that change. Within 10 years, two laboratories working independently established protocols by which the introduction of selected transcription factors changes a small proportion of the treated cells to pluripotent stem cells. This ability to produce 'induced pluripotent stem cells' is providing revolutionary new opportunities in research and cell therapy.

  7. Nuclear lipid microdomain as resting place of dexamethasone to impair cell proliferation.

    PubMed

    Cataldi, Samuela; Codini, Michela; Cascianelli, Giacomo; Tringali, Sabina; Tringali, Anna Rita; Lazzarini, Andrea; Floridi, Alessandro; Bartoccini, Elisa; Garcia-Gil, Mercedes; Lazzarini, Remo; Ambesi-Impiombato, Francesco Saverio; Curcio, Francesco; Beccari, Tommaso; Albi, Elisabetta

    2014-01-01

    The action of dexamethasone is initiated by, and strictly dependent upon, the interaction of the drug with its receptor followed by its translocation into the nucleus where modulates gene expression. Where the drug localizes at the intranuclear level is not yet known. We aimed to study the localization of the drug in nuclear lipid microdomains rich in sphingomyelin content that anchor active chromatin and act as platform for transcription modulation. The study was performed in non-Hodgkin's T cell human lymphoblastic lymphoma (SUP-T1 cell line). We found that when dexamethasone enters into the nucleus it localizes in nuclear lipid microdomains where influences sphingomyelin metabolism. This is followed after 24 h by a cell cycle block accompanied by the up-regulation of cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin-dependent kinase inhibitor 1B (CDKN1B), growth arrest and DNA-damage 45A (GADD45A), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) genes and by the reduction of signal transducer and activator of transcription 3 (STAT3) and phospho signal transducer and activator of transcription 3 (phoshoSTAT3) proteins. After 48 h some cells show morphological changes characteristic of apoptosis while the number of the cells that undergo cell division and express B-cell lymphoma-2 (Bcl-2) is very low. We suggest that the integrity of nuclear lipid microdomains is important for the response to glucocorticoids of cancer cells.

  8. Nuclear and chromatin reorganization during cell senescence and aging - a mini-review.

    PubMed

    Shin, Dong-Myung; Kucia, Magda; Ratajczak, Mariusz Z

    2011-01-01

    Genetic material in the nucleus governs mechanisms related to cell proliferation, differentiation, and function. Thus, senescence and aging are directly tied to the change of nuclear function and structure. The most important mechanisms that affect cell senescence are: (i) telomere shortening; (ii) environmental stress-mediated accumulation of DNA mutations, and (iii) the intrinsically encoded biological clock that dictates lifespan events of any particular cell type. Overall, these changes lead to modification of the expression of genes that are responsible for: (i) organization of the nuclear structure; (ii) integrity of transcriptionally inactive heterochromatin, and (iii) epigenetic modification of chromosomes due to DNA methylation and/or histone modifications. These aging-related nuclear alterations do not only affect somatic cells. More importantly, they affect stem cells, which are responsible for proper tissue rejuvenation. In this review, we focus on epigenetic changes in the chromatin structure and their impact on the biology and function of adult cells as they age. We will also address aging-related changes in a compartment of the most primitive pluripotent stem cells that were recently identified by our team and named 'very small embryonic/epiblast-like stem cells'. PMID:20134149

  9. Rac is involved in the interkinetic nuclear migration of cortical progenitor cells.

    PubMed

    Minobe, Sayaka; Sakakibara, Akira; Ohdachi, Tomoko; Kanda, Rieko; Kimura, Miyako; Nakatani, Sayaka; Tadokoro, Ryosuke; Ochiai, Wataru; Nishizawa, Yuji; Mizoguchi, Akira; Kawauchi, Takeshi; Miyata, Takaki

    2009-04-01

    The small GTPase Rac regulates neuronal behavior, but whether it also functions in neural progenitor cells has not yet been explored. Here we report that Rac contributes to the regulation of nuclear migration in neocortical progenitor cells. Rac1 is expressed by progenitor cells in a unique spatiotemporal pattern. Cross-sectional immunohistochemical examination revealed intense Rac1 immunoreactivity at the ventricular surface. Similar staining patterns were obtained by immunofluorescence for a Rac-activator, Tiam1, and by reactions to detect the GTP-bound (active) form of Rac. En face inspection of the ventricular surface revealed that apical Rac1 localization was most frequent in M-phase cells, and the endfeet of cells in other cell cycle phases also showed apical Rac1 distribution at lower frequencies. To ask whether progenitor cell behavior prior to and during M phase is Rac-dependent, we monitored individual DiI-labeled progenitor cells live in the presence of a Rac inhibitor, NSC23766. We observed significantly retarded adventricular nuclear migration, as well as cytokinesis failures. Similar inhibitory effects were obtained by forced expression of a dominant-negative Rac1. These results suggest that Rac may play a role in interkinetic nuclear migration in the developing mouse brain.

  10. Somatic cell nuclear transfer: origins, the present position and future opportunities.

    PubMed

    Wilmut, Ian; Bai, Yu; Taylor, Jane

    2015-10-19

    Nuclear transfer that involves the transfer of the nucleus from a donor cell into an oocyte or early embryo from which the chromosomes have been removed was considered first as a means of assessing changes during development in the ability of the nucleus to control development. In mammals, development of embryos produced by nuclear transfer depends upon coordination of the cell cycles of donor and recipient cells. Our analysis of nuclear potential was completed in 1996 when a nucleus from an adult ewe mammary gland cell controlled development to term of Dolly the sheep. The new procedure has been used to target the first precise genetic modification into livestock; however, the greatest inheritance of the Dolly experiment was to make biologists think differently. If unknown factors in the recipient oocyte could reprogramme the nucleus to a stage very early in development then there must be other ways of making that change. Within 10 years, two laboratories working independently established protocols by which the introduction of selected transcription factors changes a small proportion of the treated cells to pluripotent stem cells. This ability to produce 'induced pluripotent stem cells' is providing revolutionary new opportunities in research and cell therapy. PMID:26416677

  11. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    SciTech Connect

    SEIDEL CM; JAIN J; OWENS JW

    2009-02-23

    This report describes the installation, testing, and acceptance of the Waste Treatment and Immobilization Plant (WTP) procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste (HLW) samples in a hot cell environment. The work was completed by the Analytical Process Development (APD) group in accordance with Task Order 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S Laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

  12. LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

    SciTech Connect

    LOCKREM LL; OWENS JW; SEIDEL CM

    2009-03-26

    This report describes the installation, testing and acceptance of the Waste Treatment and Immobilization Plant procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste samples in a hot cell environment. The 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method.

  13. Radiations from hot nuclei

    NASA Technical Reports Server (NTRS)

    Malik, F. Bary

    1993-01-01

    The investigation indicates that nuclei with excitation energy of a few hundred MeV to BeV are more likely to radiate hot nuclear clusters than neutrons. These daughter clusters could, furthermore, de-excite emitting other hot nuclei, and the chain continues until these nuclei cool off sufficiently to evaporate primarily neutrons. A few GeV excited nuclei could radiate elementary particles preferentially over neutrons. Impact of space radiation with materials (for example, spacecraft) produces highly excited nuclei which cool down emitting electromagnetic and particle radiations. At a few MeV excitation energy, neutron emission becomes more dominant than gamma-ray emission and one often attributes the cooling to take place by successive neutron decay. However, a recent experiment studying the cooling process of 396 MeV excited Hg-190 casts some doubt on this thinking, and the purpose of this investigation is to explore the possibility of other types of nuclear emission which might out-compete with neutron evaporation.

  14. Rosae Multiflorae Fructus Hot Water Extract Inhibits a Murine Allergic Asthma Via the Suppression of Th2 Cytokine Production and Histamine Release from Mast Cells.

    PubMed

    Song, Chang Ho; Bui, Thi Tho; Piao, Chun Hua; Shin, Hee Soon; Shon, Dong-Hwa; Han, Eui-Hyeog; Kim, Hyoung Tae; Chai, Ok Hee

    2016-09-01

    Mast cell-mediated anaphylactic reactions are involved in many allergic diseases, including asthma and allergic rhinitis. In Korea, where it has been used as a traditional medicine, Rosae Multiflorae fructus (RMF) is known to have potent antioxidative, analgesic, and anti-inflammatory activities and to have no obvious acute toxicity. However, its specific effect on asthma is still unknown. In this study, we evaluated whether or not RMF hot water extracts (RMFW) could inhibit ovalbumin (OVA)-induced allergic asthma and evaluated compound 48/80-induced mast cell activation to elucidate the mechanisms of asthma inhibition by RMFW. Oral administration of RMFW decreased the number of eosinophils and lymphocytes in the lungs of mice challenged by OVA and downregulated histological changes such as eosinophil infiltration, mucus accumulation, goblet cell hyperplasia, and collagen fiber deposits. In addition, RMFW significantly reduced T helper 2 cytokines, TNF-α, IL-4, and IL-6 levels in the BAL fluid of mice challenged by OVA. Moreover, RMFW suppressed compound 48/80-induced rat peritoneal mast cell degranulation and inhibited histamine release from mast cells induced by compound 48/80 in a dose-dependent manner. These results suggest that RMFW may act as an antiallergic agent by inhibitingTh2 cytokine production from Th2 cells and histamine release from mast cells, and could be used as a therapy for patients with Th2-mediated or mast cell-mediated allergic diseases. PMID:27574849

  15. Karyometry of nuclear phenotypes in Cutaneous Squamous Cell Cancer

    PubMed Central

    Bartels, Peter H.; Bartels, Hubert G.; Alberts, David S.; Yozwiak, M.; Prasad, Anil R.; Glazer, Evan; Krouse, Robert

    2014-01-01

    Objectives The objective of this study is to establish the karyometric characteristics of the two main nuclear phenotypes in cSCC lesions. Materials and Methods The clinical materials comprised 75 cases of cSCC, 38 with aggressive lesions and 37 with non-aggressive lesions. High-resolution images of 100 nuclei/case were recorded. The data were partitioned into four subgroups covering the range of lesion progression. Four discriminant functions were derived to distinguish aggressive from non-aggressive lesions. The most typical nuclei from the phenotype predominant in aggressive lesions, and from the phenotype predominant in non-aggressive lesions were separated out by thresholding on the discriminant function score axes. For these homogeneous sets of nuclei the karyometric features were computed. Results The nuclear populations in cSCC lesions are a very heterogeneous set. There are two axes of dispersion, along the line of lesion progression and between aggressive and non-aggressive lesions. The analysis faces the difficulty that lesions from both diagnostic categories contain nuclei of the same two phenotypes with the difference between categories consisting only of differences in proportion of the two phenotypes. Conclusions The nuclei of the aggressive phenotype I and non-aggressive phenotype II have substantially different chromatin patterns and can be distinguished with a better than 90 % correct recognition rate. PMID:22590813

  16. Visible light may directly induce nuclear DNA damage triggering the death pathway in RGC-5 cells

    PubMed Central

    Fan, Bin; Ma, Tong-Hui

    2011-01-01

    Purpose Visible light has been previously demonstrated to induce retinal ganglion cell (RGC)-5 cell death through the mitochondrial pathway. The present study was designed to determine whether visible light might also directly trigger the death pathway by damaging nuclear DNA. Methods RGC-5 cells were exposed to various intensities and durations of visible light exposure. Cell viability and death were monitored with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and propidium iodide staining. Nuclear DNA damage caused by light was determined with the plasmid assay, genome DNA assay, and in situ terminal deoxynucleotidyl transferase dUTP nick end labeling. The subsequent activation of nuclear enzyme poly(ADP-ribose) polymerase-1 (PARP-1) was measured with western blot, and PARP-1’s role in the death pathway was assessed by using specific inhibitors. Poly (ADP-ribose) glycohydrolase and apoptosis-inducing factor (AIF) inhibitors were used to show their influence on light-induced cell death. Calcium influx was examined with the fura-2 assay and calcium channel blocker. Results We found that visible light induced RGC-5 cell death in a time- and intensity-dependent manner. After the light intensity was increased to 2,600 lx, activation of the death pathway in RGC-5 cells was clearly observed by detecting double-strand DNA breaks and nuclear DNA damage in vitro. Nuclear enzyme PARP-1 was promptly activated after exposure to 2,600 lx of light for 2 days, and specific inhibitors of PARP-1 had significant neuroprotective effects. The poly(ADP-ribose) glycohydrolase inhibitor tannic acid and AIF inhibitor N-phenylmaleimide partially protected RGC-5 cells from light injury. A massive calcium influx was detected after 2 days of light exposure, and a calcium channel blocker partially protected cells against light injury. Conclusions These results suggest that visible light exposure may directly cause nuclear DNA damage, which consequently activates

