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Sample records for 7sk small nuclear

  1. Solution structure of the 5'-terminal hairpin of the 7SK small nuclear RNA.

    PubMed

    Bourbigot, Sarah; Dock-Bregeon, Anne-Catherine; Eberling, Pascal; Coutant, Jérôme; Kieffer, Bruno; Lebars, Isabelle

    2016-12-01

    The small nuclear 7SK RNA regulates RNA polymerase II (RNA Pol II) transcription, by sequestering and inhibiting the positive transcription elongation factor b (P-TEFb). P-TEFb is stored in the 7SK ribonucleoprotein (RNP) that contains the three nuclear proteins Hexim1, LaRP7, and MePCE. P-TEFb interacts with the protein Hexim1 and the 7SK RNA. Once P-TEFb is released from the 7SK RNP, it activates transcription by phosphorylating the C-terminal domain of RNA Pol II. P-TEFb also plays a crucial role in the replication of the human immunodeficiency virus HIV-1, through its recruitment by the viral transactivator Tat. Previous work demonstrated that the protein Tat promotes the release of P-TEFb from the 7SK RNP through direct binding to the 7SK RNA. Hexim1 and Tat proteins both comprise conserved and similar arginine-rich motifs that were identified to bind the 7SK RNA at a repeated GAUC site located at the top of the 5'-terminal hairpin (HPI). Here, we report the solution structure of this region as determined by nuclear magnetic resonance, to identify HPI structural features recognized by Hexim1 and Tat. The HPI solution structure displays an elongated shape featuring four helical segments interrupted by one internal loop and three bulges with distinct folds. In particular, the repeated GAUC motif adopts a pre-organized geometry. Our results suggest that the binding of Hexim1 and Tat to the 7SK RNA could originate from a conformational selection of this motif, highlighting how RNA local structure could lead to an adaptive recognition of their partners.

  2. 7SK small nuclear RNA inhibits cancer cell proliferation through apoptosis induction.

    PubMed

    Keramati, Farid; Seyedjafari, Ehsan; Fallah, Parviz; Soleimani, Masoud; Ghanbarian, Hossein

    2015-04-01

    7SK small nuclear RNA (snRNA) is a 331-333-bp non-coding RNA, which recruits HEXIM 1/2 protein to inhibit positive elongation factor b (P-TEFb) activity. P-TEFb is an essential factor in alleviating promoter-proximal paused RNA polymerase II (Pol II) and initiating the productive elongation phase of gene transcription. Without this protein, Pol II will remain in its hypophosphorylated state, and no transcription occurs. In this study, we inhibited P-TEFb activity by over-expressing 7SK snRNA in human embryonic kidney (HEK) 293T cancer cell line. This inhibition led to a significant decrease in cell viability, which can be due to the transcription inhibition. Moreover, 7SK snRNA over-expression promoted apoptosis in cancerous cells. Our results suggest 7SK snRNA as a potential endogenous anti-cancer agent, and to the best of our knowledge, this is the first study that uses a long non-coding RNA's over-expression against cancer cell growth and proliferation.

  3. Genetic analysis of the structure and function of 7SK small nuclear ribonucleoprotein (snRNP) in cells.

    PubMed

    Fujinaga, Koh; Luo, Zeping; Peterlin, B Matija

    2014-07-25

    The positive transcription elongation factor b (P-TEFb), comprised of cyclin-dependent kinase 9 (CDK9) and cyclins T1 (CycT1) or T2 (CycT2), activates eukaryotic transcription elongation. In growing cells, P-TEFb exists in active and inactive forms. In the latter, it is incorporated into the 7SK small nuclear ribonucleoprotein, which contains hexamethylene bisacetamide-induced proteins (HEXIM) 1 or 2, La-related protein 7 (LaRP7), methyl phosphate capping enzyme, and 7SK small nuclear RNA (7SK). HEXIM1 inhibits the kinase activity of CDK9 via interactions between 7SK, HEXIM1, and CycT1. LaRP7 and methyl phosphate capping enzyme interact with 7SK independently of HEXIM1 and P-TEFb. To analyze genetic interactions between HEXIM1 and/or LaRP7 and 7SK using a cell-based system, we established artificial heterologous RNA tethering assays in which reporter gene expression depended on interactions between selected regions of 7SK and its cognate binding partners fused to a strong activator. This system enabled us to map the HEXIM1- and LaRP7- binding regions of 7SK. Assays with various mutant 7SK plasmid targets revealed that the 5'U-Ubulge and central loop of stem-loop I or RNA motif 3 of 7SK are required for transactivation, suggesting that HEXIM1 and CycT1 form a combinatorial binding surface for 7SK. Moreover, a region in HEXIM1 C-terminal to its previously mapped RNA-binding motif was also required for interactions between HEXIM1 and 7SK. Finally, a tyrosine-to-alanine mutation in HEXIM1, which is critical for its inhibitory effect on CDK9, changed HEXIM1 into an activator. These cell-based assays elucidate this important aspect of transcription elongation in vivo.

  4. Release of positive transcription elongation factor b (P-TEFb) from 7SK small nuclear ribonucleoprotein (snRNP) activates hexamethylene bisacetamide-inducible protein (HEXIM1) transcription.

    PubMed

    Liu, Pingyang; Xiang, Yanhui; Fujinaga, Koh; Bartholomeeusen, Koen; Nilson, Kyle A; Price, David H; Peterlin, B Matija

    2014-04-04

    By phosphorylating negative elongation factors and the C-terminal domain of RNA polymerase II (RNAPII), positive transcription elongation factor b (P-TEFb), which is composed of CycT1 or CycT2 and CDK9, activates eukaryotic transcription elongation. In growing cells, it is found in active and inactive forms. In the former, free P-TEFb is a potent transcriptional coactivator. In the latter, it is inhibited by HEXIM1 or HEXIM2 in the 7SK small nuclear ribonucleoprotein (snRNP), which contains, additionally, 7SK snRNA, methyl phosphate-capping enzyme (MePCE), and La-related protein 7 (LARP7). This P-TEFb equilibrium determines the state of growth and proliferation of the cell. In this study, the release of P-TEFb from the 7SK snRNP led to increased synthesis of HEXIM1 but not HEXIM2 in HeLa cells, and this occurred only from an unannotated, proximal promoter. ChIP with sequencing revealed P-TEFb-sensitive poised RNA polymerase II at this proximal but not the previously annotated distal HEXIM1 promoter. Its immediate upstream sequences were fused to luciferase reporters and were found to be responsive to many P-TEFb-releasing compounds. The superelongation complex subunits AF4/FMR2 family member 4 (AFF4) and elongation factor RNA polymerase II 2 (ELL2) were recruited to this proximal promoter after P-TEFb release and were required for its transcriptional effects. Thus, P-TEFb regulates its own equilibrium in cells, most likely to maintain optimal cellular homeostasis.

  5. 7SK-BAF axis controls pervasive transcription at enhancers

    PubMed Central

    Flynn, Ryan A.; Do, Brian T.; Rubin, Adam J.; Calo, Eliezer; Lee, Byron; Kuchelmeister, Hannes; Rale, Michael; Chu, Ci; Kool, Eric T.; Wysocka, Joanna; Khavari, Paul A.

    2016-01-01

    RNA functions at enhancers remain mysterious. Here we show that the 7SK small nuclear RNA (snRNA) inhibits enhancer transcription by modulating nucleosome position. 7SK occupies enhancers and super enhancers genome-wide in mouse and human cells, and 7SK is required to limit eRNA initiation and synthesis in a manner distinct from promoter pausing. Clustered elements at super enhancers uniquely require 7SK to prevent convergent transcription and DNA damage signaling. 7SK physically interacts with the BAF chromatin remodeling complex, recruit BAF to enhancers, and inhibits enhancer transcription by modulating chromatin structure. In turn, 7SK occupancy at enhancers coincides with Brd4 and is exquisitely sensitive to the bromodomain inhibitor JQ1. Thus, 7SK employs distinct mechanisms to counteract diverse consequences of pervasive transcription that distinguish super enhancers, enhancers, and promoters. PMID:26878240

  6. [Cloning and functional verification of U6 and 7SK promoter of small RNA from Bama mini-pig in Guangxi].

    PubMed

    Chen, Shi-Jin; Fan, Jing; Jiang, Qin-Yang; Lan, Gan-Qiu; Guo, Xiao-Ping; Guo, Ya-Fen

    2012-04-01

    To investigate the functions of U6 and 7SK of Bama mini-pig and produce Bama mini-pig with silenced GGTA1 gene, the siRNA promoters U6 and 7SK were cloned, ligated into pMD18-shEGFP, and co-transfected with PEGFP- N1 into PK-15 kidney cells of pigs to be used in RNAi experiments. The functions of the two promoters in pig cells were verified using pMD18-hU6-shEGFP as the positive control, pMD18-shEGFP vector without promoter as the negative control, PEGFP-N1 as the first blank control, ddH2O in replacement of the plasmid as the second blank control. The results showed that the lengths of U6 and 7SK in Bama mini-pig were 553 bp and 437 bp, respectively. Vectors pMD18-pU6- shEGFP and pMD18-p7SK-shEGFP were constructed and transfected into PK-15 cells from pigs. Promoters pU6 and p7SK proved to express high levels of siRNA activity and can be used in the experiment of silencing α-1,3galactosyltransferase gene.

  7. Cracking the control of RNA polymerase II elongation by 7SK snRNP and P-TEFb

    PubMed Central

    C. Quaresma, Alexandre J.; Bugai, Andrii; Barboric, Matjaz

    2016-01-01

    Release of RNA polymerase II (Pol II) from promoter-proximal pausing has emerged as a critical step regulating gene expression in multicellular organisms. The transition of Pol II into productive elongation requires the kinase activity of positive transcription elongation factor b (P-TEFb), which is itself under a stringent control by the inhibitory 7SK small nuclear ribonucleoprotein (7SK snRNP) complex. Here, we provide an overview on stimulating Pol II pause release by P-TEFb and on sequestering P-TEFb into 7SK snRNP. Furthermore, we highlight mechanisms that govern anchoring of 7SK snRNP to chromatin as well as means that release P-TEFb from the inhibitory complex, and propose a unifying model of P-TEFb activation on chromatin. Collectively, these studies shine a spotlight on the central role of RNA binding proteins (RBPs) in directing the inhibition and activation of P-TEFb, providing a compelling paradigm for controlling Pol II transcription with a non-coding RNA. PMID:27369380

  8. Nucleoplasmic organization of small nuclear ribonucleoproteins in cultured human cells

    PubMed Central

    1993-01-01

    The organization of eight small nuclear ribonucleoproteins (the U1, U2, U4, U5, and U6 RNAs previously studied by others and three additional snRNAs, U11, U12, and 7SK) has been investigated in cultured human cells by fluorescence in situ hybridization with antisense DNA and 2'-O- Me RNA oligonucleotides. Using highly sensitive digital imaging microscopy we demonstrate that all of these snRNAs are widespread throughout the nucleoplasm, but they are excluded from the nucleoli. In addition, the U2, U4, U5, U6, and U12 snRNAs are concentrated in discrete nuclear foci, known as coiled bodies, but U1 and 7SK are not. In addition to coiled bodies, a classic speckled pattern was observed in the nucleoplasm of monolayer-grown HeLa cells, whereas suspension- grown HeLa cells revealed a more diffuse nucleoplasmic labeling. Immunofluorescence staining using various snRNP-specific antisera shows complete agreement with that of their antisense snRNA oligonucleotide counterparts. Although U2 RNA is concentrated in coiled bodies, quantitation of the fluorescence signals from the U2 antisense probe reveals that the bulk of the U2 snRNP is located in the nucleoplasm. Furthermore, simultaneous visualization of the U2 snRNAs and the tandemly repeated U2 genes demonstrates that coiled bodies are not the sites of U2 transcription. PMID:8491767

  9. B2 RNA and 7SK RNA, RNA polymerase III transcripts, have a cap-like structure at their 5' end.

    PubMed Central

    Shumyatsky, G P; Tillib, S V; Kramerov, D A

    1990-01-01

    We found that hydrolysates of poly(A)+ RNA from Ehrlich ascites carcinoma cells which were transcribed by RNA polymerase III contained an unusual component designated as X. It was part of B2 RNA representing a transcript of B2 retroposon, typical of rodents. The component X possesses a cap-like structure, xppp5'G, where x has a non-nucleotide structure. About half of all B2 RNAs contained this group at the 5' end. Previously, Epstein et al. (1) detected a similar structure at the 5' end of small nuclear U6 RNA. Later, Singh and Reddy (2) showed methyl to be the blocking group in the component x of U6 RNA. Besides B2 RNA, we found 5' ends containing methyl groups in 7SK RNA. Images PMID:1700854

  10. Nuclear threats from small states

    SciTech Connect

    Kahan, J.H.

    1994-06-13

    What are the policy implications regarding proliferation and counter proliferation of nuclear weapons among Third World states. How does deterrence operate outside the parameters of superpower confrontation as defined by the cold war elaborate system of constraints enforced by concepts like mutual assured destruction, and counter-value and counter-force targeting. How can US policymakers devise contingencies for dealing with nuclear threats posed by countries like North Korea, Libya, Iraq, Iran, and Syria. These are some of the unsettling but nevertheless important questions addressed by the author in this monograph. In his analysis, Mr. Jerome Kahan examines the likelihood that one or more of these countries will use nuclear weapons before the year 2000. He also offers a framework that policymakers and planners might use in assessing US interests in preempting the use of nuclear weapons or in retaliating for their use. Ironically, with the end of the cold war, it is imperative that defense strategists, policymakers, and military professionals think about the `unthinkable`. In the interest of fostering debate on this important subject, the Strategic Studies Institute commends this insightful monograph.

  11. The Common Sense of Small Nuclear Arsenals

    DTIC Science & Technology

    2012-01-01

    reasons, France developed a small, independent nuclear arsenal after World War II. 4 It kept its force levels comparatively low, even during the Cold War...00-00-2012 to 00-00-2012 4 . TITLE AND SUBTITLE The Common Sense of Small Nuclear Arsenals 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...survival motive” is law-like. All human conduct is shaped in some measure by what individuals believe to be general laws. In science , laws establish

  12. Observations on the structure of two human 7SK pseudogenes and on homologous transcripts in vertebrate species.

    PubMed Central

    Humphries, P; Russell, S E; McWilliam, P; McQuaid, S; Pearson, C; Humphries, M M

    1987-01-01

    A comparison of the sequence of two human 7SK RNA pseudogenes, covering approx. 190 and 240 base-pairs of the structural gene, is presented. Both repeated elements are flanked by direct repeats and begin at the 5' end of the gene. Each terminates approx. 90 base-pairs short of the 3' end, the latter representing a continuous sequence and the former carrying an internal deletion of about 40 base-pairs, this region being flanked in the progenitor gene by short repeated sequences. Southern blotting using a human 7SK pseudogene probe illuminated a series of multiple restriction fragments in mammalian genomes, with generally fewer fragments in the genomes of birds and reptiles and a single reactive fragment in DNA from terrapin (Pseudemys scripta elegans) and Xenopus laevis (South African clawed toad). In the latter case this fragment was only detectable on long exposure under the hybridization stringencies employed. 7SK transcripts were readily detectable in all mammalian, avian, reptilian and amphibian species analysed, although the gene appeared to be expressed at rather low levels in the ovaries of Xenopus laevis, possibly accounting for its failure to have become dispersed via 'retroposition' in this species. Images Fig. 2. Fig. 3. PMID:3663152

  13. Small Nuclear Technology and Market Entry

    SciTech Connect

    Stewart, J S; Schock, R N; Brown, N W; Smith, C F

    2002-05-31

    An overview of energy-system projections into the new century leads to the conclusion that nuclear power will play a significant role. How significant a role will be determined by the marketplace. Within the range of nuclear-power technologies available, small nuclear-power plants of innovative design appear to fit the needs of a number of developing nations and states. Under similar financing options used by the airline industry and others, the capital requirement barrier that puts the nuclear industry at a disadvantage in deregulated markets could be reduced. These plants have the potential advantage of modularity, are proliferation-resistant, incorporate passive safety features, minimize waste, and could be cost-competitive with fossil-fuel plants.

  14. Inhibition of P-TEFb (CDK9/Cyclin T) kinase and RNA polymerase II transcription by the coordinated actions of HEXIM1 and 7SK snRNA.

    PubMed

    Yik, Jasper H N; Chen, Ruichuan; Nishimura, Rieko; Jennings, Jennifer L; Link, Andrew J; Zhou, Qiang

    2003-10-01

    The positive transcriptional elongation factor b (P-TEFb), consisting of CDK9 and cyclin T, stimulates transcription by phosphorylating RNA polymerase II. It becomes inactivated when associated with the abundant 7SK snRNA. Here, we show that the 7SK binding alone was not sufficient to inhibit P-TEFb. P-TEFb was inhibited by the HEXIM1 protein in a process that specifically required 7SK for mediating the HEXIM1:P-TEFb interaction. This allowed HEXIM1 to inhibit transcription both in vivo and in vitro. P-TEFb dissociated from HEXIM1 and 7SK in cells undergoing stress response, increasing the level of active P-TEFb for stress-induced transcription. P-TEFb was the predominant HEXIM1-associated protein factor, and thus likely to be the principal target of inhibition coordinated by HEXIM1 and 7SK. Since HEXIM1 expression is induced in cells treated with hexamethylene bisacetamide, a potent inducer of cell differentiation, targeting the general transcription factor P-TEFb by HEXIM1/7SK may contribute to the global control of cell growth and differentiation.

  15. Small nuclear RNAs in the ciliate Tetrahymena.

    PubMed Central

    Pedersen, N; Hellung-Larsen, P; Engberg, J

    1985-01-01

    We have isolated and partially characterized a family of small nuclear RNAs (snRNAs) from three different species of the protozoan Tetrahymena. We find six distinct snRNAs ranging in size from 100 to 250 nucleotides. The two largest snRNAs, as well as an abundant, heterogenous group of smaller snRNAs are found in the nucleolar RNA fraction. None of the snRNAs are transcription products of the ribosomal RNA gene or its flanking regions, as shown by hybridization tests. The snRNAs are metabolically stable as determined by pulse/chase experiments and several of them contain a number of modified nuclotides. The snRNAs from Tetrahymena all have slightly different sizes from mammalian snRNAs. The cap structure of the snRNAs from Tetrahymena differs from that of the snRNAs from mammalian cells, but has not yet been fully characterized. The relative amount of snRNAs to total RNA is less in Tetrahymena (greater than 0.1%) than in mammalian cells (2%). Images PMID:2409533

  16. Loss of function mutation in LARP7, chaperone of 7SK ncRNA, causes a syndrome of facial dysmorphism, intellectual disability, and primordial dwarfism.

    PubMed

    Alazami, Anas M; Al-Owain, Mohammad; Alzahrani, Fatema; Shuaib, Taghreed; Al-Shamrani, Hussain; Al-Falki, Yahya H; Al-Qahtani, Saleh M; Alsheddi, Tarfa; Colak, Dilek; Alkuraya, Fowzan S

    2012-10-01

    Primordial dwarfism (PD) is a clinically and genetically heterogeneous condition. Various molecular mechanisms are known to underlie the disease including impaired mitotic mechanics, abnormal IGF2 expression, perturbed DNA damage response, defective spliceosomal machinery, and abnormal replication licensing. Here, we describe a syndromic form of PD associated with severe intellectual disability and distinct facial features in a large multiplex Saudi family. Analysis reveals a novel underlying mechanism for PD involving depletion of 7SK, an abundant cellular noncoding RNA (ncRNA), due to mutation of its chaperone LARP7. We show that 7SK levels are tightly linked to LARP7 expression across cell lines, and that this chaperone is ubiquitously expressed in the mouse embryo. The 7SK is known to influence the expression of a wide array of genes through its inhibitory effect on the positive transcription elongation factor b (P-TEFb) as well as its competing role in HMGA1-mediated transcriptional regulation. This study documents a critical role played by ncRNA in human development and adds to the growing list of molecular mechanisms that, when perturbed, converge on the PD phenotype.

  17. Small-Volume Nuclear Magnetic Resonance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fratila, Raluca M.; Velders, Aldrik H.

    2011-07-01

    Nuclear magnetic resonance (NMR) spectroscopy is one of the most information-rich analytical techniques available. However, it is also inherently insensitive, and this drawback precludes the application of NMR spectroscopy to mass- and volume-limited samples. We review a particular approach to increase the sensitivity of NMR experiments, namely the use of miniaturized coils. When the size of the coil is reduced, the sample volume can be brought down to the nanoliter range. We compare the main coil geometries (solenoidal, planar, and microslot/stripline) and discuss their applications to the analysis of mass-limited samples. We also provide an overview of the hyphenation of microcoil NMR spectroscopy to separation techniques and of the integration with lab-on-a-chip devices and microreactors.

  18. Leading twist nuclear shadowing, nuclear generalized parton distributions and nuclear DVCS at small x

    SciTech Connect

    Guzey, Vadim; Goeke, Klaus; Siddikov, Marat

    2009-01-01

    We generalize the leading twist theory of nuclear shadowing and calculate quark and gluon generalized parton distributions (GPDs) of spinless nuclei. We predict very large nuclear shadowing for nuclear GPDs. In the limit of the purely transverse momentum transfer, our nuclear GPDs become impact parameter dependent nuclear parton distributions (PDFs). Nuclear shadowing induces non-trivial correlations between the impact parameter $b$ and the light-cone fraction $x$. We make predictions for the deeply virtual Compton scattering (DVCS) amplitude and the DVCS cross section on $^{208}$Pb at high energies. We calculate the cross section of the Bethe-Heitler (BH) process and address the issue of the extraction of the DVCS signal from the $e A \\to e \\gamma A$ cross section. We find that the $e A \\to e \\gamma A$ differential cross section is dominated by DVCS at the momentum transfer $t$ near the minima of the nuclear form factor. We also find that nuclear shadowing leads

  19. Spliceosomal small nuclear ribonucleoprotein particles repeatedly cycle through Cajal bodies.

    PubMed

    Stanek, David; Pridalová-Hnilicová, Jarmila; Novotný, Ivan; Huranová, Martina; Blazíková, Michaela; Wen, Xin; Sapra, Aparna K; Neugebauer, Karla M

    2008-06-01

    The Cajal body (CB) is a nuclear structure closely associated with import and biogenesis of small nuclear ribonucleoprotein particles (snRNPs). Here, we tested whether CBs also contain mature snRNPs and whether CB integrity depends on the ongoing snRNP splicing cycle. Sm proteins tagged with photoactivatable and color-maturing variants of fluorescent proteins were used to monitor snRNP behavior in living cells over time; mature snRNPs accumulated in CBs, traveled from one CB to another, and they were not preferentially replaced by newly imported snRNPs. To test whether CB integrity depends on the snRNP splicing cycle, two human orthologues of yeast proteins involved in distinct steps in spliceosome disassembly after splicing, hPrp22 and hNtr1, were depleted by small interfering RNA treatment. Surprisingly, depletion of either protein led to the accumulation of U4/U6 snRNPs in CBs, suggesting that reassembly of the U4/U6.U5 tri-snRNP was delayed. Accordingly, a relative decrease in U5 snRNPs compared with U4/U6 snRNPs was observed in CBs, as well as in nuclear extracts of treated cells. Together, the data show that particular phases of the spliceosome cycle are compartmentalized in living cells, with reassembly of the tri-snRNP occurring in CBs.

  20. Testing of Small Graphite Samples for Nuclear Qualification

    SciTech Connect

    Julie Chapman

    2010-11-01

    Accurately determining the mechanical properties of small irradiated samples is crucial to predicting the behavior of the overal irradiated graphite components within a Very High Temperature Reactor. The sample size allowed in a material test reactor, however, is limited, and this poses some difficulties with respect to mechanical testing. In the case of graphite with a larger grain size, a small sample may exhibit characteristics not representative of the bulk material, leading to inaccuracies in the data. A study to determine a potential size effect on the tensile strength was pursued under the Next Generation Nuclear Plant program. It focuses first on optimizing the tensile testing procedure identified in the American Society for Testing and Materials (ASTM) Standard C 781-08. Once the testing procedure was verified, a size effect was assessed by gradually reducing the diameter of the specimens. By monitoring the material response, a size effect was successfully identified.

  1. Small-animal preclinical nuclear medicine instrumentation and methodology.

    PubMed

    Rowland, Douglas J; Cherry, Simon R

    2008-05-01

    Molecular medicine enhances the clinician's ability to accurately diagnose and treat disease, and many technological advances in diverse fields have made the translation of molecular medicine to the clinic possible. Nuclear medicine encompasses 2 technologies--single-photon emission computed tomography (SPECT) and positron emission tomography (PET)--that have driven the field of molecular medicine forward. SPECT and PET, inherently molecular imaging techniques, have been at the forefront of molecular medicine for several decades. These modalities exploit the radioactive decay of nuclides with specific decay properties that make them useful for in vivo imaging. As recently as the mid-1990s, SPECT and PET were mostly restricted to use in the clinical setting because their relatively coarse spatial resolution limited their usefulness in studying animal (especially rodent) models of human disease. About a decade ago, several groups began making significant strides in improving resolution to the point that small-animal SPECT and PET as a molecular imaging technique was useful in the study of rodent disease models. The advances in these 2 techniques progressed as the result of improvements in instrumentation and data reconstruction software. Here, we review the impact of small-animal imaging and, specifically, nuclear medicine imaging techniques on the understanding of the biological basis of disease and the expectation that these advances will be translated to clinical medicine.

  2. Enrichment Zoning Options for the Small Nuclear Rocket Engine (SNRE)

    SciTech Connect

    Bruce G. Schnitzler; Stanley K. Borowski

    2010-07-01

    Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. In NASA’s recent Mars Design Reference Architecture (DRA) 5.0 study (NASA-SP-2009-566, July 2009), nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option because of its high thrust and high specific impulse (-900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art design incorporating lessons learned from the very successful technology development program. Past activities at the NASA Glenn Research Center have included development of highly detailed MCNP Monte Carlo transport models of the SNRE and other small engine designs. Preliminary core configurations typically employ fuel elements with fixed fuel composition and fissile material enrichment. Uniform fuel loadings result in undesirable radial power and temperature profiles in the engines. Engine performance can be improved by some combination of propellant flow control at the fuel element level and by varying the fuel composition. Enrichment zoning at the fuel element level with lower enrichments in the higher power elements at the core center and on the core periphery is particularly effective. Power flattening by enrichment zoning typically results in more uniform propellant exit temperatures and improved engine performance. For the SNRE, element enrichment zoning provided very flat radial power profiles with 551 of the 564

  3. Westinghouse Small Modular Reactor nuclear steam supply system design

    SciTech Connect

    Memmott, M. J.; Harkness, A. W.; Van Wyk, J.

    2012-07-01

    The Westinghouse Small Modular Reactor (SMR) is an 800 MWt (>225 MWe) integral pressurized water reactor (iPWR), in which all of the components typically associated with the nuclear steam supply system (NSSS) of a nuclear power plant are incorporated within a single reactor pressure vessel. This paper is the first in a series of four papers which describe the design and functionality of the Westinghouse SMR. Also described in this series are the key drivers influencing the design of the Westinghouse SMR and the unique passive safety features of the Westinghouse SMR. Several critical motivators contributed to the development and integration of the Westinghouse SMR design. These design driving motivators dictated the final configuration of the Westinghouse SMR to varying degrees, depending on the specific features under consideration. These design drivers include safety, economics, AP1000{sup R} reactor expertise and experience, research and development requirements, functionality of systems and components, size of the systems and vessels, simplicity of design, and licensing requirements. The Westinghouse SMR NSSS consists of an integral reactor vessel within a compact containment vessel. The core is located in the bottom of the reactor vessel and is composed of 89 modified Westinghouse 17x17 Robust Fuel Assemblies (RFA). These modified fuel assemblies have an active core length of only 2.4 m (8 ft) long, and the entirety of the core is encompassed by a radial reflector. The Westinghouse SMR core operates on a 24 month fuel cycle. The reactor vessel is approximately 24.4 m (80 ft) long and 3.7 m (12 ft) in diameter in order to facilitate standard rail shipping to the site. The reactor vessel houses hot and cold leg channels to facilitate coolant flow, control rod drive mechanisms (CRDM), instrumentation and cabling, an intermediate flange to separate flow and instrumentation and facilitate simpler refueling, a pressurizer, a straight tube, recirculating steam

  4. Shielding Analysis of a Small Compact Space Nuclear Reactor

    DTIC Science & Technology

    1987-08-01

    there will be a need for a power source that’s reliable, has a high pow,-- density, and, in some cases, portable. These reasons, and many more, make...Conventional power sources are not able to reasonably obtain these higher power levels. The Space Power 100 kWe (SP-100) space nuclear reactor is the...space nuclear reactors an attractive power source for future space missions. The idea of using space nuclear reactors in space is not new. The United

  5. Small nuclear ribonucleoproteins and heterogeneous nuclear ribonucleoproteins in the amphibian germinal vesicle: loops, spheres, and snurposomes

    PubMed Central

    1991-01-01

    We have examined the distribution of snRNPs in the germinal vesicle (GV) of frogs and salamanders by immunofluorescent staining and in situ nucleic acid hybridization. The major snRNAs involved in pre-mRNA splicing (U1, U2, U4, U5, and U6) occur together in nearly all loops of the lampbrush chromosomes, and in hundreds to thousands of small granules (1-4 microns diameter) suspended in the nucleoplasm. The loops and granules also contain several antigens that are regularly associated with snRNAs or spliceosomes (the Sm antigen, U1- and U2- specific antigens, and the splicing factor SC35). A second type of granule, often distinguishable by morphology, contains only U1 snRNA and associated antigens. We propose the term "snurposome" to describe the granules that contain snRNPs ("snurps"). Those that contain only U1 snRNA are A snurposomes, whereas those that contain all the splicing snRNAs are B snurposomes. GVs contain a third type of snRNP granule, which we call the C snurposome. C snurposomes range in size from less than 1 micron to giant structures greater than 20 microns in diameter. Usually, although not invariably, they have B snurposomes on their surface. They may also contain from one to hundreds of inclusions. Because of their remarkably spherical shape, C snurposomes with their associated B snurposomes have long been referred to as spheres or sphere organelles. Most spheres are free in the nucleoplasm, but a few are attached to chromosomes at specific chromosome loci, the sphere organizers (SOs). The relationship of sphere organelles to other snRNP- containing structures in the GV is obscure. We show by immunofluorescent staining that the lampbrush loops and B snurposomes also react with antibodies against heterogeneous nuclear ribonucleoproteins (hnRNPs). Transcription units on the loops are uniformly stained by anti-hnRNP and anti-snRNP antibodies, suggesting that nascent transcripts are associated with hnRNPs and snRNPs along their entire length, perhaps

  6. The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution

    PubMed Central

    Baniaga, Anthony E.; Arrigo, Nils; Barker, Michael S.

    2016-01-01

    The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella. We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella. Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome. PMID:27189987

  7. The Small Nuclear Genomes of Selaginella Are Associated with a Low Rate of Genome Size Evolution.

    PubMed

    Baniaga, Anthony E; Arrigo, Nils; Barker, Michael S

    2016-06-03

    The haploid nuclear genome size (1C DNA) of vascular land plants varies over several orders of magnitude. Much of this observed diversity in genome size is due to the proliferation and deletion of transposable elements. To date, all vascular land plant lineages with extremely small nuclear genomes represent recently derived states, having ancestors with much larger genome sizes. The Selaginellaceae represent an ancient lineage with extremely small genomes. It is unclear how small nuclear genomes evolved in Selaginella We compared the rates of nuclear genome size evolution in Selaginella and major vascular plant clades in a comparative phylogenetic framework. For the analyses, we collected 29 new flow cytometry estimates of haploid genome size in Selaginella to augment publicly available data. Selaginella possess some of the smallest known haploid nuclear genome sizes, as well as the lowest rate of genome size evolution observed across all vascular land plants included in our analyses. Additionally, our analyses provide strong support for a history of haploid nuclear genome size stasis in Selaginella Our results indicate that Selaginella, similar to other early diverging lineages of vascular land plants, has relatively low rates of genome size evolution. Further, our analyses highlight that a rapid transition to a small genome size is only one route to an extremely small genome.

  8. Nuclear criticality safety calculational analysis for small-diameter containers

    SciTech Connect

    LeTellier, M.S.; Smallwood, D.J.; Henkel, J.A.

    1995-11-01

    This report documents calculations performed to establish a technical basis for the nuclear criticality safety of favorable geometry containers, sometimes referred to as 5-inch containers, in use at the Portsmouth Gaseous Diffusion Plant. A list of containers currently used in the plant is shown in Table 1.0-1. These containers are currently used throughout the plant with no mass limits. The use of containers with geometries or material types other than those addressed in this evaluation must be bounded by this analysis or have an additional analysis performed. The following five basic container geometries were modeled and bound all container geometries in Table 1.0-1: (1) 4.32-inch-diameter by 50-inch-high polyethylene bottle; (2) 5.0-inch-diameter by 24-inch-high polyethylene bottle; (3) 5.25-inch-diameter by 24-inch-high steel can ({open_quotes}F-can{close_quotes}); (4) 5.25-inch-diameter by 15-inch-high steel can ({open_quotes}Z-can{close_quotes}); and (5) 5.0-inch-diameter by 9-inch-high polybottle ({open_quotes}CO-4{close_quotes}). Each container type is evaluated using five basic reflection and interaction models that include single containers and multiple containers in normal and in credible abnormal conditions. The uranium materials evaluated are UO{sub 2}F{sub 2}+H{sub 2}O and UF{sub 4}+oil materials at 100% and 10% enrichments and U{sub 3}O{sub 8}, and H{sub 2}O at 100% enrichment. The design basis safe criticality limit for the Portsmouth facility is k{sub eff} + 2{sigma} < 0.95. The KENO study results may be used as the basis for evaluating general use of these containers in the plant.

  9. Recruitment of phosphorylated small heat shock protein Hsp27 to nuclear speckles without stress

    SciTech Connect

    Bryantsev, A.L.; Chechenova, M.B.; Shelden, E.A. . E-mail: eshelden@wsu.edu

    2007-01-01

    During stress, the mammalian small heat shock protein Hsp27 enters cell nuclei. The present study examines the requirements for entry of Hsp27 into nuclei of normal rat kidney (NRK) renal epithelial cells, and for its interactions with specific nuclear structures. We find that phosphorylation of Hsp27 is necessary for the efficient entry into nuclei during heat shock but not sufficient for efficient nuclear entry under control conditions. We further report that Hsp27 is recruited to an RNAse sensitive fraction of SC35 positive nuclear speckles, but not other intranuclear structures, in response to heat shock. Intriguingly, Hsp27 phosphorylation, in the absence of stress, is sufficient for recruitment to speckles found in post-anaphase stage mitotic cells. Additionally, pseudophosphorylated Hsp27 fused to a nuclear localization peptide (NLS) is recruited to nuclear speckles in unstressed interphase cells, but wildtype and nonphosphorylatable Hsp27 NLS fusion proteins are not. The expression of NLS-Hsp27 mutants does not enhance colony forming abilities of cells subjected to severe heat shock, but does regulate nuclear speckle morphology. These data demonstrate that phosphorylation, but not stress, mediates Hsp27 recruitment to an RNAse soluble fraction of nuclear speckles and support a site-specific role for Hsp27 within the nucleus.

  10. Small molecule peptidomimetic inhibitors of importin α/β mediated nuclear transport

    PubMed Central

    Ambrus, Géza; Whitby, Landon R.; Singer, Eric L.; Trott, Oleg; Choi, Euna; Olson, Arthur J.; Boger, Dale L.; Gerace, Larry

    2010-01-01

    Nucleocytoplasmic transport of macromolecules is a fundamental process of eukaryotic cells. Translocation of proteins and many RNAs between the nucleus and cytoplasm is carried out by shuttling receptors of the β-karyopherin family, also called importins and exportins. Leptomycin B, a small molecule inhibitor of the exportin CRM1, has proved to be an invaluable tool for cell biologists, but up to now no small molecule inhibitors of nuclear import have been described. We devised a microtiter plate based permeabilized cell screen for small molecule inhibitors of the importin α/β pathway. By analyzing peptidomimetic libraries, we identified β-turn and α-helix peptidomimetic compounds that selectively inhibit nuclear import by importin α/β but not by transportin. Structure-activity relationship analysis showed that large aromatic residues and/or a histidine side chain are required for effective import inhibition by these compounds. Our validated inhibitors can be useful for in vitro studies of nuclear import, and can also provide a framework for synthesis of higher potency nuclear import inhibitors. PMID:20869252

  11. Nuclear and Cytoplasmic Soluble Proteins Extraction from a Small Quantity of Drosophila's Whole Larvae and Tissues.

    PubMed

    Lo Piccolo, Luca; Bonaccorso, Rosa; Onorati, Maria Cristina

    2015-06-01

    The identification and study of protein's function in several model organisms is carried out using both nuclear and cytoplasmic extracts. For a long time, Drosophila's embryos have represented the main source for protein extractions, although in the last year, the importance of collecting proteins extracts also from larval tissues has also been understood. Here we report a very simple protocol, improved by a previously developed method, to produce in a single extraction both highly stable nuclear and cytoplasmic protein extracts from a small quantity of whole Drosophila's larvae or tissues, suitable for biochemical analyses like co-immunoprecipitation.

  12. Plant nuclear hormone receptors: a role for small molecules in protein-protein interactions.

    PubMed

    Lumba, Shelley; Cutler, Sean; McCourt, Peter

    2010-01-01

    Plant hormones are a group of chemically diverse small molecules that direct processes ranging from growth and development to biotic and abiotic stress responses. Surprisingly, genome analyses suggest that classic animal nuclear hormone receptor homologs do not exist in plants. It now appears that plants have co-opted several protein families to perceive hormones within the nucleus. In one solution to the problem, the hormones auxin and jasmonate (JA) act as “molecular glue” that promotes protein-protein interactions between receptor F-boxes and downstream corepressor targets. In another solution, gibberellins (GAs) bind and elicit a conformational change in a novel soluble receptor family related to hormone-sensitive lipases. Abscisic acid (ABA), like GA, also acts through an allosteric mechanism involving a START-domain protein. The molecular identification of plant nuclear hormone receptors will allow comparisons with animal nuclear receptors and testing of fundamental questions about hormone function in plant development and evolution.

  13. Impact of New Nuclear Data Libraries on Small Sized Long Life CANDLE HTGR Design Parameters

    NASA Astrophysics Data System (ADS)

    Liem, Peng Hong; Hartanto, Donny; Tran, Hoai Nam

    2017-01-01

    The impact of new evaluated nuclear data libraries (JENDL-4.0, ENDF/B-VII.0 and JEFF-3.1) on the core characteristics of small-sized long-life CANDLE High Temperature Gas-Cooled Reactors (HTGRs) with uranium and thorium fuel cycles was investigated. The most important parameters of the CANDLE core characteristics investigated here covered (1) infinite multiplication factor of the fresh fuel containing burnable poison, (2) the effective multiplication factor of the equilibrium core, (3) the moving velocity of the burning region, (4) the attained discharge burnup, and (5) the maximum power density. The reference case was taken from the current JENDL-3.3 results. For the uranium fuel cycle, the impact of the new libraries was small, while significant impact was found for thorium fuel cycle. The findings indicated the needs of more accurate nuclear data libraries for nuclides involved in thorium fuel cycle in the future.