  17. Anti-proliferative effects of Salacia reticulata leaves hot-water extract on interleukin-1β-activated cells derived from the synovium of rheumatoid arthritis model mice

    PubMed Central

    2012-01-01

    Background Salacia reticulata (SR) is a plant native to Sri Lanka. In ayurvedic medicine, SR bark preparations, taken orally, are considered effective in the treatment of rheumatism and diabetes. We investigated the ability of SR leaves (SRL) to inhibit in vitro the interleukin-1β (IL-1β)-activated proliferation of synoviocyte-like cells derived from rheumatoid arthritis model mice. Findings Inflammatory synovial tissues were harvested from type II collagen antibody-induced arthritic mice. From these tissues, a synoviocyte-like cell line was established and named MTS-C H7. To determine whether SRL can suppress cell proliferation and gene expression in MTS-C H7 cells, fractionation of the SRL hot-water extract was performed by high-performance liquid chromatography (HPLC), liquid-liquid extraction, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and protease digestion. The 50% inhibitory concentration of the SRL hot-water extract against MTS-C H7 cells proliferation was ~850 μg/mL. Treatment with a low dose (25 μg dry matter per millilitre) of the extract inhibited IL-1β-induced cell proliferation and suppressed the expression of the matrix metalloproteinase (MMP) genes in MTS-C H7 cells. Various polyphenolic fractions obtained from HPLC and the fractions from liquid-liquid extraction did not affect cell proliferation. Only the residual water sample from liquid-liquid extraction significantly affected cell proliferation and the expression of MMP genes. The results of SDS-PAGE and protease digestion experiment showed that low molecular weight proteins present in SRL inhibited the IL-1β-activated cell proliferation. Conclusions We surmised that the residual water fraction of the SRL extract was involved in the inhibition of IL-1β-activated cell proliferation and regulation of mRNA expression in MTS-C H7 cells. In addition, we believe that the active ingredients in the extract are low molecular weight proteins. PMID:22537486

  18. Baculovirus infection of nondividing mammalian cells: mechanisms of entry and nuclear transport of capsids.

    PubMed

    van Loo, N D; Fortunati, E; Ehlert, E; Rabelink, M; Grosveld, F; Scholte, B J

    2001-01-01

    We have studied the infection pathway of Autographa californica multinuclear polyhedrosis virus (baculovirus) in mammalian cells. By titration with a baculovirus containing a green fluorescent protein cassette, we found that several, but not all, mammalian cell types can be infected efficiently. In contrast to previous suggestions, our data show that the asialoglycoprotein receptor is not required for efficient infection. We demonstrate for the first time that this baculovirus can infect nondividing mammalian cells, which implies that the baculovirus is able to transport its genome across the nuclear membrane of mammalian cells. Our data further show that the virus enters via endocytosis, followed by an acid-induced fusion event, which releases the nucleocapsid into the cytoplasm. Cytochalasin D strongly reduces the infection efficiency but not the delivery of nucleocapsids to the cytoplasm, suggesting involvement of actin filaments in cytoplasmic transport of the capsids. Electron microscopic analysis shows the cigar-shaped nucleocapsids located at nuclear pores of nondividing cells. Under these conditions, we observed the viral genome, major capsid protein, and electron-dense capsids inside the nucleus. This suggests that the nucleocapsid is transported through the nuclear pore. This mode of transport seems different from viruses with large spherical capsids, such as herpes simplex virus and adenovirus, which are disassembled before nuclear transport of the genome. The implications for the application of baculovirus or its capsid proteins in gene therapy are discussed.

  19. Hot Hydrogen Test Facility

    SciTech Connect

    W. David Swank

    2007-02-01

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISp. This quantity is proportional to the square root of the propellant’s absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500°C hydrogen flowing at 1500 liters per minute. The facility is intended to test non-uranium containing materials and therefore is particularly suited for testing potential cladding and coating materials. In this first installment the facility is described. Automated Data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.

  20. Hot Hydrogen Test Facility

    SciTech Connect

    Swank, W. David; Carmack, Jon; Werner, James E.; Pink, Robert J.; Haggard, DeLon C.; Johnson, Ryan

    2007-01-30

    The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISP. This quantity is proportional to the square root of the propellant's absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500 deg. C hydrogen flowing at 1500 liters per minute. The facility is intended to test low activity uranium containing materials but is also suited for testing cladding and coating materials. In this first installment the facility is described. Automated data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.

  1. Homotypic cell cannibalism, a cell-death process regulated by the nuclear protein 1, opposes to metastasis in pancreatic cancer

    PubMed Central

    Cano, Carla E; Sandí, María José; Hamidi, Tewfik; Calvo, Ezequiel L; Turrini, Olivier; Bartholin, Laurent; Loncle, Céline; Secq, Véronique; Garcia, Stéphane; Lomberk, Gwen; Kroemer, Guido; Urrutia, Raul; Iovanna, Juan L

    2012-01-01

    Pancreatic adenocarcinoma (PDAC) is an extremely deadly disease for which all treatments available have failed to improve life expectancy significantly. This may be explained by the high metastatic potential of PDAC cells, which results from their dedifferentiation towards a mesenchymal phenotype. Some PDAC present cell-in-cell structures whose origin and significance are currently unknown. We show here that cell-in-cells form after homotypic cell cannibalism (HoCC). We found PDAC patients whose tumours display HoCC develop less metastasis than those without. In vitro, HoCC was promoted by inactivation of the nuclear protein 1 (Nupr1), and was enhanced by treatment with transforming growth factor β. HoCC ends with death of PDAC cells, consistent with a metastasis suppressor role for this phenomenon. Hence, our data indicates a protective role for HoCC in PDAC and identifies Nupr1 as a molecular regulator of this process. PMID:22821859

  2. Nuclear deformability and telomere dynamics are regulated by cell geometric constraints

    PubMed Central

    Makhija, Ekta; Jokhun, D. S.; Shivashankar, G. V.

    2016-01-01

    Forces generated by the cytoskeleton can be transmitted to the nucleus and chromatin via physical links on the nuclear envelope and the lamin meshwork. Although the role of these active forces in modulating prestressed nuclear morphology has been well studied, the effect on nuclear and chromatin dynamics remains to be explored. To understand the regulation of nuclear deformability by these active forces, we created different cytoskeletal states in mouse fibroblasts using micropatterned substrates. We observed that constrained and isotropic cells, which lack long actin stress fibers, have more deformable nuclei than elongated and polarized cells. This nuclear deformability altered in response to actin, myosin, formin perturbations, or a transcriptional down-regulation of lamin A/C levels in the constrained and isotropic geometry. Furthermore, to probe the effect of active cytoskeletal forces on chromatin dynamics, we tracked the spatiotemporal dynamics of heterochromatin foci and telomeres. We observed increased dynamics and decreased correlation of the heterochromatin foci and telomere trajectories in constrained and isotropic cell geometry. The observed enhanced dynamics upon treatment with actin depolymerizing reagents in elongated and polarized geometry were regained once the reagent was washed off, suggesting an inherent structural memory in chromatin organization. We conclude that active forces from the cytoskeleton and rigidity from lamin A/C nucleoskeleton can together regulate nuclear and chromatin dynamics. Because chromatin remodeling is a necessary step in transcription control and its memory, genome integrity, and cellular deformability during migration, our results highlight the importance of cell geometric constraints as critical regulators in cell behavior. PMID:26699462

  3. Human Cytomegalovirus Nuclear Egress Proteins Ectopically Expressed in the Heterologous Environment of Plant Cells are Strictly Targeted to the Nuclear Envelope.

    PubMed

    Lamm, Christian E; Link, Katrin; Wagner, Sabrina; Milbradt, Jens; Marschall, Manfred; Sonnewald, Uwe

    2016-03-10

    In all eukaryotic cells, the nucleus forms a prominent cellular compartment containing the cell's nuclear genome. Although structurally similar, animal and plant nuclei differ substantially in details of their architecture. One example is the nuclear lamina, a layer of tightly interconnected filament proteins (lamins) underlying the nuclear envelope of metazoans. So far no orthologous lamin genes could be detected in plant genomes and putative lamin-like proteins are only poorly described in plants. To probe for potentially conserved features of metazoan and plant nuclear envelopes, we ectopically expressed the core nuclear egress proteins of human cytomegalovirus pUL50 and pUL53 in plant cells. pUL50 localizes to the inner envelope of metazoan nuclei and recruits the nuclear localized pUL53 to it, forming heterodimers. Upon expression in plant cells, a very similar localization pattern of both proteins could be determined. Notably, pUL50 is specifically targeted to the plant nuclear envelope in a rim-like fashion, a location to which coexpressed pUL53 becomes strictly corecruited from its initial nucleoplasmic distribution. Using pUL50 as bait in a yeast two-hybrid screening, the cytoplasmic re-initiation supporting protein RISP could be identified. Interaction of pUL50 and RISP could be confirmed by coexpression and coimmunoprecipitation in mammalian cells and by confocal laser scanning microscopy in plant cells, demonstrating partial pUL50-RISP colocalization in areas of the nuclear rim and other intracellular compartments. Thus, our study provides strong evidence for conserved structural features of plant and metazoan nuclear envelops and identifies RISP as a potential pUL50-interacting plant protein.

  4. Nuclear CD38 in retinoic acid-induced HL-60 cells

    SciTech Connect

    Yalcintepe, Leman . E-mail: lemany@istanbul.edu.tr; Albeniz, Isil; Adin-Cinar, Suzan; Tiryaki, Demir; Bermek, Engin; Graeff, Richard M.; Lee, Hon Cheung

    2005-02-01

    The cell surface antigen, CD38, is a 45-kDa transmembrane protein which is predominantly expressed on hematopoietic cells during differentiation. As a bifunctional ectoenzyme, it catalyzes the synthesis of cyclic ADP-ribose (cADPR) from NAD{sup +} and hydrolysis of either NAD{sup +} or cADPR to ADP-ribose. All-trans-retinoic acid (RA) is a potent and specific inducer of CD38 in myeloid cells. In this report, we demonstrate that the nuclei of RA-treated human HL-60 myeloblastic cells reveal enzymatic activities inherent to CD38. Thus, GDP-ribosyl cyclase and NAD{sup +} glycohydrolase activities in the nuclear fraction increased very significantly in response to incubation with RA. With Western blotting, we detected in the nuclear protein fraction from RA-treated cells a {approx}43-kDa protein band which was reactive with the CD38-specific monoclonal antibody OKT10. The expression of CD38 in HL-60 nuclei was also shown with FACScan analysis. RA treatment gave rise to an increase in in vitro ADP ribosylation of the {approx}43-kDa nuclear protein. Moreover, nuclei isolated from RA-treated HL-60 cells revealed calcium release in response to cADPR, whereas a similar response was not observed in control nuclei. These results suggest that CD38 is expressed in HL-60 cell nuclei during RA-induced differentiation.

  5. Somatic cell nuclear transfer: origins, the present position and future opportunities

    PubMed Central

    Wilmut, Ian; Bai, Yu; Taylor, Jane

    2015-01-01

    Nuclear transfer that involves the transfer of the nucleus from a donor cell into an oocyte or early embryo from which the chromosomes have been removed was considered first as a means of assessing changes during development in the ability of the nucleus to control development. In mammals, development of embryos produced by nuclear transfer depends upon coordination of the cell cycles of donor and recipient cells. Our analysis of nuclear potential was completed in 1996 when a nucleus from an adult ewe mammary gland cell controlled development to term of Dolly the sheep. The new procedure has been used to target the first precise genetic modification into livestock; however, the greatest inheritance of the Dolly experiment was to make biologists think differently. If unknown factors in the recipient oocyte could reprogramme the nucleus to a stage very early in development then there must be other ways of making that change. Within 10 years, two laboratories working independently established protocols by which the introduction of selected transcription factors changes a small proportion of the treated cells to pluripotent stem cells. This ability to produce ‘induced pluripotent stem cells’ is providing revolutionary new opportunities in research and cell therapy. PMID:26416677

  6. Nuclear localization of Formyl-Peptide Receptor 2 in human cancer cells.

    PubMed

    Cattaneo, Fabio; Parisi, Melania; Fioretti, Tiziana; Sarnataro, Daniela; Esposito, Gabriella; Ammendola, Rosario

    2016-08-01

    Current models of G protein-coupled receptors (GPCRs) signaling describe binding of external agonists to cell surface receptors which, in turn, trigger several biological responses. New paradigms indicate that GPCRs localize to and signal at the nucleus, thus regulating distinct signaling cascades. The formyl-peptide receptor FPR2 belongs to the GPCR super-family and is coupled to PTX-sensitive Gi proteins. We show by western blot analysis, immunofluorescence experiments and radioligand binding assays that FPR2 is expressed at nuclear level in CaLu-6 and AGS cells. Nuclear FPR2 is a functional receptor, since it participates in intra-nuclear signaling, as assessed by decreased G protein-FPR2 association and enhanced ERK2, c-Jun and c-Myc phosphorylation upon stimulation of intact nuclei with the FPR2 agonist, WKYMVm. We analyzed FPR2 sequence for the search of a nuclear localization sequence (NLS) and we found a stretch of basic aminoacids (227-KIHKK-231) in the third cytoplasmic loop of the receptor. We performed single (K230A) and multiple (H229A/K230A/K231A) mutagenesis of NLS. The constructs were individually overexpressed in HEK293 cells and immunofluorescence and western blot analysis showed that nuclear localization or translocation of FPR2 depends on the integrity of the H(229) and K(231) residues within the NLS. PMID:27177968

  7. An Unconventional Kinesin and Cytoplasmic Dynein Are Responsible for Interkinetic Nuclear Migration in Neural Stem Cells

    PubMed Central

    Tsai, Jin-Wu; Lian, Wei-Nan; Kemal, Shahrnaz; Kriegstein, Arnold; Vallee, Richard B.

    2010-01-01

    Radial glial progenitor cells (RGPCs), have been long known to exhibit a striking form of bidirectional nuclear migration. The purpose and underlying mechanism for this unusual cell cycle-dependent “interkinetic” nuclear migration has remained poorly understood. We investigated the basis for this behavior by live imaging of nuclei, centrosomes, and microtubules in embryonic rat brain slices, coupled with blebbistatin and RNAi. We observed nuclei to migrate independent of centrosomes and unidirectionally away from or toward the ventricular surface along microtubules, which we found to be uniformly oriented from the ventricular to the pial surfaces of the brain. Cytoplasmic dynein RNAi specifically inhibited apically-directed nuclear movement. An RNAi screen for kinesin genes identified KIF1A, a member of the kinesin 3 family, as the motor for basally-directed nuclear movement. These observations provide the first direct evidence for a role for kinesins in nuclear migration and neurogenesis, and suggest that a novel cell cycle-dependent switch between distinct microtubule motors drives INM. PMID:21037580

  8. Proteasome inhibitors induce apoptosis of prostate cancer cells by inducing nuclear translocation of IkappaBalpha.

    PubMed

    Vu, Hai-Yen; Juvekar, Ashish; Ghosh, Chandra; Ramaswami, Sitharam; Le, Dung Hong; Vancurova, Ivana

    2008-07-15

    Proteasome inhibitors are known to suppress the proteasome-mediated degradation of IkappaBalpha in stimulated cells. This results in the cytoplasmic retention of NFkappaB and its reduced nuclear transcriptional activity. In this study, we show that in the metastatic prostate cancer cells, the proteasome inhibitors exhibit a novel, previously unrecognized effect: they increase the cellular levels of IkappaBalpha, which then translocates to the nucleus, associates with the nuclear p65 NFkappaB, thus inhibiting the constitutive NFkappaB DNA binding activity and inducing apoptosis. The proteasome inhibition-induced nuclear translocation of IkappaBalpha is dependent on de novo protein synthesis, occurs also in other cell types, and does not require IkappaBalpha phosphorylation on Ser-32. Since NFkappaB activity is constitutively increased in many human cancers as well as in inflammatory disorders, the proteasome inhibition-induced nuclear translocation of IkappaBalpha could thus provide a new therapeutic strategy aimed at the specific inhibition of NFkappaB activity by the nuclear IkappaBalpha.

  9. Embryo production and possible species preservation by nuclear transfer of somatic cells isolated from bovine semen.

    PubMed

    Liu, Jie; Westhusin, Mark; Long, Charles; Johnson, Gregory; Burghardt, Robert; Kraemer, Duane

    2010-12-01

    Somatic cells in semen are a potential source of nuclei for nuclear transfer to produce genetically identical animals; this is especially important when an animal has died and the only viable genetic material available is frozen semen. Usefulness of somatic cells obtained from fresh (cultured) and frozen (isolated, not cultured) bovine semen for nuclear transfer was evaluated. Twelve ejaculates were collected from nine bulls representing three breeds: Charolais, Brahman, and crossbred Rodeo bull. All samples were processed immediately and cell growth was obtained from seven of the twelve ejaculates (58.3%). Cells from three bulls (with the best growth rates) were evaluated by optical microscopy and used in cloning experiments. In culture, these cells exhibited classic epithelial morphology and expressed cytokeratin and vimentin, indicating they were of epithelial origin. When cells from the three bulls were used as donor cells, 15.9% (18/113), 34.5% (29/84), and 14.4% (13/90) of the fused embryos developed into blastocysts, respectively. Of the blastocyst stage embryos, 38.9% (7/18), 72.4% (21/29), and 61.5% (8/13) hatched, respectively. Somatic cells isolated (not cultured) from frozen bovine semen were also used in the cloning experiments. Although cleavage occurred, no compact morulae or blastocysts were obtained. In conclusion, epithelial cell growth was obtained from fresh bovine ejaculates with relatively high efficiency. Somatic cells from semen can be used as nucleus donors to produce cloned blastocyst-stage embryos.

  10. KPNA7, a nuclear transport receptor, promotes malignant properties of pancreatic cancer cells in vitro

    SciTech Connect

    Laurila, Eeva; Vuorinen, Elisa; Savinainen, Kimmo; Rauhala, Hanna; Kallioniemi, Anne

    2014-03-10

    Pancreatic cancer is an aggressive malignancy and one of the leading causes of cancer deaths. The high mortality rate is mostly due to the lack of appropriate tools for early detection of the disease and a shortage of effective therapies. We have previously shown that karyopherin alpha 7 (KPNA7), the newest member of the alpha karyopherin family of nuclear import receptors, is frequently amplified and overexpressed in pancreatic cancer. Here, we report that KPNA7 expression is absent in practically all normal human adult tissues but elevated in several pancreatic cancer cell lines. Inhibition of KPNA7 expression in AsPC-1 and Hs700T pancreatic cancer cells led to a reduction in cell growth and decreased anchorage independent growth, as well as increased autophagy. The cell growth effects were accompanied by an induction of the cell cycle regulator p21 and a G1 arrest of the cell cycle. Interestingly, the p21 induction was caused by increased mRNA synthesis and not defective nuclear transport. These data strongly demonstrate that KPNA7 silencing inhibits the malignant properties of pancreatic cancer cells in vitro and thereby provide the first evidence on the functional role for KPNA7 in human cancer. - Highlights: • KPNA7 expression is elevated in several pancreatic cancer cell lines. • KPNA7 silencing in high expressing cancer cells leads to growth inhibition. • The cell growth reduction is associated with p21 induction and G1 arrest. • KPNA7 silencing is also accompanied with increased autophagy.

  11. Optimization of procedures for cloning by somatic cell nuclear transfer in mice.

    PubMed

    Chung, Young Gie; Gao, Shaorong; Latham, Keith E

    2006-01-01

    Cloning by somatic cell nuclear transfer is a complex procedure that is dependent on correct interactions between oocyte and donor cell genome. These interactions require minimal insult to either the oocyte or the transplanted nucleus. Available data also indicate that reprogramming the donor cell genome may be slow, so that the cloned embryo expresses genes typical of the donor cell, and thus has different characteristics from normal embryos. Procedures that minimize damage to the donor genome and that address the unique characteristics of the cloned construct should enhance the efficacy of the method.

  12. Wild-type human p53 transactivates the human proliferating cell nuclear antigen promoter

    SciTech Connect

    Shivakumar, C.V.; Brown, D.R.; Deb, S.; Deb, S.P.

    1995-12-01

    The p53 tumor suppressor protein negatively regulates cell growth and somatic mutations in the p53 gene lead to uncontrolled cell growth and oncogenesis. This report describes research which demonstrates, using a number of different cell lines, that at low levels, wild-type p53 transactivates the human proliferating cell nuclear antigen (PCNA) promoter. When expressed at similar levels, tumor-derived p53 mutants did not transactivate the PCNA promoter. It also reports the identification of a wild-type human p53-binding site on the human PCNA promote. 84 refs., 5 figs, 3 tabs.

  13. Oral cancer/endothelial cell fusion experiences nuclear fusion and acquisition of enhanced survival potential.

    PubMed

    Song, Kai; Song, Yong; Zhao, Xiao-Ping; Shen, Hui; Wang, Meng; Yan, Ting-Lin; Liu, Ke; Shang, Zheng-Jun

    2014-10-15

    Most previous studies have linked cancer-macrophage fusion with tumor progression and metastasis. However, the characteristics of hybrid cells derived from oral cancer and endothelial cells and their involvement in cancer remained unknown. Double-immunofluorescent staining and fluorescent in situ hybridization (FISH) were performed to confirm spontaneous cell fusion between eGFP-labeled human umbilical vein endothelial cells (HUVECs) and RFP-labeled SCC9, and to detect the expression of vementin and cytokeratin 18 in the hybrids. The property of chemo-resistance of such hybrids was examined by TUNEL assay. The hybrid cells in xenografted tumor were identified by FISH and GFP/RFP dual-immunofluoresence staining. We showed that SCC9 cells spontaneously fused with cocultured endothelial cells, and the resultant hybrid cells maintained the division and proliferation activity after re-plating and thawing. Such hybrids expressed markers of both parental cells and became more resistant to chemotherapeutic drug cisplatin as compared to the parental SCC9 cells. Our in vivo data indicated that the hybrid cells contributed to tumor composition by using of immunostaining and FISH analysis, even though the hybrid cells and SCC9 cells were mixed with 1:10,000, according to the FACS data. Our study suggested that the fusion events between oral cancer and endothelial cells undergo nuclear fusion and acquire a new property of drug resistance and consequently enhanced survival potential. These experimental findings provide further supportive evidence for the theory that cell fusion is involved in cancer progression.