  14. Nuclear Receptors: Small Molecule Sensors that Coordinate Growth, Metabolism and Reproduction.

    PubMed

    Pardee, Keith; Necakov, Aleksandar S; Krause, Henry

    2011-01-01

    One of the largest groups of metazoan transcription factors (TFs), the Nuclear Receptor superfamily, regulates genes required for virtually all aspects of development, reproduction and metabolism. Together, these master regulators can be thought of as a fundamental operating system for metazoan life. Their most distinguishing feature is a structurally conserved domain that acts as a switch, powered by the presence of small diffusible ligands. This ligand-responsive regulation has allowed the Nuclear Receptors to help their hosts adapt to a wide variety of physiological niches and roles, making them one of the most evolutionarily successful TF families. Originally discovered as receptors for steroid hormones, the Nuclear Receptor field has grown to encompass much more than traditional endocrinology. For example, recent work has highlighted the role of Nuclear Receptors as major regulators of metabolism and biological clocks. By monitoring endogenous metabolites and absorbed xenobiotics, these receptors also coordinate rapid, system-wide responses to changing metabolic and environmental states. While many new Nuclear Receptor ligands have been discovered in the past couple of decades, approximately half of the 48 human receptors are still orphans, with a significantly higher percentage of orphans in other organisms. The discovery of new ligands has led to the elucidation of new regulatory mechanisms, target genes, pathways and functions. This review will highlight both the common as well as newly emerging traits and functions that characterize this particularly unique and important TF family.

  15. Nuclear export of the small ribosomal subunit requires the Ran–GTPase cycle and certain nucleoporins

    PubMed Central

    Moy, Terence I.; Silver, Pamela A.

    1999-01-01

    After their assembly in the nucleolus, ribosomal subunits are exported from the nucleus to the cytoplasm. After export, the 20S rRNA in the small ribosomal subunit is cleaved to yield 18S rRNA and the small 5′ ITS1 fragment. The 5′ ITS1 RNA is normally degraded by the cytoplasmic Xrn1 exonuclease, but in strains lacking XRN1, the 5′ ITS1 fragment accumulates in the cytoplasm. Using the cytoplasmic localization of the 5′ ITS1 fragment as an indicator for the export of the small ribosomal subunit, we have identified genes that are required for ribosome export. Ribosome export is dependent on the Ran–GTPase as mutations in Ran or its regulators caused 5′ ITS1 to accumulate in the nucleoplasm. Mutations in the genes encoding the nucleoporin Nup82 and in the NES exporter Xpo1/Crm1 also caused the nucleoplasmic accumulation of 5′ ITS1. Mutants in a subset of nucleoporins and in the nuclear transport factors Srp1, Kap95, Pse1, Cse1, and Mtr10 accumulate the 5′ ITS1 in the nucleolus and affect ribosome assembly. In contrast, we did not detect nuclear accumulation of 5′ ITS1 in 28 yeast strains that have mutations in other genes affecting nuclear trafficking. PMID:10465789

  16. A Natural Product from Polygonum cuspidatum Sieb. Et Zucc. Promotes Tat-Dependent HIV Latency Reversal through Triggering P-TEFb’s Release from 7SK snRNP

    PubMed Central

    Lu, Huasong; You, Hongchao; Ni, Man; Shan, Wenjun; Lin, Ting; Gao, Xiang; Chen, Haifeng; Zhou, Qiang; Xue, Yuhua

    2015-01-01

    The latent reservoirs of HIV represent a major impediment to eradication of HIV/AIDS. To overcome this problem, agents that can activate latent HIV proviruses have been actively sought after, as they can potentially be used in combination with the highly active antiretroviral therapy (HAART) to eliminate the latent reservoirs. Although several chemical compounds have been shown to activate latency, they are of limited use due to high toxicity and poor clinical outcomes. In an attempt to identify natural products as effective latency activators from traditional Chinese medicinal herbs that have long been widely used in human population, we have isolated procyanidin C-13,3',3"-tri-O-gallate (named as REJ-C1G3) from Polygonum cuspidatum Sieb. et Zucc., that can activate HIV in latently infected Jurkat T cells. REJ-C1G3 preferentially stimulates HIV transcription in a process that depends on the viral encoded Tat protein and acts synergistically with prostratin (an activator of the NF-κB pathway) or JQ1 (an inhibitor of Brd4) to activate HIV latency. Our mechanistic analyses further show that REJ-C1G3 accomplishes these tasks by inducing the release of P-TEFb, a host cofactor essential for Tat-activation of HIV transcription, from the cellular P-TEFb reservoir 7SK snRNP. PMID:26569506

  17. Positive nuclear BAP1 immunostaining helps differentiate non-small cell lung carcinomas from malignant mesothelioma.

    PubMed

    Carbone, Michele; Shimizu, David; Napolitano, Andrea; Tanji, Mika; Pass, Harvey I; Yang, Haining; Pastorino, Sandra

    2016-09-13

    The differential diagnosis between pleural malignant mesothelioma (MM) and lung cancer is often challenging. Immunohistochemical (IHC) stains used to distinguish these malignancies include markers that are most often positive in MM and less frequently positive in carcinomas, and vice versa. However, in about 10-20% of the cases, the IHC results can be confusing and inconclusive, and novel markers are sought to increase the diagnostic accuracy.We stained 45 non-small cell lung cancer samples (32 adenocarcinomas and 13 squamous cell carcinomas) with a monoclonal antibody for BRCA1-associated protein 1 (BAP1) and also with an IHC panel we routinely use to help differentiate MM from carcinomas, which include, calretinin, Wilms Tumor 1, cytokeratin 5, podoplanin D2-40, pankeratin CAM5.2, thyroid transcription factor 1, Napsin-A, and p63. Nuclear BAP1 expression was also analyzed in 35 MM biopsies. All 45 non-small cell lung cancer biopsies stained positive for nuclear BAP1, whereas 22/35 (63%) MM biopsies lacked nuclear BAP1 staining, consistent with previous data. Lack of BAP1 nuclear staining was associated with MM (two-tailed Fisher's Exact Test, P = 5.4 x 10-11). Focal BAP1 staining was observed in a subset of samples, suggesting polyclonality. Diagnostic accuracy of other classical IHC markers was in agreement with previous studies. Our study indicated that absence of nuclear BAP1 stain helps differentiate MM from lung carcinomas. We suggest that BAP1 staining should be added to the IHC panel that is currently used to distinguish these malignancies.

  18. Positive nuclear BAP1 immunostaining helps differentiate non-small cell lung carcinomas from malignant mesothelioma

    PubMed Central

    Carbone, Michele; Shimizu, David; Napolitano, Andrea; Tanji, Mika; Pass, Harvey I.; Yang, Haining; Pastorino, Sandra

    2016-01-01

    The differential diagnosis between pleural malignant mesothelioma (MM) and lung cancer is often challenging. Immunohistochemical (IHC) stains used to distinguish these malignancies include markers that are most often positive in MM and less frequently positive in carcinomas, and vice versa. However, in about 10–20% of the cases, the IHC results can be confusing and inconclusive, and novel markers are sought to increase the diagnostic accuracy. We stained 45 non-small cell lung cancer samples (32 adenocarcinomas and 13 squamous cell carcinomas) with a monoclonal antibody for BRCA1-associated protein 1 (BAP1) and also with an IHC panel we routinely use to help differentiate MM from carcinomas, which include, calretinin, Wilms Tumor 1, cytokeratin 5, podoplanin D2-40, pankeratin CAM5.2, thyroid transcription factor 1, Napsin-A, and p63. Nuclear BAP1 expression was also analyzed in 35 MM biopsies. All 45 non-small cell lung cancer biopsies stained positive for nuclear BAP1, whereas 22/35 (63%) MM biopsies lacked nuclear BAP1 staining, consistent with previous data. Lack of BAP1 nuclear staining was associated with MM (two-tailed Fisher's Exact Test, P = 5.4 × 10−11). Focal BAP1 staining was observed in a subset of samples, suggesting polyclonality. Diagnostic accuracy of other classical IHC markers was in agreement with previous studies. Our study indicated that absence of nuclear BAP1 stain helps differentiate MM from lung carcinomas. We suggest that BAP1 staining should be added to the IHC panel that is currently used to distinguish these malignancies. PMID:27447750

  19. Small Reactor Designs Suitable for Direct Nuclear Thermal Propulsion: Interim Report

    SciTech Connect

    Bruce G. Schnitzler

    2012-01-01

    well as open loop systems for direct nuclear thermal propulsion. Although a number of fast spectrum reactor and engine designs suitable for direct nuclear thermal propulsion were proposed and designed, none were built. This report summarizes status results of evaluations of small nuclear reactor designs suitable for direct nuclear thermal propulsion.

  20. Affordable Development and Demonstration of a Small Nuclear Thermal Rocket (NTR) Engine and Stage: How Small Is Big Enough?

    NASA Technical Reports Server (NTRS)

    Borowski, Stanley K.; Sefcik, Robert J.; Fittje, James E.; McCurdy, David R.; Qualls, Arthur L.; Schnitzler, Bruce G.; Werner, James E.; Weitzberg, Abraham; Joyner, Claude R.

    2016-01-01

    The Nuclear Thermal Rocket (NTR) derives its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine's reactor core. It generates high thrust and has a specific impulse potential of approximately 900 specific impulse - a 100 percent increase over today's best chemical rockets. The Nuclear Thermal Propulsion (NTP) project, funded by NASA's Advanced Exploration Systems (AES) program, includes five key task activities: (1) Recapture, demonstration, and validation of heritage graphite composite (GC) fuel (selected as the Lead Fuel option); (2) Engine Conceptual Design; (3) Operating Requirements Definition; (4) Identification of Affordable Options for Ground Testing; and (5) Formulation of an Affordable Development Strategy. During fiscal year (FY) 2014, a preliminary Design Development Test and Evaluation (DDT&E) plan and schedule for NTP development was outlined by the NASA Glenn Research Center (GRC), Department of Energy (DOE) and industry that involved significant system-level demonstration projects that included Ground Technology Demonstration (GTD) tests at the Nevada National Security Site (NNSS), followed by a Flight Technology Demonstration (FTD) mission. To reduce cost for the GTD tests and FTD mission, small NTR engines, in either the 7.5 or 16.5 kilopound-force thrust class, were considered. Both engine options used GC fuel and a common fuel element (FE) design. The small approximately 7.5 kilopound-force criticality-limited engine produces approximately157 thermal megawatts and its core is configured with parallel rows of hexagonal-shaped FEs and tie tubes (TTs) with a FE to TT ratio of approximately 1:1. The larger approximately 16.5 kilopound-force Small Nuclear Rocket Engine (SNRE), developed by Los Alamos National Laboratory (LANL) at the end of the Rover program, produces approximately 367 thermal megawatts and has a FE to TT ratio of approximately 2:1. Although both engines use a common 35-inch (approximately

  1. Multi-unit Operations in Non-Nuclear Systems: Lessons Learned for Small Modular Reactors

    SciTech Connect

    OHara J. M.; Higgins, J.; DAgostino, A.

    2012-01-17

    The nuclear-power community has reached the stage of proposing advanced reactor designs to support power generation for decades to come. Small modular reactors (SMRs) are one approach to meet these energy needs. While the power output of individual reactor modules is relatively small, they can be grouped to produce reactor sites with different outputs. Also, they can be designed to generate hydrogen, or to process heat. Many characteristics of SMRs are quite different from those of current plants and may be operated quite differently. One difference is that multiple units may be operated by a single crew (or a single operator) from one control room. The U.S. Nuclear Regulatory Commission (NRC) is examining the human factors engineering (HFE) aspects of SMRs to support licensing reviews. While we reviewed information on SMR designs to obtain information, the designs are not completed and all of the design and operational information is not yet available. Nor is there information on multi-unit operations as envisioned for SMRs available in operating experience. Thus, to gain a better understanding of multi-unit operations we sought the lesson learned from non-nuclear systems that have experience in multi-unit operations, specifically refineries, unmanned aerial vehicles and tele-intensive care units. In this paper we report the lessons learned from these systems and the implications for SMRs.

  2. Successful Recovery of Nuclear Protein-Coding Genes from Small Insects in Museums Using Illumina Sequencing

    PubMed Central

    Dasenko, Mark A.

    2015-01-01

    In this paper we explore high-throughput Illumina sequencing of nuclear protein-coding, ribosomal, and mitochondrial genes in small, dried insects stored in natural history collections. We sequenced one tenebrionid beetle and 12 carabid beetles ranging in size from 3.7 to 9.7 mm in length that have been stored in various museums for 4 to 84 years. Although we chose a number of old, small specimens for which we expected low sequence recovery, we successfully recovered at least some low-copy nuclear protein-coding genes from all specimens. For example, in one 56-year-old beetle, 4.4 mm in length, our de novo assembly recovered about 63% of approximately 41,900 nucleotides in a target suite of 67 nuclear protein-coding gene fragments, and 70% using a reference-based assembly. Even in the least successfully sequenced carabid specimen, reference-based assembly yielded fragments that were at least 50% of the target length for 34 of 67 nuclear protein-coding gene fragments. Exploration of alternative references for reference-based assembly revealed few signs of bias created by the reference. For all specimens we recovered almost complete copies of ribosomal and mitochondrial genes. We verified the general accuracy of the sequences through comparisons with sequences obtained from PCR and Sanger sequencing, including of conspecific, fresh specimens, and through phylogenetic analysis that tested the placement of sequences in predicted regions. A few possible inaccuracies in the sequences were detected, but these rarely affected the phylogenetic placement of the samples. Although our sample sizes are low, an exploratory regression study suggests that the dominant factor in predicting success at recovering nuclear protein-coding genes is a high number of Illumina reads, with success at PCR of COI and killing by immersion in ethanol being secondary factors; in analyses of only high-read samples, the primary significant explanatory variable was body length, with small beetles

  3. Evaluating the Cost, Safety, and Proliferation Risks of Small Floating Nuclear Reactors.

    PubMed

    Ford, Michael J; Abdulla, Ahmed; Morgan, M Granger

    2017-01-17

    It is hard to see how our energy system can be decarbonized if the world abandons nuclear power, but equally hard to introduce the technology in nonnuclear energy states. This is especially true in countries with limited technical, institutional, and regulatory capabilities, where safety and proliferation concerns are acute. Given the need to achieve serious emissions mitigation by mid-century, and the multidecadal effort required to develop robust nuclear governance institutions, we must look to other models that might facilitate nuclear plant deployment while mitigating the technology's risks. One such deployment paradigm is the build-own-operate-return model. Because returning small land-based reactors containing spent fuel is infeasible, we evaluate the cost, safety, and proliferation risks of a system in which small modular reactors are manufactured in a factory, and then deployed to a customer nation on a floating platform. This floating small modular reactor would be owned and operated by a single entity and returned unopened to the developed state for refueling. We developed a decision model that allows for a comparison of floating and land-based alternatives considering key International Atomic Energy Agency plant-siting criteria. Abandoning onsite refueling is beneficial, and floating reactors built in a central facility can potentially reduce the risk of cost overruns and the consequences of accidents. However, if the floating platform must be built to military-grade specifications, then the cost would be much higher than a land-based system. The analysis tool presented is flexible, and can assist planners in determining the scope of risks and uncertainty associated with different deployment options.

  4. Development concept for a small, split-core, heat-pipe-cooled nuclear reactor

    NASA Technical Reports Server (NTRS)

    Lantz, E.; Breitwieser, R.; Niederauer, G. F.

    1974-01-01

    There have been two main deterrents to the development of semiportable nuclear reactors. One is the high development costs; the other is the inability to satisfy with assurance the questions of operational safety. This report shows how a split-core, heat-pipe cooled reactor could conceptually eliminate these deterrents, and examines and summarizes recent work on split-core, heat-pipe reactors. A concept for a small reactor that could be developed at a comparatively low cost is presented. The concept would extend the technology of subcritical radioisotope thermoelectric generators using 238 PuO2 to the evolution of critical space power reactors using 239 PuO2.

  5. Feasibility study on nuclear core design for soluble boron free small modular reactor

    SciTech Connect

    Rabir, Mohamad Hairie Hah, Chang Joo; Ju, Cho Sung

    2015-04-29

    A feasibility study on nuclear core design of soluble boron free (SBF) core for small size (150MWth) small modular reactor (SMR) was investigated. The purpose of this study was to design a once through cycle SMR core, where it can be used to supply electricity to a remote isolated area. PWR fuel assembly design with 17×17 arrangement, with 264 fuel rods per assembly was adopted as the basis design. The computer code CASMO-3/MASTER was used for the search of SBF core and fuel assembly analysis for SMR design. A low critical boron concentration (CBC) below 200 ppm core with 4.7 years once through cycle length was achieved using 57 fuel assemblies having 170 cm of active height. Core reactivity controlled using mainly 512 number of 4 wt% and 960 12 wt% Gd rods.

  6. Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor

    PubMed Central

    Inagaki, Takeshi; Moschetta, Antonio; Lee, Youn-Kyoung; Peng, Li; Zhao, Guixiang; Downes, Michael; Yu, Ruth T.; Shelton, John M.; Richardson, James A.; Repa, Joyce J.; Mangelsdorf, David J.; Kliewer, Steven A.

    2006-01-01

    Obstruction of bile flow results in bacterial proliferation and mucosal injury in the small intestine that can lead to the translocation of bacteria across the epithelial barrier and systemic infection. These adverse effects of biliary obstruction can be inhibited by administration of bile acids. Here we show that the farnesoid X receptor (FXR), a nuclear receptor for bile acids, induces genes involved in enteroprotection and inhibits bacterial overgrowth and mucosal injury in ileum caused by bile duct ligation. Mice lacking FXR have increased ileal levels of bacteria and a compromised epithelial barrier. These findings reveal a central role for FXR in protecting the distal small intestine from bacterial invasion and suggest that FXR agonists may prevent epithelial deterioration and bacterial translocation in patients with impaired bile flow. PMID:16473946

  7. Core structure of the U6 small nuclear ribonucleoprotein at 1.7-Å resolution.

    PubMed

    Montemayor, Eric J; Curran, Elizabeth C; Liao, Hong Hong; Andrews, Kristie L; Treba, Christine N; Butcher, Samuel E; Brow, David A

    2014-06-01

    The spliceosome is a dynamic assembly of five small nuclear ribonucleoproteins (snRNPs) that removes introns from eukaryotic pre-mRNA. U6, the most conserved of the spliceosomal small nuclear RNAs (snRNAs), participates directly in catalysis. Here, we report the crystal structure of the Saccharomyces cerevisiae U6 snRNP core containing most of the U6 snRNA and all four RRM domains of the Prp24 protein. It reveals a unique interlocked RNP architecture that sequesters the 5' splice site-binding bases of U6 snRNA. RRMs 1, 2 and 4 of Prp24 form an electropositive groove that binds double-stranded RNA and may nucleate annealing of U4 and U6 snRNAs. Substitutions in Prp24 that suppress a mutation in U6 localize to direct RNA-protein contacts. Our results provide the most comprehensive view to date of a multi-RRM protein bound to RNA and reveal striking coevolution of protein and RNA structure.

  8. Genetic characterization of clinical acanthamoeba isolates from Japan using nuclear and mitochondrial small subunit ribosomal RNA.

    PubMed

    Rahman, Md Moshiur; Yagita, Kenji; Kobayashi, Akira; Oikawa, Yosaburo; Hussein, Amjad I A; Matsumura, Takahiro; Tokoro, Masaharu

    2013-08-01

    Because of an increased number of Acanthamoeba keratitis (AK) along with associated disease burdens, medical professionals have become more aware of this pathogen in recent years. In this study, by analyzing both the nuclear 18S small subunit ribosomal RNA (18S rRNA) and mitochondrial 16S rRNA gene loci, 27 clinical Acanthamoeba strains that caused AK in Japan were classified into 3 genotypes, T3 (3 strains), T4 (23 strains), and T5 (one strain). Most haplotypes were identical to the reference haplotypes reported from all over the world, and thus no specificity of the haplotype distribution in Japan was found. The T4 sub-genotype analysis using the 16S rRNA gene locus also revealed a clear sub-conformation within the T4 cluster, and lead to the recognition of a new sub-genotype T4i, in addition to the previously reported sub-genotypes T4a-T4h. Furthermore, 9 out of 23 strains in the T4 genotype were identified to a specific haplotype (AF479533), which seems to be a causal haplotype of AK. While heterozygous nuclear haplotypes were observed from 2 strains, the mitochondrial haplotypes were homozygous as T4 genotype in the both strains, and suggested a possibility of nuclear hybridization (mating reproduction) between different strains in Acanthamoeba. The nuclear 18S rRNA gene and mitochondrial 16S rRNA gene loci of Acanthamoeba spp. possess different unique characteristics usable for the genotyping analyses, and those specific features could contribute to the establishment of molecular taxonomy for the species complex of Acanthamoeba.

  9. Sub-classification of prostate cancer circulating tumor cells (CTCs) by nuclear size reveals very-small nuclear CTCs in patients with visceral metastases

    PubMed Central

    Chen, Jie-Fu; Ho, Hao; Lichterman, Jake; Lu, Yi-Tsung; Zhang, Yang; Garcia, Mitch A.; Chen, Shang-Fu; Liang, An-Jou; Hodara, Elisabeth; Zhau, Haiyen E.; Hou, Shuang; Ahmed, Rafi S.; Luthringer, Daniel J.; Huang, Jiaoti; Li, Ker-Chau; Chung, Leland W.K.; Ke, Zunfu; Tseng, Hsian-Rong; Posadas, Edwin M.

    2015-01-01

    Background While enumeration of circulating tumor cells (CTCs) has shown some clinical value, the pool of CTCs contains a mixture of cells which contains additional information that can be extracted. Our group sub-classified CTCs by shape features focusing on nuclear size and related this to clinical information. Methods A total of 148 blood samples were obtained from 57 PC patients across the spectrum of metastatic states: no metastasis, non-visceral metastasis, and visceral metastasis. CTCs captured and enumerated on NanoVelcro Chips were subjected to pathologic review including nuclear size. The distribution of nuclear sizes was analyzed using a Gaussian Mixture Model. Correlations were made between CTC subpopulations and metastatic status. Results Statistical modeling of nuclear size distribution revealed 3 distinct subpopulations: large-nuclear (lnCTC), small-nuclear (snCTC), and very-small-nuclear CTCs (vsnCTCs). snCTC + vsnCTC identified patients with metastatic disease. vsnCTC counts alone, however, were elevated in patients with visceral metastases when compared to those without (0.36 ± 0.69 vs. 1.95 ± 3.77 cells/mL blood, p < 0.001). Serial enumerations suggested the emergence of vsnCTCs occurred prior to the detection of visceral metastases. Conclusions There are morphologic subsets of CTCs that can be identified by fundamental pathologic approaches, such as nuclear size measurement. This observational study strongly suggests that they contain relevant information on disease status. In particular, the detection of vsnCTCs correlated with the presence of visceral metastases and should be formally explored as a putative blood-borne biomarker to identify patients at risk for developing this clinical evolution of PC. PMID:25975562

  10. A novel mechanism for regulating the activity of proliferating cell nuclear antigen by a small protein.

    PubMed

    Li, Zhuo; Huang, Richard Y-C; Yopp, Daniel C; Hileman, Travis H; Santangelo, Thomas J; Hurwitz, Jerard; Hudgens, Jeffrey W; Kelman, Zvi

    2014-05-01

    Proliferating cell nuclear antigen (PCNA) forms a trimeric ring that associates with and influences the activity of many proteins participating in DNA metabolic processes and cell cycle progression. Previously, an uncharacterized small protein, encoded by TK0808 in the archaeon Thermococcus kodakarensis, was shown to stably interact with PCNA in vivo. Here, we show that this protein, designated Thermococcales inhibitor of PCNA (TIP), binds to PCNA in vitro and inhibits PCNA-dependent activities likely by preventing PCNA trimerization. Using hydrogen/deuterium exchange mass spectrometry and site-directed mutagenesis, the interacting regions of PCNA and TIP were identified. Most proteins bind to PCNA via a PCNA-interacting peptide (PIP) motif that interacts with the inter domain connecting loop (IDCL) on PCNA. TIP, however, lacks any known PCNA-interacting motif, suggesting a new mechanism for PCNA binding and regulation of PCNA-dependent activities, which may support the development of a new subclass of therapeutic biomolecules for inhibiting PCNA.

  11. Mars Sample Return and Flight Test of a Small Bimodal Nuclear Rocket and ISRU Plant

    NASA Technical Reports Server (NTRS)

    George, Jeffrey A.; Wolinsky, Jason J.; Bilyeu, Michael B.; Scott, John H.

    2014-01-01

    A combined Nuclear Thermal Rocket (NTR) flight test and Mars Sample Return mission (MSR) is explored as a means of "jump-starting" NTR development. Development of a small-scale engine with relevant fuel and performance could more affordably and quickly "pathfind" the way to larger scale engines. A flight test with subsequent inflight postirradiation evaluation may also be more affordable and expedient compared to ground testing and associated facilities and approvals. Mission trades and a reference scenario based upon a single expendable launch vehicle (ELV) are discussed. A novel "single stack" spacecraft/lander/ascent vehicle concept is described configured around a "top-mounted" downward firing NTR, reusable common tank, and "bottom-mount" bus, payload and landing gear. Requirements for a hypothetical NTR engine are described that would be capable of direct thermal propulsion with either hydrogen or methane propellant, and modest electrical power generation during cruise and Mars surface insitu resource utilization (ISRU) propellant production.

  12. Discovery of a Novel, Isothiazolonaphthoquinone-Based Small Molecule Activator of FOXO Nuclear-Cytoplasmic Shuttling

    PubMed Central

    Cautain, Bastien; Castillo, Francisco; Musso, Loana; Ferreira, Bibiana I.; de Pedro, Nuria; Rodriguez Quesada, Lorena; Machado, Susana; Vicente, Francisca; Dallavalle, Sabrina

    2016-01-01

    FOXO factors are tumour suppressor proteins commonly inactivated in human tumours by posttranslational modifications. Furthermore, genetic variation within the FOXO3a gene is consistently associated with human longevity. Therefore, the pharmacological activation of FOXO proteins is considered as an attractive therapeutic approach to treat cancer and age-related diseases. In order to identify agents capable of activating FOXOs, we tested a collection of small chemical compounds using image-based high content screening technology. Here, we report the discovery of LOM612 (compound 1a), a newly synthesized isothiazolonaphthoquinone as a potent FOXO relocator. Compound 1a induces nuclear translocation of a FOXO3a reporter protein as well as endogenous FOXO3a and FOXO1 in U2OS cells in a dose-dependent manner. This activity does not affect the subcellular localization of other cellular proteins including NFkB or inhibit CRM1-mediated nuclear export. Furthermore, compound 1a shows a potent antiproliferative effect in human cancer cell lines. PMID:27936162

  13. Functional analysis of the sea urchin U7 small nuclear RNA

    SciTech Connect

    Gilmartin, G.M.; Schaufele, F.; Schaffner, G.; Birnstiel, M.L.

    1988-03-01

    U7 small nuclear RNA (snRNA) is an essential component of the RNA-processing machinery which generates the 3' end of mature histone mRNA in the sea urchin. The U7 small nuclear ribonucleoprotein particle (snRNP) is classified as a member of the Sm-type U snRNP family by virtue of its recognition by both anti-trimethylguanosine and anti-Sm antibodies. The authors analyzed the function-structure relationship of the U7 snRNP by mutagenesis experiments. These suggested that the U7 snRNP of the sea urchin is composed of three important domains. The fist domain encompasses the 5'-terminal sequence, up to about nucleotides 7, which are accessible to micrococcal nuclease, while the remainder of the RNA is highly protected and hence presumably bound by proteins. This region contains the sequence complementarities between the U7 snRNA and the histone pre-mRNA which have previously been shown to be required for 3' processing. Nucleotides 9 to 20 constitute a second domain which includes sequences for Sm protein binding. The complementarities between the U7 snRNA sequences in this region and the terminal palindrome fo the historne mRNA appear to be fortuitous and play only a secondary, if any, role in 3' processing. The third domain is composed of the terminal palindrome of U7 snRNA, the secondary structure of which must be maintained for the U7 snRNP to function, but its sequence can be drastically altered without any observable effect on snRNP assembly or 3' processing.

  14. Structure and conformational plasticity of the U6 small nuclear ribonucleoprotein core.

    PubMed

    Montemayor, Eric J; Didychuk, Allison L; Liao, Honghong; Hu, Panzhou; Brow, David A; Butcher, Samuel E

    2017-01-01

    U6 small nuclear RNA (snRNA) is a key component of the active site of the spliceosome, a large ribonucleoprotein complex that catalyzes the splicing of precursor messenger RNA. Prior to its incorporation into the spliceosome, U6 is bound by the protein Prp24, which facilitates unwinding of the U6 internal stem-loop (ISL) so that it can pair with U4 snRNA. A previously reported crystal structure of the `core' of the U6 small nuclear ribonucleoprotein (snRNP) contained an ISL-stabilized A62G mutant of U6 bound to all four RNA-recognition motif (RRM) domains of Prp24 [Montemayor et al. (2014), Nature Struct. Mol. Biol. 21, 544-551]. The structure revealed a novel topology containing interlocked rings of protein and RNA that was not predicted by prior biochemical and genetic data. Here, the crystal structure of the U6 snRNP core with a wild-type ISL is reported. This complex crystallized in a new space group, apparently owing in part to the presence of an intramolecular cross-link in RRM1 that was not observed in the previously reported U6-A62G structure. The structure exhibits the same protein-RNA interface and maintains the unique interlocked topology. However, the orientation of the wild-type ISL is altered relative to the A62G mutant structure, suggesting inherent structural dynamics that may facilitate its pairing with U4. Consistent with their similar architectures in the crystalline state, the wild-type and A62G variants of U6 exhibit similar Prp24-binding affinities and electrophoretic mobilities when analyzed by gel-shift assay.

  15. Implementing a Nuclear Power Plant Model for Evaluating Load-Following Capability on a Small Grid

    NASA Astrophysics Data System (ADS)

    Arda, Samet Egemen

    A pressurized water reactor (PWR) nuclear power plant (NPP) model is introduced into Positive Sequence Load Flow (PSLF) software by General Electric in order to evaluate the load-following capability of NPPs. The nuclear steam supply system (NSSS) consists of a reactor core, hot and cold legs, plenums, and a U-tube steam generator. The physical systems listed above are represented by mathematical models utilizing a state variable lumped parameter approach. A steady-state control program for the reactor, and simple turbine and governor models are also developed. Adequacy of the isolated reactor core, the isolated steam generator, and the complete PWR models are tested in Matlab/Simulink and dynamic responses are compared with the test results obtained from the H. B. Robinson NPP. Test results illustrate that the developed models represents the dynamic features of real-physical systems and are capable of predicting responses due to small perturbations of external reactivity and steam valve opening. Subsequently, the NSSS representation is incorporated into PSLF and coupled with built-in excitation system and generator models. Different simulation cases are run when sudden loss of generation occurs in a small power system which includes hydroelectric and natural gas power plants besides the developed PWR NPP. The conclusion is that the NPP can respond to a disturbance in the power system without exceeding any design and safety limits if appropriate operational conditions, such as achieving the NPP turbine control by adjusting the speed of the steam valve, are met. In other words, the NPP can participate in the control of system frequency and improve the overall power system performance.

  16. Inactivation of the Nuclear Orphan Receptor COUP-TFII by Small Chemicals.

    PubMed

    Le Guével, Rémy; Oger, Frédérik; Martinez-Jimenez, Celia P; Bizot, Maud; Gheeraert, Céline; Firmin, François; Ploton, Maheul; Kretova, Miroslava; Palierne, Gaëlle; Staels, Bart; Barath, Peter; Talianidis, Iannis; Lefebvre, Philippe; Eeckhoute, Jérôme; Salbert, Gilles

    2017-01-13

    Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII/NR2F2) is an orphan member of the nuclear receptor family of transcription factors whose activities are modulated upon binding of small molecules into an hydrophobic ligand-binding pocket (LBP). Although the LBP of COUP-TFII is filled with aromatic amino-acid side chains, alternative modes of ligand binding could potentially lead to regulation of the orphan receptor. Here, we screened a synthetic and natural compound library in a yeast one-hybrid assay and identified 4-methoxynaphthol as an inhibitor of COUP-TFII. This synthetic inhibitor was able to counteract processes either positively or negatively regulated by COUP-TFII in different mammalian cell systems. Hence, we demonstrate that the true orphan receptor COUP-TFII can be targeted by small chemicals which could be used to study the physiological functions of COUP-TFII or to counteract detrimental COUP-TFII activities in various pathological conditions.

  17. A small protein inhibits proliferating cell nuclear antigen by breaking the DNA clamp

    PubMed Central

    Altieri, Amanda S.; Ladner, Jane E.; Li, Zhuo; Robinson, Howard; Sallman, Zahur F.; Marino, John P.; Kelman, Zvi

    2016-01-01

    Proliferating cell nuclear antigen (PCNA) forms a trimeric ring that encircles duplex DNA and acts as an anchor for a number of proteins involved in DNA metabolic processes. PCNA has two structurally similar domains (I and II) linked by a long loop (inter-domain connector loop, IDCL) on the outside of each monomer of the trimeric structure that makes up the DNA clamp. All proteins that bind to PCNA do so via a PCNA-interacting peptide (PIP) motif that binds near the IDCL. A small protein, called TIP, binds to PCNA and inhibits PCNA-dependent activities although it does not contain a canonical PIP motif. The X-ray crystal structure of TIP bound to PCNA reveals that TIP binds to the canonical PIP interaction site, but also extends beyond it through a helix that relocates the IDCL. TIP alters the relationship between domains I and II within the PCNA monomer such that the trimeric ring structure is broken, while the individual domains largely retain their native structure. Small angle X-ray scattering (SAXS) confirms the disruption of the PCNA trimer upon addition of the TIP protein in solution and together with the X-ray crystal data, provides a structural basis for the mechanism of PCNA inhibition by TIP. PMID:27141962

  18. A small protein inhibits proliferating cell nuclear antigen by breaking the DNA clamp

    DOE PAGES

    Altieri, Amanda S.; Ladner, Jane E.; Li, Zhuo; ...

    2016-05-03

    Here, proliferating cell nuclear antigen (PCNA) forms a trimeric ring that encircles duplex DNA and acts as an anchor for a number of proteins involved in DNA metabolic processes. PCNA has two structurally similar domains (I and II) linked by a long loop (inter-domain connector loop, IDCL) on the outside of each monomer of the trimeric structure that makes up the DNA clamp. All proteins that bind to PCNA do so via a PCNA-interacting peptide (PIP) motif that binds near the IDCL. A small protein, called TIP, binds to PCNA and inhibits PCNA-dependent activities although it does not contain amore » canonical PIP motif. The X-ray crystal structure of TIP bound to PCNA reveals that TIP binds to the canonical PIP interaction site, but also extends beyond it through a helix that relocates the IDCL. TIP alters the relationship between domains I and II within the PCNA monomer such that the trimeric ring structure is broken, while the individual domains largely retain their native structure. Small angle X-ray scattering (SAXS) confirms the disruption of the PCNA trimer upon addition of the TIP protein in solution and together with the X-ray crystal data, provides a structural basis for the mechanism of PCNA inhibition by TIP.« less

  19. A small protein inhibits proliferating cell nuclear antigen by breaking the DNA clamp

    SciTech Connect

    Altieri, Amanda S.; Ladner, Jane E.; Li, Zhuo; Robinson, Howard; Sallman, Zahur F.; Marino, John P.; Kelman, Zvi

    2016-05-03

    Here, proliferating cell nuclear antigen (PCNA) forms a trimeric ring that encircles duplex DNA and acts as an anchor for a number of proteins involved in DNA metabolic processes. PCNA has two structurally similar domains (I and II) linked by a long loop (inter-domain connector loop, IDCL) on the outside of each monomer of the trimeric structure that makes up the DNA clamp. All proteins that bind to PCNA do so via a PCNA-interacting peptide (PIP) motif that binds near the IDCL. A small protein, called TIP, binds to PCNA and inhibits PCNA-dependent activities although it does not contain a canonical PIP motif. The X-ray crystal structure of TIP bound to PCNA reveals that TIP binds to the canonical PIP interaction site, but also extends beyond it through a helix that relocates the IDCL. TIP alters the relationship between domains I and II within the PCNA monomer such that the trimeric ring structure is broken, while the individual domains largely retain their native structure. Small angle X-ray scattering (SAXS) confirms the disruption of the PCNA trimer upon addition of the TIP protein in solution and together with the X-ray crystal data, provides a structural basis for the mechanism of PCNA inhibition by TIP.

  20. A small protein inhibits proliferating cell nuclear antigen by breaking the DNA clamp

    SciTech Connect

    Altieri, Amanda S.; Ladner, Jane E.; Li, Zhuo; Robinson, Howard; Sallman, Zahur F.; Marino, John P.; Kelman, Zvi

    2016-05-03

    Proliferating cell nuclear antigen (PCNA) forms a trimeric ring that encircles duplex DNA and acts as an anchor for a number of proteins involved in DNA metabolic processes. PCNA has two structurally similar domains (I and II) linked by a long loop (inter-domain connector loop, IDCL) on the outside of each monomer of the trimeric structure that makes up the DNA clamp. All proteins that bind to PCNA do so via a PCNA-interacting peptide (PIP) motif that binds near the IDCL. A small protein, called TIP, binds to PCNA and inhibits PCNA-dependent activities although it does not contain a canonical PIP motif. The X-ray crystal structure of TIP bound to PCNA reveals that TIP binds to the canonical PIP interaction site, but also extends beyond it through a helix that relocates the IDCL. TIP alters the relationship between domains I and II within the PCNA monomer such that the trimeric ring structure is broken, while the individual domains largely retain their native structure. Small angle X-ray scattering (SAXS) confirms the disruption of the PCNA trimer upon addition of the TIP protein in solution and together with the X-ray crystal data, provides a structural basis for the mechanism of PCNA inhibition by TIP.

  1. Nuclear overexpression of lymphoid-enhancer-binding factor 1 identifies chronic lymphocytic leukemia/small lymphocytic lymphoma in small B-cell lymphomas.