  14. A Ras subfamily GTPase shows cell cycle-dependent nuclear localization

    PubMed Central

    Sutherland, Brent W.; Spiegelman, George B.; Weeks, Gerald

    2001-01-01

    Previously characterized Ras subfamily proteins have been found to be predominantly associated with the plasma membrane where they function in signal transduction pathways to convey extracellular signals to intracellular targets. Here, we provide evidence that the Dictyostelium Ras subfamily protein RasB has a novel subcellular localization and function. The protein is predominantly localized in the nucleus during most of the cell cycle. Furthermore, during mitosis and cytokinesis RasB assumes a diffuse cellular localization despite the fact that the nuclear membrane stays intact. The linkage between the position of RasB in the cell and division suggests that it may have a role in nuclear division. Consistent with this idea, rasB– cells exhibit severe growth defects and cells overexpressing an activated version of RasB are multinucleate. PMID:11606416

  15. Role of HDACs in optic nerve damage-induced nuclear atrophy of retinal ganglion cells.

    PubMed

    Schmitt, Heather M; Schlamp, Cassandra L; Nickells, Robert W

    2016-06-20

    Optic neuropathies are characterized by retinal ganglion cell (RGC) death, resulting in the loss of vision. In glaucoma, the most common optic neuropathy, RGC death is initiated by axonal damage, and can be modeled by inducing acute axonal trauma through procedures such as optic nerve crush (ONC) or optic nerve axotomy. One of the early events of RGC death is nuclear atrophy, and is comprised of RGC-specific gene silencing, histone deacetylation, heterochromatin formation, and nuclear shrinkage. These early events appear to be principally regulated by epigenetic mechanisms involving histone deacetylation. Class I histone deacetylases HDACs 1, 2, and 3 are known to play important roles in the process of early nuclear atrophy in RGCs, and studies using both inhibitors and genetic ablation of Hdacs also reveal a critical role in the cell death process. Select inhibitors, such as those being developed for cancer therapy, may also provide a viable secondary treatment option for optic neuropathies.

  16. X-ray microscopic studies of labeled nuclear cell structures

    NASA Astrophysics Data System (ADS)

    Vogt, S.; Schneider, G.; Steuernagel, A.; Lucchesi, J.; Schulze, E.; Rudolph, D.; Schmahl, G.

    2000-05-01

    In X-ray microscopy different proteins are not readily distinguishable. However, in cell biology it is often desirable to localize single proteins, e.g., inside the cell nucleus. This can be achieved by immunogold labeling. Colloidal gold conjugated antibodies are used to mark the protein specifically. With silver solution these are enlarged so as to heighten their contrast. The strong absorption of silver allows easy visualization of the label in the nuclei. In this study male specific lethal 1 protein in male Drosophila melanogaster cells was labeled. This protein forms, together with four other proteins, a complex that is associated with the male X chromosome. It regulates dosage compensation by enhancing X-linked gene transcription in males. Room temperature and cyro transmission X-ray microscopic images (taken with the Göttingen TXM at BESSY) of these labeled cells are shown. Confocal laser scan microscopy ascertains the correct identification of the label in the X-ray micrographs, and allows comparison of the structural information available from both instruments.

  17. Nuclear DAMP complex-mediated RAGE-dependent macrophage cell death

    SciTech Connect

    Chen, Ruochan; Fu, Sha; Fan, Xue-Gong; Lotze, Michael T.; Zeh, Herbert J.; Tang, Daolin; Kang, Rui

    2015-03-13

    High mobility group box 1 (HMGB1), histone, and DNA are essential nuclear components involved in the regulation of chromosome structure and function. In addition to their nuclear function, these molecules act as damage-associated molecular patterns (DAMPs) alone or together when released extracellularly. The synergistic effect of these nuclear DNA-HMGB1-histone complexes as DAMP complexes (nDCs) on immune cells remains largely unexplored. Here, we demonstrate that nDCs limit survival of macrophages (e.g., RAW264.7 and peritoneal macrophages) but not cancer cells (e.g., HCT116, HepG2 and Hepa1-6). nDCs promote production of inflammatory tumor necrosis factor α (TNFα) release, triggering reactive oxygen species-dependent apoptosis and necrosis. Moreover, the receptor for advanced glycation end products (RAGE), but not toll-like receptor (TLR)-4 and TLR-2, was required for Akt-dependent TNFα release and subsequent cell death following treatment with nDCs. Genetic depletion of RAGE by RNAi, antioxidant N-Acetyl-L-cysteine, and TNFα neutralizing antibody significantly attenuated nDC-induced cell death. These findings provide evidence supporting novel signaling mechanisms linking nDCs and inflammation in macrophage cell death. - Highlights: • Nuclear DAMP complexes (nDCs) selectively induce cell death in macrophages, but not cancer cells. • TNFα-mediated oxidative stress is required for nDC-induced death. • RAGE-mediated Akt activation is required for nDC-induced TNFα release. • Blocking RAGE and TNFα inhibits nDC-induced macrophage cell death.

  18. Cell shape and the microenvironment regulate nuclear translocation of NF-κB in breast epithelial and tumor cells

    PubMed Central

    Sero, Julia E; Sailem, Heba Zuhair; Ardy, Rico Chandra; Almuttaqi, Hannah; Zhang, Tongli; Bakal, Chris

    2015-01-01

    Although a great deal is known about the signaling events that promote nuclear translocation of NF-κB, how cellular biophysics and the microenvironment might regulate the dynamics of this pathway is poorly understood. In this study, we used high-content image analysis and Bayesian network modeling to ask whether cell shape and context features influence NF-κB activation using the inherent variability present in unperturbed populations of breast tumor and non-tumor cell lines. Cell–cell contact, cell and nuclear area, and protrusiveness all contributed to variability in NF-κB localization in the absence and presence of TNFα. Higher levels of nuclear NF-κB were associated with mesenchymal-like versus epithelial-like morphologies, and RhoA-ROCK-myosin II signaling was critical for mediating shape-based differences in NF-κB localization and oscillations. Thus, mechanical factors such as cell shape and the microenvironment can influence NF-κB signaling and may in part explain how different phenotypic outcomes can arise from the same chemical cues. PMID:25735303

  19. Quantitative Differences in Nuclear β-catenin and TCF Pattern Embryonic Cells in C. elegans

    PubMed Central

    Zacharias, Amanda L.; Walton, Travis; Preston, Elicia; Murray, John Isaac

    2015-01-01

    The Wnt signaling pathway plays a conserved role during animal development in transcriptional regulation of distinct targets in different developmental contexts but it remains unclear whether quantitative differences in the nuclear localization of effector proteins TCF and β-catenin contribute to context-specific regulation. We investigated this question in Caenorhabditis elegans embryos by quantifying nuclear localization of fluorescently tagged SYS-1/β-catenin and POP-1/TCF and expression of Wnt ligands at cellular resolution by time-lapse microscopy and automated lineage tracing. We identified reproducible, quantitative differences that generate a subset of Wnt-signaled cells with a significantly higher nuclear concentration of the TCF/β-catenin activating complex. Specifically, β-catenin and TCF are preferentially enriched in nuclei of daughter cells whose parents also had high nuclear levels of that protein, a pattern that could influence developmental gene expression. Consistent with this, we found that expression of synthetic reporters of POP-1-dependent activation is biased towards cells that had high nuclear SYS-1 in consecutive divisions. We identified new genes whose embryonic expression patterns depend on pop-1. Most of these require POP-1 for either transcriptional activation or repression, and targets requiring POP-1 for activation are more likely to be expressed in the cells with high nuclear SYS-1 in consecutive divisions than those requiring POP-1 for repression. Taken together, these results indicate that SYS-1 and POP-1 levels are influenced by the parent cell’s SYS-1/POP-1 levels and this may provide an additional mechanism by which POP-1 regulates distinct targets in different developmental contexts. PMID:26488501

  20. RanBP3 Regulates Melanoma Cell Proliferation via Selective Control of Nuclear Export.

    PubMed

    Pathria, Gaurav; Garg, Bhavuk; Wagner, Christine; Garg, Kanika; Gschaider, Melanie; Jalili, Ahmad; Wagner, Stephan N

    2016-01-01

    Chromosome region maintenance 1-mediated nucleocytoplasmic transport has been shown as a potential anticancer target in various malignancies. However, the role of the most characterized chromosome region maintenance 1 cofactor ran binding protein 3 (RanBP3) in cancer cell biology has never been investigated. Utilizing a loss-of-function experimental setting in a vast collection of genetically varied melanoma cell lines, we observed the requirement of RanBP3 in melanoma cell proliferation and survival. Mechanistically, we suggest the reinstatement of transforming growth factor-β (TGF-β)-Smad2/3-p21(Cip1) tumor-suppressor axis as part of the RanBP3 silencing-associated antiproliferative program. Employing extensive nuclear export sequence analyses and immunofluorescence-based protein localization studies, we further present evidence suggesting the requirement of RanBP3 function for the nuclear exit of the weak nuclear export sequence-harboring extracellular signal-regulated kinase protein, although it is dispensable for general CRM1-mediated nuclear export of strong nuclear export sequence-harboring cargoes. Rendering mechanistic support to RanBP3 silencing-mediated apoptosis, consequent to extracellular signal-regulated kinase nuclear entrapment, we observed increased levels of cytoplasmically restricted nonphosphorylated/active proapoptotic Bcl-2-antagonist of cell death (BAD) protein. Last, we present evidence suggesting the frequently activated mitogen-activated protein kinase signaling in melanoma as a potential founding basis for a deregulated post-translational control of RanBP3 activity. Collectively, the presented data suggest RanBP3 as a potential target for therapeutic intervention in human melanoma.

  1. Probing nuclear localization signal-importin alpha binding equilibria in living cells.

    PubMed

    Cardarelli, Francesco; Bizzarri, Ranieri; Serresi, Michela; Albertazzi, Lorenzo; Beltram, Fabio

    2009-12-25

    The regulated process of protein import into the nucleus of a eukaryotic cell is mediated by specific nuclear localization signals (NLSs) that are recognized by protein-import receptors. In this study, we present fluorescence-based methods to quantitatively address the physicochemical details of NLS recognition by the receptor protein importin alpha (Impalpha) in living cells. First, by combining fluorescence recovery after photobleaching measurements and protein-concentration calibration, we quantitatively define nuclear import saturability and afford an affinity value for NLS-Impalpha binding. Second, by fluorescence lifetime imaging microscopy, we directly monitor the occurrence of NLS-Impalpha interaction and measure its effective dissociation constant (K(D)) in the actual cellular environment. Our kinetic and thermodynamic analyses independently indicate that the subsaturation of Impalpha with the expressed NLS cargo regulates nuclear import rates in living cells, in contrast to what can be predicted on the basis of available in vitro data. Finally, our experiments also provide evidence for the regulation of nuclear import mediated by the intrasteric importin beta-binding domain of Impalpha and yield the first estimate of its autoinhibition energy in living cells.

  2. Acridine Orange Conjugated Polymersomes for Simultaneous Nuclear Delivery of Gemcitabine and Doxorubicin to Pancreatic Cancer Cells.

    PubMed

    Anajafi, Tayebeh; Scott, Michael D; You, Seungyong; Yang, Xiaoyu; Choi, Yongki; Qian, Steven Y; Mallik, Sanku

    2016-03-16

    Considering the systemic toxicity of chemotherapeutic agents, there is an urgent need to develop new targeted drug delivery systems. Herein, we have developed a new nuclear targeted, redox sensitive, drug delivery vehicle to simultaneously deliver the anticancer drugs gemcitabine and doxorubicin to the nuclei of pancreatic cancer cells. We prepared polymeric bilayer vesicles (polymersomes), and actively encapsulated the drug combination by the pH gradient method. A redox-sensitive polymer (PEG-S-S-PLA) was incorporated to sensitize the formulation to reducing agent concentration. Acridine orange (AO) was conjugated to the surface of the polymersomes imparting nuclear localizing property. The polymersomes' toxicity and efficacy were compared with those of a free drug combination using monolayer and three-dimensional spheroid cultures of pancreatic cancer cells. We observed that the redox sensitive, nuclear-targeted polymersomes released more than 60% of their encapsulated contents in response to 50 mM glutathione. The nanoparticles are nontoxic; however, the drug encapsulated vesicles have significant toxicity. The prepared formulation can increase the drug's therapeutic index by delivering the drugs directly to the cells' nuclei, one of the key organelles in the cells. This study is likely to initiate research in targeted nuclear delivery using other drug formulations in other types of cancers.

  3. NLS peptide conjugated molecular beacons for visualizing nuclear RNA in living cells.

    PubMed

    Nitin, Nitin; Bao, Gang

    2008-11-19

    Imaging the expression and localization of RNAs in live-cell nucleus can provide important information on RNA synthesis, processing, and transport. Here, we report the development of a bifunctional molecular beacon (NLS-MB) composed of a single nuclear localization sequence (NLS) peptide conjugated to a molecular beacon for efficient delivery and imaging of endogenous RNAs in the nuclei of living cells. We characterized the NLS-MBs by comparing their signal-to-noise ratios with unmodified molecular beacons and determined their efficiency of nuclear import. We demonstrated the specificity and sensitivity of the method by observing in living cells the localization and colocalization of small nuclear RNAs (snRNA) U1 and U2 at discrete foci in the nucleoplasm, and the localization of small nucleolar RNA U3 in the nucleolus. These snRNAs were chosen because of their essential roles in RNA biogenesis. The results were validated using in situ hybridization as positive control and random beacons as negative control. This novel approach may be applied to imaging other nuclear RNAs and pre-mRNAs in living cells.

  4. Human Cytomegalovirus Nuclear Egress Proteins Ectopically Expressed in the Heterologous Environment of Plant Cells are Strictly Targeted to the Nuclear Envelope

    PubMed Central

    Lamm, Christian E.; Link, Katrin; Wagner, Sabrina; Milbradt, Jens; Marschall, Manfred; Sonnewald, Uwe

    2016-01-01

    In all eukaryotic cells, the nucleus forms a prominent cellular compartment containing the cell’s nuclear genome. Although structurally similar, animal and plant nuclei differ substantially in details of their architecture. One example is the nuclear lamina, a layer of tightly interconnected filament proteins (lamins) underlying the nuclear envelope of metazoans. So far no orthologous lamin genes could be detected in plant genomes and putative lamin-like proteins are only poorly described in plants. To probe for potentially conserved features of metazoan and plant nuclear envelopes, we ectopically expressed the core nuclear egress proteins of human cytomegalovirus pUL50 and pUL53 in plant cells. pUL50 localizes to the inner envelope of metazoan nuclei and recruits the nuclear localized pUL53 to it, forming heterodimers. Upon expression in plant cells, a very similar localization pattern of both proteins could be determined. Notably, pUL50 is specifically targeted to the plant nuclear envelope in a rim-like fashion, a location to which coexpressed pUL53 becomes strictly corecruited from its initial nucleoplasmic distribution. Using pUL50 as bait in a yeast two-hybrid screening, the cytoplasmic re-initiation supporting protein RISP could be identified. Interaction of pUL50 and RISP could be confirmed by coexpression and coimmunoprecipitation in mammalian cells and by confocal laser scanning microscopy in plant cells, demonstrating partial pUL50-RISP colocalization in areas of the nuclear rim and other intracellular compartments. Thus, our study provides strong evidence for conserved structural features of plant and metazoan nuclear envelops and identifies RISP as a potential pUL50-interacting plant protein. PMID:26978388

  5. Nuclear colocalization of cellular and viral myc proteins with HSP70 in myc-overexpressing cells.

    PubMed Central

    Koskinen, P J; Sistonen, L; Evan, G; Morimoto, R; Alitalo, K

    1991-01-01

    The c-myc oncogene and its viral counterpart v-myc encode phosphoproteins which have been located within cell nuclei, excluding nucleoli. We have expressed the c-myc gene under the simian virus 40 early promoter and studied the distribution of its protein product in transient expression assays in COS, HeLa, and 293 cells. We found three distinct patterns of c-myc immunofluorescence in the transfected cells: one-third of the c-myc-positive cells displayed a diffuse nuclear distribution, and in two-thirds of the cells the c-myc fluorescence was accumulated either in small amorphous or in large multilobed phase-dense nuclear structures. Unexpectedly, these structures also stained for the HSP70 heat shock protein in both heat-shocked and untreated cells. Our results indicate that both transient and stable overexpression of either the c-myc or v-myc protein induces translocation of the endogenous HSP70 protein from the cytoplasm to the nucleus, where it becomes sequestered in structures containing the myc protein. Interestingly, the closely related N-myc protein does not stimulate substantial nuclear expression of the HSP70 protein. Studies with chimeric myc proteins revealed that polypeptide sequences encoded by the second exon of c-myc are involved in colocalization with HSP70. Images PMID:1846202

  6. Methods to Characterize Vapor Cell Performance for Nuclear Magnetic Resonance Applications

    NASA Astrophysics Data System (ADS)

    Mirijanian, James; Larsen, Michael

    2012-06-01

    The Advanced Sensors Development team at Northrop Grumman, Navigation Systems Division is developing a Nuclear Magnetic Resonance Gyroscope (NMRG). Various methods to measure atomic spin lifetimes in vapor cells for predicting NMRG performance have been investigated. Certain methods show clear advantages over others by reducing required testing times and improving test data resolution. New modifications of methods were also developed to study and improve the precision and repeatability of test results. These methods help correlate vapor cell performance to cell filling and sealing methods for cell fabrication process improvement. The vapor cells produced in conjunction with these techniques have exhibited significant and consistent increases in both the noble gas spin lifetimes and the NMR signal strengths compared to previous cell fabrication processes, providing more precise insight into cell development techniques.

  7. Isotropic 3D Nuclear Morphometry of Normal, Fibrocystic and Malignant Breast Epithelial Cells Reveals New Structural Alterations

    PubMed Central

    Nandakumar, Vivek; Kelbauskas, Laimonas; Hernandez, Kathryn F.; Lintecum, Kelly M.; Senechal, Patti; Bussey, Kimberly J.; Davies, Paul C. W.; Johnson, Roger H.; Meldrum, Deirdre R.

    2012-01-01

    Background Grading schemes for breast cancer diagnosis are predominantly based on pathologists' qualitative assessment of altered nuclear structure from 2D brightfield microscopy images. However, cells are three-dimensional (3D) objects with features that are inherently 3D and thus poorly characterized in 2D. Our goal is to quantitatively characterize nuclear structure in 3D, assess its variation with malignancy, and investigate whether such variation correlates with standard nuclear grading criteria. Methodology We applied micro-optical computed tomographic imaging and automated 3D nuclear morphometry to quantify and compare morphological variations between human cell lines derived from normal, benign fibrocystic or malignant breast epithelium. To reproduce the appearance and contrast in clinical cytopathology images, we stained cells with hematoxylin and eosin and obtained 3D images of 150 individual stained cells of each cell type at sub-micron, isotropic resolution. Applying volumetric image analyses, we computed 42 3D morphological and textural descriptors of cellular and nuclear structure. Principal Findings We observed four distinct nuclear shape categories, the predominant being a mushroom cap shape. Cell and nuclear volumes increased from normal to fibrocystic to metastatic type, but there was little difference in the volume ratio of nucleus to cytoplasm (N/C ratio) between the lines. Abnormal cell nuclei had more nucleoli, markedly higher density and clumpier chromatin organization compared to normal. Nuclei of non-tumorigenic, fibrocystic cells exhibited larger textural variations than metastatic cell nuclei. At p<0.0025 by ANOVA and Kruskal-Wallis tests, 90% of our computed descriptors statistically differentiated control from abnormal cell populations, but only 69% of these features statistically differentiated the fibrocystic from the metastatic cell populations. Conclusions Our results provide a new perspective on nuclear structure variations

  8. Cell and nuclear enlargement of SW480 cells induced by a plant lignan, arctigenin: evaluation of cellular DNA content using fluorescence microscopy and flow cytometry.

    PubMed

    Kang, Kyungsu; Lee, Hee Ju; Yoo, Ji-Hye; Jho, Eun Hye; Kim, Chul Young; Kim, Minkyun; Nho, Chu Won

    2011-08-01

    Arctigenin is a natural plant lignan previously shown to induce G(2)/M arrest in SW480 human colon cancer cells as well as AGS human gastric cancer cells, suggesting its use as a possible cancer chemopreventive agent. Changes in cell and nuclear size often correlate with the functionality of cancer-treating agents. Here, we report that arctigenin induces cell and nuclear enlargement of SW480 cells. Arctigenin clearly induced the formation of giant nuclear shapes in SW480, as demonstrated by fluorescence microscopic observation and quantitative determination of nuclear size. Cell and nuclear size were further assessed by flow cytometric analysis of light scattering and fluorescence pulse width after propidium iodide staining. FSC-H and FL2-W values (parameters referring to cell and nuclear size, respectively) significantly increased after arctigenin treatment; the mean values of FSC-H and FL2-W in arctigenin-treated SW480 cells were 572.6 and 275.1, respectively, whereas those of control cells were 482.0 and 220.7, respectively. Our approach may provide insights into the mechanism behind phytochemical-induced cell and nuclear enlargement as well as functional studies on cancer-treating agents.

  9. Induced pluripotent stem-induced cells show better constitutive heterochromatin remodeling and developmental potential after nuclear transfer than their parental cells.

    PubMed

    Liu, Zichuan; Wan, Haifeng; Wang, Eryao; Zhao, Xiaoyang; Ding, Chenhui; Zhou, Shuya; Li, Tianda; Shuai, Ling; Feng, Chunjing; Yu, Yang; Zhou, Qi; Beaujean, Nathalie

    2012-11-01

    Recently, reprogramming of somatic cells from a differentiated to pluripotent state by overexpression of specific external transcription factors has been accomplished. It has been widely speculated that an undifferentiated state may make donor cells more efficient for nuclear transfer. To test this hypothesis, we derived induced pluripotent stem cells (iPS cells) from several somatic cell lines: mouse embryonic fibroblast (MEF), adult tail tip fibroblast (TTF), and brain neural stem cells (NSCs). Three dimensional (3D)-fluorescent in situ hybridization (FISH) and quantitative-FISH (Q-FISH) were then used to evaluate constitutive (pericentric and telomeric) heterochromatin organization in these iPS cells and in their parental differentiated cells. Here, we show that important nuclear remodeling and telomeres rejuvenation occur in these iPS cells regardless of their parental origin. When we used these cells as donors for nuclear transfer, we produced live-born cloned mice at much higher rates with the iPS-induced cells than with the parental cell lines. Interestingly, we noticed that developmental potential after nuclear transfer could be correlated with telomere length of the donor cells. Altogether, our findings suggest that constitutive heterochromatin organization from differentiated somatic cells can be reprogrammed to the pluripotent state by induction of iPS cells, which in turn support nuclear transfer procedure quite efficiently. PMID:22657835

  10. MicroRNA-34c Expression in Donor Cells Influences the Early Development of Somatic Cell Nuclear Transfer Bovine Embryos

    PubMed Central

    Wang, Bo; Wang, Yongsheng; Zhang, Man; Du, Yue; Zhang, Yijun; Xing, Xupeng; Zhang, Lei; Su, JianMin

    2014-01-01

    Abstract The essence of the reprogramming activity of somatic cell nuclear transfer (SCNT) embryos is to produce normal fertilized embryos. However, reprogramming of somatic cells is not as efficient as the reprogramming of sperm. In this report, we describe the effect of an inducible, specific miR-34 microRNA expression in donor cells that enables a similar level of sperm:transgene expression on the early development of SCNT embryos. Our results showed that donor cells with doxycycline (dox)-induced miR-34c expression for the preparation of SCNT embryos resulted in altered developmental rates, histone modification (H3K9ac and H3K4me3), and extent of apoptosis. The cleavage rate and blastocyst formation of the induced nuclear transfer (NT) group were significantly increased. The immunofluorescence signal of H3K9ac in embryos in the induced NT group significantly increased in two-cell- and eight-cell-stage embryos; that of H3K4me3 increased significantly in eight-cell-stage embryos. Although significant differences in staining signals of apoptosis were not detected between groups, lower apoptosis levels were observed in the induced NT group. In conclusion, miR-34c expression induced by dox treatment enhances the developmental potential of SCNT embryos, modifies the epigenetic status, and changes blastocyst quality. PMID:25437869

  11. Retinoic acid induces nuclear accumulation of Raf1 during differentiation of HL-60 cells

    SciTech Connect

    Smith, James; Bunaciu, Rodica P.; Reiterer, Gudrun; Coder, David; George, Thaddeus; Asaly, Michael; Yen, Andrew

    2009-08-01

    All trans-retinoic acid (RA) is a standard therapeutic agent used in differentiation induction therapy treatment of acute promyelocytic leukemia (APL). RA and its metabolites use a diverse set of signal transduction pathways during the differentiation program. In addition to the direct transcriptional targets of the nuclear RAR and RXR receptors, signals derived from membrane receptors and the Raf-MEK-ERK pathway are required. Raf1 phosphorylation and the prolonged activation of Raf1 persisting during the entire differentiation process are required for RA-dependent differentiation of HL-60 cells. Here we identify a nuclear redistribution of Raf1 during the RA-induced differentiation of HL-60 cells. In addition, the nuclear accumulation of Raf1 correlates with an increase in Raf1 phosphorylated at serine 621. The serine 621 phosphorylated Raf1 is predominantly localized in the nucleus. The RA-dependent nuclear accumulation of Raf1 suggests a novel nuclear role for Raf1 during the differentiation process.