    PubMed

    Tandon, Bevan; Peterson, Loann; Gao, Juehua; Nelson, Beverly; Ma, Shuo; Rosen, Steven; Chen, Yi-Hua

    2011-11-01

    Lymphoid-enhancer-binding factor 1 (LEF1), coupling with β-catenin, functions as a key nuclear mediator of WNT/β-catenin signaling, which regulates cell proliferation and survival. LEF1 has an important role in lymphopoiesis, and is normally expressed in T and pro-B cells but not mature B cells. However, gene expression profiling demonstrates overexpression of LEF1 in chronic lymphocytic leukemia, and knockdown of LEF1 decreases the survival of the leukemic cells. So far, the data on LEF1 expression in B-cell lymphomas are limited. This study represents the first attempt to assess LEF1 by immunohistochemistry in a large series (290 cases) of B-cell lymphomas. Strong nuclear staining of LEF1 was observed in virtually all neoplastic cells in 92 of 92 (100%) chronic lymphocytic leukemia/small lymphocytic lymphomas including two CD5- cases, with strongest staining in cells with Richter's transformation. LEF1 also highlighted the morphologically inconspicuous small lymphocytic lymphoma component in three composite lymphomas. All 53 mantle cell lymphomas, 31 low-grade follicular lymphomas and 31 marginal zone lymphomas, including 3 CD5+ cases, were negative. In 12 grade 3 follicular lymphomas, LEF1 was positive in a small subset (5-15%) of cells. Diffuse large B-cell lymphoma, however, demonstrated significant variability in LEF1 expression with overall positivity in 27 of 71 (38%) cases. Our results demonstrate that nuclear overexpression of LEF1 is highly associated with chronic lymphocytic leukemia/small lymphocytic lymphoma, and may serve as a convenient marker for differential diagnosis of small B-cell lymphomas. The expression of β-catenin, the coactivator of LEF1 in WNT signaling, was examined in 50 chronic lymphocytic leukemia/small lymphocytic lymphomas, of which 44 (88%) showed negative nuclear staining. The findings of universal nuclear overexpression of LEF1 but lack of nuclear β-catenin in the majority of chronic lymphocytic leukemia/small lymphocytic

  2. Small molecule and peptide-mediated inhibition of Epstein-Barr virus nuclear antigen 1 dimerization

    SciTech Connect

    Kim, Sun Young; Song, Kyung-A; Kieff, Elliott; Kang, Myung-Soo

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer Evidence that targeting EBNA1 dimer, an EBV onco-antigen, can be achievable. Black-Right-Pointing-Pointer A small molecule and a peptide as EBNA1 dimerization inhibitors identified. Black-Right-Pointing-Pointer Both inhibitors associated with EBNA1 and blocked EBNA1 DNA binding activity. Black-Right-Pointing-Pointer Also, prevented its dimerization, and repressed viral gene transcription. -- Abstract: Latent Epstein-Barr virus (EBV) infection is associated with human B cell lymphomas and certain carcinomas. EBV episome persistence, replication, and gene expression are dependent on EBV-encoded nuclear antigen 1 (EBNA1)'s DNA binding domain (DBD)/dimerization domain (DD)-mediated sequence-specific DNA binding activity. Homodimerization of EBNA1 is essential for EBNA1 DNA binding and transactivation. In this study, we characterized a novel small molecule EBNA1 inhibitor EiK1, screened from the previous high throughput screening (HTS). The EiK1 compound specifically inhibited the EBNA1-dependent, OriP-enhanced transcription, but not EBNA1-independent transcription. A Surface Plasmon Resonance Biacore assay revealed that EiK1 associates with EBNA1 amino acid 459-607 DBD/DD. Consistent with the SPR data, in vitro gel shift assays showed that EiK1 suppressed the activity of EBNA1 binding to the cognate familial repeats (FR) sequence, but not control RBP-J{kappa} binding to the J{kappa} site. Subsequently, a cross-linker-mediated in vitro multimerization assay and EBNA1 homodimerization-dependent yeast two-hybrid assay showed that EiK1 significantly inhibited EBNA1 dimerization. In an attempt to identify more highly specific peptide inhibitors, small peptides encompassing the EBNA1 DBD/DD were screened for inhibition of EBNA1 DBD-mediated DNA binding function. The small peptide P85, covering EBNA1 a.a. 560-574, significantly blocked EBNA1 DNA binding activity in vitro, prevented dimerization in vitro and in vivo, associated with

  3. Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Schnitzler, Bruce G.; Borowski, Stanley K.

    2012-01-01

    Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified as the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine operations and the engine and stage design were

  4. Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion

    SciTech Connect

    Bruce G. Schnitzler; Stanley K. Borowski

    2012-07-01

    Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified as the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine

  5. NUCLEAR EGFR PROTEIN EXPRESSION PREDICTS POOR SURVIVAL IN EARLY STAGE NON-SMALL CELL LUNG CANCER

    PubMed Central

    Traynor, Anne M.; Weigel, Tracey L.; Oettel, Kurt R.; Yang, David T.; Zhang, Chong; Kim, KyungMann; Salgia, Ravi; Iida, Mari; Brand, Toni M.; Hoang, Tien; Campbell, Toby C.; Hernan, Hilary R.; Wheeler, Deric L.

    2013-01-01

    Introduction Nuclear EGFR (nEGFR) has been identified in various human tumor tissues, including cancers of the breast, ovary, oropharynx, and esophagus, and has predicted poor patient outcomes. We sought to determine if protein expression of nEGFR is prognostic in early stage non-small cell lung cancer (NSCLC). Methods Resected stage I and II NSCLC specimens were evaluated for nEGFR protein expression using immunohistochemistry (IHC). Cases with at least one replicate core containing ≥5% of tumor cells demonstrating strong dot-like nucleolar EGFR expression were scored as nEGFR positive. Results Twenty-three (26.1% of the population) of 88 resected specimens stained positively for nEGFR. Nuclear EGFR protein expression was associated with higher disease stage (45.5% of stage II vs. 14.5% of stage I; p=0.023), histology (41.7% in squamous cell carcinoma vs. 17.1% in adenocarcinoma; p=0.028), shorter progression-free survival (PFS) (median PFS 8.7 months [95% CI 5.1–10.7 mo] for nEGFR positive vs. 14.5 months [95% CI 9.5–17.4 mo] for nEGFR negative; hazard ratio (HR) of 1.89 [95% CI 1.15–3.10]; p=0.011), and shorter overall survival (OS) (median OS 14.1 months [95% CI 10.3–22.7 mo] for nEGFR positive vs. 23.4 months [95% CI 20.1–29.4 mo] for nEGFR negative; HR of 1.83 [95% CI 1.12–2.99]; p=0.014). Conclusions Expression of nEGFR protein was associated with higher stage and squamous cell histology, and predicted shorter PFS and OS, in this patient cohort. Nuclear EGFR serves as a useful independent prognostic variable and as a potential therapeutic target in NSCLC. PMID:23628526

  6. Monoclonal autoantibody recognizing a unique set of small nuclear ribonucleoprotein complexes.

    PubMed

    Winkler, A; Watson-McKown, R; Wise, K S

    1988-01-01

    A murine IgG2a, kappa-monoclonal autoantibody (mAb) F78 is described that recognizes a novel epitope associated with small nuclear ribonucleoprotein complexes (snRNP). F78 selectively immunoprecipitated a unique pattern of small nuclear RNA (U1, U2, and U4 to U6) characterized by a marked depletion of U1 and an elevated proportion of U2 compared with known patterns immunoprecipitated by previously described anti-RNP (2.73) and anti-Sm (7.13, Y12) mAb. Analysis of immunoprecipitated RNA from extracts previously cleared with mAb F78 and probed with anti-RNP mAb 2.73 further indicated the presence of two distinct subsets of U1. Immunoblots of whole cell extracts separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) without heating showed that F78 selectively bound to a trypsin-sensitive component of apparent m.w. greater than 120,000 which was decreased in size following RNase A treatment. The anti-Sm mAb, but not the anti-RNP mAb, also recognized this component in unheated samples. Heating before SDS-PAGE resulted in abrogation of binding to the F78 epitope. Immunoprecipitation of unlabeled or [35S]methionine-labeled cell extracts with F78 revealed the presence of most snRNP peptides, but the absence of peptide C and the 68,000 m.w. component, known to be selectively associated with U1-specific snRNP. Two-dimensional SDS-PAGE analysis of F78 immunoprecipitates confirmed that the epitope recognized by this mAb resides on a heat-dissociable complex containing snRNP-related peptides B, B', D, E, F, and G, but lacking U1-associated peptides. F78 mAb therefore defines a subset of snRNP which lack anti-RNP associated U1 RNA as well as peptides known to be selectively associated with this RNA species. It apparently recognizes an epitope associated with an assembled form of these particles and may be useful in examining structures involved in RNA processing.

  7. Tissue-specific expression and cDNA cloning of small nuclear ribonucleoprotein-associated polypeptide N

    SciTech Connect

    McAllister, G.; Amara, S.G.; Lerner, M.R. )

    1988-07-01

    Sera from some patients with systemic lupus erythematosus and other autoimmune diseases have antibodies against nuclear antigens. An example is anti-Sm sera, which recognize proteins associated with small nuclear RNA molecules (small nuclear ribonucleoprotein (snRNP) particles). In this paper anti-Sm sera were used to probe immunoblots of various rat tissues. A previously unidentified M{sub r} 28,000 polypeptide was recognized by these anti-Sm sera. This polypeptide, referred to as N, is expressed in a tissue-specific manner, being most abundant in rat brain, less so in heart, and undetectable in the other tissues examined. Immunoprecipitation experiments using antibodies directed against the cap structure of small nuclear RNAs have demonstrated that N is a snRNP-associated polypeptide. Anti-Sm serum was also used to isolate a partial cDNA clone ({lambda}rb91) from a rat brain phage {lambda}gt11 cDNA expression library. A longer cDNA clone was obtained by rescreening the library with {lambda}rb91. In vitro transcription and subsequent translation of this subcloned, longer insert (pGMA2) resulted in a protein product with the same electrophoretic and immunological properties as N, confirming that pGMA2 encodes N. The tissue distribution of N and the involvement of snRNP particles in nuclear pre-mRNA processing may imply a role for N in tissue-specific pre-mRNA splicing.

  8. Nuclear effects on ion heating within the small-angle charged-particle elastic-scattering regime

    NASA Astrophysics Data System (ADS)

    Andrade, A.; Hale, G. M.

    1984-10-01

    The effects of nuclear forces (in contrast to pure Coulomb interaction) on the ion heating rate which results from small-angle scattering processes between charged particles in plasmas are investigated within the framework of Fokker-Planck theory. These effects are included through the addition of analytic Coulomb-nuclear interference and nuclear elastic cross sections in the scattering integrals of the dynamical friction coefficient and dispersion tensor. It is found that corrections to traditional Fokker-Planck predictions of the ion-ion energy exchange rate can be calculated and that these corrections are sensitive to the choice of the maximum scattering angle defining the cutoff between small- and large-angle scattering.

  9. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    PubMed

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

  10. Analysis of Tertiary Interactions between SART3 and U6 Small Nuclear RNA Using Modified Nanocapillaries.

    PubMed

    Lee, Choongman; Park, Joon Kyu; Youn, Yeoan; Kim, Joo Hyoung; Lee, Kyo-Seok; Kim, Nak-Kyoon; Kim, Eunji; Kim, Eunice Eunkyeong; Yoo, Kyung-Hwa

    2017-02-21

    We employed modified glass nanocapillaries to investigate interactions between the RNA-binding protein, known as cell carcinoma antigen recognized by T cells-3 (SART3), and the noncoding spliceosome component, U6 small nuclear RNA (snRNA), at the single-molecule level. We functionalized the nanocapillaries with U6 snRNA fragments, which were hybridized to DNA molecules and then covalently attached to the nanocapillary surface. When transported through the modified nanocapillaries, two different SART3-derived constructs, HAT-RRM1-RRM2 and RRM1-RRM2, exhibited resistive ionic current pulses with different dwell times, which represented their different binding affinities to tethered U6 snRNAs. The dissociation constants (KD), estimated from the bias voltage dependence of translocation events, were approximately 1.9 μM and 201 μM for HAT-RRM1-RRM2 and RRM1-RRM2, respectively. These values were comparable to corresponding values obtained with isothermal titration calorimetry, demonstrating that the modified glass nanocapillaries are applicable to analyses of protein-ligand interactions at the single-molecule level.

  11. A novel mechanism for regulating the activity of proliferating cell nuclear antigen by a small protein

    PubMed Central

    Li, Zhuo; Huang, Richard Y.-C.; Yopp, Daniel C.; Hileman, Travis H.; Santangelo, Thomas J.; Hurwitz, Jerard; Hudgens, Jeffrey W.; Kelman, Zvi

    2014-01-01

    Proliferating cell nuclear antigen (PCNA) forms a trimeric ring that associates with and influences the activity of many proteins participating in DNA metabolic processes and cell cycle progression. Previously, an uncharacterized small protein, encoded by TK0808 in the archaeon Thermococcus kodakarensis, was shown to stably interact with PCNA in vivo. Here, we show that this protein, designated Thermococcales inhibitor of PCNA (TIP), binds to PCNA in vitro and inhibits PCNA-dependent activities likely by preventing PCNA trimerization. Using hydrogen/deuterium exchange mass spectrometry and site-directed mutagenesis, the interacting regions of PCNA and TIP were identified. Most proteins bind to PCNA via a PCNA-interacting peptide (PIP) motif that interacts with the inter domain connecting loop (IDCL) on PCNA. TIP, however, lacks any known PCNA-interacting motif, suggesting a new mechanism for PCNA binding and regulation of PCNA-dependent activities, which may support the development of a new subclass of therapeutic biomolecules for inhibiting PCNA. PMID:24728986

  12. U1 small nuclear ribonucleoprotein complex and RNA splicing alterations in Alzheimer’s disease

    PubMed Central

    Bai, Bing; Hales, Chadwick M.; Chen, Ping-Chung; Gozal, Yair; Dammer, Eric B.; Fritz, Jason J.; Wang, Xusheng; Xia, Qiangwei; Duong, Duc M.; Street, Craig; Cantero, Gloria; Cheng, Dongmei; Jones, Drew R.; Wu, Zhiping; Li, Yuxin; Diner, Ian; Heilman, Craig J.; Rees, Howard D.; Wu, Hao; Lin, Li; Szulwach, Keith E.; Gearing, Marla; Mufson, Elliott J.; Bennett, David A.; Montine, Thomas J.; Seyfried, Nicholas T.; Wingo, Thomas S.; Sun, Yi E.; Jin, Peng; Hanfelt, John; Willcock, Donna M.; Levey, Allan; Lah, James J.; Peng, Junmin

    2013-01-01

    Deposition of insoluble protein aggregates is a hallmark of neurodegenerative diseases. The universal presence of β-amyloid and tau in Alzheimer’s disease (AD) has facilitated advancement of the amyloid cascade and tau hypotheses that have dominated AD pathogenesis research and therapeutic development. However, the underlying etiology of the disease remains to be fully elucidated. Here we report a comprehensive study of the human brain-insoluble proteome in AD by mass spectrometry. We identify 4,216 proteins, among which 36 proteins accumulate in the disease, including U1-70K and other U1 small nuclear ribonucleoprotein (U1 snRNP) spliceosome components. Similar accumulations in mild cognitive impairment cases indicate that spliceosome changes occur in early stages of AD. Multiple U1 snRNP subunits form cytoplasmic tangle-like structures in AD but not in other examined neurodegenerative disorders, including Parkinson disease and frontotemporal lobar degeneration. Comparison of RNA from AD and control brains reveals dysregulated RNA processing with accumulation of unspliced RNA species in AD, including myc box-dependent-interacting protein 1, clusterin, and presenilin-1. U1-70K knockdown or antisense oligonucleotide inhibition of U1 snRNP increases the protein level of amyloid precursor protein. Thus, our results demonstrate unique U1 snRNP pathology and implicate abnormal RNA splicing in AD pathogenesis. PMID:24023061

  13. Small-molecule targeting of proliferating cell nuclear antigen chromatin association inhibits tumor cell growth.

    PubMed

    Tan, Zongqing; Wortman, Matthew; Dillehay, Kelsey L; Seibel, William L; Evelyn, Chris R; Smith, Shanna J; Malkas, Linda H; Zheng, Yi; Lu, Shan; Dong, Zhongyun

    2012-06-01

    Proliferating cell nuclear antigen (PCNA), a potential anticancer target, forms a homotrimer and is required for DNA replication and numerous other cellular processes. The purpose of this study was to identify novel small molecules that modulate PCNA activity to affect tumor cell proliferation. An in silico screen of a compound library against a crystal structure of PCNA and a subsequent structural similarity search of the ZINC chemical database were carried out to derive relevant docking partners. Nine compounds, termed PCNA inhibitors (PCNA-Is), were selected for further characterization. PCNA-I1 selectively bound to PCNA trimers with a dissociation constant (K(d)) of ~0.2 to 0.4 μM. PCNA-Is promoted the formation of SDS-refractory PCNA trimers. PCNA-I1 dose- and time-dependently reduced the chromatin-associated PCNA in cells. Consistent with its effects on PCNA trimer stabilization, PCNA-I1 inhibited the growth of tumor cells of various tissue types with an IC(50) of ~0.2 μM, whereas it affected the growth of nontransformed cells at significantly higher concentrations (IC(50), ~1.6 μM). Moreover, uptake of BrdU was dose-dependently reduced in cells treated with PCNA-I1. Mechanistically the PCNA-Is mimicked the effect of PCNA knockdown by siRNA, inducing cancer cell arrest at both the S and G(2)/M phases. Thus, we have identified a class of compounds that can directly bind to PCNA, stabilize PCNA trimers, reduce PCNA association with chromatin, and inhibit tumor cell growth by inducing a cell cycle arrest. They are valuable tools in studying PCNA function and may be useful for future PCNA-targeted cancer therapy.

  14. A diversity of U1 small nuclear RNAs in the silk moth Bombyx mori.

    PubMed

    Sierra-Montes, J M; Pereira-Simon, S; Freund, A V; Ruiz, L M; Szmulewicz, M N; Herrera, R J

    2003-01-01

    Variants of U1 small nuclear RNAs (snRNAs) have been previously detected in a permanent cell line (BmN) of the silk moth Bombyx mori. In this study, the existence of U1 snRNA isoforms in the silk gland (SG) of the organism is investigated. The polyploidy (approximately 200,000X the 2N somatic value) state of the B. mori silk gland cells represents a unique system to explore the potential presence and differential expression of multiple U1 variants in a normal tissue. B. mori U1-specific RT-PCR libraries from the silk gland were generated and five U1 isoforms were isolated and characterized. Nucleotide differences, structural alterations, as well as protein and RNA interaction sites were examined in these variants and compared to the previously reported isoforms from the transformed BmN cell line. In all these SG U1 variants, variant sites and inter-species differences are located in moderately conserved regions. Substitutional or compensatory changes were found in the double stranded areas and clustered in moderately conserved regions. Some of the changes generate stronger base pairing. Calculated free energy (DeltaG) values for the entire U1 snRNA secondary structures and for the individual stem/loops (I, II, III and IV) domains of the isoforms were generated and compared to determine their structural stability. Using phylogenetic analysis, an evolutionary parallelism is observed between the polymorphic sites in B. mori and variant locations found among animal and plant species.

  15. Coilin Can Form a Complex with the U7 Small Nuclear Ribonucleoprotein

    PubMed Central

    Bellini, Michel; Gall, Joseph G.

    1998-01-01

    Coiled bodies (CBs) in the amphibian oocyte nucleus are spherical structures up to 10 μm or more in diameter, much larger than their somatic counterparts, which rarely exceed 1 μm. Oocyte CBs may have smaller granules attached to their surface or embedded within them, which are identical in structure and composition to the many hundreds of B-snurposomes found free in the nucleoplasm. The matrix of the CBs contains the diagnostic protein p80-coilin, which is colocalized with the U7 small nuclear ribonucleoprotein (snRNP), whereas the attached and embedded B-snurposomes contain splicing snRNPs. A few of the 50–100 CBs in the oocyte nucleus are attached to lampbrush chromosomes at the histone gene loci. By coimmunoprecipitation we show that coilin and the U7 snRNP can form a weak but specific complex in the nucleoplasm, which is dependent on the special U7 Sm-binding site. Under the same conditions coilin does not associate with the U1 and U2 snRNPs. Coilin is a nucleic acid-binding protein, as shown by its interaction with single-stranded DNA and with poly r(U) and poly r(G). We suggest that an important function of coilin is to form a transient complex with the U7 snRNP and accompany it to the CBs. In the case of CBs attached to chromosomes at the histone gene loci, the U7 snRNP is thus brought close to the actual site of histone pre-mRNA transcription. PMID:9763457

  16. Abundant pseudogenes for small nuclear RNAs are dispersed in the human genome.

    PubMed Central

    Denison, R A; Van Arsdell, S W; Bernstein, L B; Weiner, A M

    1981-01-01

    We have cloned and partially characterized 24 loci from the human genome which are complementary to U1, U2, or U3, the three major species of small nuclear RNA (snRNA) in HeLa cells. When compared to the known U1 (human) and U2 (rat) snRNA sequences, the DNA sequences we report here for the complementary regions from two of the clones, U1.11 and U2.7, reveal the presence of truncated and divergent gene copies. Furthermore, most if not all of the 24 cloned loci contain gene copies that are significantly divergent from the homologous HeLa snRNA species because DNA from every recombinant phage except U1.7 and U1.15 proved unable to form snRNA.DNA hybrids which protect full-length HeLa snRNA from ild digestion with ribonuclease T1. Hence, we refer to these loci as snRNA pseudogenes. In both clones U1.11 and U2.7, an element of the dominant middle repetitive DNA sequence family in the human genome, the Alu family, is located upstream from the snRNA pseudogene and in the same orientation. Alu elements in the same location and orientation relative to bona fide genes have previously been found in the human beta-globin gene cluster [Duncan, C. H., Biro, P. A., Choudary, P. V., Elder, J. T., Wang, R. C., Forget, G. B., deRiel, J. K. & Weissman, S. M. (1979) Proc. Natl. Acad. Sci. USA 76, 5095-5099]. We discuss the significance of these findings in relation to the nature of snRNA multigene families and other reported examples of pseudogenes. Images PMID:6165010

  17. Genetic analysis of small nuclear RNAs in Saccharomyces cerevisiae: viable sextuple mutant.

    PubMed Central

    Parker, R; Simmons, T; Shuster, E O; Siliciano, P G; Guthrie, C

    1988-01-01

    Saccharomyces cerevisiae contains at least 24 distinct small nuclear RNAs (snRNAs), several of which are known to be essential for viability and to participate in the splicing of pre-mRNAs; the RNAs in this subset contain binding sites for the Sm antigen, a hallmark of metazoan snRNAs involved in mRNA processing. In contrast, we showed previously that the single-copy genes for three other snRNAs (snR3, snR4, and snR10) are not required for viability, although cells lacking snR10 are growth impaired at low temperature. None of these RNAs associates with the Sm antigen. To assess this apparent correlation, we cloned and sequenced the genes encoding three additional non-Sm snRNAs. Comparison of these genes with nine additional yeast snRNA genes revealed a highly conserved TATA box located 92 +/- 8 nucleotides 5' of the transcriptional start site. By using the technique of gene replacement with null alleles, each of these three single copy genes was shown to be completely dispensable. We constructed multiple mutants to test the hypothesis that, individually, each of these snRNAs is nonessential because the snRNAs play functionally overlapping roles. A mutant lacking five snRNAs (snR3, snR4, snR5, snR8, snR9) was indistinguishable from the wild type, and growth of the sextuple mutant was no more impaired than that in strains lacking only snR10. This widespread dispensability of snRNAs was completely unexpected and forces us to reconsider the possible roles of these ubiquitous RNAs. Images PMID:2905424

  18. On the calculations of the nuclear spin spin coupling constants in small water clusters

    NASA Astrophysics Data System (ADS)

    Cybulski, Hubert; Pecul, Magdalena; Sadlej, Joanna

    2006-08-01

    The calculations of the nuclear spin-spin coupling constants were carried out for small water clusters (H 2O) n, n = 2-6, 12, and 17, using density functional theory (DFT) and second-order polarization propagator method (SOPPA). A wide range of different standard and modified basis sets was tested to enable the choice of the possibly smallest and most flexible basis set. The changes in the oxygen-proton coupling constants upon the cluster formation between the nuclei involved in hydrogen bonding cover a range of ca. 13 Hz. The range of the calculated changes in intramolecular 1JOH couplings shows that the simple model of rigid water clusters seems to be sufficient to reproduce properly the sign and to estimate the magnitude of the gas-to-liquid shift. The sign of the complexation-induced changes in the intramolecular 2JHH coupling constant is different for molecules with a different coordination number. While the sign is positive for the molecules of the single donor-single acceptor (DA) and single donor-double acceptor (DAA) types, it is negative for the double donor-single acceptor (DDA) molecules. In the four-coordinated double donor-double acceptor (DDAA) molecules the sign of Δ 2JHH varies. The hydrogen-bond transmitted intermolecular coupling constants are substantial: 1hJOH spans the range from 2.8 to 8.4 Hz while 2hJOO varies from -0.6 to 7.5 Hz. The average intermolecular 1hJOH coupling constant decays slowly with the H⋯O distance in the cyclic clusters n = 2-6. The average 2hJOO coupling decreases exponentially with the O⋯O separation for the cyclic clusters n = 2-6.

  19. Fluorescence-enhanced optical tomography and nuclear imaging system for small animals

    NASA Astrophysics Data System (ADS)

    Tan, I.-Chih; Lu, Yujie; Darne, Chinmay; Rasmussen, John C.; Zhu, Banghe; Azhdarinia, Ali; Yan, Shikui; Smith, Anne M.; Sevick-Muraca, Eva M.

    2012-03-01

    Near-infrared (NIR) fluorescence is an alternative modality for molecular imaging that has been demonstrated in animals and recently in humans. Fluorescence-enhanced optical tomography (FEOT) using continuous wave or frequency domain photon migration techniques could be used to provide quantitative molecular imaging in vivo if it could be validated against "gold-standard," nuclear imaging modalities, using dual-labeled imaging agents. Unfortunately, developed FEOT systems are not suitable for incorporation with CT/PET/SPECT scanners because they utilize benchtop devices and require a large footprint. In this work, we developed a miniaturized fluorescence imaging system installed in the gantry of the Siemens Inveon PET/CT scanner to enable NIR transillumination measurements. The system consists of a CCD camera equipped with NIR sensitive intensifier, a diode laser controlled by a single board compact controller, a 2-axis galvanometer, and RF circuit modules for homodyne detection of the phase and amplitude of fluorescence signals. The performance of the FEOT system was tested and characterized. A mouse-shaped solid phantom of uniform optical properties with a fluorescent inclusion was scanned using CT, and NIR fluorescence images at several projections were collected. The method of high-order approximation to the radioactive transfer equation was then used to reconstruct the optical images. Dual-labeled agents were also used on a tumor bearing mouse to validate the results of the FEOT against PET/CT image. The results showed that the location of the fluorophore obtained from the FEOT matches the location of tumor obtained from the PET/CT images. Besides validation of FEOT, this hybrid system could allow multimodal molecular imaging (FEOT/PET/CT) for small animal imaging.

  20. Small modular reactor modeling using modelica for nuclear-renewable hybrid energy systems applications

    DOE PAGES

    Mikkelson, Daniel; Chang, Chih -Wei; Cetiner, Sacit M.; ...

    2015-10-01

    Here, the U.S. Department of Energy (DOE) supports research and development (R&D) that could lead to more efficient utilization of clean energy generation sources, including renewable and nuclear options, to meet grid demand and industrial thermal energy needs [1]. One hybridization approach being investigated by the DOE Offices of Nuclear Energy (NE) and the DOE Energy Efficiency and Renewable Energy (EERE) is tighter coupling of nuclear and renewable energy sources to better manage overall energy use for the combined electricity, industrial manufacturing, and transportation sectors.

  1. Small ubiquitin-related modifier 1 is involved in hepatocellular carcinoma progression via mediating p65 nuclear translocation

    PubMed Central

    Liu, Jun; Tao, Xiaofang; Zhang, Jin; Wang, Peng; Sha, Manqi; Ma, Yong; Geng, Xiaoping; Feng, Lijie; Shen, Yujun; Yu, Yifan; Wang, Siying; Fang, Shengyun; Shen, Yuxian

    2016-01-01

    Small ubiquitin-related modifier (SUMO) proteins participate in a post-translational modification called SUMOylation and regulate a variety of intracellular processes, such as targeting proteins for nuclear import. The nuclear transport of p65 results in the activation of NF-κB, and p65 contains several SUMO interacting motifs (SIMs). However, the relationship between p65 and SUMO1 in hepatocellular carcinoma (HCC) remains unclear. In this study, we demonstrated the potential roles of SUMO1 in HCC via the regulation of p65 subcellular localization. We found that either SUMO1- or p65-positive immunoreactivity was remarkably increased in the nuclei of tumor tissues in HCC patients compared with non-tumor tissues, and further analysis suggested a correlation between SUMO1- and nuclear p65-positive immunoreactivities (R = 0.851, P = 0.002). We also verified the interaction between p65 and SUMO1 in HCC by co-immunoprecipitation. TNF-α and hypoxia increased SUMO1 protein levels and enhanced SUMO1-modified p65 SUMOylation. Moreover, the knockdown of SUMO1 decreased p65 nuclear translocation and inhibited NF-κB transcriptional activity. Further the results of this study revealed that the knockdown of SUMO1 suppressed the proliferation and migration of hepatoma cells. These results suggest that SUMO1 contributes to HCC progression by promoting p65 nuclear translocation and regulating NF-κB activity. PMID:26993772

  2. Small human sperm vacuoles observed under high magnification are pocket-like nuclear concavities linked to chromatin condensation failure.

    PubMed

    Boitrelle, F; Albert, M; Petit, J-M; Ferfouri, F; Wainer, R; Bergere, M; Bailly, M; Vialard, F; Selva, J

    2013-08-01

    Since an embryo's ability to grow to the blastocyst stage and implant can be improved by selection of a normal spermatozoon with a vacuole-free head, this study set out to determine the nature of small sperm vacuoles observed under high magnification (>×6300). For 15 infertile men with various sperm profiles, high-magnification microscopy was used to select motile, morphometrically normal spermatozoa with no vacuoles (n=450) or more than two small vacuoles (each of which occupied less than 4% of the head's area; n=450). Spermatozoa acrosome reaction status and degree of chromatin condensation were analysed. Three-dimensional deconvolution microscopy was used to accurately image the nucleus and acrosome at all depths in all spermatozoa. In all 450 spermatozoa with small vacuoles, the latter were seen to be abnormal, DNA-free nuclear concavities. Spermatozoa with small vacuoles were significantly more likely than vacuole-free spermatozoa to have noncondensed chromatin (39.8% versus 9.3%, respectively; P<0.0001). There was no significant difference between the two groups of spermatozoa in terms of acrosome reaction status. No association between chromatin condensation and acrosome reaction status was observed. Small human sperm vacuoles observed under high magnification are pocket-like nuclear concavities related to failure of chromatin condensation.

  3. Another Inconvenient Truth: Even a Small Nuclear War Could be Much Worse Than you Think

    NASA Astrophysics Data System (ADS)

    Toon, O. B.

    2008-05-01

    The number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986. However, the potential exists for numerous regional nuclear arms races, and for a significant expansion in the number of nuclear weapons states. Eight countries are known to have nuclear weapons, 2 are constructing them, and an additional 32 nations already have the fissile material needed to build weapons if they so desire. Population and economic activity worldwide are congregated to an increasing extent in "megacities", which are ideal targets for nuclear weapons. Based upon observations of the damage caused by nuclear explosions in World War II and in nuclear tests, a group of researchers has estimated the area that might be consumed in firestorms following a regional war between the smallest current nuclear states involving 100, 15-kt explosions (less than 0.1% of the explosive yield of the current global nuclear arsenal). Based upon observations of large forest fires these firestorms should inject smoke into the upper troposphere. Using estimates of the mass of flammable material in the areas that would burn we find that 5x1012 g of elemental carbon could be injected into the upper troposphere in a regional nuclear war. A suite of numerical models show that this upper tropospheric soot will be transported due to solar heating into the stratosphere and will rise to altitudes above 40 km. The elemental carbon will absorb sunlight, heating the stratosphere and cooling the ground. The heating of the stratosphere could cause column ozone losses in excess of 20% globally, 25-45% at mid-latitudes, and 50- 70% at northern high latitudes persisting for 5 years, with substantial losses continuing for 5 additional years. Column ozone amounts would remain near or below 220 Dobson units at all latitudes even after three years, constituting an extra-tropical "ozone hole". The cooling at the ground would reduce precipitation globally by about 10%, create lower

  4. Management of the pediatric nuclear medicine patient (or children are not small adults)

    SciTech Connect

    Kieffer, C.T.; Suto, P.A.

    1983-03-01

    The first of a four-part continuing education series on pediatric nuclear medicine is presented. Included are: (1) clinical indications for performing nuclear medicine studies in children; (2) comparison of nuclear medicine procedures for adult and pedicatric patients; (3) appropriate radiopharmaceuticals for performing pediatric studies; (4) radiation protection techniques (5) the principles of pediatric radiopharmaceutical dose calculation and common calculation methods; (6) possible injection sites and administration methods (7) radiopharmaceutical clearance times and imaging times in adults and children; (8) the collimators of choice for most procedures performed in children; (9) certain behaviors exhibited by children according to their stage of emotional development and children's response to the hospital setting; and (10) patient immobilization techniques and advantages of physical restraint over sedation. (JMT)

  5. HETEROGENEOUS NUCLEAR REACTOR EMPLOYING SMALL UNCLAD BODIES OF FISSIONABLE MATERIAL AS FUEL

    DOEpatents

    Hyman, H.H.; Katz, J.J.

    1961-05-01

    A nuclear reactor in which fuel pellets are continuously dissolved in a moderator liquid is described. The fuel pellets are fed into the top of elongated baskets which are submerged in moderator liquid, and a portion of the moderator liquid is continuously withdrawn and processed to recove r reaction products.

  6. Evidence for high dispersal ability and mito-nuclear discordance in the small brown planthopper, Laodelphax striatellus.

    PubMed

    Sun, Jing-Tao; Wang, Man-Man; Zhang, Yan-Kai; Chapuis, Marie-Pierre; Jiang, Xin-Yu; Hu, Gao; Yang, Xian-Ming; Ge, Cheng; Xue, Xiao-Feng; Hong, Xiao-Yue

    2015-01-27

    Understanding dispersal ability in pest species is critical for both theoretical aspects of evolutionary and population biology and from a practical standpoint, such as implementing effective forecasting systems. The small brown planthopper (SBPH), Laodelphax striatellus (Fallén), is an economically important pest, but few data exist on its dispersal ability. Here, we used mitochondrial and nuclear markers to elucidate the population genetic structure of SBPH and of the parasitic bacterium Wolbachia throughout temperate and subtropical China. Our results showed that the SBPH populations in China lack significant differences in genetic structure, suggesting extensive gene flow. Multilocus sequence typing revealed that Wolbachia infection was systematic and due to the same strain (wStri) within and across populations. However, the mtDNA haplogroups had a nonrandom distribution across the sampling localities, which correlated to latitudinal and climatic gradients. We explain this mito-nuclear discordance as a result of historical population recolonization or mitochondria adaptation to climate.

  7. Evidence for high dispersal ability and mito-nuclear discordance in the small brown planthopper, Laodelphax striatellus

    PubMed Central

    Sun, Jing-Tao; Wang, Man-Man; Zhang, Yan-Kai; Chapuis, Marie-Pierre; Jiang, Xin-Yu; Hu, Gao; Yang, Xian-Ming; Ge, Cheng; Xue, Xiao-Feng; Hong, Xiao-Yue

    2015-01-01

    Understanding dispersal ability in pest species is critical for both theoretical aspects of evolutionary and population biology and from a practical standpoint, such as implementing effective forecasting systems. The small brown planthopper (SBPH), Laodelphax striatellus (Fallén), is an economically important pest, but few data exist on its dispersal ability. Here, we used mitochondrial and nuclear markers to elucidate the population genetic structure of SBPH and of the parasitic bacterium Wolbachia throughout temperate and subtropical China. Our results showed that the SBPH populations in China lack significant differences in genetic structure, suggesting extensive gene flow. Multilocus sequence typing revealed that Wolbachia infection was systematic and due to the same strain (wStri) within and across populations. However, the mtDNA haplogroups had a nonrandom distribution across the sampling localities, which correlated to latitudinal and climatic gradients. We explain this mito-nuclear discordance as a result of historical population recolonization or mitochondria adaptation to climate. PMID:25622966

  8. Rotatable Small Permanent Magnet Array for Ultra-Low Field Nuclear Magnetic Resonance Instrumentation: A Concept Study

    PubMed Central

    Vegh, Viktor; Reutens, David C.

    2016-01-01

    Object We studied the feasibility of generating the variable magnetic fields required for ultra-low field nuclear magnetic resonance relaxometry with dynamically adjustable permanent magnets. Our motivation was to substitute traditional electromagnets by distributed permanent magnets, increasing system portability. Materials and Methods The finite element method (COMSOL®) was employed for the numerical study of a small permanent magnet array to calculate achievable magnetic field strength, homogeneity, switching time and magnetic forces. A manually operated prototype was simulated and constructed to validate the numerical approach and to verify the generated magnetic field. Results A concentric small permanent magnet array can be used to generate strong sample pre-polarisation and variable measurement fields for ultra-low field relaxometry via simple prescribed magnet rotations. Using the array, it is possible to achieve a pre-polarisation field strength above 100 mT and variable measurement fields ranging from 20–50 μT with 200 ppm absolute field homogeneity within a field-of-view of 5 x 5 x 5 cubic centimetres. Conclusions A dynamic small permanent magnet array can generate multiple highly homogeneous magnetic fields required in ultra-low field nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) instruments. This design can significantly reduce the volume and energy requirements of traditional systems based on electromagnets, improving portability considerably. PMID:27271886

  9. A full-configuration-interaction nuclear orbital approach and application for small doped He clusters

    SciTech Connect

    Lara-Castells, M. P. de Aguirre, N. F. Delgado-Barrio, G. Villarreal, P.; Mitrushchenkov, A. O.

    2015-01-22

    An efficient full-configuration-interaction 'nuclear orbital' treatment was developed as a benchmark quantum-chemistry-like method to calculate, ground and excited, fermionic 'solvent' wave-functions and applied to {sup 3}He{sub N} clusters with atomic or molecular impurities [J. Chem. Phys. (Communication) 125, 221101 (2006)]. The main difficulty in handling doped {sup 3}He{sub N} clusters lies in the Fermi-Dirac nuclear statistics, the wide amplitudes of the He-dopant and He-He motions, and the hard-core He-He interaction at short distances. This paper overviews the theoretical approach and its recent applications to energetic, structural and spectroscopic aspects of different dopant-{sup 3}He{sub N} clusters. Preliminary results by using the latest version of the FCI-NO computational implementation, to bosonic Cl{sub 2}(X)-({sup 4}He){sub N} clusters, are also shown.