  12. Prometheus Hot Leg Piping Concept

    SciTech Connect

    Gribik, Anastasia M.; DiLorenzo, Peter A.

    2007-01-30

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  13. Promethus Hot Leg Piping Concept

    SciTech Connect

    AM Girbik; PA Dilorenzo

    2006-01-24

    The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.

  14. Cell type-specific adaptation of cellular and nuclear volume in micro-engineered 3D environments.

    PubMed

    Greiner, Alexandra M; Klein, Franziska; Gudzenko, Tetyana; Richter, Benjamin; Striebel, Thomas; Wundari, Bayu G; Autenrieth, Tatjana J; Wegener, Martin; Franz, Clemens M; Bastmeyer, Martin

    2015-11-01

    Bio-functionalized three-dimensional (3D) structures fabricated by direct laser writing (DLW) are structurally and mechanically well-defined and ideal for systematically investigating the influence of three-dimensionality and substrate stiffness on cell behavior. Here, we show that different fibroblast-like and epithelial cell lines maintain normal proliferation rates and form functional cell-matrix contacts in DLW-fabricated 3D scaffolds of different mechanics and geometry. Furthermore, the molecular composition of cell-matrix contacts forming in these 3D micro-environments and under conventional 2D culture conditions is identical, based on the analysis of several marker proteins (paxillin, phospho-paxillin, phospho-focal adhesion kinase, vinculin, β1-integrin). However, fibroblast-like and epithelial cells differ markedly in the way they adapt their total cell and nuclear volumes in 3D environments. While fibroblast-like cell lines display significantly increased cell and nuclear volumes in 3D substrates compared to 2D substrates, epithelial cells retain similar cell and nuclear volumes in 2D and 3D environments. Despite differential cell volume regulation between fibroblasts and epithelial cells in 3D environments, the nucleus-to-cell (N/C) volume ratios remain constant for all cell types and culture conditions. Thus, changes in cell and nuclear volume during the transition from 2D to 3D environments are strongly cell type-dependent, but independent of scaffold stiffness, while cells maintain the N/C ratio regardless of culture conditions.

  15. Characterization of baculovirus Autographa californica multiple nuclear polyhedrosis virus infection in mammalian cells.

    PubMed

    Kitajima, Masayuki; Hamazaki, Hiroyuki; Miyano-Kurosaki, Naoko; Takaku, Hiroshi

    2006-05-01

    The baculovirus Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) is used as a vector in many gene therapy studies. Wild-type AcMNPV infects many mammalian cell types in vitro, but does not replicate. We investigated the dynamics of AcMNPV genomic DNA in infected mammalian cells and used flow cytometric analysis to demonstrate that recombinant baculovirus containing a cytomegalovirus immediate early promoter/enhancer with green fluorescent protein (GFP) expressed high levels of GFP in Huh-7 cells, but not B16, Raw264.7, or YAC-1 cells. The addition of butyrate, a deacetylase inhibitor, markedly enhanced the percentage of GFP-expressing Huh-7 and B16 cells, but not Raw264.7 and YAC-1 cells. The addition of 5-aza-2'-deoxycytidine, a DNA methylation inhibitor, had no enhancing effect. Polymerase chain reaction analysis using AcMNPV-gp64-specific primers indicated that AcMNPV infected not only Huh-7 and B16 cells, but also Raw264.7 and YAC-1 cells in vitro. The genomic DNA was detected in Huh-7 and B16 cells 96 h after infection. Genomic AcMNPV DNA in YAC-1 cells was not transported to the nucleus. Luciferase assay indicated that AcMNPV p35 gene mRNA and p35 promoter activity were clearly expressed only in Huh-7 and B16 cells. These results suggest that viral genomic DNA expression is restricted by different host cell factors, such as degradation, deacetylation, and inhibition of nuclear transport, depending on the mammalian cell type. PMID:16545777

  16. Characterization of baculovirus Autographa californica multiple nuclear polyhedrosis virus infection in mammalian cells

    SciTech Connect

    Kitajima, Masayuki; Hamazaki, Hiroyuki; Miyano-Kurosaki, Naoko; Takaku, Hiroshi . E-mail: hiroshi.takaku@it-chiba.ac.jp

    2006-05-05

    The baculovirus Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) is used as a vector in many gene therapy studies. Wild-type AcMNPV infects many mammalian cell types in vitro, but does not replicate. We investigated the dynamics of AcMNPV genomic DNA in infected mammalian cells and used flow cytometric analysis to demonstrate that recombinant baculovirus containing a cytomegalovirus immediate early promoter/enhancer with green fluorescent protein (GFP) expressed high levels of GFP in Huh-7 cells, but not B16, Raw264.7, or YAC-1 cells. The addition of butyrate, a deacetylase inhibitor, markedly enhanced the percentage of GFP-expressing Huh-7 and B16 cells, but not Raw264.7 and YAC-1 cells. The addition of 5-aza-2'-deoxycytidine, a DNA methylation inhibitor, had no enhancing effect. Polymerase chain reaction analysis using AcMNPV-gp64-specific primers indicated that AcMNPV infected not only Huh-7 and B16 cells, but also Raw264.7 and YAC-1 cells in vitro. The genomic DNA was detected in Huh-7 and B16 cells 96 h after infection. Genomic AcMNPV DNA in YAC-1 cells was not transported to the nucleus. Luciferase assay indicated that AcMNPV p35 gene mRNA and p35 promoter activity were clearly expressed only in Huh-7 and B16 cells. These results suggest that viral genomic DNA expression is restricted by different host cell factors, such as degradation, deacetylation, and inhibition of nuclear transport, depending on the mammalian cell type.

  17. Nuclear distribution of eIF3g and its interacting nuclear proteins in breast cancer cells

    PubMed Central

    ZHENG, QIAOLI; LIU, HAO; YE, JINGJIA; ZHANG, HUI; JIA, ZHENYU; CAO, JIANG

    2016-01-01

    Eukaryotic translation initiation factor 3 subunit g (eIF3g) is a core subunit of the eukaryotic translation initiation factor 3 complex, and is important in the initiation of translation. It is also involved in caspase-mediated apoptosis, and is upregulated in multidrug-resistant cancer cells. In the present study, the nuclear distribution of eIF3g was determined by performing co-immunoprecipitation of proteins that potentially interact with eIF3g in the nucleus. Mass spectrometry characterization showed that three proteins, heterogeneous nuclear ribonucleoprotein U/scaffold attachment factor A, HSZFP36/zinc finger protein 823 and β-actin, were among the candidate eIF3g-interacting proteins in the nucleus. The protein-protein interaction was further confirmed by cross-linking and a glutathione S-transferase pull-down assay, followed by western blotting. The co-localization of these proteins was determined by confocal microscopy. These findings provide novel insight into the possible functions of eIF3g in the nucleus and serves as an important first step for further investigation of the roles of eIF3g in cancer development. PMID:26935993

  18. Evaluating Nuclear Membrane Irregularity for the Classification of Cervical Squamous Epithelial Cells

    PubMed Central

    Tang, Jing Rui; Mat Isa, Nor Ashidi; Ch’ng, Ewe Seng

    2016-01-01

    Pap test involves searching of morphological changes in cervical squamous epithelial cells by pathologists or cytotechnologists to identify potential cancerous cells in the cervix. Nuclear membrane irregularity is one of the morphological changes of malignancy. This paper proposes two novel techniques for the evaluation of nuclear membrane irregularity. The first technique, namely, penalty-driven smoothing analysis, introduces different penalty values for nuclear membrane contour with different degrees of irregularity. The second technique, which can be subdivided into mean- or median-type residual-based analysis, computes the number of points of nuclear membrane contour that deviates from the mean or median of the nuclear membrane contour. Performance of the proposed techniques was compared to three state-of-the-art techniques, namely, radial asymmetric, shape factor, and rim difference. Friedman and post hoc tests using Holm, Shaffer, and Bergmann procedures returned significant differences for all the three classes, i.e., negative for intraepithelial lesion or malignancy (NILM) versus low grade squamous intraepithelial lesion (LSIL), NILM versus high grade squamous intraepithelial lesion (HSIL), and LSIL versus HSIL when the span value equaled 3 was employed with linear penalty function. When span values equaled 5, 7, and 9, NILM versus LSIL and HSIL showed significant differences regardless of the penalty functions. In addition, the results of penalty-driven smoothing analysis were comparable with those of other state-of-the-art techniques. Residual-based analysis returned significant differences for the comparison among the three diagnostic classes. Findings of this study proved the significance of nuclear membrane irregularity as one of the features to differentiate the different diagnostic classes of cervical squamous epithelial cells. PMID:27741266

  19. Hepatocyte nuclear factor-4 prevents silencing of hepatocyte nuclear factor-1 expression in hepatoma x fibroblast cell hybrids.

    PubMed Central

    Bulla, G A

    1997-01-01

    Hepatocyte nuclear factors-1alpha (HNF1alpha) and -4 (HNF4) are components of a liver-enriched transcription activation pathway which is thought to play a critical role in hepatocyte-specific gene expression, including activation of alpha1-antitrypsin gene expression. HNF1alpha, HNF4 and alpha1-antitrypsin (alpha1AT) genes are extinguished in hepatoma/fibroblast somatic cell hybrids, suggesting that fibroblasts contain a repressor-like activity. To determine the molecular basis for silencing of these genes in cell hybrids, ectopic expression of HNF1alpha and HNF4 was used. Results show that constitutive expression of HNF4 prevents extinction of HNF1alpha gene expression in hepatoma/fibroblast hybrids. In contrast, forced HNF1alpha expression failed to prevent extinction of the HNF4 locus in cell hybrids. Likewise, the alpha1AT gene remained silent in the presence of both HNF1alpha and HNF4. These results suggest that extinction of HNF1alpha is a simple lack-of-activation phenotype, whereas extinction of HNF4 andalpha1AT loci is more complex, perhaps involving negative regulation. PMID:9171105

  20. A Cell-Free Assay Using Xenopus laevis Embryo Extracts to Study Mechanisms of Nuclear Size Regulation.

    PubMed

    Edens, Lisa J; Levy, Daniel L

    2016-08-08

    A fundamental question in cell biology is how cell and organelle sizes are regulated. It has long been recognized that the size of the nucleus generally scales with the size of the cell, notably during embryogenesis when dramatic reductions in both cell and nuclear sizes occur. Mechanisms of nuclear size regulation are largely unknown and may be relevant to cancer where altered nuclear size is a key diagnostic and prognostic parameter. In vivo approaches to identifying nuclear size regulators are complicated by the essential and complex nature of nuclear function. The in vitro approach described here to study nuclear size control takes advantage of the normal reductions in nuclear size that occur during Xenopus laevis development. First, nuclei are assembled in X. laevis egg extract. Then, these nuclei are isolated and resuspended in cytoplasm from late stage embryos. After a 30 - 90 min incubation period, nuclear surface area decreases by 20 - 60%, providing a useful assay to identify cytoplasmic components present in late stage embryos that contribute to developmental nuclear size scaling. A major advantage of this approach is the relative facility with which the egg and embryo extracts can be biochemically manipulated, allowing for the identification of novel proteins and activities that regulate nuclear size. As with any in vitro approach, validation of results in an in vivo system is important, and microinjection of X. laevis embryos is particularly appropriate for these studies.

  1. A Cell-Free Assay Using Xenopus laevis Embryo Extracts to Study Mechanisms of Nuclear Size Regulation.

    PubMed

    Edens, Lisa J; Levy, Daniel L

    2016-01-01

    A fundamental question in cell biology is how cell and organelle sizes are regulated. It has long been recognized that the size of the nucleus generally scales with the size of the cell, notably during embryogenesis when dramatic reductions in both cell and nuclear sizes occur. Mechanisms of nuclear size regulation are largely unknown and may be relevant to cancer where altered nuclear size is a key diagnostic and prognostic parameter. In vivo approaches to identifying nuclear size regulators are complicated by the essential and complex nature of nuclear function. The in vitro approach described here to study nuclear size control takes advantage of the normal reductions in nuclear size that occur during Xenopus laevis development. First, nuclei are assembled in X. laevis egg extract. Then, these nuclei are isolated and resuspended in cytoplasm from late stage embryos. After a 30 - 90 min incubation period, nuclear surface area decreases by 20 - 60%, providing a useful assay to identify cytoplasmic components present in late stage embryos that contribute to developmental nuclear size scaling. A major advantage of this approach is the relative facility with which the egg and embryo extracts can be biochemically manipulated, allowing for the identification of novel proteins and activities that regulate nuclear size. As with any in vitro approach, validation of results in an in vivo system is important, and microinjection of X. laevis embryos is particularly appropriate for these studies. PMID:27584618

  2. Efficient nuclear DNA cleavage in human cancer cells by synthetic bleomycin mimics.

    PubMed

    Li, Qian; van der Wijst, Monique G P; Kazemier, Hinke G; Rots, Marianne G; Roelfes, Gerard

    2014-04-18

    Iron complexes of N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)-methylamine (N4Py) have proven to be excellent synthetic mimics of the Bleomycins (BLMs), which are a family of natural antibiotics used clinically in the treatment of certain cancers. However, most investigations of DNA cleavage activity of these and related metal complexes were carried out in cell-free systems using plasmid DNA as substrate. The present study evaluated nuclear DNA cleavage activity and cell cytotoxicity of BLM and its synthetic mimics based on the ligand N4Py. The N4Py-based reagents induced nuclear DNA cleavage in living cells as efficiently as BLM and Fe(II)-BLM. Treatment of 2 cancer cell lines and 1 noncancerous cell line indicated improved cytotoxicity of N4Py when compared to BLM. Moreover, some level of selectivity was observed for N4Py on cancerous versus noncancerous cells. It was demonstrated that N4Py-based reagents and BLM induce cell death via different mechanistic pathways. BLM was shown to induce cell cycle arrest, ultimately resulting in mitotic catastrophe. In contrast, N4Py-based reagents were shown to induce apoptosis effectively. To the best of our knowledge, the present study is the first demonstration of efficient nuclear DNA cleavage activity of a synthetic BLM mimic within cells. The results presented here show that it is possible to design synthetic bioinorganic model complexes that are at least as active as the parent natural product and thereby are potentially interesting alternatives for BLM to induce antitumor activity.

  3. Nuclear Retention of Multiply Spliced HIV-1 RNA in Resting CD4+ T Cells

    PubMed Central

    Lassen, Kara G; Ramyar, Kasra X; Bailey, Justin R; Zhou, Yan; Siliciano, Robert F

    2006-01-01

    HIV-1 latency in resting CD4+ T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART). We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4+ T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS) HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4+ T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4+ T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB) was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4+ T cells. Overexpression of PTB in resting CD4+ T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4+ T cells. Virus culture experiments showed that overexpression of PTB in resting CD4+ T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications. PMID:16839202

  4. Improvement in antiproliferative activity of Angelica gigas Nakai by solid dispersion formation via hot-melt extrusion and induction of cell cycle arrest and apoptosis in HeLa cells.

    PubMed

    Jiang, Yunyao; Piao, Jingpei; Cho, Hyun-Jong; Kang, Wie-Soo; Kim, Hye-Young

    2015-01-01

    Angelica gigas Nakai (AGN) is one of the most popular herbal medicines and widely used as a functional food product. In this study, AGN was firstly processed by a low-temperature turbo mill and a hot melting extruder to reduce particle size and form solid dispersion (SD). Anticancer activity against HeLa cells was then examined. AGN-SD based on Soluplus was formed via hot-melt extrusion (HME) and showed the strongest cytotoxic effect on HeLa cells. In addition, the possible mechanism of cell death induced by AGN-SD on HeLa cells was also investigated. AGN-SD decreased cell viability, induced apoptosis, increased the production of reactive oxygen species, regulated the expression of Bcl-2 and Bax, and induced G2/M phase arrest in HeLa cells. This study suggested that AGN-SD based on Soluplus and the method to improve antiproliferative effect by SD formation via HME may be suitable for application in the pharmaceutical industry. PMID:26057458

  5. Improvement in antiproliferative activity of Angelica gigas Nakai by solid dispersion formation via hot-melt extrusion and induction of cell cycle arrest and apoptosis in HeLa cells.

    PubMed

    Jiang, Yunyao; Piao, Jingpei; Cho, Hyun-Jong; Kang, Wie-Soo; Kim, Hye-Young

    2015-01-01

    Angelica gigas Nakai (AGN) is one of the most popular herbal medicines and widely used as a functional food product. In this study, AGN was firstly processed by a low-temperature turbo mill and a hot melting extruder to reduce particle size and form solid dispersion (SD). Anticancer activity against HeLa cells was then examined. AGN-SD based on Soluplus was formed via hot-melt extrusion (HME) and showed the strongest cytotoxic effect on HeLa cells. In addition, the possible mechanism of cell death induced by AGN-SD on HeLa cells was also investigated. AGN-SD decreased cell viability, induced apoptosis, increased the production of reactive oxygen species, regulated the expression of Bcl-2 and Bax, and induced G2/M phase arrest in HeLa cells. This study suggested that AGN-SD based on Soluplus and the method to improve antiproliferative effect by SD formation via HME may be suitable for application in the pharmaceutical industry.

  6. Effects of nuclear transfer procedures on ES cell cloning efficiency in the mouse.

    PubMed

    Yabuuchi, Akiko; Yasuda, Yoshiko; Kato, Yoko; Tsunoda, Yukio

    2004-04-01

    Enucleated oocytes receiving mouse embryonic stem (ES) cells develop into fertile young. The developmental potential to young is low, however, and the rate of postnatal death is high. We examined the effect of various nuclear transfer procedures on the in vitro and in vivo developmental potential of nuclear-transferred oocytes. The potential of oocytes receiving ES cells at M phase to develop into blastocysts after fusion by Sendai virus was high compared with that after direct injection (67% vs. 30%). The developmental potential of oocytes receiving ES cells at the M phase is higher than that of oocytes receiving ES cells at the G(1) phase (30-67% vs. 2-5%). Developmental ability to live young was low in all groups (0-4%). Different activation protocols affected the potential to develop into blastocysts to a different extent (27-62%), but did not affect the potential to develop into live young (0-3%). The present study demonstrated that the various conditions examined did not affect the potential of nuclear-transferred oocytes receiving ES cells to develop into live young or the incidence of postnatal death.

  7. Nuclear actin modulates cell motility via transcriptional regulation of adhesive and cytoskeletal genes

    PubMed Central

    Sharili, Amir S.; Kenny, Fiona N.; Vartiainen, Maria K.; Connelly, John T.

    2016-01-01

    The actin cytoskeleton is a classic biomechanical mediator of cell migration. While it is known that actin also shuttles in and out of the nucleus, its functions within this compartment remain poorly understood. In this study, we investigated how nuclear actin regulates keratinocyte gene expression and cell behavior. Gene expression profiling of normal HaCaT keratinocytes compared to HaCaTs over-expressing wild-type β-actin or β-actin tagged with a nuclear localization sequence (NLS-actin), identified multiple adhesive and cytoskeletal genes, such as MYL9, ITGB1, and VCL, which were significantly down-regulated in keratinocytes with high levels of nuclear actin. In addition, genes associated with transcriptional regulation and apoptosis were up-regulated in cells over expressing NLS-actin. Functionally, accumulation of actin in the nucleus altered cytoskeletal and focal adhesion organization and inhibited cell motility. Exclusion of endogenous actin from the nucleus by knocking down Importin 9 reversed this phenotype and enhanced cell migration. Based on these findings, we conclude that the level of actin in the nucleus is a transcriptional regulator for tuning keratinocyte migration. PMID:27650314

  8. Nuclear actin modulates cell motility via transcriptional regulation of adhesive and cytoskeletal genes.

    PubMed

    Sharili, Amir S; Kenny, Fiona N; Vartiainen, Maria K; Connelly, John T

    2016-01-01

    The actin cytoskeleton is a classic biomechanical mediator of cell migration. While it is known that actin also shuttles in and out of the nucleus, its functions within this compartment remain poorly understood. In this study, we investigated how nuclear actin regulates keratinocyte gene expression and cell behavior. Gene expression profiling of normal HaCaT keratinocytes compared to HaCaTs over-expressing wild-type β-actin or β-actin tagged with a nuclear localization sequence (NLS-actin), identified multiple adhesive and cytoskeletal genes, such as MYL9, ITGB1, and VCL, which were significantly down-regulated in keratinocytes with high levels of nuclear actin. In addition, genes associated with transcriptional regulation and apoptosis were up-regulated in cells over expressing NLS-actin. Functionally, accumulation of actin in the nucleus altered cytoskeletal and focal adhesion organization and inhibited cell motility. Exclusion of endogenous actin from the nucleus by knocking down Importin 9 reversed this phenotype and enhanced cell migration. Based on these findings, we conclude that the level of actin in the nucleus is a transcriptional regulator for tuning keratinocyte migration. PMID:27650314

  9. Nuclear alterations associated to programmed cell death in larval salivary glands of Apis mellifera (Hymenoptera: Apidae).

    PubMed

    Silva-Zacarin, E C M; Taboga, S R; Silva de Moraes, R L M

    2008-01-01

    The silk glands of bees are a good model for the study of cell death in insects. With the objective to detect the nuclear features during glandular regression stage, larvae at the last instar and pre-pupae were collected and their silk glands were dissected and processed for ultrastructural analysis and histologically for cytochemical and imunocytochemical analysis. The results showed that the cellular nuclei exhibited characteristics of death by atypical apoptosis as well as autophagic cell death. Among the apoptosis characteristic were: nuclear strangulation with bleb formation in some nuclei, DNA fragmentation in most of the nuclei and nucleolar fragmentation. Centripetal chromatin compaction was observed in many nuclei, forming a perichromatin halo differing from typical apoptotic nuclei. With regards to the characteristics of autophagic-programmed cell death, most relevant was the delay in the collapse of many nuclei.

  10. Comparison of proliferating cell nuclear antigen index in benign and malignant salivary pleomorphic adenoma.

    PubMed

    Yang, L; Liu, B; Qin, C; Hashimura, K; Yamada, T; Sumitomo, S; Mori, M

    1994-01-01

    The expression of proliferating cell nuclear antigen (PCNA) was studied in benign and malignant pleomorphic adenomas by using monoclonal antibody to PCNA. Carcinoma in pleomorphic adenoma (n = 8), cell-rich variant (n = 6) and typical pleomorphic adenoma (n = 6) were selected in this study. The PCNA index in carcinoma in pleomorphic adenoma showed a higher index of nuclear staining (mean 22.9%, S.D. 6.2) than in typical pleomorphic adenoma (mean 6.9%, S.D. 3.4) or a cell-rich variant of pleomorphic adenoma (mean 8.8%, S.D. 3.3). A significant difference in PCNA index was found between benign and malignant pleomorphic adenoma (P < 0.05). The present study suggests that PCNA index significantly differs between pleomorphic adenoma and carcinoma in pleomorphic adenoma, but in the prediction of malignant transformation potential it should be combined with routine histopathological examination.