  10. The behavior of ANGRA 2 nuclear power plant core for a small break LOCA simulated with RELAP5 code

    SciTech Connect

    Sabundjian, Gaiane; Andrade, Delvonei A.; Belchior, Antonio Jr.; Silva Rocha, Marcelo da; Conti, Thadeu N.; Torres, Walmir M.; Macedo, Luiz A.; Umbehaun, Pedro E.; Mesquita, Roberto N.; Masotti, Paulo H. F.; Souza Lima, Ana Cecilia de

    2013-05-06

    This work discusses the behavior of Angra 2 nuclear power plant core, for a postulate Loss of Coolant Accident (LOCA) in the primary circuit for Small Break Loss Of Coolant Accident (SBLOCA). A pipe break of the hot leg Emergency Core Cooling System (ECCS) was simulated with RELAP 5 code. The considered rupture area is 380 cm{sup 2}, which represents 100% of the ECCS pipe flow area. Results showed that the cooling is enough to guarantee the integrity of the reactor core.

  11. Children's (Pediatric) Nuclear Medicine

    MedlinePlus Videos and Cool Tools

    ... Professions Site Index A-Z Children's (Pediatric) Nuclear Medicine Children’s (pediatric) nuclear medicine imaging uses small amounts ... Children's Nuclear Medicine? What is Children's (Pediatric) Nuclear Medicine? Nuclear medicine is a branch of medical imaging ...

  12. Identification of Egyptian Fasciola species by PCR and restriction endonucleases digestion of the nuclear small subunit ribosomal RNA gene.

    PubMed

    El-Gozamy, Bothina R; Shoukry, Nahla M

    2009-08-01

    Fascioliasis is one of the familiar zoonotic health problems of worldwide distribution including Egypt. In this study, a simple and rapid polymerase chain reaction/restriction fragment length polymorphisms (PCR/RFLPs) assay, using the common restriction endonucleases Aval, EcoRI, Eael, Sac11 and Avail was applied to differentiate between both Fasciola gigantica and F. hepatica. The five restriction endonucleases were used to differentiate between the two species of Fasciola based on -1950 bp long sequence of the 18S nuclear small subunit ribosomal RNA gene. Aval and EcoRI restriction endonucleases failed to differentiate between the two Fasciola species when each restriction enzyme gave the same restriction patterns in both of them. However, F. gigantica and F. hepatica were well-differentiated when their small subunit ribosomal DNA were digested with Eael and Sac 11 restriction endonucleases.

  13. Calculations of atomic magnetic nuclear shielding constants based on the two-component normalized elimination of the small component method.

    PubMed

    Yoshizawa, Terutaka; Zou, Wenli; Cremer, Dieter

    2017-04-07

    A new method for calculating nuclear magnetic resonance shielding constants of relativistic atoms based on the two-component (2c), spin-orbit coupling including Dirac-exact NESC (Normalized Elimination of the Small Component) approach is developed where each term of the diamagnetic and paramagnetic contribution to the isotropic shielding constant σiso is expressed in terms of analytical energy derivatives with regard to the magnetic field B and the nuclear magnetic moment . The picture change caused by renormalization of the wave function is correctly described. 2c-NESC/HF (Hartree-Fock) results for the σiso values of 13 atoms with a closed shell ground state reveal a deviation from 4c-DHF (Dirac-HF) values by 0.01%-0.76%. Since the 2-electron part is effectively calculated using a modified screened nuclear shielding approach, the calculation is efficient and based on a series of matrix manipulations scaling with (2M)(3) (M: number of basis functions).

  14. Proteomic analyses identify a diverse array of nuclear processes affected by small ubiquitin-like modifier conjugation in Arabidopsis.

    PubMed

    Miller, Marcus J; Barrett-Wilt, Gregory A; Hua, Zhihua; Vierstra, Richard D

    2010-09-21

    The covalent attachment of SUMO (small ubiquitin-like modifier) to other intracellular proteins affects a broad range of nuclear processes in yeast and animals, including chromatin maintenance, transcription, and transport across the nuclear envelope, as well as protects proteins from ubiquitin addition. Substantial increases in SUMOylated proteins upon various stresses have also implicated this modification in the general stress response. To help understand the role(s) of SUMOylation in plants, we developed a stringent method to isolate SUMO-protein conjugates from Arabidopsis thaliana that exploits a tagged SUMO1 variant that faithfully replaces the wild-type protein. Following purification under denaturing conditions, SUMOylated proteins were identified by tandem mass spectrometry from both nonstressed plants and those exposed to heat and oxidative stress. The list of targets is enriched for factors that direct SUMOylation and for nuclear proteins involved in chromatin remodeling/repair, transcription, RNA metabolism, and protein trafficking. Targets of particular interest include histone H2B, components in the LEUNIG/TOPLESS corepressor complexes, and proteins that control histone acetylation and DNA methylation, which affect genome-wide transcription. SUMO attachment site(s) were identified in a subset of targets, including SUMO1 itself to confirm the assembly of poly-SUMO chains. SUMO1 also becomes conjugated with ubiquitin during heat stress, thus connecting these two posttranslational modifications in plants. Taken together, we propose that SUMOylation represents a rapid and global mechanism for reversibly manipulating plant chromosomal functions, especially during environmental stress.

  15. Structure and expression of the Drosophila melanogaster gene for the U1 small nuclear ribonucleoprotein particle 70K protein.

    PubMed Central

    Mancebo, R; Lo, P C; Mount, S M

    1990-01-01

    A genomic clone encoding the Drosophila U1 small nuclear ribonucleoprotein particle 70K protein was isolated by hybridization with a human U1 small nuclear ribonucleoprotein particle 70K protein cDNA. Southern blot and in situ hybridizations showed that this U1 70K gene is unique in the Drosophila genome, residing at cytological position 27D1,2. Polyadenylated transcripts of 1.9 and 3.1 kilobases were observed. While the 1.9-kilobase mRNA is always more abundant, the ratio of these two transcripts is developmentally regulated. Analysis of cDNA and genomic sequences indicated that these two RNAs encode an identical protein with a predicted molecular weight of 52,879. Comparison of the U1 70K proteins predicted from Drosophila, human, and Xenopus cDNAs revealed 68% amino acid identity in the most amino-terminal 214 amino acids, which include a sequence motif common to many proteins which bind RNA. The carboxy-terminal half is less well conserved but is highly charged and contains distinctive arginine-rich regions in all three species. These arginine-rich regions contain stretches of arginine-serine dipeptides like those found in transformer, transformer-2, and suppressor-of-white-apricot proteins, all of which have been identified as regulators of mRNA splicing in Drosophila melanogaster. Images PMID:1692955

  16. Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant

    SciTech Connect

    Ghan, L.S.; Ortiz, M.G.

    1991-01-01

    A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission's (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions.

  17. Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant

    SciTech Connect

    Ghan, L.S.; Ortiz, M.G.

    1991-12-31

    A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B&W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission`s (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B&W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions.

  18. Orphan nuclear receptor small heterodimer partner inhibits transforming growth factor-beta signaling by repressing SMAD3 transactivation.

    PubMed

    Suh, Ji Ho; Huang, Jiansheng; Park, Yun-Yong; Seong, Hyun-A; Kim, Dongwook; Shong, Minho; Ha, Hyunjung; Lee, In-Kyu; Lee, Keesook; Wang, Li; Choi, Hueng-Sik

    2006-12-22

    Orphan nuclear receptor small heterodimer partner (SHP) is an atypical member of the nuclear receptor superfamily; SHP regulates the nuclear receptor-mediated transcription of target genes but lacks a conventional DNA binding domain. In this study, we demonstrate that SHP represses transforming growth factor-beta (TGF-beta)-induced gene expression through a direct interaction with Smad, a transducer of TGF-beta signaling. Transient transfection studies demonstrate that SHP represses Smad3-induced transcription. In vivo and in vitro protein interaction assays revealed that SHP directly interacts with Smad2 and Smad3 but not with Smad4. Mapping of domains mediating the interaction between SHP and Smad3 showed that the entire N-terminal domain (1-159 amino acids) of SHP and the linker domain of Smad3 are involved in this interaction. In vitro glutathione S-transferase pulldown competition experiments revealed the SHP-mediated repression of Smad3 transactivation through competition with its co-activator p300. SHP also inhibits the activation of endogenous TGF-beta-responsive gene promoters, the p21, Smad7, and plasminogen activator inhibitor-1 (PAI-1) promoters. Moreover, adenovirus-mediated overexpression of SHP decreases PAI-1 mRNA levels, and down-regulation of SHP by a small interfering RNA increases both the transactivation of Smad3 and the PAI-1 mRNA levels. Finally, the PAI-1 gene is expressed in SHP(-/-) mouse hepatocytes at a higher level than in normal hepatocytes. Taken together, these data indicate that SHP is a novel co-regulator of Smad3, and this study provides new insights into regulation of TGF-beta signaling.

  19. Measuring the Fr Weak Nuclear Charge by Observing a Linear Stark Shift with Small Atomic Samples

    SciTech Connect

    Bouchiat, Marie-Anne

    2008-03-28

    We study the chirality of ground-state alkali atoms in E and B fields, dressed with a circularly-polarized beam near-detuned (< or approx. )1 GHz) from an E-field-assisted forbidden transition such as 7S-8S in Fr. We predict parity violating energy shifts of their sublevels, linear in E and the weak nuclear charge Q{sub W}. A dressing beam of 10 kW/cm{sup 2} at 506 nm produces a shift of {approx}100 {mu}Hz at E=100 V/cm, B > or approx. 50 mG which should be observable with {approx}10{sup 4} Fr atoms confined in an optical dipole trap. We discuss optimal conditions, parameter reversals, and a calibration procedure to measure Q{sub W}.

  20. Small-scale characterisation of irradiated nuclear materials: Part I – Microstructure

    DOE PAGES

    Edmondson, P. D.; London, A.; Xu, A.; ...

    2014-11-26

    The behaviour of nanometre-scale precipitates in oxide dispersion strengthened (ODS) ferritic alloys and tungsten-rhenium alloys for nuclear applications has been examined by atom probe tomography (APT). Low Re content tungsten alloys showed no evidence of Re clustering following self-ion irradiation whereas the 25 at.% Re resulted in cluster formation. The size and composition of clusters varied depending on the material form during irradiation (pre-sharpened needle or bulk). Lastly, these results highlight the care that must be taken in interpreting data from ion irradiated pre-sharpened needles due to the presence of free surfaces. Self-ion irradiation of the ODS ferritic alloy resultedmore » in a change in the composition of the clusters, indicating a transition from a near-stoichiometric Y2Ti2O7 composition towards a Ti2YO5.« less

  1. Small-scale characterisation of irradiated nuclear materials: Part I – Microstructure

    SciTech Connect

    Edmondson, P. D.; London, A.; Xu, A.; Armstrong, D. E. J.; Roberts, S. G.

    2014-11-26

    The behaviour of nanometre-scale precipitates in oxide dispersion strengthened (ODS) ferritic alloys and tungsten-rhenium alloys for nuclear applications has been examined by atom probe tomography (APT). Low Re content tungsten alloys showed no evidence of Re clustering following self-ion irradiation whereas the 25 at.% Re resulted in cluster formation. The size and composition of clusters varied depending on the material form during irradiation (pre-sharpened needle or bulk). Lastly, these results highlight the care that must be taken in interpreting data from ion irradiated pre-sharpened needles due to the presence of free surfaces. Self-ion irradiation of the ODS ferritic alloy resulted in a change in the composition of the clusters, indicating a transition from a near-stoichiometric Y2Ti2O7 composition towards a Ti2YO5.

  2. Small-scale characterisation of irradiated nuclear materials: Part I - Microstructure

    NASA Astrophysics Data System (ADS)

    Edmondson, P. D.; London, A.; Xu, A.; Armstrong, D. E. J.; Roberts, S. G.

    2015-07-01

    The behaviour of nanometre-scale precipitates in oxide dispersion strengthened (ODS) ferritic alloys and tungsten-rhenium alloys for nuclear applications has been examined by atom probe tomography (APT). Low Re content tungsten alloys showed no evidence of Re clustering following self-ion irradiation whereas the 25 at.% Re resulted in cluster formation. The size and composition of clusters varied depending on the material form during irradiation (pre-sharpened needle or bulk). These results highlight the care that must be taken in interpreting data from ion irradiated pre-sharpened needles due to the presence of free surfaces. Self-ion irradiation of the ODS ferritic alloy resulted in a change in the composition of the clusters, indicating a transition from a near-stoichiometric Y2Ti2O7 composition towards a Ti2YO5.

  3. Small Nuclear Reactors for Military Installations: Capabilities, Costs, and Technological Implications

    DTIC Science & Technology

    2011-02-01

    Energy and water now make up 70 percent of the logistics burden for troops operating in forward locations in the wars in Afghanistan and Iraq. This...vulnerability. Wind, solar , and hydro generation along with tailored cuts of energy use in the field can reduce the number of convoys needed to...by reducing its logistics tail. Another way that small reactors could potentially be used in the field is to power hydrogen electrolysis units to

  4. Advanced Nuclear Technology: Advanced Light Water Reactors Utility Requirements Document Small Modular Reactors Inclusion Summary

    SciTech Connect

    Loflin, Leonard; McRimmon, Beth

    2014-12-18

    This report summarizes a project by EPRI to include requirements for small modular light water reactors (smLWR) into the EPRI Utility Requirements Document (URD) for Advanced Light Water Reactors. The project was jointly funded by EPRI and the U.S. Department of Energy (DOE). The report covers the scope and content of the URD, the process used to revise the URD to include smLWR requirements, a summary of the major changes to the URD to include smLWR, and how to use the URD as revised to achieve value on new plant projects.

  5. All Adjunct Galilean Satellite Orbiter Concept Using a Small Nuclear Power Source

    NASA Astrophysics Data System (ADS)

    Randolph, James E.; Abelson, Robert D.; Alkalai, Leon; Collins, David H.; Moore, William V.

    2005-02-01

    An adjunct spacecraft concept known as the Galilean Satellite Orbiter (GSO) could gather and return significant science data using a payload consisting of plasma science and other instruments in orbit around each of three Galilean satellites using many advanced technology elements. The key to the viability of this concept is the existence of a small Radioisotope Power System (RPS) (single GPHS) and a mother spacecraft that could deliver the GSO to its final orbit and act as a relay communications path back to the Earth. Thus, the GSO would be dependant at Jupiter on the proposed Jupiter Icy Moons Orbiter (JIMO) or similar spacecraft for orbit insertion, propulsion to its target, and communications while at its target. Because of this highly capable supporting vehicle, the energy requirements for daily operations of GSO could be easily met with a small RPS system, which is now being studied by NASA and DOE, joined with a secondary battery system. The science payload would consist of a plasma instrument set (magnetometer, plasma spectrometer, plasma wave detector, and high energy particle detector), a wide angle camera, and a Doppler extractor for gravity field measurements. A small RPS now under study that would have a cylindrical shape and reject its internal heat through an end of the cylinder could enable this concept. This topology lends itself to a unique configuration concept for the GSO spacecraft using a long cylinder as the heat rejection (radiator) system for the RPS. This long cylinder has another application - it creates a long thin configuration that would enable gravity gradient attitude control of the spacecraft. This architecture would place the instruments at one end of the spacecraft and the RPS at the other allowing the maximum separation between them. Another technology element used in this design would be the Low Cost Adjunct Microspacecraft (LCAM), originally intended as a free-flying Earth orbiting inspector spacecraft. The LCAM is configured

  6. Small supernumerary marker chromosomes and the nuclear architecture of sperm - a study in a fertile and an infertile brother.

    PubMed

    Karamysheva, Tatyana; Kosyakova, Nadezda; Guediche, Narjes; Liehr, Thomas

    2015-01-01

    Small supernumerary marker chromosomes (sSMC) are found about four times more frequently in subfertile compared to the general population. The reason for this finding is still unclear. However, a connection of interphase architecture and genome function is suggested. And as we found in a previous study the presence of sSMC influences the nuclear architecture of peripheral blood cells and fibroblasts, we hypothesized that sSMC could have similar effects in sperm cells possibly leading to infertility. Here we applied for the first time 3-dimensional interphase fluorescence in situ hybridization (3D-FISH) to characterize the position of an extra-chromosome with respect to its sister- and selected other chromosomes (6, 15, 18, 19, 21, X, and Y) in sperm. Two sSMC carrier brothers with the identical sSMC derived from chromosome 15 were studied. One of the brothers was fertile and the other brother was infertile. Deviations from the normal positioning of chromosomes 21 and Y were seen in both brothers and for chromosomes 19 and X only in the infertile brother. Most striking were high rates of nullisomy and/or disomy for chromosomes 15, including sSMC (15), and 18 exclusively seen in the infertile brother. Overall, further evidence is provided that sSMC influence the nuclear architecture of a cell, including sperm. Further studies are necessary in sperm of fertile and infertile sSMC carriers to elaborate if the detected aneuploidy like that seen in the infertile brother is due to sSMC presence and disturbance of nuclear architecture.

  7. A preliminary phylogeny of the scale insects (Hemiptera: Sternorrhyncha: Coccoidea) based on nuclear small-subunit ribosomal DNA.

    PubMed

    Cook, Lyn G; Gullan, Penny J; Trueman, Holly E

    2002-10-01

    Scale insects (Hemiptera: Sternorrhyncha: Coccoidea) are a speciose and morphologically specialized group of plant-feeding bugs in which evolutionary relationships and thus higher classification are controversial. Sequences derived from nuclear small-subunit ribosomal DNA were used to generate a preliminary molecular phylogeny for the Coccoidea based on 39 species representing 14 putative families. Monophyly of the archaeococcoids (comprising Ortheziidae, Margarodidae sensu lato, and Phenacoleachia) was equivocal, whereas monophyly of the neococcoids was supported. Putoidae, represented by Puto yuccae, was found to be outside the remainder of the neococcoid clade. These data are consistent with a single origin (in the ancestor of the neococcoid clade) of a chromosome system involving paternal genome elimination in males. Pseudococcidae (mealybugs) appear to be sister to the rest of the neococcoids and there are indications that Coccidae (soft scales) and Kerriidae (lac scales) are sister taxa. The Eriococcidae (felt scales) was not recovered as a monophyletic group and the eriococcid genus Eriococcus sensu lato was polyphyletic.

  8. Molecular cloning of Xenopus fibrillarin, a conserved U3 small nuclear ribonucleoprotein recognized by antisera from humans with autoimmune disease.

    PubMed Central

    Lapeyre, B; Mariottini, P; Mathieu, C; Ferrer, P; Amaldi, F; Amalric, F; Caizergues-Ferrer, M

    1990-01-01

    Autoantibodies against U3 small nuclear ribonucleoprotein are associated with scleroderma autoimmune disease. They were shown to react with fibrillarin, a 34- to 36-kilodalton protein that has been detected in all eukaryotes tested from humans to yeasts. We isolated a 1.6-kilobase cDNA encoding fibrillarin from a Xenopus laevis cDNA library. The protein contains a 79-residue-long Gly-Arg-rich domain in its N-terminal region and a putative RNA-binding domain with ribonucleoprotein consensus sequence in its central portion. This is the first report of cloning of fibrillarin, and the deduced protein sequence is in agreement with the involvement of the protein in a ribonucleoprotein particle. Images PMID:2136767

  9. Design Study of Modular Nuclear Power Plant with Small Long Life Gas Cooled Fast Reactors Utilizing MOX Fuel

    NASA Astrophysics Data System (ADS)

    Ilham, Muhammad; Su’ud, Zaki

    2017-01-01

    Growing energy needed due to increasing of the world’s population encourages development of technology and science of nuclear power plant in its safety and security. In this research, it will be explained about design study of modular fast reactor with helium gas cooling (GCFR) small long life reactor, which can be operated over 20 years. It had been conducted about neutronic design GCFR with Mixed Oxide (UO2-PuO2) fuel in range of 100-200 MWth NPPs of power and 50-60% of fuel fraction variation with cylindrical pin cell and cylindrical balance of reactor core geometry. Calculation method used SRAC-CITATION code. The obtained results are the effective multiplication factor and density value of core reactor power (with geometry optimalization) to obtain optimum design core reactor power, whereas the obtained of optimum core reactor power is 200 MWth with 55% of fuel fraction and 9-13% of percentages.

  10. Crystal structures of the Lsm complex bound to the 3' end sequence of U6 small nuclear RNA.

    PubMed

    Zhou, Lijun; Hang, Jing; Zhou, Yulin; Wan, Ruixue; Lu, Guifeng; Yin, Ping; Yan, Chuangye; Shi, Yigong

    2014-02-06

    Splicing of precursor messenger RNA (pre-mRNA) in eukaryotic cells is carried out by the spliceosome, which consists of five small nuclear ribonucleoproteins (snRNPs) and a number of accessory factors and enzymes. Each snRNP contains a ring-shaped subcomplex of seven proteins and a specific RNA molecule. The U6 snRNP contains a unique heptameric Lsm protein complex, which specifically recognizes the U6 small nuclear RNA at its 3' end. Here we report the crystal structures of the heptameric Lsm complex, both by itself and in complex with a 3' fragment of U6 snRNA, at 2.8 Å resolution. Each of the seven Lsm proteins interacts with two neighbouring Lsm components to form a doughnut-shaped assembly, with the order Lsm3-2-8-4-7-5-6. The four uridine nucleotides at the 3' end of U6 snRNA are modularly recognized by Lsm3, Lsm2, Lsm8 and Lsm4, with the uracil base specificity conferred by a highly conserved asparagine residue. The uracil base at the extreme 3' end is sandwiched by His 36 and Arg 69 from Lsm3, through π-π and cation-π interactions, respectively. The distinctive end-recognition of U6 snRNA by the Lsm complex contrasts with RNA binding by the Sm complex in the other snRNPs. The structural features and associated biochemical analyses deepen mechanistic understanding of the U6 snRNP function in pre-mRNA splicing.

  11. DNA damage response (DDR) induced by topoisomerase II poisons requires nuclear function of the small GTPase Rac.

    PubMed

    Wartlick, Friedrich; Bopp, Anita; Henninger, Christian; Fritz, Gerhard

    2013-12-01

    Here, we investigated the influence of Rac family small GTPases on mechanisms of the DNA damage response (DDR) stimulated by topoisomerase II poisons. To this end, we examined the influence of the Rac-specific small molecule inhibitor EHT1864 on Ser139 phosphorylation of histone H2AX, a widely used marker of the DDR triggered by DNA double-strand breaks. EHT1864 attenuated the doxorubicin-stimulated DDR in a subset of cell lines tested, including HepG2 hepatoma cells. EHT1864 reduced the level of DNA strand breaks and increased viability following treatment of HepG2 cells with topo II poisons. Protection by EHT1864 was observed in both p53 wildtype (HepG2) and p53 deficient (Hep3B) human hepatoma cells and, furthermore, remained unaffected upon pharmacological inhibition of p53 in HepG2. Apparently, the impact of Rac on the DDR is independent of p53. Protection from doxorubicin-induced DNA damage by EHT1864 comprises both S and G2 phase cells. The inhibitory effect of EHT1864 on doxorubicin-stimulated DDR was mimicked by pharmacological inhibition of various protein kinases, including JNK, ERK, PI3K, PAK and CK1. EHT1864 and protein kinase inhibitors also attenuated the formation of the topo II-DNA cleavable complex. Moreover, EHT1864 mitigated the constitutive phosphorylation of topoisomerase IIα at positions S1106, S1213 and S1247. Doxorubicin transport, nuclear import/export of topoisomerase II and Hsp90-related mechanisms are likely not of relevance for doxorubicin-stimulated DDR impaired by EHT1864. We suggest that multiple kinase-dependent but p53- and heat shock protein-independent Rac-regulated nuclear mechanisms are required for activation of the DDR following treatment with topo II poisons.

  12. Identification of Novel Small Molecule Activators of Nuclear Factor-κB With Neuroprotective Action Via High-Throughput Screening

    PubMed Central

    Manuvakhova, Marina S.; Johnson, Guyla G.; White, Misti C.; Ananthan, Subramaniam; Sosa, Melinda; Maddox, Clinton; McKellip, Sara; Rasmussen, Lynn; Wennerberg, Krister; Hobrath, Judith V.; White, E. Lucile; Maddry, Joseph A.; Grimaldi, Maurizio

    2012-01-01

    Neuronal noncytokine-dependent p50/p65 nuclear factor-κB (the primary NF-κB complex in the brain) activation has been shown to exert neuroprotective actions. Thus neuronal activation of NF-κB could represent a viable neuroprotective target. We have developed a cell-based assay able to detect NF-κB expression enhancement, and through its use we have identified small molecules able to up-regulate NF-κB expression and hence trigger its activation in neurons. We have successfully screened approximately 300,000 compounds and identified 1,647 active compounds. Cluster analysis of the structures within the hit population yielded 14 enriched chemical scaffolds. One high-potency and chemically attractive representative of each of these 14 scaffolds and four singleton structures were selected for follow-up. The experiments described here highlighted that seven compounds caused noncanonical long-lasting NF-κB activation in primary astrocytes. Molecular NF-κB docking experiments indicate that compounds could be modulating NF-κB-induced NF-κB expression via enhancement of NF-κB binding to its own promoter. Prototype compounds increased p65 expression in neurons and caused its nuclear translocation without affecting the inhibitor of NF-κB (I-κB). One of the prototypical compounds caused a large reduction of glutamate-induced neuronal death. In conclusion, we have provided evidence that we can use small molecules to activate p65 NF-κB expression in neurons in a cytokine receptor-independent manner, which results in both long-lasting p65 NF-κB translocation/activation and decreased glutamate neurotoxicity. PMID:21046675

  13. SU-E-P-34: Dose Perturbation Caused by Sun Nuclear QED Diode When Used for Very Small Electron Fields

    SciTech Connect

    Klash, S; Steinman, J; Stanley, T

    2015-06-15

    Purpose: Diodes are utilized by radiotherapy departments to help verify that treatment fields are being delivered correctly to the patient. Some treatment fields utilize electron beams along with a cerrobend cutout to shape the beam to the area to be treated. Cerrobend cutouts can sometimes be very small < 2×2-cm2. Some published work has addressed diode perturbation for cutout sizes down to 1.5-cm, this work addresses the diode perturbation of the Sun Nuclear QEDTM diode for cutouts as small as 0.5-cm in diameter. Methods: Measurements were taken with an A16 Exradin micro-chamber in Solid Water to 100-cm SSD. Dmax was determined for each cutout using various amounts of Solid Water in 1–2 mm increments to account for the dmax shifting in small fields. The diode was placed on top of the solid water to 100-cm SSD in the center of the cutout. Measurements were taken with no diode for comparison. The cutouts ranged in diameter from 0.5-cm to 5.0-cm and included the open 6×6 insert. Measurements were made for energies 6, 9, 12, 15,&18 MeV. Results: For 6 MeV, the percent dose reduction from the diode in the cutout field compared to the field without the diode ranged from 35% to 25% as a function of cutout size. For higher energies, this percentage decreased and generally was 25% to 15%. It was observed that dmax shifts significantly upstream for very small cutouts (<2-cm diameter) to less than 1 cm for all energies. Conclusion: The presence of diodes in small electron fields is enough to cause significant dose perturbation to the target volume. It is recommended that diodes for very small electron fields be used sparingly or possibly with a dose correction per treatment fraction(s), if the total projected delivered dose is going to be significantly different from that prescribed by the physician.

  14. Ancient Origin of the U2 Small Nuclear RNA Gene-Targeting Non-LTR Retrotransposons Utopia

    PubMed Central

    Kojima, Kenji K.

    2015-01-01

    Most non-long terminal repeat (non-LTR) retrotransposons encoding a restriction-like endonuclease show target-specific integration into repetitive sequences such as ribosomal RNA genes and microsatellites. However, only a few target-specific lineages of non-LTR retrotransposons are distributed widely and no lineage is found across the eukaryotic kingdoms. Here we report the most widely distributed lineage of target sequence-specific non-LTR retrotransposons, designated Utopia. Utopia is found in three supergroups of eukaryotes: Amoebozoa, SAR, and Opisthokonta. Utopia is inserted into a specific site of U2 small nuclear RNA genes with different strength of specificity for each family. Utopia families from oomycetes and wasps show strong target specificity while only a small number of Utopia copies from reptiles are flanked with U2 snRNA genes. Oomycete Utopia families contain an “archaeal” RNase H domain upstream of reverse transcriptase (RT), which likely originated from a plant RNase H gene. Analysis of Utopia from oomycetes indicates that multiple lineages of Utopia have been maintained inside of U2 genes with few copy numbers. Phylogenetic analysis of RT suggests the monophyly of Utopia, and it likely dates back to the early evolution of eukaryotes. PMID:26556480

  15. Ancient Origin of the U2 Small Nuclear RNA Gene-Targeting Non-LTR Retrotransposons Utopia.

    PubMed

    Kojima, Kenji K; Jurka, Jerzy

    2015-01-01

    Most non-long terminal repeat (non-LTR) retrotransposons encoding a restriction-like endonuclease show target-specific integration into repetitive sequences such as ribosomal RNA genes and microsatellites. However, only a few target-specific lineages of non-LTR retrotransposons are distributed widely and no lineage is found across the eukaryotic kingdoms. Here we report the most widely distributed lineage of target sequence-specific non-LTR retrotransposons, designated Utopia. Utopia is found in three supergroups of eukaryotes: Amoebozoa, SAR, and Opisthokonta. Utopia is inserted into a specific site of U2 small nuclear RNA genes with different strength of specificity for each family. Utopia families from oomycetes and wasps show strong target specificity while only a small number of Utopia copies from reptiles are flanked with U2 snRNA genes. Oomycete Utopia families contain an "archaeal" RNase H domain upstream of reverse transcriptase (RT), which likely originated from a plant RNase H gene. Analysis of Utopia from oomycetes indicates that multiple lineages of Utopia have been maintained inside of U2 genes with few copy numbers. Phylogenetic analysis of RT suggests the monophyly of Utopia, and it likely dates back to the early evolution of eukaryotes.

  16. Proposals for the construction of space systems based on small spacecraft and a transport and power module with a nuclear power plant

    NASA Astrophysics Data System (ADS)

    Barabanov, A. A.; Papchenko, B. P.; Pichkhadze, K. M.; Rebrov, S. G.; Semenkin, A. V.; Sysoev, V. K.; Yanchur, S. V.

    2016-12-01

    The concept of interconnected satellite systems for various scientific and engineering applications based on small spacecraft and a transport and power module with a nuclear power plant is discussed. The system is connected by laser radiation from the transport and power module that supplies power to small satellites, establishes high-speed data transmission, and is used to perform high-precision measurements of intersatellite distances. Several practical use cases for such a connected system are considered.

  17. Identification of a small molecule inhibitor of importin beta mediated nuclear import by confocal on-bead screening of tagged one-bead one-compound libraries

    PubMed Central

    Hintersteiner, Martin; Ambrus, Géza; Bednenko, Janna; Schmied, Mario; Knox, Andrew J.S.; Gstach, Hubert; Seifert, Jan-Marcus; Singer, Eric L.; Gerace, Larry; Auer, Manfred

    2010-01-01

    In eukaryotic cells, proteins and RNA are transported between the nucleus and the cytoplasm by nuclear import and export receptors. Over the past decade, small molecules that inhibit the nuclear export receptor CRM1 have been identified, most notably leptomycin B. However, up to now no small molecule inhibitors of nuclear import have been described. Here we have used our automated Confocal Nanoscanning and bead picking method (CONA) for on-bead screening of a one bead/one compound library to identify the first such import inhibitor, karyostatin 1A. Karyostatin 1A binds importin β with high nanomolar affinity and specifically inhibits importin α/β mediated nuclear import at low micromolar concentrations in vitro and in living cells, without perturbing transportin mediated nuclear import or CRM1 mediated nuclear export. Surface plasmon resonance binding experiments suggest that karyostatin 1A acts by disrupting the interaction between importin β and the GTPase Ran. As a selective inhibitor of the importin α/β import pathway, karyostatin 1A will provide a valuable tool for future studies of nucleocytoplasmic trafficking. PMID:20677820

  18. Saccharomyces cerevisiae U1 small nuclear RNA secondary structure contains both universal and yeast-specific domains.

    PubMed Central

    Kretzner, L; Krol, A; Rosbash, M

    1990-01-01

    The five small nuclear RNAs (snRNAs) involved in mammalian pre-mRNA splicing (U1, U2, U4, U5, and U6) are well conserved in length, sequence, and especially secondary structure. These five snRNAs from Saccharomyces cerevisiae show notable size and sequence differences from their metazoan counterparts. This is most striking for the large S. cerevisiae U1 and U2 snRNAs, for which no secondary structure models currently exist. Because of the importance of U1 snRNA in the early steps of "spliceosome" assembly, we wanted to compare the highly conserved secondary structure of metazoan U1 snRNA (approximately 165 nucleotides) with that of S. cerevisiae U1 snRNA (568 nucleotides). To this end, we have cloned and sequenced the U1 gene from two other yeast species possessing large U1 RNAs. Using computer-derived structure predictions, phylogenetic comparisons, and structure probing, we have arrived at a secondary structure model for S. cerevisiae U1 snRNA. The results show that most elements of higher eukaryotic U1 snRNA secondary structure are conserved in S. cerevisiae. The hundreds of "extra" nucleotides of yeast U1 RNA, also highly structured, suggest that large insertions and/or deletions have occurred during the evolution of the U1 gene. Images PMID:2405391

  19. A molecular phylogeny of the marine red algae (Rhodophyta) based on the nuclear small-subunit rRNA gene.

    PubMed Central

    Ragan, M A; Bird, C J; Rice, E L; Gutell, R R; Murphy, C A; Singh, R K

    1994-01-01

    A phylogeny of marine Rhodophyta has been inferred by a number of methods from nucleotide sequences of nuclear genes encoding small subunit rRNA from 39 species in 15 orders. Sequence divergences are relatively large, especially among bangiophytes and even among congeners in this group. Subclass Bangiophycidae appears polyphyletic, encompassing at least three lineages, with Porphyridiales distributed between two of these. Subclass Florideophycidae is monophyletic, with Hildenbrandiales, Corallinales, Ahnfeltiales, and a close association of Nemaliales, Acrochaetiales, and Palmariales forming the four deepest branches. Cermiales may represent a convergence of vegetative and reproductive morphologies, as family Ceramiaceae is at best weakly related to the rest of the order, and one of its members appears to be allied to Gelidiales. Except for Gigartinales, for which more data are required, the other florideophyte orders appear distinct and taxonomically justified. A good correlation was observed with taxonomy based on pit-plug ultrastructure. Tests under maximum-likelihood and parsimony of alternative phylogenies based on structure and chemistry refuted suggestions that Acrochaetiales is the most primitive florideophyte order and that Gelidiales and Hildenbrandiales are sister groups. PMID:8041780

  20. Cloning of the cDNA for U1 small nuclear ribonucleoprotein particle 70K protein from Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Reddy, A. S.; Czernik, A. J.; An, G.; Poovaiah, B. W.

    1992-01-01

    We cloned and sequenced a plant cDNA that encodes U1 small nuclear ribonucleoprotein (snRNP) 70K protein. The plant U1 snRNP 70K protein cDNA is not full length and lacks the coding region for 68 amino acids in the amino-terminal region as compared to human U1 snRNP 70K protein. Comparison of the deduced amino acid sequence of the plant U1 snRNP 70K protein with the amino acid sequence of animal and yeast U1 snRNP 70K protein showed a high degree of homology. The plant U1 snRNP 70K protein is more closely related to the human counter part than to the yeast 70K protein. The carboxy-terminal half is less well conserved but, like the vertebrate 70K proteins, is rich in charged amino acids. Northern analysis with the RNA isolated from different parts of the plant indicates that the snRNP 70K gene is expressed in all of the parts tested. Southern blotting of genomic DNA using the cDNA indicates that the U1 snRNP 70K protein is coded by a single gene.

  1. Nuclear domain ‘knock-in’ screen for the evaluation and identification of small molecule enhancers of CRISPR-based genome editing

    PubMed Central

    Pinder, Jordan; Salsman, Jayme; Dellaire, Graham

    2015-01-01

    CRISPR is a genome-editing platform that makes use of the bacterially-derived endonuclease Cas9 to introduce DNA double-strand breaks at precise locations in the genome using complementary guide RNAs. We developed a nuclear domain knock-in screen, whereby the insertion of a gene encoding the green fluorescent protein variant Clover is inserted by Cas9-mediated homology directed repair (HDR) within the first exon of genes that are required for the structural integrity of subnuclear domains such as the nuclear lamina and promyelocytic leukemia nuclear bodies (PML NBs). Using this approach, we compared strategies for enhancing CRISPR-mediated HDR, focusing on known genes and small molecules that impact non-homologous end joining (NHEJ) and homologous recombination (HR). Ultimately, we identified the small molecule RS-1 as a potent enhancer of CRISPR-based genome editing, enhancing HDR 3- to 6-fold depending on the locus and transfection method. We also characterized U2OS human osteosarcoma cells expressing Clover-tagged PML and demonstrate that this strategy generates cell lines with PML NBs that are structurally and functionally similar to bodies in the parental cell line. Thus, the nuclear domain knock-in screen that we describe provides a simple means of rapidly evaluating methods and small molecules that have the potential to enhance Cas9-mediated HDR. PMID:26429972

  2. Nuclear domain 'knock-in' screen for the evaluation and identification of small molecule enhancers of CRISPR-based genome editing.

    PubMed

    Pinder, Jordan; Salsman, Jayme; Dellaire, Graham

    2015-10-30

    CRISPR is a genome-editing platform that makes use of the bacterially-derived endonuclease Cas9 to introduce DNA double-strand breaks at precise locations in the genome using complementary guide RNAs. We developed a nuclear domain knock-in screen, whereby the insertion of a gene encoding the green fluorescent protein variant Clover is inserted by Cas9-mediated homology directed repair (HDR) within the first exon of genes that are required for the structural integrity of subnuclear domains such as the nuclear lamina and promyelocytic leukemia nuclear bodies (PML NBs). Using this approach, we compared strategies for enhancing CRISPR-mediated HDR, focusing on known genes and small molecules that impact non-homologous end joining (NHEJ) and homologous recombination (HR). Ultimately, we identified the small molecule RS-1 as a potent enhancer of CRISPR-based genome editing, enhancing HDR 3- to 6-fold depending on the locus and transfection method. We also characterized U2OS human osteosarcoma cells expressing Clover-tagged PML and demonstrate that this strategy generates cell lines with PML NBs that are structurally and functionally similar to bodies in the parental cell line. Thus, the nuclear domain knock-in screen that we describe provides a simple means of rapidly evaluating methods and small molecules that have the potential to enhance Cas9-mediated HDR.