  11. Time differentiated nuclear resonance spectroscopy coupled with pulsed laser heating in diamond anvil cells.

    PubMed

    Kupenko, I; Strohm, C; McCammon, C; Cerantola, V; Glazyrin, K; Petitgirard, S; Vasiukov, D; Aprilis, G; Chumakov, A I; Rüffer, R; Dubrovinsky, L

    2015-11-01

    Developments in pulsed laser heating applied to nuclear resonance techniques are presented together with their applications to studies of geophysically relevant materials. Continuous laser heating in diamond anvil cells is a widely used method to generate extreme temperatures at static high pressure conditions in order to study the structure and properties of materials found in deep planetary interiors. The pulsed laser heating technique has advantages over continuous heating, including prevention of the spreading of heated sample and/or the pressure medium and, thus, a better stability of the heating process. Time differentiated data acquisition coupled with pulsed laser heating in diamond anvil cells was successfully tested at the Nuclear Resonance beamline (ID18) of the European Synchrotron Radiation Facility. We show examples applying the method to investigation of an assemblage containing ε-Fe, FeO, and Fe3C using synchrotron Mössbauer source spectroscopy, FeCO3 using nuclear inelastic scattering, and Fe2O3 using nuclear forward scattering. These examples demonstrate the applicability of pulsed laser heating in diamond anvil cells to spectroscopic techniques with long data acquisition times, because it enables stable pulsed heating with data collection at specific time intervals that are synchronized with laser pulses. PMID:26628151

  12. Time differentiated nuclear resonance spectroscopy coupled with pulsed laser heating in diamond anvil cells

    SciTech Connect

    Kupenko, I. Strohm, C.; McCammon, C.; Cerantola, V.; Petitgirard, S.; Dubrovinsky, L.; Glazyrin, K.; Vasiukov, D.; Aprilis, G.; Chumakov, A. I.; Rüffer, R.

    2015-11-15

    Developments in pulsed laser heating applied to nuclear resonance techniques are presented together with their applications to studies of geophysically relevant materials. Continuous laser heating in diamond anvil cells is a widely used method to generate extreme temperatures at static high pressure conditions in order to study the structure and properties of materials found in deep planetary interiors. The pulsed laser heating technique has advantages over continuous heating, including prevention of the spreading of heated sample and/or the pressure medium and, thus, a better stability of the heating process. Time differentiated data acquisition coupled with pulsed laser heating in diamond anvil cells was successfully tested at the Nuclear Resonance beamline (ID18) of the European Synchrotron Radiation Facility. We show examples applying the method to investigation of an assemblage containing ε-Fe, FeO, and Fe{sub 3}C using synchrotron Mössbauer source spectroscopy, FeCO{sub 3} using nuclear inelastic scattering, and Fe{sub 2}O{sub 3} using nuclear forward scattering. These examples demonstrate the applicability of pulsed laser heating in diamond anvil cells to spectroscopic techniques with long data acquisition times, because it enables stable pulsed heating with data collection at specific time intervals that are synchronized with laser pulses.

  13. Calmodulin Involvement in Stress-Activated Nuclear Localization of Albumin in JB6 Epithelial Cells.

    SciTech Connect

    Weber, Thomas J.; Negash, Sewite; Smallwood, Heather S.; Ramos, Kenneth S.; Thrall, Brian D.; Squier, Thomas C.

    2004-06-15

    We report that in response to oxidative stress, albumin is translocated to the nucleus where it binds in concert with known transcription factors to an antioxidant response element (ARE), which controls the expression of glutathione-S-transferase and other antioxidant enzymes, functioning to mediate adaptive cellular responses. To investigate the mechanisms underlying this adaptive cell response, we have identified linkages between calcium signaling and the nuclear translocation of albumin in JB6 epithelial cells. Under resting conditions, albumin and the calcium regulatory protein, calmodulin (CaM), co-immunoprecipitate using antibodies against either protein, indicating a tight association. Calcium activation of CaM disrupts the association between CaM and albumin, suggesting that transient increases in cytosolic calcium levels function to mobilize intracellular albumin to facilitate its translocation into the nucleus. Likewise, nuclear translocation of albumin is induced by exposure of cells to hydrogen peroxide or a phorbol ester, indicating a functional linkage between reactive oxygen species, calcium, and PKC-signaling pathways. Inclusion of an antioxidant enzyme (i.e., superoxide dismutase) blocks nuclear translocation, suggesting that the oxidation of sensitive proteins functions to coordinate the adaptive cellular response. These results suggest that elevated calcium transients, and associated increases in reactive oxygen species, contribute to adaptive cellular responses through the mobilization and nuclear translocation of cellular albumin to mediate the transcriptional regulation of antioxidant responsive elements.

  14. Development of porcine tetraploid somatic cell nuclear transfer embryos is influenced by oocyte nuclei.

    PubMed

    Fu, Bo; Liu, Di; Ma, Hong; Guo, Zhen-Hua; Wang, Liang; Li, Zhong-Qiu; Peng, Fu-Gang; Bai, Jing

    2016-02-01

    Cloning efficiency in mammalian systems remains low because reprogramming of donor cells is frequently incomplete. Nuclear factors in the oocyte are removed by enucleation, and this removal may adversely affect reprogramming efficiency. Here, we investigated the role of porcine oocyte nuclear factors during reprogramming. We introduced somatic cell nuclei into intact MII oocytes to establish tetraploid somatic cell nuclear transfer (SCNT) embryos containing both somatic nuclei and oocyte nuclei. We then examined the influence of the oocyte nucleus on tetraploid SCNT embryo development by assessing characteristics including pronucleus formation, cleavage rate, and blastocyst formation. Overall, tetraploid SCNT embryos have a higher developmental competence than do standard diploid SCNT embryos. Therefore, we have established an embryonic model in which a fetal fibroblast nucleus and an oocyte metaphase II plate coexist. Tetraploid SCNT represents a new research platform that is potentially useful for examining interactions between donor nuclei and oocyte nuclei. This platform should facilitate further understanding of the roles played by nuclear factors during reprogramming.

  15. Live Cell Dynamics of Promyelocytic Leukemia Nuclear Bodies upon Entry into and Exit from Mitosis

    PubMed Central

    Chen, Yi-Chun M.; Kappel, Constantin; Beaudouin, Joel; Eils, Roland

    2008-01-01

    Promyelocytic leukemia nuclear bodies (PML NBs) have been proposed to be involved in tumor suppression, viral defense, DNA repair, and/or transcriptional regulation. To study the dynamics of PML NBs during mitosis, we developed several U2OS cell lines stably coexpressing PML-enhanced cyan fluorescent protein with other individual marker proteins. Using three-dimensional time-lapse live cell imaging and four-dimensional particle tracking, we quantitatively demonstrated that PML NBs exhibit a high percentage of directed movement when cells progressed from prophase to prometaphase. The timing of this increased dynamic movement occurred just before or upon nuclear entry of cyclin B1, but before nuclear envelope breakdown. Our data suggest that entry into prophase leads to a loss of tethering between regions of chromatin and PML NBs, resulting in their increased dynamics. On exit from mitosis, Sp100 and Fas death domain-associated protein (Daxx) entered the daughter nuclei after a functional nuclear membrane was reformed. However, the recruitment of these proteins to PML NBs was delayed and correlated with the timing of de novo PML NB formation. Together, these results provide insight into the dynamic changes associated with PML NBs during mitosis. PMID:18480407

  16. Nuclear reprogramming and induced pluripotent stem cells: a review for surgeons.

    PubMed

    Qi, Sara D; Smith, Paul D; Choong, Peter F

    2014-06-01

    Induced pluripotent stem cells (iPSCs) are generated from somatic cells by the exogenous expression of defined transcription factors. iPSCs share the defining features of embryonic stem cells (ESCs) in that they are able to self-renew indefinitely and maintain the potential to develop into all cell types of the body. These cells have key advantages over ESCs in that they are autologous to the donor cells and can be generated from individuals at any age. iPSCs also circumvent ethical and political issues surrounding the destruction of embryos that is necessary in the isolation of ESCs. This review briefly describes the advent of iPSC technology and the concepts of nuclear reprogramming, and discusses the potential application of this powerful biological tool in both surgical research and regenerative medicine.

  17. Nuclear reprogramming and induced pluripotent stem cells: a review for surgeons.

    PubMed

    Qi, Sara D; Smith, Paul D; Choong, Peter F

    2014-06-01

    Induced pluripotent stem cells (iPSCs) are generated from somatic cells by the exogenous expression of defined transcription factors. iPSCs share the defining features of embryonic stem cells (ESCs) in that they are able to self renew indefinitely and maintain the potential to develop into all cell types of the body. These cells have key advantages over ESCs in that they are autologous to the donor cells and can be generated from individuals at any age. iPSCs also circumvent ethical and political issues surrounding the destruction of embryos that is necessary in the isolation of ESCs. This review briefly describes the advent of iPSC technology and the concepts of nuclear reprogramming, and discusses the potential application of this powerful biological tool in both surgical research and regenerative medicine.

  18. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    SciTech Connect

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-22

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  19. Hydrogen Gas Production from Nuclear Power Plant in Relation to Hydrogen Fuel Cell Technologies Nowadays

    NASA Astrophysics Data System (ADS)

    Yusibani, Elin; Kamil, Insan; Suud, Zaki

    2010-06-01

    Recently, world has been confused by issues of energy resourcing, including fossil fuel use, global warming, and sustainable energy generation. Hydrogen may become the choice for future fuel of combustion engine. Hydrogen is an environmentally clean source of energy to end-users, particularly in transportation applications because without release of pollutants at the point of end use. Hydrogen may be produced from water using the process of electrolysis. One of the GEN-IV reactors nuclear projects (HTGRs, HTR, VHTR) is also can produce hydrogen from the process. In the present study, hydrogen gas production from nuclear power plant is reviewed in relation to commercialization of hydrogen fuel cell technologies nowadays.

  20. Nuclear donor cell lines considerably influence cloning efficiency and the incidence of large offspring syndrome in bovine somatic cell nuclear transfer.

    PubMed

    Liu, J; Wang, Y; Su, J; Luo, Y; Quan, F; Zhang, Y

    2013-08-01

    Total five ear skin fibroblast lines (named F1, F2, F3, F4 and F5) from different newborn Holstein cows have been used as nuclear donor cells for producing cloned cows by somatic cell nuclear transfer (SCNT). The effects of these cell lines on both in vitro and in vivo developmental rates of cloned embryos, post-natal survivability and incidence of large offspring syndrome (LOS) were examined in this study. We found that the different cell lines possessed the same capacity to support pre-implantation development of cloned embryos, the cleavage and blastocyst formation rates ranged from 80.2 ± 0.9 to 84.5 ± 2.5% and 28.5 ± 0.9 to 33.3 ± 1.4%, respectively. However, their capacities to support the in vivo development of SCNT embryos showed significant differences (p < 0.05). The pregnancy rates at 90 and 240 day were significantly lower in groups F2 (4.9% and 3.3%) and F3 (5.4% and 5.4%) compared to groups F1 (23.3% and 16.3%), F4 (25.7% and 18.6%) and F5 (25.9% and 19.8%) (p < 0.05). The cloning efficiency was significantly higher in group F5 than those in group F1, F2, F3 and F4 (9.3% vs 4.1%, 1.2%, 2.0% and 5.0%, respectively, p < 0.05). Moreover, large offspring syndrome (LOS) incidence in group F5 was significantly lower than those in other groups (p < 0.05). All cloned offspring from cell line F1, F2, F3 and F4 showed LOS and gestation length delay, while all cloned offspring from F5 showed normal birthweight and gestation length. We concluded that the nuclear donor cell lines have significant impact on the in vivo development of cloned embryos and the incidence of LOS in cloned calves.