  3. Relativistic calculation of nuclear magnetic shielding tensor using the regular approximation to the normalized elimination of the small component. III. Introduction of gauge-including atomic orbitals and a finite-size nuclear model

    NASA Astrophysics Data System (ADS)

    Hamaya, S.; Maeda, H.; Funaki, M.; Fukui, H.

    2008-12-01

    The relativistic calculation of nuclear magnetic shielding tensors in hydrogen halides is performed using the second-order regular approximation to the normalized elimination of the small component (SORA-NESC) method with the inclusion of the perturbation terms from the metric operator. This computational scheme is denoted as SORA-Met. The SORA-Met calculation yields anisotropies, Δσ =σ∥-σ⊥, for the halogen nuclei in hydrogen halides that are too small. In the NESC theory, the small component of the spinor is combined to the large component via the operator σ⃗ṡπ⃗U/2c, in which π⃗=p⃗+A⃗, U is a nonunitary transformation operator, and c ≅137.036 a.u. is the velocity of light. The operator U depends on the vector potential A⃗ (i.e., the magnetic perturbations in the system) with the leading order c-2 and the magnetic perturbation terms of U contribute to the Hamiltonian and metric operators of the system in the leading order c-4. It is shown that the small Δσ for halogen nuclei found in our previous studies is related to the neglect of the U(0,1) perturbation operator of U, which is independent of the external magnetic field and of the first order with respect to the nuclear magnetic dipole moment. Introduction of gauge-including atomic orbitals and a finite-size nuclear model is also discussed.

  4. Relativistic calculation of nuclear magnetic shielding tensor using the regular approximation to the normalized elimination of the small component. III. Introduction of gauge-including atomic orbitals and a finite-size nuclear model.

    PubMed

    Hamaya, S; Maeda, H; Funaki, M; Fukui, H

    2008-12-14

    The relativistic calculation of nuclear magnetic shielding tensors in hydrogen halides is performed using the second-order regular approximation to the normalized elimination of the small component (SORA-NESC) method with the inclusion of the perturbation terms from the metric operator. This computational scheme is denoted as SORA-Met. The SORA-Met calculation yields anisotropies, Delta sigma = sigma(parallel) - sigma(perpendicular), for the halogen nuclei in hydrogen halides that are too small. In the NESC theory, the small component of the spinor is combined to the large component via the operator sigma x piU/2c, in which pi = p + A, U is a nonunitary transformation operator, and c approximately = 137.036 a.u. is the velocity of light. The operator U depends on the vector potential A (i.e., the magnetic perturbations in the system) with the leading order c(-2) and the magnetic perturbation terms of U contribute to the Hamiltonian and metric operators of the system in the leading order c(-4). It is shown that the small Delta sigma for halogen nuclei found in our previous studies is related to the neglect of the U(0,1) perturbation operator of U, which is independent of the external magnetic field and of the first order with respect to the nuclear magnetic dipole moment. Introduction of gauge-including atomic orbitals and a finite-size nuclear model is also discussed.

  5. Involvement of the spliceosomal U4 small nuclear RNA in heterochromatic gene silencing at fission yeast centromeres.

    PubMed

    Chinen, Madoka; Morita, Misato; Fukumura, Kazuhiro; Tani, Tokio

    2010-02-19

    prp13-1 is one of the mutants isolated in a screen for defective pre-mRNA splicing at a nonpermissive temperature in fission yeast Schizosaccharomyces pombe. We cloned the prp13(+) gene and found that it encodes U4 small nuclear RNA (snRNA) involved in the assembly of the spliceosome. The prp13-1 mutant produced elongated cells, a phenotype similar to cell division cycle mutants, and displays a high incidence of lagging chromosomes on anaphase spindles. The mutant is hypersensitive to the microtubule-destabilizing drug thiabendazole, supporting that prp13-1 has a defect in chromosomal segregation. We found that the prp13-1 mutation resulted in expression of the ura4(+) gene inserted in the pericentromeric heterochromatin region and reduced recruitment of the heterochromatin protein Swi6p to that region, indicating defects in the formation of pericentromeric heterochromatin, which is essential for the segregation of chromosomes, in prp13-1. The formation of centromeric heterochromatin is induced by the RNA interference (RNAi) system in S. pombe. In prp13-1, the processing of centromeric noncoding RNAs to siRNAs, which direct the heterochromatin formation, was impaired and unprocessed noncoding RNAs were accumulated. These results suggest that U4 snRNA is required for the RNAi-directed heterochromatic gene silencing at the centromeres. In relation to the linkage between the spliceosomal U4 snRNA and the RNAi-directed formation of heterochromatin, we identified a mRNA-type intron in the centromeric noncoding RNAs. We propose a model in which the assembly of the spliceosome or a sub-spliceosome complex on the intron-containing centromeric noncoding RNAs facilitates the RNAi-directed formation of heterochromatin at centromeres, through interaction with the RNA-directed RNA polymerase complex.

  6. Preparation and identification of anti-transforming growth factor β1 U1 small nuclear RNA chimeric ribozyme in vitro

    PubMed Central

    Lin, Ju-Sheng; Song, Yu-Hu; Kong, Xin-Juan; Li, Bin; Liu, Nan-Zhi; Wu, Xiao-Li; Jin, You-Xin

    2003-01-01

    AIM: To study the preparation and cleavage activity of anti-transforming growth factor (TGF)β1 U1 small nuclear (sn) RNA chimeric hammerhead ribozymes in vitro. METHODS: TGFβ1 partial gene fragment was cloned into T-vector at the downstream of T7 promoter. 32p-labeled TGFβ1 partial transcripts as target RNA were transcribed in vitro and purified by denaturing polyacrylamide gel electrophoresis (PAGE). Anti-TGFβ1 ribozymes were designed by computer, then synthetic ribozyme fragments were cloned into the U1 ribozyme vector pZeoU1EcoSpe containing U1 snRNA promoter/enhancer and terminator. 32p-labeled U1 snRNA chimeric ribozyme transcripts were gel-purified, incubated with target-RNAs at different conditions and autoradiographed after running denaturing PAGE. RESULTS: Active U1snRNA chimeric ribozyme (U1Rz803) had the best cleavage activity at 50 °C; at 37 °C, it was active, Km = 34.48 nmol/L, Kcat = 0.14 min-1; while the point mutant ribozyme U1Rz803m had no cleavage activity, so these indicated the design of U1Rz803 was correct. CONCLUSION: U1Rz803 prepared in this study possessed the perfect specific catalytic cleavage activity. These results indicate U1 snRNA chimeric ribozyme U1Rz803 may suppress the expression of TGFβ1 in vivo, therefore it may provide a new avenue for the treatment of liver fibrosis in the future. PMID:12632521

  7. Circulating U2 small nuclear RNA fragments as a novel diagnostic biomarker for primary central nervous system lymphoma

    PubMed Central

    Baraniskin, Alexander; Zaslavska, Elena; Nöpel-Dünnebacke, Stefanie; Ahle, Guido; Seidel, Sabine; Schlegel, Uwe; Schmiegel, Wolff; Hahn, Stephan; Schroers, Roland

    2016-01-01

    Background Primary central nervous system lymphomas (PCNSLs) are highly aggressive tumors. Chemotherapy has improved prognosis significantly; however, early diagnosis is crucial for effective treatment. Presently, the diagnosis of PCNSL depends on histopathology of tumor biopsies. We have previously demonstrated differential expression of microRNAs in cerebrospinal fluid (CSF) samples from patients with PCNSL. Based on promising findings about circulating U2 small nuclear RNA fragments (RNU2-1f) as novel blood-based biomarkers for pancreatic, colorectal, and lung cancer, we investigated RNU2-1f in the CSF of PCNSL patients. Methods CSF was collected from patients with PCNSL (n = 72) and control patients with various neurologic disorders (n = 47). Sequential CSF samples were collected from 9 PCNSL patients. RNU2-1f levels were measured by real-time polymerase chain reaction. Results Measurement of RNU2-1f levels in CSF enabled the differentiation of patients with PCNSL from controls with an area under the curve (AUC) of 0.909 with a sensitivity of 68.1% and a specificity of 91.4%. The diagnostic accuracy was further improved by combined determination of RNU2-1f and miR-21, resulting in AUC of 0.987 with a sensitivity of 91.7% and a specificity of 95.7%. In consecutive measurements of RNU2-1f, which were performed in 9 patients at different stages of the disease course, RNU2-1f CSF levels paralleled the course of the disease. Conclusions Our data suggest that the measurement of RNU2-1f detected in CSF can be used as a diagnostic marker and also as a possible marker for treatment monitoring. These promising results need to be evaluated within a larger patient cohort. PMID:26250566

  8. Involvement of the Spliceosomal U4 Small Nuclear RNA in Heterochromatic Gene Silencing at Fission Yeast Centromeres*

    PubMed Central

    Chinen, Madoka; Morita, Misato; Fukumura, Kazuhiro; Tani, Tokio

    2010-01-01

    prp13-1 is one of the mutants isolated in a screen for defective pre-mRNA splicing at a nonpermissive temperature in fission yeast Schizosaccharomyces pombe. We cloned the prp13+ gene and found that it encodes U4 small nuclear RNA (snRNA) involved in the assembly of the spliceosome. The prp13-1 mutant produced elongated cells, a phenotype similar to cell division cycle mutants, and displays a high incidence of lagging chromosomes on anaphase spindles. The mutant is hypersensitive to the microtubule-destabilizing drug thiabendazole, supporting that prp13-1 has a defect in chromosomal segregation. We found that the prp13-1 mutation resulted in expression of the ura4+ gene inserted in the pericentromeric heterochromatin region and reduced recruitment of the heterochromatin protein Swi6p to that region, indicating defects in the formation of pericentromeric heterochromatin, which is essential for the segregation of chromosomes, in prp13-1. The formation of centromeric heterochromatin is induced by the RNA interference (RNAi) system in S. pombe. In prp13-1, the processing of centromeric noncoding RNAs to siRNAs, which direct the heterochromatin formation, was impaired and unprocessed noncoding RNAs were accumulated. These results suggest that U4 snRNA is required for the RNAi-directed heterochromatic gene silencing at the centromeres. In relation to the linkage between the spliceosomal U4 snRNA and the RNAi-directed formation of heterochromatin, we identified a mRNA-type intron in the centromeric noncoding RNAs. We propose a model in which the assembly of the spliceosome or a sub-spliceosome complex on the intron-containing centromeric noncoding RNAs facilitates the RNAi-directed formation of heterochromatin at centromeres, through interaction with the RNA-directed RNA polymerase complex. PMID:20018856

  9. Repression of the nuclear receptor small heterodimer partner by steatotic drugs and in advanced nonalcoholic fatty liver disease.

    PubMed

    Benet, Marta; Guzmán, Carla; Pisonero-Vaquero, Sandra; García-Mediavilla, M Victoria; Sánchez-Campos, Sonia; Martínez-Chantar, M Luz; Donato, M Teresa; Castell, José Vicente; Jover, Ramiro

    2015-04-01

    The small heterodimer partner (SHP) (NR0B2) is an atypical nuclear receptor that lacks a DNA-binding domain. It interacts with and inhibits many transcription factors, affecting key metabolic processes, including bile acid, cholesterol, fatty acid, and drug metabolism. Our aim was to determine the influence of steatotic drugs and nonalcoholic fatty liver disease (NAFLD) on SHP expression and investigate the potential mechanisms. SHP was found to be repressed by steatotic drugs (valproate, doxycycline, tetracycline, and cyclosporin A) in cultured hepatic cells and the livers of different animal models of NAFLD: iatrogenic (tetracycline-treated rats), genetic (glycine N-methyltransferase-deficient mice), and nutritional (mice fed a methionine- and choline-deficient diet). Among the different transcription factors investigated, CCAAT-enhancer-binding protein α (C/EBPα) showed the strongest dominant-repressive effect on SHP expression in HepG2 and human hepatocytes. Reporter assays revealed that the inhibitory effect of C/EBPα and steatotic drugs colocalize between -340 and -509 base pair of the SHP promoter, and mutation of a predicted C/EBPα response element at -473 base pair abolished SHP repression by both C/EBPα and drugs. Moreover, inhibition of major stress signaling pathways demonstrated that the mitogen-activated protein kinase kinase 1/2 pathway activates, while the phosphatidylinositol 3 kinase pathway represses SHP in a C/EBP-dependent manner. We conclude that SHP is downregulated by several steatotic drugs and in advanced NAFLD. These conditions can activate signals that target C/EBPα and consequently repress SHP, thus favoring the progression and severity of NAFLD.

  10. A small molecule induces integrin β4 nuclear translocation and apoptosis selectively in cancer cells with high expression of integrin β4

    PubMed Central

    Liu, ShuYan; Ge, Di; Chen, LiNa; Zhao, Jing; Su, Le; Zhang, ShangLi; Miao, JunYing; Zhao, BaoXiang

    2016-01-01

    Increased integrin β4 (ITGB4) level is accompanied by malignant progression of multiple carcinomas. However, selective therapeutic strategies against cancer cells expressing a high level of ITGB4 have not been reported. Here, for the first time, we report that a chiral small molecule, SEC, selectively promotes apoptosis in cancer cells expressing a high level of ITGB4 by inducing ITGB4 nuclear translocation. Nuclear ITGB4 can bind to the ATF3 promoter region and activate the expression of ATF3, then upregulate the downstream pro-apoptosis genes. Furthermore, SEC promoted the binding of annexin A7 (ANXA7) to ITGB4 and increased ANXA7 GTPase activity. Activated ANXA7 promoted ITGB4 nuclear translocation by triggering ITGB4 phosphorylation at Y1494. SEC also inhibited the growth of xenograft tumors in the avian embryo model. We identified a small molecule, SEC, with selective pro-apoptosis effects on cancer cells with high expression of ITGB4, both in vitro and in vivo, by triggering the binding of ITGB4 and ANXA7, ITGB4 nuclear trafficking, and pro-apoptosis gene expression. PMID:26918348

  11. Nuclear HDAC6 inhibits invasion by suppressing NF-κB/MMP2 and is inversely correlated with metastasis of non-small cell lung cancer

    PubMed Central

    Yang, Chih-Jen; Liu, Yu-Peng; Dai, Hong-Ying; Shiue, Yow-Ling; Tsai, Chia-Jung; Huang, Ming-Shyan; Yeh, Yao-Tsung

    2015-01-01

    Histone deacetylase 6 (HDAC6) is a unique member of the histone deacetylase family. Although HDAC6 is mainly localized in the cytoplasm, it can regulate the activities of the transcription factors in the nucleus. However, a correlation of intracellular distribution of HDAC6 with tumor progression is lacking. In this study, we found that a low frequency of nuclear HDAC6-positive cells in tumors was associated with distant metastasis and a worse overall survival in 134 patients with non-small cell lung cancer (NSCLC). Ectopic expression of wild-type HDAC6 promoted migration and invasion of A549 and H661 cells. However, the enforced expression of nuclear export signal-deleted HDAC6 inhibited the invasion but not the migration of both cell lines. The inhibitory effect of nuclear HDAC6 on invasion was mediated by the deacetylation of the p65 subunit of nuclear factor-κB, which decreased its DNA-binding activity to the MMP2 promoter, leading to the downregulation of MMP2 expression. Our findings indicated that the loss of nuclear HDAC6 may be a potential biomarker for predicting metastasis in patients with NSCLC. PMID:26388610

  12. Application of laboratory data from small-scale simulators to human performance issues in the nuclear industry

    SciTech Connect

    Spettell, C.M.

    1986-01-01

    Laboratory analogs of nuclear power plant tasks were simulated on personal computers in two experimental studies. Human performance data were collected during each experimental study. The goal of the first experiment was to validate a quantitative model of dependence among human errors during testing, calibration, and maintenance activities. This model, the Multiple Sequential Failure (MSF) model (NUREG/CR-2211) has been used to quantify dependent human error failure probabilities for human reliability analyses in Probabilistic Risk Assessments (PRAs). The goal of the second experiment was to examine the relationship among psychological and behavioral characteristics of individuals and their performance at controlling a simulated nuclear power plant. These studies demonstrated the usefulness of the experimental psychology approach for validating models of human performance at nuclear power plant tasks.

  13. Structural and functional characterization of mouse U7 small nuclear RNA active in 3' processing of histone pre-mRNA

    SciTech Connect

    Soldati, D.; Schumperli, D.

    1988-04-01

    Oligonucleotides derived from the spacer element of the histone RNA 3' processing signal were used to characterize mouse U7 small nuclear RNA (snRNA), i.e., the snRNA component active in 3' processing of histone pre-mRNA. Under RNase H conditions, such oligonucleotides inhibited the processing reaction, indicating the formation of a DNA-RNA hybrid with a functional ribonucleoprotein component. Moreover, these oligonucleotides hybridized to a single nuclear RNA species of approximately 65 nucleotides. The sequence of this RNA was determined by primer extension experiments and was found to bear several structural similarities with sea urchin U7 snRNA. The comparison of mouse and sea urchin U7 snRNA structure yields some further insight into the mechanism of histone RNA 3' processing.

  14. Modeling the effect in of criticality from changes in key parameters for small High Temperature Nuclear Reactor (U-BatteryTM) using MCNP4C

    NASA Astrophysics Data System (ADS)

    Pauzi, A. M.

    2013-06-01

    The neutron transport code, Monte Carlo N-Particle (MCNP) which was wellkown as the gold standard in predicting nuclear reaction was used to model the small nuclear reactor core called "U-batteryTM", which was develop by the University of Manchester and Delft Institute of Technology. The paper introduces on the concept of modeling the small reactor core, a high temperature reactor (HTR) type with small coated TRISO fuel particle in graphite matrix using the MCNPv4C software. The criticality of the core were calculated using the software and analysed by changing key parameters such coolant type, fuel type and enrichment levels, cladding materials, and control rod type. The criticality results from the simulation were validated using the SCALE 5.1 software by [1] M Ding and J L Kloosterman, 2010. The data produced from these analyses would be used as part of the process of proposing initial core layout and a provisional list of materials for newly design reactor core. In the future, the criticality study would be continued with different core configurations and geometries.

  15. Amifostine alleviates radiation-induced lethal small bowel damage via promotion of 14-3-3σ-mediated nuclear p53 accumulation.

    PubMed

    Huang, Eng-Yen; Wang, Feng-Sheng; Chen, Yu-Min; Chen, Yi-Fan; Wang, Chung-Chi; Lin, I-Hui; Huang, Yu-Jie; Yang, Kuender D

    2014-10-30

    Amifostine (AM) is a radioprotector that scavenges free radicals and is used in patients undergoing radiotherapy. p53 has long been implicated in cell cycle arrest for cellular repair after radiation exposure. We therefore investigated the protective p53-dependent mechanism of AM on small bowel damage after lethal whole-abdominal irradiation (WAI). AM increased both the survival rate of rats and crypt survival following lethal 18 Gy WAI. The p53 inhibitor PFT-α compromised AM-mediated effects when administered prior to AM administration. AM significantly increased clonogenic survival in IEC-6 cells expressing wild type p53 but not in p53 knockdown cells. AM significantly increased p53 nuclear accumulation and p53 tetramer expression before irradiation through the inhibition of p53 degradation. AM inhibited p53 interactions with MDM2 but enhanced p53 interactions with 14-3-3σ. Knockdown of 14-3-3σ also compromised the effect of AM on clonogenic survival and p53 nuclear accumulation in IEC-6 cells. For the first time, our data reveal that AM alleviates lethal small bowel damage through the induction of 14-3-3σ and subsequent accumulation of p53. Enhancement of the p53/14-3-3σ interaction results in p53 tetramerization in the nucleus that rescues lethal small bowel damage.

  16. Study Neutronic of Small Pb-Bi Cooled Non-Refuelling Nuclear Power Plant Reactor (SPINNOR) with Hexagonal Geometry Calculation

    NASA Astrophysics Data System (ADS)

    Nur Krisna, Dwita; Su’ud, Zaki

    2017-01-01

    Nuclear reactor technology is growing rapidly, especially in developing Nuclear Power Plant (NPP). The utilization of nuclear energy in power generation systems has been progressing phase of the first generation to the fourth generation. This final project paper discusses the analysis neutronic one-cooled fast reactor type Pb-Bi, which is capable of operating up to 20 years without refueling. This reactor uses Thorium Uranium Nitride as fuel and operating on power range 100-500MWtNPPs. The method of calculation used a computer simulation program utilizing the SRAC. SPINNOR reactor is designed with the geometry of hexagonal shaped terrace that radially divided into three regions, namely the outermost regions with highest percentage of fuel, the middle regions with medium percentage of fuel, and most in the area with the lowest percentage. SPINNOR fast reactor operated for 20 years with variations in the percentage of Uranium-233 by 7%, 7.75%, and 8.5%. The neutronic calculation and analysis show that the design can be optimized in a fast reactor for thermal power output SPINNOR 300MWt with a fuel fraction 60% and variations of Uranium-233 enrichment of 7%-8.5%.

  17. Organellar genome, nuclear ribosomal DNA repeat unit, and microsatellites isolated from a small-scale of 454 GS FLX sequencing on two mosses.

    PubMed

    Liu, Yang; Forrest, Laura L; Bainard, Jillian D; Budke, Jessica M; Goffinet, Bernard

    2013-03-01

    Recent innovations in high-throughput DNA sequencing methodology (next generation sequencing technologies [NGS]) allow for the generation of large amounts of high quality data that may be particularly critical for resolving ambiguous relationships such as those resulting from rapid radiations. Application of NGS technology to bryology is limited to assembling entire nuclear or organellar genomes of selected exemplars of major lineages (e.g., classes). Here we outline how organellar genomes and the entire nuclear ribosomal DNA repeat can be obtained from minimal amounts of moss tissue via small-scale 454 GS FLX sequencing. We sampled two Funariaceae species, Funaria hygrometrica and Entosthodon obtusus, and assembled nearly complete organellar genomes and the whole nuclear ribosomal DNA repeat unit (18S-ITS1-5.8S-ITS2-26S-IGS1-5S-IGS2) for both taxa. Sequence data from these species were compared to sequences from another Funariaceae species, Physcomitrella patens, revealing low overall degrees of divergence of the organellar genomes and nrDNA genes with substitutions spread rather evenly across their length, and high divergence within the external spacers of the nrDNA repeat. Furthermore, we detected numerous microsatellites among the 454 assemblies. This study demonstrates that NGS methodology can be applied to mosses to target large genomic regions and identify microsatellites.

  18. A small nuclear GTP-binding protein from tomato suppresses a Schizosaccharomyces pombe cell-cycle mutant.

    PubMed Central

    Ach, R A; Gruissem, W

    1994-01-01

    Ran is a 25-kDa Ras-related nuclear GTP-binding protein which is very highly conserved in humans, Saccharomyces cerevisiae, and Schizosaccharomyces pombe. Ran has been found to form a stable, noncovalent complex with the chromatin-associated protein RCC1, a negative regulator of mitosis. In Sch. pombe, a temperature-sensitive mutation in the RCC1 homolog encoded by the pim1 gene causes premature induction of mitosis, and this mutation can be suppressed by overexpression of the Ran homolog encoded by spi1. We report here the cloning of three Ran cDNAs from tomato. The Ran protein is very highly conserved among plants, animals, and fungi. In tomato, Ran mRNA is expressed in all tissues examined, even those with little or no cell division, indicating that Ran in plants may have functions other than just control of mitosis. We have found that the tomato Ran protein can direct a beta-glucuronidase reporter protein to the plant cell nucleus, confirming that Ran is a nuclear protein in plants. We show that the tomato Ran protein can suppress the Sch. pombe pim1 mutation, indicating that the tomato Ran protein and the Sch. pombe spi1 protein are functionally homologous. Images PMID:8016079

  19. Advanced Nuclear Technology. Using Technology for Small Modular Reactor Staff Optimization, Improved Effectiveness, and Cost Containment, 3002007071

    SciTech Connect

    Loflin, Leonard

    2016-03-21

    Through this grant, the U.S. Department of Energy (DOE) will review several functional areas within a nuclear power plant, including fire protection, operations and operations support, refueling, training, procurement, maintenance, site engineering, and others. Several functional areas need to be examined since there appears to be no single staffing area or approach that alone has the potential for significant staff optimization at new nuclear power plants. Several of the functional areas will require a review of technology options such as automation, remote monitoring, fleet wide monitoring, new and specialized instrumentation, human factors engineering, risk informed analysis and PRAs, component and system condition monitoring and reporting, just in time training, electronic and automated procedures, electronic tools for configuration management and license and design basis information, etc., that may be applied to support optimization. Additionally, the project will require a review key regulatory issues that affect staffing and could be optimized with additional technology input. Opportunities to further optimize staffing levels and staffing functions by selection of design attributes of physical systems and structures need also be identified. A goal of this project is to develop a prioritized assessment of the functional areas, and R&D actions needed for those functional areas, to provide the best optimization

  20. Impact of thermal spectrum small modular reactors on performance of once-through nuclear fuel cycles with low-enriched uranium

    DOE PAGES

    Brown, Nicholas R.; Worrall, Andrew; Todosow, Michael

    2016-11-18

    Small modular reactors (SMRs) offer potential benefits, such as enhanced operational flexibility. However, it is vital to understand the holistic impact of SMRs on nuclear fuel cycle performance. The focus of this paper is the fuel cycle impacts of light water SMRs in a once-through fuel cycle with low-enriched uranium fuel. A key objective of this paper is to describe preliminary example reactor core physics and fuel cycle analyses conducted in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Options Campaign. The hypothetical light water SMR example case considered in these preliminary scoping studies ismore » a cartridge type one-batch core with slightly less than 5.0% enrichment. Challenges associated with SMRs include increased neutron leakage, fewer assemblies in the core (and therefore fewer degrees of freedom in the core design), complex enrichment and burnable absorber loadings, full power operation with inserted control rods, the potential for frequent load-following operation, and shortened core height. Each of these will impact the achievable discharge burnup in the reactor and the fuel cycle performance. This paper summarizes a list of the factors relevant to SMR fuel, core, and operation that will impact fuel cycle performance. The high-level issues identified and preliminary scoping calculations in this paper are intended to inform on potential fuel cycle impacts of one-batch thermal spectrum SMRs. In particular, this paper highlights the impact of increased neutron leakage and reduced number of batches on the achievable burnup of the reactor. Fuel cycle performance metrics for a hypothetical example SMR are compared with those for a conventional three-batch light water reactor in the following areas: nuclear waste management, environmental impact, and resource utilization. The metrics performance for such an SMR is degraded for the mass of spent nuclear fuel and high-level waste disposed of, mass of depleted uranium

  1. Impact of thermal spectrum small modular reactors on performance of once-through nuclear fuel cycles with low-enriched uranium

    SciTech Connect

    Brown, Nicholas R.; Worrall, Andrew; Todosow, Michael

    2016-11-18

    Small modular reactors (SMRs) offer potential benefits, such as enhanced operational flexibility. However, it is vital to understand the holistic impact of SMRs on nuclear fuel cycle performance. The focus of this paper is the fuel cycle impacts of light water SMRs in a once-through fuel cycle with low-enriched uranium fuel. A key objective of this paper is to describe preliminary example reactor core physics and fuel cycle analyses conducted in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Options Campaign. The hypothetical light water SMR example case considered in these preliminary scoping studies is a cartridge type one-batch core with slightly less than 5.0% enrichment. Challenges associated with SMRs include increased neutron leakage, fewer assemblies in the core (and therefore fewer degrees of freedom in the core design), complex enrichment and burnable absorber loadings, full power operation with inserted control rods, the potential for frequent load-following operation, and shortened core height. Each of these will impact the achievable discharge burnup in the reactor and the fuel cycle performance. This paper summarizes a list of the factors relevant to SMR fuel, core, and operation that will impact fuel cycle performance. The high-level issues identified and preliminary scoping calculations in this paper are intended to inform on potential fuel cycle impacts of one-batch thermal spectrum SMRs. In particular, this paper highlights the impact of increased neutron leakage and reduced number of batches on the achievable burnup of the reactor. Fuel cycle performance metrics for a hypothetical example SMR are compared with those for a conventional three-batch light water reactor in the following areas: nuclear waste management, environmental impact, and resource utilization. The metrics performance for such an SMR is degraded for the mass of spent nuclear fuel and high-level waste disposed of, mass of depleted uranium disposed

  2. Small effect of fragmentation on the genetic diversity of Dalbergia monticola, an endangered tree species of the eastern forest of Madagascar, detected by chloroplast and nuclear microsatellites

    PubMed Central

    Andrianoelina, O.; Favreau, B.; Ramamonjisoa, L.; Bouvet, J.-M.

    2009-01-01

    Background and Aims The oriental forest ecosystem in Madagascar has been seriously impacted by fragmentation. The pattern of genetic diversity was analysed on a tree species, Dalbergia monticola, which plays an important economic role in Madagascar and is one of the many endangered tree species in the eastern forest. Methods Leaves from 546 individuals belonging to 18 small populations affected by different levels of fragmentation were genotyped using eight nuclear (nuc) and three chloroplast (cp) microsatellite markers. Key Results For nuclear microsatellites, allelic richness (R) and heterozygosity (He,nuc) differed between types of forest: R = 7·36 and R = 9·55, He,nuc = 0·64 and He,nuc = 0·80 in fragmented and non-fragmented forest, respectively, but the differences were not significant. Only the mean number of alleles (Na,nuc) and the fixation index FIS differed significantly: Na,nuc = 9·41 and Na,nuc = 13·18, FIS = 0·06 and FIS = 0·15 in fragmented and non-fragmented forests, respectively. For chloroplast microsatellites, estimated genetic diversity was higher in non-fragmented forest, but the difference was not significant. No recent bottleneck effect was detected for either population. Overall differentiation was low for nuclear microsatellites (FST,nuc = 0·08) and moderate for chloroplast microsatellites (FST,cp = 0·49). A clear relationship was observed between genetic and geographic distance (r = 0·42 P < 0·01 and r = 0·42 P = 0·03 for nuclear and chloroplast microsatellites, respectively), suggesting a pattern of isolation by distance. Analysis of population structure using the neighbor-joining method or Bayesian models separated southern populations from central and northern populations with nuclear microsatellites, and grouped the population according to regions with chloroplast microsatellites, but did not separate the fragmented populations. Conclusions Residual diversity and genetic structure of populations of D. monticola in

  3. Risks of nuclear waste disposal in space. III - Long-term orbital evolution of small particle distribution

    NASA Technical Reports Server (NTRS)

    Friedlander, A. L.; Wells, W. C.

    1980-01-01

    A study of long term risks is presented that treats an additional pathway that could result in earth reentry, namely, small radioactive particles released in solar orbit due to payload fragmentation by accidental explosion or meteoroid impact. A characterization of such an event and of the initial mass size distribution of particles is given for two extremes of waste form strength. Attention is given to numerical results showing the mass-time distribution of material and the fraction of initial mass intercepted by earth. It is concluded that it appears that program planners need not be to concerned about the risks of this particular failure mechanism and return pathway.

  4. The immunolocalization of small nuclear ribonucleoprotein particles in testicular cells during the cycle of the seminiferous epithelium of the adult rat.

    PubMed

    Moussa, F; Oko, R; Hermo, L

    1994-11-01

    The objective of this study was to determine the cellular and subcellular distribution of small nuclear ribonucleoprotein particles (snRNPs) in the adult rat testis in relation to the different cell types at the various stages of the cycle of the seminiferous epithelium. The distribution of snRNPs in the nucleus and cytoplasm of germ cells was quantitated in an attempt to correlate RNA processing with morphological and functional changes occurring during the development of these cells. Light-microscopic immunoperoxidase staining of rat testes with polyclonal anti-Sm and monoclonal anti-Y12 antibodies localized spliceosome snRNPs in the nuclei and cytoplasm of germ cells up to step 10 spermatids. Nuclear staining was intense in Sertoli cells, spermatogonia, spermatocytes, and in the early steps of round spermatid development. Although comparatively weaker, cytoplasmic staining for snRNPs was strongest in mid and late pachytene spermatocytes and early round spermatids. Quantitative electron-microscopic immunogold labeling of Lowicryl embedded testicular sections confirmed the light-microscopic observations but additionally showed that the snRNP content peaked in the cytoplasm of midpachytene spermatocytes and in the nuclei of late pachytene spermatocytes. The immunogold label tended to aggregate into distinct loci over the nuclear chromatin. The chromatoid body of spermatids and spermatocytes and the finely granular material in the interstices of mitochondrial aggregates of spermatocytes were found to be additional sites of snRNP localization and were intensely labeled. This colocalization suggests that these dense cytoplasmic structures may be functionally related. Anti-U1 snRNP antibodies applied to frozen sections showed the same LM localization pattern as spliceosome snRNPs. Anti-U3 snRNP antibodies applied to frozen sections stained nucleoli of germ cells where pre-rRNA is spliced.

  5. Nuclear p26, a small heat shock/alpha-crystallin protein, and its relationship to stress resistance in Artemia franciscana embryos.

    PubMed

    Willsie, J K; Clegg, J S

    2001-07-01

    The role of the small heat shock/alpha-crystallin protein, p26, in transcription in Artemia franciscana embryos was examined using isolated nuclei, containing either control or elevated levels of p26, in transcription run-on assays. Heat shock or anoxia in vivo and acid pH in vitro were used to transfer p26 into nuclei. The results suggest that parameters other than, or in addition to, p26 are responsible for the reduced transcription rates observed and that decreases in pHi are involved. In vivo experiments indicate that RNA synthesis and, to a lesser extent, protein synthesis are downregulated in intact embryos recovering from heat shock and that the precursor pool is not limiting. Confocal microscopy confirmed that p26 moves into nuclei in response to heat shock and anoxia in vivo, and to low pH in vitro, and indicated that the nuclear distribution of p26 is similar under all three conditions. We present evidence that unstressed (control) embryos containing p26 in all their nuclei will not hatch, even under permissive conditions, and propose that they are unable to terminate diapause. Potential nuclear targets of p26 chaperone activity are discussed.

  6. Morphological changes and nuclear translocation of DLC1 tumor suppressor protein precede apoptosis in human non-small cell lung carcinoma cells

    SciTech Connect

    Yuan Baozhu Jefferson, Amy M.; Millecchia, Lyndell; Popescu, Nicholas C.; Reynolds, Steven H.

    2007-11-01

    We have previously shown that reactivation of DLC1, a RhoGAP containing tumor suppressor gene, inhibits tumorigenicity of human non-small cell lung carcinoma cells (NSCLC). After transfection of NSCLC cells with wild type (WT) DLC1, changes in cell morphology were observed. To determine whether such changes have functional implications, we generated several DLC1 mutants and examined their effects on cell morphology, proliferation, migration and apoptosis in a DLC1 deficient NSCLC cell line. We show that WT DLC1 caused actin cytoskeleton-based morphological alterations manifested as cytoplasmic extensions and membrane blebbings in most cells. Subsequently, a fraction of cells exhibiting DLC1 protein nuclear translocation (PNT) underwent caspase 3-dependent apoptosis. We also show that the RhoGAP domain is essential for the occurrence of morphological alterations, PNT and apoptosis, and the inhibition of cell migration. DLC1 PNT is dependent on a bipartite nuclear localizing sequence and most likely is regulated by a serine-rich domain at N-terminal part of the DLC1 protein. Also, we found that DLC1 functions in the cytoplasm as an inhibitor of tumor cell proliferation and migration, but in the nucleus as an inducer of apoptosis. Our analyses provide evidence for a possible link between morphological alterations, PNT and proapoptotic and anti-oncogenic activities of DLC1 in lung cancer.

  7. Leucine periodicity of U2 small nuclear ribonucleoprotein particle (snRNP) A' protein is implicated in snRNP assembly via protein-protein interactions.

    PubMed Central

    Fresco, L D; Harper, D S; Keene, J D

    1991-01-01

    Recombinant A' protein could be reconstituted into U2 small nuclear ribonucleoprotein particles (snRNPs) upon addition to HeLa cell extracts as determined by coimmunoprecipitation and particle density; however, direct binding to U2 RNA could not be demonstrated except in the presence of the U2 snRNP B" protein. Mutational analysis indicated that a central core region of A' was required for particle reconstitution. This region consists of five tandem repeats of approximately 24 amino acids each that exhibit a periodicity of leucine and asparagine residues that is distinct from the leucine zipper. Similar leucine-rich (Leu-Leu motif) repeats are characteristic of a diverse array of soluble and membrane-associated proteins from yeasts to humans but have not been reported previously to reside in nuclear proteins. Several of these proteins, including Toll, chaoptin, RNase/angiogenin inhibitors, lutropin-choriogonadotropin receptor, carboxypeptidase N, adenylyl cyclase, CD14, and human immunodeficiency virus type 1 Rev, may be involved in protein-protein interactions. Our findings suggest that in cell extracts the Leu-Leu motif of A' is required for reconstitution with U2 snRNPs and perhaps with other components involved in splicing through protein-protein interactions. Images PMID:1825347

  8. Evaluation of the applicability of existing nuclear power plant regulatory requirements in the U.S. to advanced small modular reactors.

    SciTech Connect

    LaChance, Jeffrey L.; Wheeler, Timothy A.; Farnum, Cathy Ottinger; Middleton, Bobby D.; Jordan, Sabina Erteza; Duran, Felicia Angelica; Baum, Gregory A.

    2013-05-01

    The current wave of small modular reactor (SMR) designs all have the goal of reducing the cost of management and operations. By optimizing the system, the goal is to make these power plants safer, cheaper to operate and maintain, and more secure. In particular, the reduction in plant staffing can result in significant cost savings. The introduction of advanced reactor designs and increased use of advanced automation technologies in existing nuclear power plants will likely change the roles, responsibilities, composition, and size of the crews required to control plant operations. Similarly, certain security staffing requirements for traditional operational nuclear power plants may not be appropriate or necessary for SMRs due to the simpler, safer and more automated design characteristics of SMRs. As a first step in a process to identify where regulatory requirements may be met with reduced staffing and therefore lower cost, this report identifies the regulatory requirements and associated guidance utilized in the licensing of existing reactors. The potential applicability of these regulations to advanced SMR designs is identified taking into account the unique features of these types of reactors.

  9. 'CATT' A project on Co-operation and Technology Transfer on Long-Term Radioactive Waste Management for EU Member States with Small Nuclear Programmes

    SciTech Connect

    Mathieson, J.; Lindberg, C.

    2006-07-01

    Many of the European Union's (EU) 25 countries have considerable inventories of long-lived radioactive waste that will remain potentially hazardous for many thousands of years. Of these, several have advanced concepts and programmes for the treatment and disposal (and other long - term management options) for spent fuel and long-lived radioactive waste. Collectively, these Member States have spent the equivalent of many billions of euros in developing such concepts and some have further developed the concepts into proposed operational facilities. Member States with small nuclear programmes, face the expensive and daunting prospect o f developing their own concepts for dealing with their spent fuel and high level waste. One answer would be to seek solutions which could take advantage of the investment costs in the technology and underpinning science already incurred in the more established programmes. Thus technology transfer between Member States in areas of high level waste and spent fuel encapsulation, repository development etc. would allow the establishment of disposal facilities within any Member State for it to deal with its own wastes. The national waste management organisations of the UK (Mirex), Sweden (SKB), German y (DBE), Lithuania (RATA), Bulgaria (DPRAO) and Slovenia (ARAO), together with JRC of the Netherlands, are to undertake a project under the auspices of the EU's 6. R and D Framework Programme (FP6). The 18 month project will examine the technical, intellectual property, legal, financial and societal implications of the idea. It goes by the acronym 'CATT' - 'Cooperation and technology transfer on long term radioactive waste management for Member States with small nuclear programmes'. This paper describes the CATT project which will look at technology transfer methodologies by which Member States could co-operate. It covers the potential issues which may arise and ho w these may be addressed. (authors)

  10. Hydrochemical patterns of a small lake and a stream in an uplifting area proposed as a repository site for spent nuclear fuel, Forsmark, Sweden

    NASA Astrophysics Data System (ADS)

    Rönnback, Pernilla; Åström, Mats

    2007-10-01

    SummaryThe overall aim of this study was to increase the understanding of the chemical dynamics of small catchments. The focus was on a small oligotropic lake and its major inflow stream in an uplifting area in eastern Sweden (Forsmark) proposed as a repository site for spent nuclear fuel. The hydrochemical sampling campaign lasted for nearly 4 years with sample collection monthly to semi-monthly, and continuous flow measurements carried out over the last 20 months. All this was done as part of the Swedish Nuclear Fuel and Waste Management Company's (SKBs) Site Investigation Programme. The major findings were: (1) as a result of the calcareous overburden caused by redistributed Paleozoic deposits, pH and the Ca and HCO3- concentrations were relatively high in both the stream and lake throughout the period, (2) limnic primary production resulted in decreased concentrations of Ca, HCO3-, NH4+, NO3- and Si, and increased pH and concentrations of chlorophyll a, O 2, DON, POC, PON and POP in the lake in summer, while in other seasons (in winter in particular) when the production was minimal or non-existent the concentrations in the lake and the inflow stream were similar, (3) intrusion of brackish-water resulted in moderately to strongly increased concentrations of Cl -, Na, Mg, Br -, SO42-, K and Sr in the lake: the ratio versus Cl - were for Na and Br - always similar to those in sea water, for Mg and SO42- similar to those in sea water at elevated Cl - concentrations (>3 mM), while K and Sr always occurred in relative excess as compared to sea water, (4) high U concentrations in both the stream and the lake was derived most likely from reduced U-minerals in the overburden and was predicted to be carried to >90% in the form of calcium uranyl carbonate, in a model in which colloidal Fe and Al oxyhydroxides were not considered, (5) the rare earth elements (REEs) had similar concentrations and fractionation patterns in the stream and lake, unlike those found in the

  11. RBC nuclear scan

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  12. Status of development of the Small Secure Transportable Autonomous Reactor (SSTAR) for worldwide sustainable nuclear energy supply.

    SciTech Connect

    Sienicki, J. J.; Moisseytsev, A.; Wade, D. C.; Nikiforova, A.; Nuclear Engineering Division; Massachusetts Institute of Tech.

    2008-01-01

    Significant progress and improvements have been made on development of a pre-conceptual design of the Secure Transportable Autonomous Reactor (SSTAR) Lead-Cooled Fast Reactor (LFR) concept since it was last reported on at ICAPP 05. SSTAR is a small, 20 MWe (45 MWt), exportable, natural circulation, fast reactor plant concept incorporating proliferation resistance for deployment in non-fuel cycle states and developing nations, fissile self-sufficiency for efficient utilization of uranium resources, autonomous load following making it suitable for small or immature grid applications, and a high degree of passive safety. Customers of SSTAR include: (1) clients looking for energy security at small capital outlay; (2) cities in developing nations; and (3) deregulated independent power producers in developed nations. The SSTAR pre-conceptual design integrates three major features: primary coolant natural circulation heat transport; lead (Pb) coolant; and transuranic nitride fuel in a pool vessel configuration. The Pb coolant flows upward through the core which is an open-lattice of large-diameter (2.5 centimeter) fuel pins containing transuranic nitride pellets clad bonded with liquid Pb to silicon-enhanced ferritic/martensitic (F/M) stainless steel arranged on a triangular pitch with spacing maintained by grid spacers; the core does not incorporate removable fuel assemblies as one means of restricting access to the fuel. The whole core is a single removable assembly with a long lifetime (30 years) at which time refueling equipment is brought onsite. Conversion of the core thermal energy to electricity is accomplished using a supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle energy converter providing higher plant efficiencies and lower balance of plant costs than the traditional Rankine steam cycle operating at the same reactor core outlet temperature. A control strategy has been developed for automatic control of the S-CO{sub 2} Brayton cycle in principle

  13. An extended conventional fuel cycle for the B and W mPower{sup TM} small modular nuclear reactor

    SciTech Connect

    Scarangella, M. J.

    2012-07-01

    The B and W mPower{sup TM} reactor is a small pressurized water reactor (PWR) with an integral once-through steam generator and a thermal output of about 500 MW; it is intended to replace aging fossil power plants of similar output. The core is composed of 69 reduced-height PWR assemblies with the familiar 17 x 17 fuel rod array. The Babcock and Wilcox Company (B and W) is offering a core loading and cycle management plan for a four-year cycle based on its presumed attractiveness to potential customers. This option is a once-through fuel cycle in which the entire core is discharged and replaced after four years. In addition, a conventional fuel utilization strategy, employing a periodic partial reload and shuffle, was developed as an alternative to the four-year once-through fuel cycle. This study, which was performed using the Studsvik core design code suite, is a typical multi-cycle projection analysis of the type performed by most fuel management organizations such as fuel vendors and utilities. In the industry, the results of such projections are used by the financial arms of these organizations to assist in making long-term decisions. In the case of the B and W mPower reactor, this analysis demonstrates flexibility for customers who consider the once-through fuel cycle unacceptable from a fuel utilization standpoint. As expected, when compared to the once-through concept, reloads of the B and W mPower reactor will achieve higher batch average discharge exposure, will have adequate shut-down margin, and will have a relatively flat hot excess reactivity trend at the expense of slightly increased peaking. (authors)

  14. Added resolution among ordinal level relationships of tapeworms (Platyhelminthes: Cestoda) with complete small and large subunit nuclear ribosomal RNA genes.

    PubMed

    Waeschenbach, Andrea; Webster, Bonnie L; Bray, Rodney A; Littlewood, D T J

    2007-10-01

    The addition of large subunit ribosomal DNA (lsrDNA) to small subunit ribosomal DNA (ssrDNA) has been shown to add resolution to phylogenies at various taxonomic levels for a diversity of phyla. We added nearly complete lsrDNA (4057-4593bp) sequences to ssrDNA (1940-2228bp) for 26 ingroup and 3 outgroup taxa in an attempt to provide an improved ordinal phylogeny for the Cestoda. Ten lsrDNA and seven ssrDNA sequences were generated from new taxa and 13 existing partial lsrDNA sequences were sequenced to completion. The majority of phylogenetic signal in the combined analysis came from lsrDNA (69.6% of parsimonious informative sites, as opposed to 30.4% obtained from ssrDNA), resulting in almost identical topologies for lsrDNA and lsr+ssrDNA (pairwise symmetric distance=6) in model-based analyses. Topology testing found trees based on partial lsrDNA (domains D1-D3)+ssrDNA and complete lsr+ssrDNA to differ significantly; the addition of lsrDNA domains D4-D12 had a significant effect on topology. Overall nodal support was greatest in the combined analysis and weakest for ssrDNA only. Our molecular phylogenies differed significantly from those based on morphology alone. Acetabulate lineages form a monophyletic group, with the Tetraphyllidea being paraphyletic. Support for the combined data was high for the following topology: (Litobothriidea (Lecanicephalidea (Rhinebothrium/Rhodobothrium (Clistobothrium (Pachybothrium(Acanthobothrium Proteocephalidea) (Mesocestoididae, Nippotaeniidea, Cyclophyllidea, Tetrabothriidea)))))); all genus names refer to tetraphyllidean lineages. Although the interrelationships among the four most derived taxa remain uncertain, overall ambiguity of the acetabulate interrelationships was reduced. The Pseudophyllidea were recovered as polyphyletic, with support for a sister-group relationship between Diphyllobothriidae and Haplobothriidea. The monophyly of the Trypanorhyncha was recovered for the first time based on molecular data. The positions

  15. Nuclear Brachyury Expression Is Consistent in Chordoma, Common in Germ Cell Tumors and Small Cell Carcinomas, and Rare in Other Carcinomas and Sarcomas: An Immunohistochemical Study of 5229 Cases.

    PubMed

    Miettinen, Markku; Wang, Zengfeng; Lasota, Jerzy; Heery, Christopher; Schlom, Jeffrey; Palena, Claudia

    2015-10-01

    Brachyury is a transcription factor of the T-box family typically expressed in notochord and chordoma. Some studies report brachyury as highly specific for chordoma, whereas others have concluded that brachyury is expressed in many types of common carcinomas by reverse transcription polymerase chain reaction and immunohistochemistry and could be involved in the epithelial-mesenchymal transition and metastatic process. In this study, we immunohistochemically evaluated 5229 different tumors for nuclear brachyury expression using a new rabbit monoclonal antibody and automated immunostaining (Leica Bond Max). Only nuclear labeling was scored, and antibody dilution of 1:2000 was used. In normal tissues, only rare cells in seminiferous tubules were labeled; all other organs were negative. All chordomas (75/76), except a sarcomatous one, were positive, whereas chondrosarcomas were negative. Among epithelial tumors, positivity was often detected in embryonal carcinoma (74%) and seminoma (45%). Pulmonary small cell carcinoma was often positive (41%), whereas pulmonary and pancreatic adenocarcinomas only rarely showed nuclear brachyury positivity (3% to 4%). Common carcinomas such as ductal carcinomas of the breast or adenocarcinomas of the prostate only exceptionally showed nuclear positivity (<1%). No colorectal, hepatocellular, renal cell, squamous cell, thyroid or urothelial carcinoma, or mesothelioma showed nuclear brachyury positivity. Among mesenchymal and neuroectodermal tumors, only isolated cases of melanoma, malignant peripheral nerve sheath tumor, rhabdomyosarcoma, synovial sarcoma, and follicular lymphoma showed nuclear expression. However, as shown previously with lung carcinoma, experiments with lower antibody dilutions (1:200 to 1:500) showed weak cytoplasmic and nuclear labeling in breast cancers. In addition to chordoma, we show here for the first time that nuclear brachyury expression is prevalent in embryonal carcinoma, seminoma, and small cell carcinoma

  16. The phylogenetically invariant ACAGAGA and AGC sequences of U6 small nuclear RNA are more tolerant of mutation in human cells than in Saccharomyces cerevisiae.

    PubMed Central

    Datta, B; Weiner, A M

    1993-01-01

    U6 small nuclear RNA (snRNA) is the most highly conserved of the five spliceosomal snRNAs that participate in nuclear mRNA splicing. The proposal that U6 snRNA plays a key catalytic role in splicing [D. Brow and C. Guthrie, Nature (London) 337:14-15, 1989] is supported by the phylogenetic conservation of U6, the sensitivity of U6 to mutation, cross-linking of U6 to the vicinity of the 5' splice site, and genetic evidence for extensive base pairing between U2 and U6 snRNAs. We chose to mutate the phylogenetically invariant 41-ACAGAGA-47 and 53-AGC-55 sequences of human U6 because certain point mutations within the homologous regions of Saccharomyces cerevisiae U6 selectively block the first or second step of mRNA splicing. We found that both sequences are more tolerant to mutation in human cells (assayed by transient expression in vivo) than in S. cerevisiae (assayed by effects on growth or in vitro splicing). These differences may reflect different rate-limiting steps in the particular assays used or differential reliance on redundant RNA-RNA or RNA-protein interactions. The ability of mutations in U6 nucleotides A-45 and A-53 to selectively block step 2 of splicing in S. cerevisiae had previously been construed as evidence that these residues might participate directly in the second chemical step of splicing; an indirect, structural role seems more likely because the equivalent mutations have no obvious phenotype in the human transient expression assay. Images PMID:8355689

  17. The near boiling reactor: Conceptual design of a small inherently safe nuclear reactor to extend the operational capability of the Victoria Class submarine

    NASA Astrophysics Data System (ADS)

    Cole, Christopher J. P.

    Nuclear power has several unique advantages over other air independent energy sources for nuclear combat submarines. An inherently safe, small nuclear reactor, capable of supply the hotel load of the Victoria Class submarines, has been conceptually developed. The reactor is designed to complement the existing diesel electric power generation plant presently onboard the submarine. The reactor, rated at greater than 1 MW thermal, will supply electricity to the submarine's batteries through an organic Rankine cycle energy conversion plant at 200 kW. This load will increase the operational envelope of the submarine by providing up to 28 continuous days submerged, allowing for an enhanced indiscretion ratio (ratio of time spent on the surface versus time submerged) and a limited under ice capability. The power plant can be fitted into the existing submarine by inserting a 6 m hull plug. With its simplistic design and inherent safety features, the reactor plant will require a minimal addition to the crew. The reactor employs TRISO fuel particles for increased safety. The light water coolant remains at atmospheric pressure, exiting the core at 96°C. Burn-up control and limiting excess reactivity is achieved through movable reflector plates. Shut down and regulatory control is achieved through the thirteen hafnium control rods. Inherent safety is achieved through the negative prompt and delayed temperature coefficients, as well as the negative void coefficient. During a transient, the boiling of the moderator results in a sudden drop in reactivity, essentially shutting down the reactor. It is this characteristic after which the reactor has been named. The design of the reactor was achieved through modelling using computer codes such as MCNP5, WIMS-AECL, FEMLAB, and MicroShield5, in addition to specially written software for kinetics, heat transfer and fission product poisoning calculations. The work has covered a broad area of research and has highlighted additional areas

  18. Tumor necrosis factor alpha induces spermidine/spermine N1-acetyltransferase through nuclear factor kappaB in non-small cell lung cancer cells.

    PubMed

    Babbar, Naveen; Hacker, Amy; Huang, Yi; Casero, Robert A

    2006-08-25

    Tumor necrosis factor alpha (TNFalpha) is a potent pleiotropic cytokine produced by many cells in response to inflammatory stress. The molecular mechanisms responsible for the multiple biological activities of TNFalpha are due to its ability to activate multiple signal transduction pathways, including nuclear factor kappaB (NFkappaB), which plays critical roles in cell proliferation and survival. TNFalpha displays both apoptotic and antiapoptotic properties, depending on the nature of the stimulus and the activation status of certain signaling pathways. Here we show that TNFalpha can lead to the induction of NFkappaB signaling with a concomitant increase in spermidine/spermine N(1)-acetyltransferase (SSAT) expression in A549 and H157 non-small cell lung cancer cells. Induction of SSAT, a stress-inducible gene that encodes a rate-limiting polyamine catabolic enzyme, leads to lower intracellular polyamine contents and has been associated with decreased cell growth and increased apoptosis. Stable overexpression of a mutant, dominant negative IkappaBalpha protein led to the suppression of SSAT induction by TNFalpha in these cells, thereby substantiating a role of NFkappaB in the induction of SSAT by TNFalpha. SSAT promoter deletion constructs led to the identification of three potential NFkappaB response elements in the SSAT gene. Electromobility shift assays, chromatin immunoprecipitation experiments and mutational studies confirmed that two of the three NFkappaB response elements play an important role in the regulation of SSAT in response to TNFalpha. The results of these studies indicate that a common mediator of inflammation can lead to the induction of SSAT expression by activating the NFkappaB signaling pathway in non-small cell lung cancer cells.

  19. Gd(iii) and Mn(ii) complexes for dynamic nuclear polarization: small molecular chelate polarizing agents and applications with site-directed spin labeling of proteins.

    PubMed

    Kaushik, Monu; Bahrenberg, Thorsten; Can, Thach V; Caporini, Marc A; Silvers, Robert; Heiliger, Jörg; Smith, Albert A; Schwalbe, Harald; Griffin, Robert G; Corzilius, Björn

    2016-10-21

    We investigate complexes of two paramagnetic metal ions Gd(3+) and Mn(2+) to serve as polarizing agents for solid-state dynamic nuclear polarization (DNP) of (1)H, (13)C, and (15)N at magnetic fields of 5, 9.4, and 14.1 T. Both ions are half-integer high-spin systems with a zero-field splitting and therefore exhibit a broadening of the mS = -1/2 ↔ +1/2 central transition which scales inversely with the external field strength. We investigate experimentally the influence of the chelator molecule, strong hyperfine coupling to the metal nucleus, and deuteration of the bulk matrix on DNP properties. At small Gd-DOTA concentrations the narrow central transition allows us to polarize nuclei with small gyromagnetic ratio such as (13)C and even (15)N via the solid effect. We demonstrate that enhancements observed are limited by the available microwave power and that large enhancement factors of >100 (for (1)H) and on the order of 1000 (for (13)C) can be achieved in the saturation limit even at 80 K. At larger Gd(iii) concentrations (≥10 mM) where dipolar couplings between two neighboring Gd(3+) complexes become substantial a transition towards cross effect as dominating DNP mechanism is observed. Furthermore, the slow spin-diffusion between (13)C and (15)N, respectively, allows for temporally resolved observation of enhanced polarization spreading from nuclei close to the paramagnetic ion towards nuclei further removed. Subsequently, we present preliminary DNP experiments on ubiquitin by site-directed spin-labeling with Gd(3+) chelator tags. The results hold promise towards applications of such paramagnetically labeled proteins for DNP applications in biophysical chemistry and/or structural biology.

  20. Identification of small molecule proliferating cell nuclear antigen (PCNA) inhibitor that disrupts interactions with PIP-box proteins and inhibits DNA replication.

    PubMed

    Punchihewa, Chandanamali; Inoue, Akira; Hishiki, Asami; Fujikawa, Yoshihiro; Connelly, Michele; Evison, Benjamin; Shao, Youming; Heath, Richard; Kuraoka, Isao; Rodrigues, Patrick; Hashimoto, Hiroshi; Kawanishi, Masanobu; Sato, Mamoru; Yagi, Takashi; Fujii, Naoaki

    2012-04-20

    We have discovered that 3,3',5-triiodothyronine (T3) inhibits binding of a PIP-box sequence peptide to proliferating cell nuclear antigen (PCNA) protein by competing for the same binding site, as evidenced by the co-crystal structure of the PCNA-T3 complex at 2.1 Å resolution. Based on this observation, we have designed a novel, non-peptide small molecule PCNA inhibitor, T2 amino alcohol (T2AA), a T3 derivative that lacks thyroid hormone activity. T2AA inhibited interaction of PCNA/PIP-box peptide with an IC(50) of ~1 μm and also PCNA and full-length p21 protein, the tightest PCNA ligand protein known to date. T2AA abolished interaction of PCNA and DNA polymerase δ in cellular chromatin. De novo DNA synthesis was inhibited by T2AA, and the cells were arrested in S-phase. T2AA inhibited growth of cancer cells with induction of early apoptosis. Concurrently, Chk1 and RPA32 in the chromatin are phosphorylated, suggesting that T2AA causes DNA replication stress by stalling DNA replication forks. T2AA significantly inhibited translesion DNA synthesis on a cisplatin-cross-linked template in cells. When cells were treated with a combination of cisplatin and T2AA, a significant increase in phospho(Ser(139))histone H2AX induction and cell growth inhibition was observed.

  1. Topical Anti-Nuclear Factor-Kappa B Small Interfering RNA with Functional Peptides Containing Sericin-Based Hydrogel for Atopic Dermatitis

    PubMed Central

    Kanazawa, Takanori; Shizawa, Yuki; Takeuchi, Mayu; Tamano, Kuniko; Ibaraki, Hisako; Seta, Yasuo; Takashima, Yuuki; Okada, Hiroaki

    2015-01-01

    The small interfering RNA (siRNA) is suggested to offer a novel means of treating atopic dermatitis (AD) because it allows the specific silencing of genes related to AD pathogenesis. In our previous study, we found that siRNA targeted against RelA, an important nuclear factor-kappa B (NF-κB) subdomain, with functional peptides, showed therapeutic effects in a mouse model of AD. In the present study, to develop a topical skin application against AD, we prepared a hydrogel containing anti-RelA siRNA and functional peptides and determined the intradermal permeation and the anti-AD effects in an AD mouse model. We selected the silk protein, sericin (SC), which is a versatile biocompatible biomaterial to prepare hydrogel as an aqueous gel base. We found that the siRNA was more widely delivered to the site of application in AD-induced ear skin of mice after topical application via the hydrogel containing functional peptides than via the preparation without functional peptides. In addition, the ear thickness and clinical skin severity of the AD-induced mice treated with hydrogel containing anti-RelA siRNA with functional peptides improved more than that of mice treated with the preparation formulated with negative siRNA. PMID:26371030

  2. The Oct-1 POU-specific domain can stimulate small nuclear RNA gene transcription by stabilizing the basal transcription complex SNAPc.

    PubMed Central

    Mittal, V; Cleary, M A; Herr, W; Hernandez, N

    1996-01-01

    The RNA polymerase II and III human small nuclear RNA promoters have a common basal element, the proximal sequence element, which binds the TATA box-binding protein-containing complex SNAPc. They also contain an enhancer characterized by a highly conserved octamer sequence, which constitutes a binding site for the broadly expressed POU domain transcription factor Oct-1. The POU domain is a bipartite DNA-binding domain consisting of a POU-homeo (POUH) domain and a POU-specific (POUs) domain joined by a flexible linker. Here, we show that the Oct-1 POU domain but not the related Pit-1 POU domain can facilitate the binding of SNAPc to the proximal sequence element, and activate transcription. The effect is probably mediated by protein-protein contacts, and 1 of 30 amino acid differences between the Oct-1 and Pit-1 POUs domains is the key determinant for the differential interaction with SNAPc and the ability to activate transcription. These results show that a function that is the hallmark of activation domains, namely, recruitment of a basal transcription complex resulting in activation of transcription, can be performed by a DNA-binding domain. In this case, subtle changes between activator DNA-binding domains, as subtle as a single amino acid difference, can profoundly affect interaction with the basal transcription machinery. PMID:8628262

  3. Identification of Small Molecule Proliferating Cell Nuclear Antigen (PCNA) Inhibitor That Disrupts Interactions with PIP-box Proteins and Inhibits DNA Replication*

    PubMed Central

    Punchihewa, Chandanamali; Inoue, Akira; Hishiki, Asami; Fujikawa, Yoshihiro; Connelly, Michele; Evison, Benjamin; Shao, Youming; Heath, Richard; Kuraoka, Isao; Rodrigues, Patrick; Hashimoto, Hiroshi; Kawanishi, Masanobu; Sato, Mamoru; Yagi, Takashi; Fujii, Naoaki

    2012-01-01

    We have discovered that 3,3′,5-triiodothyronine (T3) inhibits binding of a PIP-box sequence peptide to proliferating cell nuclear antigen (PCNA) protein by competing for the same binding site, as evidenced by the co-crystal structure of the PCNA-T3 complex at 2.1 Å resolution. Based on this observation, we have designed a novel, non-peptide small molecule PCNA inhibitor, T2 amino alcohol (T2AA), a T3 derivative that lacks thyroid hormone activity. T2AA inhibited interaction of PCNA/PIP-box peptide with an IC50 of ∼1 μm and also PCNA and full-length p21 protein, the tightest PCNA ligand protein known to date. T2AA abolished interaction of PCNA and DNA polymerase δ in cellular chromatin. De novo DNA synthesis was inhibited by T2AA, and the cells were arrested in S-phase. T2AA inhibited growth of cancer cells with induction of early apoptosis. Concurrently, Chk1 and RPA32 in the chromatin are phosphorylated, suggesting that T2AA causes DNA replication stress by stalling DNA replication forks. T2AA significantly inhibited translesion DNA synthesis on a cisplatin-cross-linked template in cells. When cells were treated with a combination of cisplatin and T2AA, a significant increase in phospho(Ser139)histone H2AX induction and cell growth inhibition was observed. PMID:22383522

  4. Pro-recombination Role of Srs2 Protein Requires SUMO (Small Ubiquitin-like Modifier) but Is Independent of PCNA (Proliferating Cell Nuclear Antigen) Interaction.

    PubMed

    Kolesar, Peter; Altmannova, Veronika; Silva, Sonia; Lisby, Michael; Krejci, Lumir

    2016-04-01

    Srs2 plays many roles in DNA repair, the proper regulation and coordination of which is essential. Post-translational modification by small ubiquitin-like modifier (SUMO) is one such possible mechanism. Here, we investigate the role of SUMO in Srs2 regulation and show that the SUMO-interacting motif (SIM) of Srs2 is important for the interaction with several recombination factors. Lack of SIM, but not proliferating cell nuclear antigen (PCNA)-interacting motif (PIM), leads to increased cell death under circumstances requiring homologous recombination for DNA repair. Simultaneous mutation of SIM in asrs2ΔPIMstrain leads to a decrease in recombination, indicating a pro-recombination role of SUMO. Thus SIM has an ambivalent function in Srs2 regulation; it not only mediates interaction with SUMO-PCNA to promote the anti-recombination function but it also plays a PCNA-independent pro-recombination role, probably by stimulating the formation of recombination complexes. The fact that deletion of PIM suppresses the phenotypes of Srs2 lacking SIM suggests that proper balance between the anti-recombination PCNA-bound and pro-recombination pools of Srs2 is crucial. Notably, sumoylation of Srs2 itself specifically stimulates recombination at the rDNA locus.

  5. Investigations of active interrogation techniques to detect special nuclear material in maritime environments: Standoff interrogation of small- and medium-sized cargo ships

    NASA Astrophysics Data System (ADS)

    Miller, Thomas M.; Patton, Bruce W.; Grogan, Brandon R.; Henkel, James J.; Murphy, Brian D.; Johnson, Jeffrey O.; Mihalczo, John T.

    2013-12-01

    In this work, several active interrogation (AI) sources are evaluated to determine their usefulness in detecting the presence of special nuclear material (SNM) in fishing trawlers, small cargo transport ships, and luxury yachts at large standoff distances from the AI source and detector. This evaluation is performed via computational analysis applying Monte Carlo methods with advanced variance reduction techniques. The goal is to determine the AI source strength required to detect the presence of SNM. The general conclusion of this study is that AI is not reliable when SNM is heavily shielded and not tightly coupled geometrically with the source and detector, to the point that AI should not be considered a via interrogation option in these scenarios. More specifically, when SNM is shielded by hydrogenous material large AI source strengths are required if detection is based on neutrons, which is not surprising. However, if the SNM is shielded by high-Z material the required AI source strengths are not significantly different if detection is based on neutrons or photons, which is somewhat surprising. Furthermore, some of the required AI source strengths that were calculated are very large. These results coupled with the realities of two ships moving independently at sea and other assumptions made during this analysis make the use of standoff AI in the maritime environment impractical.

  6. Plant small nuclear RNAs. II. U6 RNA and a 4.5SI-like RNA are present in plant nuclei.

    PubMed Central

    Kiss, T; Antal, M; Solymosy, F

    1987-01-01

    Two small nuclear RNA species (U6 RNA and a 4.5SI-like RNA) not described so far for plants were detected in broad bean (Vicia faba L.) nuclei. U6 RNA is 98 nucleotides long, contains psi and methylated nucleotides and shows a surprisingly high degree of sequence homology (80%) with its rat counterpart, particularly in the middle part (a 57 nucleotide-long stretch) of the molecule, where it amounts to 98%. The 4.5SI-like RNA, similar in its structure to 4.5SI RNA detected so far only in rodent nuclei, is 94 nucleotides long, contains psi and an unidentified nucleotide and exhibits 52% overall sequence homology with rat 4.5SI RNA. A block of 20 consecutive nucleotides at the 5' end of the molecule is conserved between broad bean 4.5SI-like RNA and rat 4.5SI RNA. The presence of the two RNA polymerase III internal promoter consensus sequences in 4.5SI-like RNA suggests that it is an RNA polymerase III transcript. Images PMID:2434924

  7. [Identification and expression analysis of a full-length cDNA encoding Brassica napus small nuclear ribonucleoprotein BnSmD1].

    PubMed

    Yuan, Xiao-Meng; Zhou, Yun-Tao; Zhang, Hong-Yan; Xue, Hua; Zhou, Lin; Zhao, Yun

    2007-12-01

    By using substractive hybridization (SSH) and rapid amplification of cDNA ends-polymerase chain reaction (RACE-PCR), a full-length cDNA encoding Brassica napus small nuclear ribonucleoprotein, named BnSmD1, was obtained. It had 484 base pairs in length containing an open reading frame (ORF) of 354 bp and encoding a predicted protein of 118 amino acids with a molecular weight of 13 kDa. The BnSmD1 protein shares two highly conserved Sm folds (Sm-1 and Sm-2) and a C-terminal RG dipeptide repeat. Northern blot analysis revealed that BnSmD1 was expressed in all tested organs in B. napus, but its transcript level in early floral buds was much higher than that in leaf and stem tissues. No obvious expression difference was observed in leaf and stem tissues between the apetalous line Apet33-10 petalled near-isogenic line Pet33-10. Compared with wild type, the expression of BnSmD1 in the early floral buds of apetalous mutant Apet33-10 was significantly reduced. Taken together, our results suggest that BnSmD1 may play an important role in early floral petal development in B. napus.

  8. In vitro correction of a pseudoexon-generating deep intronic mutation in LGMD2A by antisense oligonucleotides and modified small nuclear RNAs.

    PubMed

    Blázquez, Lorea; Aiastui, Ana; Goicoechea, Maria; Martins de Araujo, Mafalda; Avril, Aurélie; Beley, Cyriaque; García, Luis; Valcárcel, Juan; Fortes, Puri; López de Munain, Adolfo

    2013-10-01

    Limb-girdle muscular dystrophy type 2A (LGMD2A) is the most frequent autosomal recessive muscular dystrophy. It is caused by mutations in the calpain-3 (CAPN3) gene. The majority of the mutations described to date are located in the coding sequence of the gene. However, it is estimated that 25% of the mutations are present at exon-intron boundaries and modify the pre-mRNA splicing of the CAPN3 transcript. We have previously described the first deep intronic mutation in the CAPN3 gene: c.1782+1072G>C mutation. This mutation causes the pseudoexonization of an intronic sequence of the CAPN3 gene in the mature mRNA. In the present work, we show that the point mutation generates the inclusion of the pseudoexon in the mRNA using a minigene assay. In search of a treatment that restores normal splicing, splicing modulation was induced by RNA-based strategies, which included antisense oligonucleotides and modified small-nuclear RNAs. The best effect was observed with antisense sequences, which induced pseudoexon skipping in both HeLa cells cotransfected with mutant minigene and in fibroblasts from patients. Finally, transfection of antisense sequences and siRNA downregulation of serine/arginine-rich splicing factor 1 (SRSF1) indicate that binding of this factor to splicing enhancer sequences is involved in pseudoexon activation.

  9. Evidence for a base-pairing interaction between U6 small nuclear RNA and 5' splice site during the splicing reaction in yeast.

    PubMed Central

    Sawa, H; Abelson, J

    1992-01-01

    U6 small nuclear RNA (snRNA) is an essential factor in mRNA splicing. On the basis of the high conservation of its sequence, it has been proposed that U6 snRNA may function catalytically during the splicing reaction. If this is the case, it is likely that U6 snRNA interacts with the splice sites in the spliceosome to catalyze the reaction. We have used UV crosslinking to analyze the interactions of U6 snRNA with the splicing substrates during the yeast splicing reaction. Crosslinked products in which the central region of U6 snRNA was joined to the 5' splice site region of mRNA precursor and lariat intermediate were identified. The crosslinking sites were precisely located in one of these products. The results suggest a possible base-pairing interaction between U6 snRNA and the 5' splice site of the mRNA precursor. Images PMID:1333604

  10. Analysis of a cDNA clone expressing a human autoimmune antigen: full-length sequence of the U2 small nuclear RNA-associated B antigen

    SciTech Connect

    Habets, W.J.; Sillekens, P.T.G.; Hoet, M.H.; Schalken, J.A.; Roebroek, A.J.M.; Leunissen, J.A.M.; Van de Ven, W.J.M.; Van Venrooij, W.J.

    1987-04-01

    A U2 small nuclear RNA-associated protein, designated B'', was recently identified as the target antigen for autoimmune sera from certain patients with systemic lupus erythematosus and other rheumatic diseases. Such antibodies enabled them to isolate cDNA clone lambdaHB''-1 from a phage lambdagt11 expression library. This clone appeared to code for the B'' protein as established by in vitro translation of hybrid-selected mRNA. The identity of clone lambdaHB''-1 was further confirmed by partial peptide mapping and analysis of the reactivity of the recombinant antigen with monospecific and monoclonal antibodies. Analysis of the nucleotide sequence of the 1015-base-pair cDNA insert of clone lambdaHB''-1 revealed a large open reading frame of 800 nucleotides containing the coding sequence for a polypeptide of 25,457 daltons. In vitro transcription of the lambdaHB''-1 cDNA insert and subsequent translation resulted in a protein product with the molecular size of the B'' protein. These data demonstrate that clone lambdaHB''-1 contains the complete coding sequence of this antigen. The deduced polypeptide sequence contains three very hydrophilic regions that might constitute RNA binding sites and/or antigenic determinants. These findings might have implications both for the understanding of the pathogenesis of rheumatic diseases as well as for the elucidation of the biological function of autoimmune antigens.

  11. Sequences more than 500 base pairs upstream of the human U3 small nuclear RNA gene stimulate the synthesis of U3 RNA in frog oocytes

    SciTech Connect

    Suh, D.; Reddy, R. ); Wright, D. )

    1991-06-04

    Small nuclear RNA (snRNA) genes contain strong promoters capable of initiating transcription once every 4 s. Studies on the human U1 snRNA gene, carried out in other laboratories, showed that sequences within 400 bp of the 5' flanking region are sufficient for maximal levels of transcription both in vivo and in frog oocytes (reviewed in Dahlberg and Lund (1988)). The authors studied the expression of a human U3 snRNA gene by injecting 5' deletion mutants into frog oocytes. The results show that sequences more than 500 bp upstream of the U3 snRNA gene have a 2-3-fold stimulatory effect on the U3 snRNA synthesis. These results indicate that the human U3 snRNA gene is different from human U1 snRNA gene in containing regulatory elements more than 500 bp upstream. The U3 snRNA gene upstream sequences contain an AluI homologous sequence in the {minus}1,200 region; these AluI sequences were transcribed in vitro and in frog oocytes but were not detectable in Hela cells.

  12. The phylogenetic position of eriophyoid mites (superfamily Eriophyoidea) in Acariformes inferred from the sequences of mitochondrial genomes and nuclear small subunit (18S) rRNA gene.

    PubMed

    Xue, Xiao-Feng; Dong, Yan; Deng, Wei; Hong, Xiao-Yue; Shao, Renfu

    2017-04-01

    Eriophyoid mites (superfamily Eriophyoidea) comprise >4400 species worldwide. Despite over a century of study, the phylogenetic position of these mites within Acariformes is still poorly resolved. Currently, Eriophyoidea is placed in the order Trombidiformes. We inferred the high-level phylogeny of Acari with the mitochondrial (mt) genome sequences of 110 species including four eriophyoid species, and the nuclear small subunit (18S) rRNA gene sequences of 226 species including 25 eriophyoid species. Maximum likelihood (ML), Bayesian inference (BI) and Maximum parsimony (MP) methods were used to analyze the sequence data. Divergence times were estimated for major lineages of Acari using Bayesian approaches. Our analyses consistently recovered the monophyly of Eriophyoidea but rejected the monophyly of Trombidiformes. The eriophyoid mites were grouped with the sarcoptiform mites, or were the sister group of sarcoptiform mites+non-eriophyoid trombidiform mites, depending on data partition strategies. Eriophyoid mites diverged from other mites in the Devonian (384Mya, 95% HPD, 352-410Mya). The origin of eriophyoid mites was dated to the Permian (262Mya, 95% HPD 230-307Mya), mostly prior to the radiation of gymnosperms (Triassic-Jurassic) and angiosperms (early Cretaceous). We propose that the placement of Eriophyoidea in the order Trombidiformes under the current classification system should be reviewed.

  13. Proliferation of Small Nuclear Forces.

    DTIC Science & Technology

    1983-04-30

    Defense and Department of Energy, 1977). ** CEP is " circular error probable" or the radius from the aim point within which 50% of the launched warheads...L. Eagleburger ATTN: J. Ruina ATTN: Under Sec S&T&SA, S. Sinkiewiez ATTN: R. Kennedy Columbia University ATTN: L. Dunn ATTN: W. Schilling ATTN: J

  14. Recognition of U1 and U2 small nuclear RNAs can be altered by a 5-amino-acid segment in the U2 small nuclear ribonucleoprotein particle (snRNP) B" protein and through interactions with U2 snRNP-A' protein.

    PubMed Central

    Bentley, R C; Keene, J D

    1991-01-01

    We have investigated the sequence elements influencing RNA recognition in two closely related small nuclear ribonucleoprotein particle (snRNP) proteins, U1 snRNP-A and U2 snRNP-B". A 5-amino-acid segment in the RNA-binding domain of the U2 snRNP-B" protein was found to confer U2 RNA recognition when substituted into the corresponding position in the U1 snRNP-A protein. In addition, B", but not A, was found to require the U2 snRNP-A' protein as an accessory factor for high-affinity binding to U2 RNA. The pentamer segment in B" that conferred U2 RNA recognition was not sufficient to allow the A' enhancement of U2 RNA binding by B", thus implicating other sequences in this protein-protein interaction. Sequence elements involved in these interactions have been localized to variable loops of the RNA-binding domain as determined by nuclear magnetic resonance spectroscopy (D. Hoffman, C.C. Query, B. Golden, S.W. White, and J.D. Keene, Proc. Natl. Acad. Sci. USA, in press). These findings suggest a role for accessory proteins in the formation of RNP complexes and pinpoint amino acid sequences that affect the specificity of RNA recognition in two members of a large family of proteins involved in RNA processing. Images PMID:1826042

  15. Nuclear Energy Policy

    DTIC Science & Technology

    2010-05-27

    small modular reactors and extend the lives and improve the operation of existing commercial nuclear power plants. 40 Interdisciplinary MIT Study, The Future of Nuclear Power, Massachusetts Institute of Technology, 2003, p. 79. 41 Gronlund, Lisbeth, David Lochbaum, and Edwin Lyman, Nuclear Power in a Warming World, Union of Concerned Scientists, December 2007. 42 Travis Madsen, Tony Dutzik, and Bernadette Del Chiaro, et al., Generating Failure: How Building Nuclear Power Plants

  16. Modulation of expression of the nuclear receptor NR0B2 (small heterodimer partner 1) and its impact on proliferation of renal carcinoma cells.

    PubMed

    Prestin, Katharina; Olbert, Maria; Hussner, Janine; Isenegger, Tamara L; Gliesche, Daniel G; Böttcher, Kerstin; Zimmermann, Uwe; Meyer Zu Schwabedissen, Henriette E

    2016-01-01

    Mammalian nuclear receptors (NRs) are transcription factors regulating the expression of target genes that play an important role in drug metabolism, transport, and cellular signaling pathways. The orphan and structurally unique receptor small heterodimer partner 1 (syn NR0B2) is not only known for its modulation of drug response, but has also been reported to be involved in hepatocellular carcinogenesis. Indeed, previous studies show that NR0B2 is downregulated in human hepatocellular carcinoma, suggesting that NR0B2 acts as a tumor suppressor via inhibition of cellular growth and activation of apoptosis in this tumor entity. The aim of our study was to elucidate whether NR0B2 may also play a role in other tumor entities. Comparing NR0B2 expression in renal cell carcinoma and adjacent nonmalignant transformed tissue revealed significant downregulation in vivo. Additionally, the impact of heterologous expression of NR0B2 on cell cycle progression and proliferation in cells of renal origin was characterized. Monitoring fluorescence intensity of resazurin turnover in RCC-EW cells revealed no significant differences in metabolic activity in the presence of NR0B2. However, there was a significant decrease of cellular proliferation in cells overexpressing this NR, and NR0B2 was more efficient than currently used antiproliferative agents. Furthermore, flow cytometry analysis showed that heterologous overexpression of NR0B2 significantly reduced the amount of cells passing the G1 phase, while on the other hand, more cells in S/G2 phase were detected. Taken together, our data suggest that downregulation of NR0B2 may also play a role in renal cell carcinoma development and progression.

  17. Y-box-binding protein-1 expression is not correlated with p53 expression but with proliferating cell nuclear antigen expression in non-small cell lung cancer.

    PubMed

    Yoshimatsu, Takashi; Uramoto, Hidetaka; Oyama, Tsunehiro; Yashima, Yasunori; Gu, Chundong; Morita, Masaru; Sugio, Kenji; Kohno, Kimitoshi; Yasumoto, Kosei

    2005-01-01

    Transcription factor Y-box-binding protein 1 (YB-1), which binds to the inverted CCAAT box, is not only involved in the transcription of various genes, but also in cell proliferation and DNA repair. The aim of this study was to detect YB-1 and p53 expression and their relationship to proliferating cell nuclear antigen (PCNA) in non-small cell lung cancer (NSCLC) using immunohistochemical (IHC) staining, and to evaluate the relationship between their expression levels and the prognosis of patients with NSCLC. Positive expressions of YB-1, p53 and PCNA were detected in NSCLC cells in 43 (45.7%), 33 (35.0%) and 45 (47.9%) out of 94 patients, respectively. No significant differences were observed between YB-1 expression and the patients' gender, age at surgery, pathological stage, pathological T status, pathological N status, or pathological M status. The mean PCNA-labelling index (LI) for cells was 40.7+/-2.6. Also, a significant correlation between YB-1 and PCNA-LI was found (p<0.01), but none was found between p53 expression and PCNA. The positive expression of YB-1 was associated with squamous cell carcinoma and large cell carcinoma, compared with adenocarcinomas (p<0.01), and higher levels of PCNA-LI were associated with large cell carcinoma compared with adenocarcinomas and squamous cell carcinoma (p<0.01). These results suggest that YB-1 expression is correlated with PCNA expression in NSCLC. In addition, the DNA repair pathway and tumor proliferation mediated by YB-1 linking to PCNA may be responsible for controlling the growth of NSCLC.

  18. Eubacterial components similar to small nuclear ribonucleoproteins: identification of immunoprecipitable proteins and capped RNAs in a cyanobacterium and a gram-positive eubacterium.

    PubMed Central

    Kovacs, S A; O'Neil, J; Watcharapijarn, J; Moe-Kirvan, C; Vijay, S; Silva, V

    1993-01-01

    Small nuclear ribonucleoprotein (snRNP) particles play an important role in the processing of pre-mRNA. snRNPs have been identified immunologically in a variety of cells, but none have ever been observed in prokaryotic systems. This report provides the first evidence for the presence of snRNP-like components in two types of prokaryotic cells: those of the cyanobacterium Synechococcus leopoliensis and those of the gram-positive eubacterium Bacillus subtilis. These components consist of snRNP-immunoreactive proteins and RNAs, including some with the snRNP-unique 5' m2,2,7G (m3G) cap. Immunoreactivity was determined by immunoprecipitation procedures, with either antinuclear-antibody-positive (RNP- and Sm-monospecific) patient sera or a m3G monoclonal antibody, with radiolabelled cell extracts that were preadsorbed with antinuclear-antibody-negative sera. S. leopoliensis immunoprecipitates showed the presence of high-molecular-mass proteins (14 to 70 kDa) and RNAs (138 to 243 nucleotides) that are analogous in size to proteins and RNAs found in human (HEp-2) cell immunoprecipitates but absent in Escherichia coli immunoprecipitates. Thin-layer chromatography of S. leopoliensis immunoprecipitates confirmed the presence of a capped nucleotide similar to a capped nucleotide in HEp-2 immunoprecipitates; no such nucleotide was observed in E. coli immunoprecipitates. Immunoreactive RNAs (117-170 nucleotides) were identified in a second eubacterium, B. subtilis, as well. This work suggests that snRNPs or their evolutionary predecessors predate the emergence of eukaryotic cells. Images PMID:8458830

  19. Primary structures of the heterogeneous nuclear ribonucleoprotein A2, B1, and C2 proteins: a diversity of RNA binding proteins is generated by small peptide inserts.

    PubMed Central

    Burd, C G; Swanson, M S; Görlach, M; Dreyfuss, G

    1989-01-01

    We have isolated cDNAs for the major heterogeneous nuclear ribonucleoprotein (hnRNP) A2, B1, and C2 proteins and determined their nucleotide and deduced amino acid sequences. The A2 and B1 cDNAs are identical except for a 36-nucleotide in-frame insert in B1. Similarly, the sequence of the C2 protein cDNA is related to that of C1 in that C2 contains an extra 39 in-frame nucleotides. Therefore, the B1 amino acid sequence is identical to A2 except for the insertion of 12 amino acids near its amino terminus, and C1 and C2 are also identical to each other except for an extra 13 amino acids near the middle of C2. All three proteins are members of a large family of RNA binding proteins that contain the consensus sequence-type RNA binding domain (CS-RBD). The A2 and B1 proteins have a modular structure similar to that of the hnRNP protein A1: they contain two CS-RBDs and a glycine-rich auxiliary domain at the carboxyl terminus. The CS-RBDs of A2 and B1 have approximately 80% amino acid identity with those of A1, whereas the glycine-rich auxiliary domain is considerably more divergent with less than 30% of the amino acids being identical. These findings indicate that the addition of small peptides, probably by alternative pre-mRNA splicing, generates some of the diversity apparent among hnRNP proteins. Images PMID:2557628

  20. Ginsenoside Rg3 sensitizes human non-small cell lung cancer cells to γ-radiation by targeting the nuclear factor-κB pathway.

    PubMed

    Wang, Lei; Li, Xiankui; Song, Yi-Min; Wang, Bin; Zhang, Fu-Rui; Yang, Rui; Wang, Hua-Qi; Zhang, Guo-Jun

    2015-07-01

    At present, it is elusive how non-small cell lung cancer (NSCLC) develops resistance to γ-radiation; however, the transcription factor nuclear factor-κB (NF-κB) and NF-κB-regulated gene products have been proposed as mediators. Ginsenoside Rg3 is a steroidal saponin, which was isolated from Panax ginseng. Ginsenoside Rg3 possesses high pharmacological activity and has previously been shown to suppress NF-κB activation in various types of tumor cell. Therefore, the present study aimed to determine whether Rg3 could suppress NF-κB activation in NSCLC cells and sensitize NSCLC to γ-radiation, using an NSCLC cell line and NSCLC xenograft. A clone formation assay and lung tumor xenograft experiment were used to assess the radiosensitizing effects of ginsenoside Rg3. NF-κB/inhibitor of NF-κB (IκB) modulation was ascertained using an electrophoretic mobility shift assay and western blot analysis. NF-κB-regulated gene products were monitored by western blot analysis. The present study demonstrated that ginsenoside Rg3 was able to sensitize A549 and H1299 lung carcinoma cells to γ-radiation and significantly enhance the efficacy of radiation therapy in C57BL/6 mice bearing a Lewis lung carcinoma cell xenograft tumor. Furthermore, ginsenoside Rg3 suppressed NF-κB activation, phosphorylation of IκB protein and expression of NF-κB-regulated gene products (cyclin D1, c-myc, B-cell lymphoma 2, cyclooxygenase-2, matrix metalloproteinase-9 and vascular endothelial growth factor), a number of which were induced by radiation therapy and mediate radioresistance. In conclusion, the results of the present study suggested that ginsenoside Rg3 may potentiate the antitumor effects of radiation therapy in NSCLC by suppressing NF-κB activity and NF-κB-regulated gene products, leading to the inhibition of tumor progression.

  1. Homeobox A9 directly targeted by miR-196b regulates aggressiveness through nuclear Factor-kappa B activity in non-small cell lung cancer cells.

    PubMed

    Yu, Seong-Lan; Lee, Dong Chul; Sohn, Hyun Ahm; Lee, Soo Young; Jeon, Hyo Sung; Lee, Joon H; Park, Chang Gyo; Lee, Hoi Young; Yeom, Young Il; Son, Ji Woong; Yoon, Yoo Sang; Kang, Jaeku

    2016-12-01

    MicroRNAs (miRNAs) are recognized as crucial posttranscriptional regulators of gene expression, and play critical roles as oncogenes or tumor suppressors in various cancers. Here, we show that miR-196b is upregulated in mesenchymal-like-state non-small cell lung cancer (NSCLC) cells and lung cancer tissues. Moreover, miR-196b upregulation stimulates cell invasion and a change in cell morphology to a spindle shape via loss of cell-to-cell contacts. We identified homeobox A9 (HOXA9) as a target gene of miR-196b by using public databases such as TargetScan, miRDB, and microRNA.org. HOXA9 expression is inversely correlated with miR-196b levels in clinical NSCLC samples as compared to that in corresponding control samples, and with the migration and invasion of NSCLC cells. Ectopic expression of HOXA9 resulted in a suppression of miR-196b-induced cell invasion, and HOXA9 reexpression increased E-cadherin expression. Furthermore, HOXA9 potently attenuated the expression of snail family zinc finger 2 (SNAI2/SLUG) and matrix metallopeptidase 9 (MMP9) by controlling the binding of nuclear factor-kappa B to the promoter of SLUG and MMP9 genes, respectively. Therefore, we suggest that HOXA9 plays a central role in controlling the aggressive behavior of lung cancer cells and that miR-196b can serve as a potential target for developing anticancer agents. © 2015 Wiley Periodicals, Inc.

  2. Contrast variation by dynamic nuclear polarization and time-of-flight small-angle neutron scattering. I. Application to industrial multi-component nanocomposites1

    PubMed Central

    Noda, Yohei; Koizumi, Satoshi; Masui, Tomomi; Mashita, Ryo; Kishimoto, Hiroyuki; Yamaguchi, Daisuke; Kumada, Takayuki; Takata, Shin-ichi; Ohishi, Kazuki; Suzuki, Jun-ichi

    2016-01-01

    Dynamic nuclear polarization (DNP) at low temperature (1.2 K) and high magnetic field (3.3 T) was applied to a contrast variation study in small-angle neutron scattering (SANS) focusing on industrial rubber materials. By varying the scattering contrast by DNP, time-of-flight SANS profiles were obtained at the pulsed neutron source of the Japan Proton Accelerator Research Complex (J-PARC). The concentration of a small organic molecule, (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO), was carefully controlled by a doping method using vapour sorption into the rubber specimens. With the assistance of microwave irradiation (94 GHz), almost full polarization of the paramagnetic electronic spin of TEMPO was transferred to the spin state of hydrogen (protons) in the rubber materials to obtain a high proton spin polarization (P H). The following samples were prepared: (i) a binary mixture of styrene–butadiene random copolymer (SBR) with silica particles (SBR/SP); and (ii) a ternary mixture of SBR with silica and carbon black particles (SBR/SP/CP). For the binary mixture (SBR/SP), the intensity of SANS significantly increased or decreased while keeping its q dependence for P H = −35% or P H = 40%, respectively. The q behaviour of SANS for the SBR/SP mixture can be reproduced using the form factor of a spherical particle. The intensity at low q (∼0.01 Å−1) varied as a quadratic function of P H and indicated a minimum value at P H = 30%, which can be explained by the scattering contrast between SP and SBR. The scattering intensity at high q (∼0.3 Å−1) decreased with increasing P H, which is attributed to the incoherent scattering from hydrogen. For the ternary mixture (SBR/SP/CP), the q behaviour of SANS was varied by changing P H. At P H = −35%, the scattering maxima originating from the form factor of SP prevailed, whereas at P H = 29% and P H = 38%, the scattering maxima disappeared. After decomposition of the total SANS according to inverse matrix

  3. Contrast variation by dynamic nuclear polarization and time-of-flight small-angle neutron scattering. I. Application to industrial multi-component nanocomposites.

    PubMed

    Noda, Yohei; Koizumi, Satoshi; Masui, Tomomi; Mashita, Ryo; Kishimoto, Hiroyuki; Yamaguchi, Daisuke; Kumada, Takayuki; Takata, Shin-Ichi; Ohishi, Kazuki; Suzuki, Jun-Ichi

    2016-12-01

    Dynamic nuclear polarization (DNP) at low temperature (1.2 K) and high magnetic field (3.3 T) was applied to a contrast variation study in small-angle neutron scattering (SANS) focusing on industrial rubber materials. By varying the scattering contrast by DNP, time-of-flight SANS profiles were obtained at the pulsed neutron source of the Japan Proton Accelerator Research Complex (J-PARC). The concentration of a small organic molecule, (2,2,6,6-tetramethylpiperidine-1-yl)oxy (TEMPO), was carefully controlled by a doping method using vapour sorption into the rubber specimens. With the assistance of microwave irradiation (94 GHz), almost full polarization of the paramagnetic electronic spin of TEMPO was transferred to the spin state of hydrogen (protons) in the rubber materials to obtain a high proton spin polarization (PH). The following samples were prepared: (i) a binary mixture of styrene-butadiene random copolymer (SBR) with silica particles (SBR/SP); and (ii) a ternary mixture of SBR with silica and carbon black particles (SBR/SP/CP). For the binary mixture (SBR/SP), the intensity of SANS significantly increased or decreased while keeping its q dependence for PH = -35% or PH = 40%, respectively. The q behaviour of SANS for the SBR/SP mixture can be reproduced using the form factor of a spherical particle. The intensity at low q (∼0.01 Å(-1)) varied as a quadratic function of PH and indicated a minimum value at PH = 30%, which can be explained by the scattering contrast between SP and SBR. The scattering intensity at high q (∼0.3 Å(-1)) decreased with increasing PH, which is attributed to the incoherent scattering from hydrogen. For the ternary mixture (SBR/SP/CP), the q behaviour of SANS was varied by changing PH. At PH = -35%, the scattering maxima originating from the form factor of SP prevailed, whereas at PH = 29% and PH = 38%, the scattering maxima disappeared. After decomposition of the total SANS according to inverse matrix calculations

  4. Nuclear reactor

    DOEpatents

    Wade, Elman E.

    1979-01-01

    A nuclear reactor including two rotatable plugs and a positive top core holddown structure. The top core holddown structure is divided into two parts: a small core cover, and a large core cover. The small core cover, and the upper internals associated therewith, are attached to the small rotating plug, and the large core cover, with its associated upper internals, is attached to the large rotating plug. By so splitting the core holddown structures, under-the-plug refueling is accomplished without the necessity of enlarging the reactor pressure vessel to provide a storage space for the core holddown structure during refueling. Additionally, the small and large rotating plugs, and their associated core covers, are arranged such that the separation of the two core covers to permit rotation is accomplished without the installation of complex lifting mechanisms.

  5. Nuclear Security for Floating Nuclear Power Plants

    SciTech Connect

    Skiba, James M.; Scherer, Carolynn P.

    2015-10-13

    Recently there has been a lot of interest in small modular reactors. A specific type of these small modular reactors (SMR,) are marine based power plants called floating nuclear power plants (FNPP). These FNPPs are typically built by countries with extensive knowledge of nuclear energy, such as Russia, France, China and the US. These FNPPs are built in one country and then sent to countries in need of power and/or seawater desalination. Fifteen countries have expressed interest in acquiring such power stations. Some designs for such power stations are briefly summarized. Several different avenues for cooperation in FNPP technology are proposed, including IAEA nuclear security (i.e. safeguards), multilateral or bilateral agreements, and working with Russian design that incorporates nuclear safeguards for IAEA inspections in non-nuclear weapons states

  6. Nuclear Models

    NASA Astrophysics Data System (ADS)

    Fossión, Rubén

    2010-09-01

    The atomic nucleus is a typical example of a many-body problem. On the one hand, the number of nucleons (protons and neutrons) that constitute the nucleus is too large to allow for exact calculations. On the other hand, the number of constituent particles is too small for the individual nuclear excitation states to be explained by statistical methods. Another problem, particular for the atomic nucleus, is that the nucleon-nucleon (n-n) interaction is not one of the fundamental forces of Nature, and is hard to put in a single closed equation. The nucleon-nucleon interaction also behaves differently between two free nucleons (bare interaction) and between two nucleons in the nuclear medium (dressed interaction). Because of the above reasons, specific nuclear many-body models have been devised of which each one sheds light on some selected aspects of nuclear structure. Only combining the viewpoints of different models, a global insight of the atomic nucleus can be gained. In this chapter, we revise the the Nuclear Shell Model as an example of the microscopic approach, and the Collective Model as an example of the geometric approach. Finally, we study the statistical properties of nuclear spectra, basing on symmetry principles, to find out whether there is quantum chaos in the atomic nucleus. All three major approaches have been rewarded with the Nobel Prize of Physics. In the text, we will stress how each approach introduces its own series of approximations to reduce the prohibitingly large number of degrees of freedom of the full many-body problem to a smaller manageable number of effective degrees of freedom.

  7. Reduced IgG anti-small nuclear ribonucleoprotein autoantibody production in systemic lupus erythematosus patients with positive IgM anti-cytomegalovirus antibodies

    PubMed Central

    Palafox Sánchez, Claudia Azucena; Satoh, Minoru; Chan, Edward KL; Carcamo, Wendy C; Muñoz Valle, José Francisco; Orozco Barocio, Gerardo; Oregon Romero, Edith; Navarro Hernández, Rosa Elena; Salazar Páramo, Mario; Cabral Castañeda, Antonio; Vázquez del Mercado, Mónica

    2009-01-01

    Introduction Systemic lupus erythematosus is characterized by production of autoantibodies to RNA or DNA–protein complexes such as small nuclear ribonucleoproteins (snRNPs). A role of Epstein–Barr virus in the pathogenesis has been suggested. Similar to Epstein–Barr virus, cytomegalovirus (CMV) infects the majority of individuals at a young age and establishes latency with a potential for reactivation. Homology of CMV glycoprotein B (UL55) with the U1snRNP-70 kDa protein (U1–70 k) has been described; however, the role of CMV infection in production of anti-snRNPs is controversial. We investigated the association of CMV serology and autoantibodies in systemic lupus erythematosus. Methods Sixty-one Mexican patients with systemic lupus erythematosus were tested for CMV and Epstein–Barr virus serology (viral capsid antigen, IgG, IgM) and autoantibodies by immunoprecipitation and ELISA (IgG and IgM class, U1RNP/Sm, U1–70 k, P peptide, rheumatoid factor, dsDNA, β2-glycoprotein I). Results IgG anti-CMV and IgM anti-CMV were positive in 95% (58/61) and 33% (20/61), respectively, and two cases were negative for both. Clinical manifestation and autoantibodies in the IgM anti-CMV(+) group (n = 20) versus the IgM anti-CMV(-)IgG (+) (n = 39) group were compared. Most (19/20) of the IgM anti-CMV(+) cases were IgG anti-CMV(+), consistent with reactivation or reinfection. IgM anti-CMV was unrelated to rheumatoid factor or IgM class autoantibodies and none was positive for IgM anti-Epstein–Barr virus–viral capsid antigen, indicating that this is not simply due to false positive results caused by rheumatoid factor or nonspecific binding by certain IgM. The IgM anti-CMV(+) group has significantly lower levels of IgG anti-U1RNP/Sm and IgG anti-U1–70 k (P = 0.0004 and P = 0.0046, respectively). This finding was also confirmed by immunoprecipitation. Among the IgM anti-CMV(-) subset, anti-Su was associated with anti-U1RNP and anti-Ro (P < 0.05). High levels of Ig

  8. Children's (Pediatric) Nuclear Medicine

    MedlinePlus

    ... nuclear medicine facility. Through the natural process of radioactive decay, the small amount of radiotracer in your child’s body will lose its radioactivity over time. In many cases, the radioactivity will ...

  9. Vented nuclear fuel element

    DOEpatents

    Grossman, Leonard N.; Kaznoff, Alexis I.

    1979-01-01

    A nuclear fuel cell for use in a thermionic nuclear reactor in which a small conduit extends from the outside surface of the emitter to the center of the fuel mass of the emitter body to permit escape of volatile and gaseous fission products collected in the center thereof by virtue of molecular migration of the gases to the hotter region of the fuel.

  10. Thermodynamics of nuclear transport

    NASA Astrophysics Data System (ADS)

    Wang, Ching-Hao; Mehta, Pankaj; Elbaum, Michael

    Molecular transport across the nuclear envelope is important for eukaryotes for gene expression and signaling. Experimental studies have revealed that nuclear transport is inherently a nonequilibrium process and actively consumes energy. In this work we present a thermodynamics theory of nuclear transport for a major class of nuclear transporters that are mediated by the small GTPase Ran. We identify the molecular elements responsible for powering nuclear transport, which we term the ``Ran battery'' and find that the efficiency of transport, measured by the cargo nuclear localization ratio, is limited by competition between cargo molecules and RanGTP to bind transport receptors, as well as the amount of NTF2 (i.e. RanGDP carrier) available to circulate the energy flow. This picture complements our current understanding of nuclear transport by providing a comprehensive thermodynamics framework to decipher the underlying biochemical machinery. Pm and CHW were supported by a Simons Investigator in the Mathematical Modeling in Living Systems grant (to PM).

  11. Deletion of small nuclear ribonucleoprotein polypeptide N (SNRPN) in Prader-Willi syndrome detected by fluorescence in situ hybridization: Two sibs with the typical phenotype without a cytogenetic deletion in chromosome 15q

    SciTech Connect

    Ishikawa, Tatsuya; Kibe, Tetsuya; Wada, Yoshiro

    1996-04-24

    The small nuclear ribonucleoprotein polypeptide N (SNRPN) gene is regarded as one of the candidates for Prader-Willi syndrome (PWS). We describe two sibs with typical PWS presenting deletion of SNRPN detected by fluorescence in situ hybridization (FISH). Neither a cytogenetically detectable 15q12 deletion nor a deletion for the D15S11, D15S10, and GABRB3 cosmid probes were found in either patient. This implies a smaller deletion limited to the PWS critical region. FISH with a SNRPN probe will permit analysis of PWS patients with limited deletions not detectable with other probes. 22 refs., 1 fig.

  12. Path integral molecular dynamic study of nuclear quantum effect on small chloride water clusters of Cl-(H2O)1-4

    NASA Astrophysics Data System (ADS)

    Wang, Qi; Suzuki, Kimichi; Nagashima, Umpei; Tachikawa, Masanori; Yan, Shiwei

    2013-06-01

    The nuclear quantum effect, which plays important roles on ionic hydrogen bonded structures of Cl-(H2O)n (n = 1-4) clusters, was explored by carrying out path integral molecular dynamic simulations. An outer shell coordinate rl(Cl⋯O) is selected to display the rearrangement of single and multi hydration shell cluster structures. By incorporating the nuclear quantum effect, it is shown that the probability for single shell structures is decreased while the probability for multi shell structures is increased. On the other hand, the correlations between changing of bonded H∗ atom to Cl- (defined as δ) and other cluster vibration coordinates are studied. We have found that δ strongly correlates with proton transfer motion while it has little correlation with ion-water stretching motion. Contrary to θ(H-O-H∗) coordinate, the correlations between δ and other coordinates are decreased by inclusion of nuclear quantum effect. The results indicate that the water-water hydrogen bond interactions are encouraged by quantum simulations.

  13. NUCLEAR REACTOR

    DOEpatents

    Grebe, J.J.

    1959-07-14

    High temperature reactors which are uniquely adapted to serve as the heat source for nuclear pcwered rockets are described. The reactor is comprised essentially of an outer tubular heat resistant casing which provides the main coolant passageway to and away from the reactor core within the casing and in which the working fluid is preferably hydrogen or helium gas which is permitted to vaporize from a liquid storage tank. The reactor core has a generally spherical shape formed entirely of an active material comprised of fissile material and a moderator material which serves as a diluent. The active material is fabricated as a gas permeable porous material and is interlaced in a random manner with very small inter-connecting bores or capillary tubes through which the coolant gas may flow. The entire reactor is divided into successive sections along the direction of the temperature gradient or coolant flow, each section utilizing materials of construction which are most advantageous from a nuclear standpoint and which at the same time can withstand the operating temperature of that particular zone. This design results in a nuclear reactor characterized simultaneously by a minimum critiral size and mass and by the ability to heat a working fluid to an extremely high temperature.

  14. Nuclear rights - nuclear wrongs

    SciTech Connect

    Paul, E.F.; Miller, F.D.; Paul, J.; Ahrens, J.

    1986-01-01

    This book contains 11 selections. The titles are: Three Ways to Kill Innocent Bystanders: Some Conundrums Concerning the Morality of War; The International Defense of Liberty; Two Concepts of Deterrence; Nuclear Deterrence and Arms Control; Ethical Issues for the 1980s; The Moral Status of Nuclear Deterrent Threats; Optimal Deterrence; Morality and Paradoxical Deterrence; Immoral Risks: A Deontological Critique of Nuclear Deterrence; No War Without Dictatorship, No Peace Without Democracy: Foreign Policy as Domestic Politics; Marxism-Leninism and its Strategic Implications for the United States; Tocqueveille War.

  15. Path-Integral Calculations of Nuclear Quantum Effects in Model Systems, Small Molecules, and Enzymes via Gradient-Based Forward Corrector Algorithms.

    PubMed

    Azuri, Asaf; Engel, Hamutal; Doron, Dvir; Major, Dan Thomas

    2011-05-10

    A practical approach to treat nuclear quantum mechanical (QM) effects in simulations of condensed phases, such as enzymes, is via Feynman path integral (PI) formulations. Typically, the standard primitive approximation (PA) is employed in enzymatic PI simulations. Nonetheless, these PI simulations are computationally demanding due to the large number of discretizations, or beads, required to obtain converged results. The efficiency of PI simulations may be greatly improved if higher order factorizations of the density matrix operator are employed. Herein, we compare the results of model calculations obtained employing the standard PA, the improved operator of Takahashi and Imada (TI), and several gradient-based forward corrector algorithms due to Chin (CH). The quantum partition function is computed for the harmonic oscillator, Morse, symmetric, and asymmetric double well potentials. These potentials are simple models for nuclear quantum effects, such as zero-point energy and tunneling. It is shown that a unique set of CH parameters may be employed for a variety of systems. Additionally, the nuclear QM effects of a water molecule, treated with density functional theory, are computed. Finally, we derive a practical perturbation expression for efficient computation of isotope effects in chemical systems using the staging algorithm. This new isotope effect approach is tested in conjunction with the PA, TI, and CH methods to compute the equilibrium isotope effect in the Schiff base-oxyanion keto-enol tautomerism in the cofactor pyridoxal-5'-phosphate in the enzyme alanine racemase. The study of the different factorization methods reveals that the higher-order actions converge substantially faster than the PA approach, at a moderate computational cost.

  16. In vitro transcription of a Drosophila U1 small nuclear RNA gene requires TATA box-binding protein and two proximal cis-acting elements with stringent spacing requirements.

    PubMed Central

    Zamrod, Z; Tyree, C M; Song, Y; Stumph, W E

    1993-01-01

    Transcription of a Drosophila U1 small nuclear RNA gene was functionally analyzed in cell extracts derived from 0- to 12-h embryos. Two promoter elements essential for efficient initiation of transcription in vitro by RNA polymerase II were identified. The first, termed PSEA, is located between positions -41 and -61 relative to the transcription start site, is crucial for promoter activity, and is the dominant element for specifying the transcription initiation site. PSEA thus appears to be functionally homologous to the proximal sequence element of vertebrate small nuclear RNA genes. The second element, termed PSEB, is located at positions -25 to -32 and is required for an efficient level of transcription initiation because mutation of PSEB, or alteration of the spacing between PSEA and PSEB, severely reduced transcriptional activity relative to that of the wild-type promoter. Although the PSEB sequence does not have any obvious sequence similarity to a TATA box, conversion of PSEB to the canonical TATA sequence dramatically increased the efficiency of the U1 promoter and simultaneously relieved the requirement for the upstream PSEA. Despite these effects, introduction of the TATA sequence into the U1 promoter had no effect on the choice of start site or on the RNA polymerase II specificity of the promoter. Finally, evidence is presented that the TATA box-binding protein is required for transcription from the wild-type U1 promoter as well as from the TATA-containing U1 promoter. Images PMID:8355718

  17. Clustered basic amino acids of the small sendai virus C protein Y1 are critical to its RAN GTPase-mediated nuclear localization.

    PubMed

    Irie, Takashi; Yoshida, Asuka; Sakaguchi, Takemasa

    2013-01-01

    The Sendai virus (SeV) C proteins are shown to exert multiple functions during the course of infection. Perhaps reflecting their many functions, they occur at multiple sites of the cell. In this study, we focused on the nuclear-localizing ability of the smaller C protein, Y1, and found that this translocation is mediated by Ran GTPase but not by passive diffusion, and that basic residues within the 149-157 amino acid region are critical for that. The mechanism of inhibition of interferon (IFN)-signaling seemed to differ between the C and Y1 proteins, since deletion of 12 C-terminal amino acids resulted in a loss of the function for the C but not for the Y1 protein. The ability of Y1 mutants to inhibit IFN-α-induced, ISRE-driven expression of a reporter gene almost paralleled with that to localize in the nucleus. These results suggest that nuclear localization of the Y1 protein might be important for the inhibitory effect on type-I IFN-stimulated gene expression.

  18. Nuclear Medicine.

    ERIC Educational Resources Information Center

    Badawi, Ramsey D.

    2001-01-01

    Describes the use of nuclear medicine techniques in diagnosis and therapy. Describes instrumentation in diagnostic nuclear medicine and predicts future trends in nuclear medicine imaging technology. (Author/MM)

  19. 77 FR 39442 - Receipts-Based, Small Business Size Standard

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ..., which are administrative in nature, include updating the receipts-based, small business size standard... protection, Nuclear materials, Nuclear power plants and reactors, Penalties, Sex discrimination,...

  20. Sequential autoantigenic determinants of the small nuclear ribonucleoprotein Sm D shared by human lupus autoantibodies and MRL lpr/lpr antibodies.

    PubMed

    James, J A; Mamula, M J; Harley, J B

    1994-12-01

    Autoantibodies directed against the Sm proteins of the spliceosome complex are found in approximately 25% of systemic lupus erythematosus (SLE) patients sera. To determine which regions of the Sm D polypeptide are involved in the lupus autoimmune response, binding to overlapping octapeptides of Sm D has been evaluated with sera from nine Sm D-positive patients, six patients with other autoimmune serology, and five normal human sera. Lupus patient sera which are Sm precipitin-positive bind various combinations of five regions of the peptide. The major antigenic region, Epitope 5 (REAVA(GR)10GGPRR), is bound by eight of nine Sm precipitin-positive sera tested. This region of Sm D shows significant sequence homology with Epstein-Barr nuclear antigen-1. To determine the fine specificity of the murine Sm response, four unique Sm D MoAbs derived from MRL lpr/lpr mice and three adult anti-Sm-positive MRL lpr/lpr mouse sera have been analysed. Two of these monoclonals, KSm 4 and Y12, as well as the MRL lpr/lpr sera tested, show binding with Epitope 5. Another of these monoclonals, KSm 2, binds octapeptides 84-91, DVEPKVKSKKREAVAG, which corresponds to Epitope 4 of this study. Antibodies from SLE patients with autoimmune serology other than anti-Sm bind the carboxyl glycine-arginine repeat (GR)10 peptides of Sm D. However, none of the antibodies tested from patients who do not have lupus and who have different autoimmune serology binds any of the Sm D octapeptides. Normal controls did not significantly bind any of the Sm D octapeptides. These results describe two major regions of shared antigenicity of Sm D between sera from SLE patients and MRL lpr/lpr mice, thereby establishing a basis for the cross-species similarity of autoimmunity to the Sm autoantigen in SLE.

  1. Nuclear Fuel Cycle

    SciTech Connect

    Dale, Deborah J.

    2014-10-28

    These slides will be presented at the training course “International Training Course on Implementing State Systems of Accounting for and Control (SSAC) of Nuclear Material for States with Small Quantity Protocols (SQP),” on November 3-7, 2014 in Santa Fe, New Mexico. The slides provide a basic overview of the Nuclear Fuel Cycle. This is a joint training course provided by NNSA and IAEA.

  2. Relativistic calculation of nuclear magnetic shielding tensor using the regular approximation to the normalized elimination of the small component. II. Consideration of perturbations in the metric operator.

    PubMed

    Maeda, H; Ootani, Y; Fukui, H

    2007-05-07

    A previous relativistic shielding calculation theory based on the regular approximation to the normalized elimination of the small component approach is improved by the inclusion of the magnetic interaction term contained in the metric operator. In order to consider effects of the metric perturbation, the self-consistent perturbation theory is used for the case of perturbation-dependent overlap integrals. The calculation results show that the second-order regular approximation results obtained for the isotropic shielding constants of halogen nuclei are well improved by the inclusion of the metric perturbation to reproduce the fully relativistic four-component Dirac-Hartree-Fock results. However, it is shown that the metric perturbation hardly or does not affect the anisotropy of the halogen shielding tensors and the proton magnetic shieldings.

  3. Vertical nuclear proliferation.

    PubMed

    Sidel, Victor W

    2007-01-01

    All the nuclear-weapon states are working to develop new nuclear-weapon systems and upgrade their existing ones. Although the US Congress has recently blocked further development of small nuclear weapons and earth-penetrating nuclear weapons, the United States is planning a range of new warheads under the Reliable Replacement Warhead programme, and renewing its nuclear weapons infrastructure. The United Kingdom is spending 1 billion pounds sterling on updating the Atomic Weapons Establishment at Aldermaston, and about 20 billion pounds sterling on replacing its Vanguard submarines and maintaining its Trident warhead stockpile. The US has withdrawn from the Anti-Ballistic Missile Treaty and plans to install missile defence systems in Poland and the Czech Republic; Russia threatens to upgrade its nuclear countermeasures. The nuclear-weapon states should comply with their obligations under Article VI of the Non-Proliferation Treaty, as summarised in the 13-point plan agreed at the 2000 NPT Review Conference, and they should negotiate a Nuclear Weapons Convention.

  4. Efficiency gains in tracer identification for nuclear imaging: can in vivo LC-MS/MS evaluation of small molecules screen for successful PET tracers?

    PubMed

    Joshi, Elizabeth M; Need, Anne; Schaus, John; Chen, Zhaogen; Benesh, Dana; Mitch, Charles; Morton, Stuart; Raub, Thomas J; Phebus, Lee; Barth, Vanessa

    2014-12-17

    Positron emission tomography (PET) imaging has become a useful noninvasive technique to explore molecular biology within living systems; however, the utility of this method is limited by the availability of suitable radiotracers to probe specific targets and disease biology. Methods to identify potential areas of improvement in the ability to predict small molecule performance as tracers prior to radiolabeling would speed the discovery of novel tracers. In this retrospective analysis, we characterized the brain penetration or peak SUV (standardized uptake value), binding potential (BP), and brain exposure kinetics across a series of known, nonradiolabeled PET ligands using in vivo LC-MS/MS (liquid chromatography coupled to mass spectrometry) and correlated these parameters with the reported PET ligand performance in nonhuman primates and humans available in the literature. The PET tracers studied included those reported to label G protein-coupled receptors (GPCRs), intracellular enzymes, and transporters. Additionally, data for each tracer was obtained from a mouse brain uptake assay (MBUA), previously published, where blood-brain barrier (BBB) penetration and clearance parameters were assessed and compared against similar data collected on a broad compound set of central nervous system (CNS) therapeutic compounds. The BP and SUV identified via nonradiolabeled LC-MS/MS, while different from the published values observed in the literature PET tracer data, allowed for an identification of initial criteria values we sought to facilitate increased potential for success from our early discovery screening paradigm. Our analysis showed that successful, as well as novel, clinical PET tracers exhibited BP of greater than 1.5 and peak SUVs greater than approximately 150% at 5 min post dose in rodents. The brain kinetics appeared similar between both techniques despite differences in tracer dose, suggesting linearity across these dose ranges. The assessment of tracers in a

  5. Nuclear Scans

    MedlinePlus

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  6. Nuclear Winter.

    ERIC Educational Resources Information Center

    Ehrlich, Anne

    1984-01-01

    "Nuclear Winter" was recently coined to describe the climatic and biological effects of a nuclear war. These effects are discussed based on models, simulations, scenarios, and projections. Effects on human populations are also considered. (JN)

  7. Nuclear Chemistry.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1979

    1979-01-01

    Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

  8. In situ small-angle x-ray and nuclear resonant scattering study of the evolution of structural and magnetic properties of an Fe thin film on MgO (001)

    NASA Astrophysics Data System (ADS)

    Sharma, Gagan; Gupta, Ajay; Gupta, Mukul; Schlage, Kai; Wille, H.-C.

    2015-12-01

    Growth of magnetron sputtered Fe films on clean single crystalline MgO (001) substrate has been studied using in situ grazing incidence small angle x-ray scattering (GISAXS) and grazing incidence nuclear resonant scattering (GINRS) measurements. While GISAXS provides information about morphological changes, GINRS provides information about structural and magnetic properties, thus making it possible to correlate the evolution of magnetic properties with that of morphology and structure of the film. The film exhibits a Volmer-Weber type growth, with percolation transition occurring around 2 nm film thickness. Presence of a finite quadrupole splitting, as seen in GINRS measurements, suggests a significant distortion from cubic symmetry up to a film thickness of 3.5 nm, which can be attributed to hybridization between Fe 3 d and O 2 p orbitals at the interface as well as in-plane tensile strain induced as a result of coalescence of islands. Initially Fe islands exhibit superparamagnetic relaxation, while finite magnetic moment appears upon formation of macroscopic percolation islands. The film exhibits a weak perpendicular magnetic anisotropy (PMA), which vanishes concurrently with disappearance of structural distortion, suggesting that the observed PMA at least partly originates from inherent strain in the film. No presence of any known oxide of Fe was detected at the interface. More precise information about topological and magnetic structure of the interfaces between Fe and MgO layers is obtained using combined x-ray reflectivity and nuclear resonance reflectivity measurements on a 57Fe/MgO multilayer. Measurements show that about two monolayers of Fe at the interface have a reduced hyperfine field, providing evidence for hybridization with O atoms, as predicted by theory.

  9. Nuclear weapons, nuclear effects, nuclear war

    SciTech Connect

    Bing, G.F.

    1991-08-20

    This paper provides a brief and mostly non-technical description of the militarily important features of nuclear weapons, of the physical phenomena associated with individual explosions, and of the expected or possible results of the use of many weapons in a nuclear war. Most emphasis is on the effects of so-called ``strategic exchanges.``

  10. Nuclear Fuels.

    ERIC Educational Resources Information Center

    Nash, J. Thomas

    1983-01-01

    Trends in and factors related to the nuclear industry and nuclear fuel production are discussed. Topics addressed include nuclear reactors, survival of the U.S. uranium industry, production costs, budget cuts by the Department of Energy and U.S. Geological survey for resource studies, mining, and research/development activities. (JN)

  11. Fantasy physics for nuclear testers

    NASA Astrophysics Data System (ADS)

    Cartlidge, Edwin

    2014-09-01

    In November a group of scientists will scour a small patch of the Middle East for signs that a nuclear explosion has taken place. Edwin Cartlidge describes their delicate mission and the sophisticated gadgetry they will rely on.

  12. Ligand-dependent regulation of the activity of the orphan nuclear receptor, small heterodimer partner (SHP), in the repression of bile acid biosynthetic CYP7A1 and CYP8B1 genes.

    PubMed

    Miao, Ji; Choi, Sung-E; Seok, Sun Mi; Yang, Linda; Zuercher, William J; Xu, Yong; Willson, Timothy M; Xu, H Eric; Kemper, Jongsook Kim

    2011-07-01

    Small heterodimer partner (SHP) plays important roles in diverse biological processes by directly interacting with transcription factors and inhibiting their activities. SHP has been designated an orphan nuclear receptor, but whether its activity can be modulated by ligands has been a long-standing question. Recently, retinoid-related molecules, including 4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3Cl-AHPC), were shown to bind to SHP and enhance apoptosis. We have examined whether 3Cl-AHPC acts as an agonist and increases SHP activity in the repression of bile acid biosynthetic CYP7A1 and CYP8B1 genes and delineated the underlying mechanisms. Contrary to this expectation, micromolar concentrations of 3Cl-AHPC increased CYP7A1 expression but indirectly via p38 kinase signaling. Nanomolar concentrations, however, repressed CYP7A1 expression and decreased bile acid levels in HepG2 cells, and little repression was observed when SHP was down-regulated by small hairpin RNA. Mechanistic studies revealed that 3Cl-AHPC bound to SHP, increased the interaction of SHP with liver receptor homologue (LRH)-1, a hepatic activator for CYP7A1 and CYP8B1 genes, and with repressive cofactors, Brahma, mammalian Sin3a, and histone deacetylase-1, and, subsequently, increased the occupancy of SHP and these cofactors at the promoters. Mutation of Leu-100, predicted to contact 3Cl-AHPC within the SHP ligand binding pocket by molecular modeling, severely impaired the increased interaction with LRH-1, and repression of LRH-1 activity mediated by 3Cl-AHPC. 3Cl-AHPC repressed SHP metabolic target genes in a gene-specific manner in human primary hepatocytes and HepG2 cells. These data suggest that SHP may act as a ligand-regulated receptor in metabolic pathways. Modulation of SHP activity by synthetic ligands may be a useful therapeutic strategy.

  13. Small GTPase Rho signaling is involved in {beta}1 integrin-mediated up-regulation of intercellular adhesion molecule 1 and receptor activator of nuclear factor {kappa}B ligand on osteoblasts and osteoclast maturation

    SciTech Connect

    Hirai, Fumihiko; Nakayamada, Shingo; Okada, Yosuke; Saito, Kazuyoshi; Kurose, Hitoshi; Mogami, Akira; Tanaka, Yoshiya . E-mail: tanaka@med.uoeh-u.ac.jp

    2007-04-27

    We assessed the characteristics of human osteoblasts, focusing on small GTPase Rho signaling. {beta}1 Integrin were highly expressed on osteoblasts. Engagement of {beta}1 integrins by type I collagen augmented expression of intercellular adhesion molecule 1 (ICAM-1) and receptor activator of nuclear factor {kappa}B ligand (RANKL) on osteoblasts. Rho was activated by {beta}1 stimulation in osteoblasts. {beta}1 Integrin-induced up-regulation of ICAM-1 and RANKL was inhibited by transfection with adenoviruses encoding C3 transferase or pretreated with Y-27632, specific Rho and Rho-kinase inhibitors. Engagement of {beta}1 integrin on osteoblasts induced formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (MNC) in a coculture system of osteoblasts and peripheral monocytes, but this action was completely abrogated by transfection of C3 transferase. Our results indicate the direct involvement of Rho-mediated signaling in {beta}1 integrin-induced up-regulation of ICAM-1 and RANKL and RANKL-dependent osteoclast maturation. Thus, Rho-mediated signaling in osteoblasts seems to introduce major biases to bone resorption.

  14. Nuclear astrophysics

    SciTech Connect

    Haxton, W.C.

    1992-01-01

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized.

  15. Nuclear astrophysics

    SciTech Connect

    Haxton, W.C.

    1992-12-31

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized.

  16. Nuclear Fission

    NASA Astrophysics Data System (ADS)

    Denschlag, J. O.

    This chapter first gives a survey on the history of the discovery of nuclear fission. It briefly presents the liquid-drop and shell models and their application to the fission process. The most important quantities accessible to experimental determination such as mass yields, nuclear charge distribution, prompt neutron emission, kinetic energy distribution, ternary fragment yields, angular distributions, and properties of fission isomers are presented as well as the instrumentation and techniques used for their measurement. The contribution concentrates on the fundamental aspects of nuclear fission. The practical aspects of nuclear fission are discussed in http://dx.doi.org/10.1007/978-1-4419-0720-2_57 of Vol. 6.

  17. Small heterodimer partner attenuates hydrogen peroxide-induced expression of cyclooxygenase-2 and inducible nitric oxide synthase by suppression of activator protein-1 and nuclear factor-κB in renal proximal tubule epithelial cells.

    PubMed

    Park, Jung Sun; Choi, Hoon In; Bae, Eun Hui; Ma, Seong Kwon; Kim, Soo Wan

    2017-03-01

    The orphan nuclear receptor, small heterodimer partner (SHP), plays a negative regulatory role in innate immune responses and is involved in various inflammatory signaling pathways. In the present study, we aimed to ascertain whether SHP is effective in preventing hydrogen peroxide (H2O2)-induced kidney tubular inflammation and explored the molecular mechanisms underlying the protective effects of SHP. Renal ischemia/reperfusion (I/R) injury was induced in mice by clamping both renal pedicles for 30 min. The effects of H2O2 on cell viability in human renal proximal tubule (HK-2) cells were determined using MTT assays. 2',7'-DCF-DA was used to determine intracellular reactive oxygen species (ROS). SHP, cyclooxygenase-2 (COX-2) levels, and inducible nitric oxide synthase (iNOS) expression levels were determined by semi-quantitative immunoblotting and real-time polymerase chain reaction. In addition, SHP, nuclear factor-κB (NF-κB), and activator protein-1 (AP-1) promoter activities were determined by luciferase assays. SHP mRNA and protein expression levels were reduced, whereas COX-2 and iNOS levels were increased in mice subjected to renal I/R. H2O2 treatment in HK-2 cells decreased cell viability, increased ROS production, and induced COX-2 and iNOS expression. These changes were counteracted by transient transfection with SHP. H2O2 treatment decreased SHP luciferase activity, which was recovered by treatment with the NF-κB inhibitor Bay11-7082, transfection with dominant-negative c-Jun or treatment with N-acetyl cysteine (NAC). AP-1 and NF-κB promoter activities were increased by H2O2 and this increase was blocked by SHP transfection. To conclude, SHP protected HK-2 cells from H2O2-induced tubular injury by inhibition of COX-2 and iNOS through suppression of AP-1 and NF-κB promoter activities.

  18. Nuclear Innovation Workshops Report

    SciTech Connect

    Jackson, John Howard; Allen, Todd Randall; Hildebrandt, Philip Clay; Baker, Suzanne Hobbs

    2015-09-01

    The Nuclear Innovation Workshops were held at six locations across the United States on March 3-5, 2015. The data collected during these workshops has been analyzed and sorted to bring out consistent themes toward enhancing innovation in nuclear energy. These themes include development of a test bed and demonstration platform, improved regulatory processes, improved communications, and increased public-private partnerships. This report contains a discussion of the workshops and resulting themes. Actionable steps are suggested at the end of the report. This revision has a small amount of the data in Appendix C removed in order to avoid potential confusion.

  19. Superpower nuclear minimalism

    SciTech Connect

    Graben, E.K.

    1992-01-01

    During the Cold War, the United States and the Soviet Union competed in building weapons -- now it seems like America and Russia are competing to get rid of them the fastest. The lengthy process of formal arms control has been replaced by exchanges of unilateral force reductions and proposals for reciprocal reductions not necessarily codified by treaty. Should superpower nuclear strategies change along with force postures President Bush has yet to make a formal pronouncement on post-Cold War American nuclear strategy, and it is uncertain if the Soviet/Russian doctrine of reasonable sufficiency formulated in the Gorbachev era actually heralds a change in strategy. Some of the provisions in the most recent round of unilateral proposals put forth by Presidents Bush and Yeltsin in January 1992 are compatible with a change in strategy. Whether such a change has actually occurred remains to be seen. With the end of the Cold War and the breakup of the Soviet Union, the strategic environment has fundamentally changed, so it would seem logical to reexamine strategy as well. There are two main schools of nuclear strategic thought: a maximalist school, mutual assured destruction (MAD) which emphasizes counterforce superiority and nuclear war- fighting capability, and a MAD-plus school, which emphasizes survivability of an assured destruction capability along with the ability to deliver small, limited nuclear attacks in the event that conflict occurs. The MAD-plus strategy is based on an attempt to conventionalize nuclear weapons which is unrealistic.

  20. Nuclear safety

    NASA Technical Reports Server (NTRS)

    Buden, D.

    1991-01-01

    Topics dealing with nuclear safety are addressed which include the following: general safety requirements; safety design requirements; terrestrial safety; SP-100 Flight System key safety requirements; potential mission accidents and hazards; key safety features; ground operations; launch operations; flight operations; disposal; safety concerns; licensing; the nuclear engine for rocket vehicle application (NERVA) design philosophy; the NERVA flight safety program; and the NERVA safety plan.

  1. Nuclear privatization

    SciTech Connect

    Jeffs, E.

    1995-11-01

    The United Kingdom government announced in May 1995 plans to privatize the country`s two nuclear generating companies, Nuclear Electric and Scottish Nuclear. Under the plan, the two companies will become operating divisions of a unified holding company, to be called British Electric, with headquarters in Scotland. Britain`s nuclear plants were left out of the initial privatization in 1989 because the government believed the financial community would be unwilling to accept the open-ended liability of decommissioning the original nine stations based on the Magnox gas-cooled reactor. Six years later, the government has found a way around this by retaining these power stations in state ownership, leaving the new nuclear company with the eight Advanced Gas-cooled Reactor (AGR) stations and the recently completed Sizewell B PWR stations. The operating Magnox stations are to be transferred to BNFL, which operates two Magnox stations of their own at Calder Hall and Chapelcross.

  2. A small molecule inhibitor of monoubiquitinated Proliferating Cell Nuclear Antigen (PCNA) inhibits repair of interstrand DNA cross-link, enhances DNA double strand break, and sensitizes cancer cells to cisplatin.

    PubMed

    Inoue, Akira; Kikuchi, Sotaro; Hishiki, Asami; Shao, Youming; Heath, Richard; Evison, Benjamin J; Actis, Marcelo; Canman, Christine E; Hashimoto, Hiroshi; Fujii, Naoaki

    2014-03-07

    Small molecule inhibitors of proliferating cell nuclear antigen (PCNA)/PCNA interacting protein box (PIP-Box) interactions, including T2 amino alcohol (T2AA), inhibit translesion DNA synthesis. The crystal structure of PCNA in complex with T2AA revealed that T2AA bound to the surface adjacent to the subunit interface of the homotrimer of PCNA in addition to the PIP-box binding cavity. Because this site is close to Lys-164, which is monoubiquitinated by RAD18, we postulated that T2AA would affect monoubiquitinated PCNA interactions. Binding of monoubiquitinated PCNA and a purified pol η fragment containing the UBZ and PIP-box was inhibited by T2AA in vitro. T2AA decreased PCNA/pol η and PCNA/REV1 chromatin colocalization but did not inhibit PCNA monoubiquitination, suggesting that T2AA hinders interactions of pol η and REV1 with monoubiquitinated PCNA. Interstrand DNA cross-links (ICLs) are repaired by mechanisms using translesion DNA synthesis that is regulated by monoubiquitinated PCNA. T2AA significantly delayed reactivation of a reporter plasmid containing an ICL. Neutral comet analysis of cells receiving T2AA in addition to cisplatin revealed that T2AA significantly enhanced formation of DNA double strand breaks (DSBs) by cisplatin. T2AA promoted colocalized foci formation of phospho-ATM and 53BP1 and up-regulated phospho-BRCA1 in cisplatin-treated cells, suggesting that T2AA increases DSBs. When cells were treated by cisplatin and T2AA, their clonogenic survival was significantly less than that of those treated by cisplatin only. These findings show that the inhibitors of monoubiquitinated PCNA chemosensitize cells by inhibiting repair of ICLs and DSBs.

  3. Highly sensitive detection of neodymium ion in small amount of spent nuclear fuel samples using novel fluorescent macrocyclic hexadentate polyaminocarboxylate probe in capillary electrophoresis-laser-induced fluorescence detection.

    PubMed

    Saito, Shingo; Sato, Yoshiyuki; Haraga, Tomoko; Nakano, Yuta; Asai, Shiho; Kameo, Yutaka; Takahashi, Kuniaki; Shibukawa, Masami

    2012-04-06

    A rapid and high-sensitive detection method for the total concentration of Nd ion (total Nd) in a small amount of a spent nuclear fuel sample is urgently required since the precise quantification of total Nd ion makes it possible for burnup (degree of fuel consumption) to be determined. In this work, a capillary electrophoresis-laser-induced fluorescent detection method (CE-LIF) is proposed for the analysis of total Nd in a spent fuel sample solution, with the use of a newly synthesized metal fluorescent probe which has a fluorescein and a macrocylic hexadentate chelating group, FTC-ABNOTA, for lanthanide (Ln) ions. Ln ions were derivatized to form a strongly fluorescent complex with the probe to suppress the quenching of the ligand-centered emission. The detection of Ln complexes in the CE-LIF indicated that the interaction between Ln ions and the FTC-ABNOTA was strong enough not to dissociate during migration. The mutual separation among the Ln-FTC-ABNOTA complexes in CE-LIF was achieved by pH control providing a dynamic ternary complexation (DTC) with hydroxide ions. Using the DTC separation mode, a high resolution of Nd from other Ln ions with high resolution of 1.3-1.9 and a theoretical plate number of 68,000, and a very low detection limit of 22 pM (3.2 ppt, 0.11 attomole amount basis) were successfully obtained. A simulated spent fuel sample containing various metal ions was examined in this method with a good quantification result of 102.1% recovery obtained even with a large excess of U.

  4. Nuclear stress test

    MedlinePlus

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  5. Nuclear reprogramming.

    PubMed

    Halley-Stott, Richard P; Pasque, Vincent; Gurdon, J B

    2013-06-01

    There is currently particular interest in the field of nuclear reprogramming, a process by which the identity of specialised cells may be changed, typically to an embryonic-like state. Reprogramming procedures provide insight into many mechanisms of fundamental cell biology and have several promising applications, most notably in healthcare through the development of human disease models and patient-specific tissue-replacement therapies. Here, we introduce the field of nuclear reprogramming and briefly discuss six of the procedures by which reprogramming may be experimentally performed: nuclear transfer to eggs or oocytes, cell fusion, extract treatment, direct reprogramming to pluripotency and transdifferentiation.

  6. Nuclear Speckles

    PubMed Central

    Spector, David L.; Lamond, Angus I.

    2011-01-01

    Nuclear speckles, also known as interchromatin granule clusters, are nuclear domains enriched in pre-mRNA splicing factors, located in the interchromatin regions of the nucleoplasm of mammalian cells. When observed by immunofluorescence microscopy, they usually appear as 20–50 irregularly shaped structures that vary in size. Speckles are dynamic structures, and their constituents can exchange continuously with the nucleoplasm and other nuclear locations, including active transcription sites. Studies on the composition, structure, and dynamics of speckles have provided an important paradigm for understanding the functional organization of the nucleus and the dynamics of the gene expression machinery. PMID:20926517

  7. NUCLEAR MEMBRANES FROM MAMMALIAN LIVER

    PubMed Central

    Franke, Werner W.; Deumling, Barbara; Ermen, Baerbel; Jarasch, Ernst-Dieter; Kleinig, Hans

    1970-01-01

    Nuclear membranes were isolated from rat and pig liver by sonication of highly purified nuclear fractions and subsequent removal of adhering nucleoproteins in a high salt medium. The fractions were examined in the electron microscope by both negative staining and thin sectioning techniques and were found to consist of nuclear envelope fragments of widely varying sizes. Nuclear pore complex constituents still could frequently be recognized. The chemical composition of the nuclear membrane fractions was determined and compared with those of microsomal fractions prepared in parallel. For total nuclei as well as for nuclear membranes and microsomes, various enzyme activities were studied. The results indicate that a similarity exists between both fractions of cytomembranes, nuclear envelope, and endoplasmic reticulum, with respect to their RNA:protein ratio and their content of polar and nonpolar lipids. Both membranous fractions had many proteins in common including some membrane-bound enzymes. Activities in Mg-ATPase and the two examined cytochrome reductases were of the same order of magnitude. The content of cytochrome b5 as well as of P-450 was markedly lower in the nuclear membranes. The nuclear membranes were found to have a higher buoyant density and to be richer in protein. The glucose-6-phosphatase and Na-K-ATPase activities in the nuclear membrane fraction were very low. In the gel electrophoresis, in addition to many common protein bands, some characteristic ones for either microsomal or nuclear membranous material were detected. Significant small amounts of DNA and RNA were found to remain closely associated with the nuclear envelope fragments. Our findings indicate that nuclear and endoplasmic reticulum membranes which are known to be in morphological continuity have, besides a far-reaching similarity, some characteristic differences. PMID:4317731

  8. Climatic Consequences of Nuclear Conflict

    NASA Astrophysics Data System (ADS)

    Robock, A.

    2011-12-01

    A nuclear war between Russia and the United States could still produce nuclear winter, even using the reduced arsenals of about 4000 total nuclear weapons that will result by 2017 in response to the New START treaty. A nuclear war between India and Pakistan, with each country using 50 Hiroshima-sized atom bombs as airbursts on urban areas, could produce climate change unprecedented in recorded human history. This scenario, using much less than 1% of the explosive power of the current global nuclear arsenal, would produce so much smoke from the resulting fires that it would plunge the planet to temperatures colder than those of the Little Ice Age of the 16th to 19th centuries, shortening the growing season around the world and threatening the global food supply. Crop model studies of agriculture in the U.S. and China show massive crop losses, even for this regional nuclear war scenario. Furthermore, there would be massive ozone depletion with enhanced ultraviolet radiation reaching the surface. These surprising conclusions are the result of recent research (see URL) by a team of scientists including those who produced the pioneering work on nuclear winter in the 1980s, using the NASA GISS ModelE and NCAR WACCM GCMs. The soot is self-lofted into the stratosphere, and the effects of regional and global nuclear war would last for more than a decade, much longer than previously thought. Nuclear proliferation continues, with nine nuclear states now, and more working to develop or acquire nuclear weapons. The continued environmental threat of the use of even a small number of nuclear weapons must be considered in nuclear policy deliberations in Russia, the U.S., and the rest of the world.

  9. JPRS Report Nuclear Developments

    DTIC Science & Technology

    2007-11-02

    BANGLADESH Atomic Energy Commission Chairman Sacked [Delhi Domestic Service 9 Nov] 5 EGYPT West Germans Build Small Nuclear Power Stations...Brazil has geologial uranium reserves calculated at 301,400 metric tons, and the world market allows annual business involving up to $65 million, "a...country. JPRS-TND-88-020 28 November 1988 NEAR EAST & SOUTH ASIA BANGLADESH Atomic Energy Commission Chairman Sacked BK0911075888 Delhi Domestic

  10. (Nuclear theory). [Research in nuclear physics

    SciTech Connect

    Haxton, W.

    1990-01-01

    This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion. (LSP)

  11. Nuclear battlefields

    SciTech Connect

    Arkin, W.M.; Fieldhouse, R.W.

    1985-01-01

    This book provides complete data on the nuclear operations and research facilities in the U.S.A., the U.S.S.R., France, China and the U.K. It describes detailed estimates on the U.S.S.R.'s nuclear stockpile for over 500 locations. It shows how non-nuclear countries cooperate with the world-wide war machine. And it maps the U.S. nuclear facilities from Little America, WY, and Charleston, SC, to the battleships patroling the world's oceans and subs stalking under the sea. The data were gathered from unclassified sources through the Freedom of Information Act, from data supplied to military installations, and from weapons source books. It provides guidance for policymakers, government and corporate officials.

  12. NUCLEAR REACTOR

    DOEpatents

    Sherman, J.; Sharbaugh, J.E.; Fauth, W.L. Jr.; Palladino, N.J.; DeHuff, P.G.

    1962-10-23

    A nuclear reactor incorporating seed and blanket assemblies is designed. Means are provided for obtaining samples of the coolant from the blanket assemblies and for varying the flow of coolant through the blanket assemblies. (AEC)

  13. Nuclear Medicine

    MedlinePlus

    ... here Home » Science Education » Science Topics » Nuclear Medicine SCIENCE EDUCATION SCIENCE EDUCATION Science Topics Resource Links for ... administered by inhalation, by oral ingestion, or by direct injection into an organ. The mode of tracer ...

  14. Nuclear accidents

    SciTech Connect

    Mobley, J.A.

    1982-05-01

    A nuclear accident with radioactive contamination can happen anywhere in the world. Because expert nuclear emergency teams may take several hours to arrive at the scene, local authorities must have a plan of action for the hours immediately following an accident. The site should be left untouched except to remove casualties. Treatment of victims includes decontamination and meticulous wound debridement. Acute radiation syndrome may be an overwhelming sequela.

  15. Nuclear cardiac

    SciTech Connect

    Slutsky, R.; Ashburn, W.L.

    1982-01-01

    The relationship between nuclear medicine and cardiology has continued to produce a surfeit of interesting, illuminating, and important reports involving the analysis of cardiac function, perfusion, and metabolism. To simplify the presentation, this review is broken down into three major subheadings: analysis of myocardial perfusion; imaging of the recent myocardial infarction; and the evaluation of myocardial function. There appears to be an increasingly important relationship between cardiology, particularly cardiac physiology, and nuclear imaging techniques. (KRM)

  16. Nuclear Data

    SciTech Connect

    White, Morgan C.

    2014-01-23

    PowerPoint presentation targeted for educational use. Nuclear data comes from a variety of sources and in many flavors. Understanding where the data you use comes from and what flavor it is can be essential to understand and interpret your results. This talk will discuss the nuclear data pipeline with particular emphasis on providing links to additional resources that can be used to explore the issues you will encounter.

  17. Nuclear Nonproliferation

    SciTech Connect

    Atkins-Duffin, C E

    2008-12-10

    With an explosion equivalent of about 20kT of TNT, the Trinity test was the first demonstration of a nuclear weapon. Conducted on July 16, 1945 in Alamogordo, NM this site is now a Registered National Historic Landmark. The concept and applicability of nuclear power was demonstrated on December 20, 1951 with the Experimental Breeder Reactor Number One (EBR-1) lit four light bulbs. This reactor is now a Registered National Historic Landmark, located near Arco, ID. From that moment forward it had been clearly demonstrated that nuclear energy has both peaceful and military applications and that the civilian and military fuel cycles can overlap. For the more than fifty years since the Atoms for Peace program, a key objective of nuclear policy has been to enable the wider peaceful use of nuclear energy while preventing the spread of nuclear weapons. Volumes have been written on the impact of these two actions on the world by advocates and critics; pundits and practioners; politicians and technologists. The nations of the world have woven together a delicate balance of treaties, agreements, frameworks and handshakes that are representative of the timeframe in which they were constructed and how they have evolved in time. Collectively these vehicles attempt to keep political will, nuclear materials and technology in check. This paper captures only the briefest abstract of the more significant aspects on the Nonproliferation Regime. Of particular relevance to this discussion is the special nonproliferation sensitivity associated with the uranium isotope separation and spent fuel reprocessing aspects of the nuclear fuel cycle.

  18. Nuclear telemedicine

    NASA Astrophysics Data System (ADS)

    Morrison, R. T.; Szasz, I. J.

    1990-06-01

    Diagnostic nuclear medicine patient images have been transniitted for 8 years from a regional conununity hospital to a university teaching hospital 700 kiloinetres away employing slow scan TV and telephone. Transruission and interpretation were done at the end of each working day or as circumstances required in cases of emergencies. Referring physicians received the nuclear medicine procedure report at the end of the completion day or within few minutes of completion in case of emergency procedures. To date more than 25 patient studies have been transmitted for interpretation. Blinded reinterpretation of the original hard copy data of 350 patient studies resulted in 100 agreement with the interpretation of transmitted data. This technique provides high quality diagnostic and therapeutic nuclear medicine services in remote hospitals where the services of an on-site nuclear physician is not available. 2. HISTORY Eight years ago when the nuclear medicine physician at Trail Regional Hospital left the Trail area and an other could not be recruited we examined the feasibility of image transmission by phone for interpretation since closing the department would have imposed unacceptable physical and financial hardship and medical constraints on the patient population the nearest nuclear medicine facility was at some 8 hours drive away. In hospital patients would have to be treated either based purely on physical findings or flown to Vancouver at considerable cost to the health care system (estimated cost $1500.

  19. Nuclear deterrence in South Asia

    SciTech Connect

    Hagerty, D.T.

    1995-12-31

    Did India and Pakistan nearly fight a nuclear war in 1990? In a provocative 1993 article, Seymour M. Hersh claims that they did. During a crisis with India over the rapidly escalating insurgency in Kashmir, Pakistan openly deployed its main armored tank units along the Indian border and, in secret, placed its nuclear-weapons arsenal on alert. As a result, the Bush Administration became convinced that the world was on the edge of a nuclear exchange between Pakistan and India. Universe of cases is admittedly small, but my argument is supported by recent research indicating that preemptive attacks of any kind have been historically rarer than conventionally believed. The nuclear era has seen two instances of preventive attacks against nuclear facilities-the 1981 Israeli bombing of Iraq`s Osirak nuclear facility and the allied coalition`s 1991 air war against Iraq-but both of these actions were taken without fear of nuclear reprisal. In situations where nuclear retaliation has been a possibility, no leader of nuclear weapon state has chosen to launch a preemptive first strike. 97 refs.

  20. Helping nuclear power help us

    SciTech Connect

    Schecker, Jay A

    2009-01-01

    After a prolonged absence, the word 'nuclear' has returned to the lexicon of sustainable domestic energy resources. Due in no small part to its demonstrated reliability, nuclear power is poised to playa greater role in the nation's energy future, producing clean, carbon-neutral electricity and contributing even more to our energy security. To nuclear scientists, the resurgence presents an opportunity to inject new technologies into the industry to maximize the benefits that nuclear energy can provide. 'By developing new options for waste management and exploiting new materials to make key technological advances, we can significantly impact the use of nuclear energy in our future energy mix,' says Chris Stanek, a materials scientist at Los Alamos National Laboratory. Stanek approaches the big technology challenges by thinking way small, all the way down to the atoms. He and his colleagues are using cutting edge atomic-scale simulations to address a difficult aspect of nuclear waste -- predicting its behavior far into the future. Their research is part of a broader, coordinated effort on the part of the Laboratory to use its considerable experimental, theoretical, and computational capabilities to explore advanced materials central to not only waste issues, but to nuclear fuels as well.

  1. Nuclear risk

    SciTech Connect

    Levenson, M.

    1989-01-01

    The title of our session, Nuclear Risk Versus Other Power Options, is provocative. It is also a title with different meanings to different people. To the utility chief executive officer, nuclear power is a high-risk financial undertaking because of political and economic barriers to cost recovery. To the utility dispatcher, it is a high-risk future power source since plant completion and start-up dates can be delayed for very long times due to uncertain legal and political issues. To the environmentalist, concerned about global effects such as greenhouse and acid rain, nuclear power is a relatively low risk energy source. To the financial people, nuclear power is a cash cow turned sour because of uncertainties as to what new plants will cost and whether they will even be allowed to operate. The statistics on risk are known and the results of probability risk assessment calculations of risks are known. The challenge is not to make nuclear power safer, it is already one of the safest, if not the safest, source of power currently available. The challenge is to find a way to communicate this to the public.

  2. Nuclear winter: implications for US and Soviet nuclear strategy

    SciTech Connect

    Romero, P.J.

    1984-12-01

    In November 1983 Dr. Carl Sagan and his colleagues reported to press on the results of their study of the atmospheric consequences of nuclear war. The TTAPS study found that for a wide range of possible U.S. -Soviet nuclear exchanges, including relatively small ones, the fires from nuclear detonations would inject into the stratosphere quantities of dust and soot that would obscure sunlight for months. Under the cloud, which would spread over most of the Northern Hemisphere, temperatures might drop scores of degrees, well below the freezing point of water; thus, nuclear winter. The TTAPS team's findings suggested that the consequences of a nuclear war might be even more gruesome than previously supposed, and the long-term climatic and biological results might be nearly as severe for a war of 100 megatons as for 5,000. From the point of view of informing policymakers and the public concerning the consequences of wars involving nuclear weapons, the politicization of the nuclear winter issue is unfortunate. We can hope that in the next few years the criticism and defense of the initial TTAPS work will give rise to significant additional analyses, to illuminate the question. Realistically, further study will probably include both confirmations and contradictions of the original findings, without necessarily resolving the issue. Sadly, the surrounding political atmosphere may obstruct sober consideration of the policy implications of the possibility of nuclear winter.

  3. Nuclear waste

    SciTech Connect

    Not Available

    1988-05-01

    This paper discusses how, as part of the Department of Energy's implementation of the Nuclear Waste Policy Act of 1982, DOE is required to investigate a site at Yucca Mountain, Nevada and, if it determines that the site is suitable, recommend to the President its selection for a nuclear waste repository. The Nuclear Regulatory Commission, in considering development of the plan, issued five objections, one of which is DOE's failure to recognize the range of alternative conceptual models of the Yucca Mountain site that can be supported by the limited existing technical data. At the end of the quarter DOE directed its project offices in Washington and Texas to begin orderly phase-out of all site-specific repository activities. Costs for this phase-out are $53 million for the Deaf Smith site and $85 million for the Hanford site.

  4. Nuclear pursuits

    SciTech Connect

    Not Available

    1993-05-01

    This table lists quantities of warheads (in stockpile, peak number per year, total number built, number of known test explosions), weapon development milestones (developers of the atomic bomb and hydrogen bomb, date of first operational ICBM, first nuclear-powered naval SSN in service, first MIRVed missile deployed), and testing milestones (first fission test, type of boosted fission weapon, multistage thermonuclear test, number of months from fission bomb to multistage thermonuclear bomb, etc.), and nuclear infrastructure (assembly plants, plutonium production reactors, uranium enrichment plants, etc.). Countries included in the tally are the United States, Soviet Union, Britain, France, and China.

  5. Hadrons in the Nuclear Medium

    SciTech Connect

    Misak Sargsian; G.A. Miller; John Arrington; William Bertozzi; Werner Boeglin; Carl Carlson; Donal Day; Leonid Frankfurt; Kim Egiyan; Rolf Ent; Shalev Gilad; Keith Griffioen; Douglas Higinbotham; Sebastian Kuhn; Wally Melnitchouk; Eliezer Piasetzky; Stepan Stepanyan; Mark Strikman; Lawrence Weinstein

    2002-10-01

    Quantum Chromodynamics, the microscopic theory of strong interactions, has not yet been applied to the calculation of nuclear wave functions. However, it certainly provokes a number of specific questions and suggests the existence of novel phenomena in nuclear physics which are not part of the traditional framework of the meson-nucleon description of nuclei. Many of these phenomena are related to high nuclear densities and the role of color in nucleonic interactions. Quantum fluctuations in the spatial separation between nucleons may lead to local high density configurations of cold nuclear matter in nuclei, up to four times larger than typical nuclear densities. We argue here that experiments utilizing the higher energies available upon completion of the Jefferson Laboratory energy upgrade will be able to probe the quark-gluon structure of such high density configurations and therefore elucidate the fundamental nature of nuclear matter. We review three key experimental programs: quasi-elastic electro-disintegration of light nuclei, deep inelastic scattering from nuclei at x>1, and the measurement of tagged structure functions. These interrelated programs are all aimed at the exploration of the quark structure of high density nuclear configurations. The study of the QCD dynamics of elementary hard processes is another important research direction and nuclei provide a unique avenue to explore these dynamics. We argue that the use of nuclear targets and large values of momentum transfer at would allow us to determine whether the physics of the nucleon form factors is dominated by spatially small configurations of three quarks.

  6. Nuclear Systems Kilopower Overview

    NASA Technical Reports Server (NTRS)

    Palac, Don; Gibson, Marc; Mason, Lee; Houts, Michael; McClure, Patrick; Robinson, Ross

    2016-01-01

    The Nuclear Systems Kilopower Project was initiated by NASAs Space Technology Mission Directorate Game Changing Development Program in fiscal year 2015 to demonstrate subsystem-level technology readiness of small space fission power in a relevant environment (Technology Readiness Level 5) for space science and human exploration power needs. The Nuclear Systems Kilopower Project consists of two elements. The primary element is the Kilopower Prototype Test, also called the Kilopower Reactor Using Stirling Technology(KRUSTY) Test. This element consists of the development and testing of a fission ground technology demonstrator of a 1 kWe fission power system. A 1 kWe system matches requirements for some robotic precursor exploration systems and future potential deep space science missions, and also allows a nuclear ground technology demonstration in existing nuclear test facilities at low cost. The second element, the Mars Kilopower Scalability Study, consists of the analysis and design of a scaled-up version of the 1 kWe reference concept to 10 kWe for Mars surface power projected requirements, and validation of the applicability of the KRUSTY experiment to key technology challenges for a 10 kWe system. If successful, these two elements will lead to initiation of planning for a technology demonstration of a 10 kWe fission power capability for Mars surface outpost power.

  7. Nuclear spin circular dichroism

    SciTech Connect

    Vaara, Juha; Rizzo, Antonio; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia

    2014-04-07

    Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.

  8. Beloyarsk Nuclear Power Plant

    SciTech Connect

    1997-08-01

    The Beloyarsk Nuclear Power Plant (BNPP) is located in Zarechny, approximately 60 km east of Ekaterinberg along the Trans-Siberian Highway. Zarechny, a small city of approximately 30,000 residents, was built to support BNPP operations. It is a closed city to unescorted visitors. Residents must show identification for entry. BNPP is one of the first and oldest commercial nuclear power plants in Russia and began operations in 1964. As for most nuclear power plants in the Russian Federation, BNPP is operated by Rosenergoatom, which is subordinated to the Ministry of Atomic Energy of the Russian Federation (Minatom). BNPP is the site of three nuclear reactors, Units 1, 2, and 3. Units 1 and 2, which have been shut-down and defueled, were graphite moderated reactors. The units were shut-down in 1981 and 1989. Unit 3, a BN-600 reactor, is a 600 MW(electric) sodium-cooled fast breeder reactor. Unit 3 went on-line in April 1980 and produces electric power which is fed into a distribution grid and thermal power which provides heat to Zarechny. The paper also discusses the SF NIKIET, the Sverdiovsk Branch of NIKIET, Moscow, which is the research and development branch of the parent NIKEIT and is primarily a design institute responsible for reactor design. Central to its operations is a 15 megawatt IVV research reactor. The paper discusses general security and fissile material control and accountability at these two facilities.

  9. Nuclear orbiting

    SciTech Connect

    Shapira, D.

    1988-01-01

    Nuclear orbiting following collisions between sd and p shell nuclei is discussed. The dependence of this process on the real and imaginary parts of the nucleus-nucleus potential is discussed, as well as the evolution of the dinucleus toward a fully equilibrated fused system. 26 refs., 15 figs.

  10. Nuclear Misinformation

    ERIC Educational Resources Information Center

    Ford, Daniel F.; Kendall, Henry W.

    1975-01-01

    Many scientists feel that research into nuclear safety has been diverted or distorted, and the results of the research concealed or inaccurately reported on a large number of occasions. Of particular concern have been the emergency cooling systems which have not, as yet, been adequately tested. (Author/MA)

  11. Nuclear Terrorism.

    SciTech Connect

    Hecker, Siegfried S.

    2001-01-01

    As pointed out by several speakers, the level of violence and destruction in terrorist attacks has increased significantly during the past decade. Fortunately, few have involved weapons of mass destruction, and none have achieved mass casualties. The Aum Shinrikyo release of lethal nerve agent, sarin, in the Tokyo subway on March 20, 1995 clearly broke new ground by crossing the threshold in attempting mass casualties with chemical weapons. However, of all weapons of mass destruction, nuclear weapons still represent the most frightening threat to humankind. Nuclear weapons possess an enormous destructive force. The immediacy and scale of destruction are unmatched. In addition to destruction, terrorism also aims to create fear among the public and governments. Here also, nuclear weapons are unmatched. The public's fear of nuclear weapons or, for that matter, of all radioactivity is intense. To some extent, this fear arises from a sense of unlimited vulnerability. That is, radioactivity is seen as unbounded in three dimensions - distance, it is viewed as having unlimited reach; quantity, it is viewed as having deadly consequences in the smallest doses (the public is often told - incorrectly, of course - that one atom of plutonium will kill); and time, if it does not kill you immediately, then it will cause cancer decades hence.

  12. Nuclear medicine

    SciTech Connect

    Wagner, H.N. Jr.

    1986-10-17

    In 1985 and 1986 nuclear medicine became more and more oriented toward in vov chemistry, chiefly as a result of advances in positron emission tomography (PET). The most important trend was the extension of PET technology into the care of patients with brain tumors, epilepsy, and heart disease. A second trend was the increasing use of single-photon emission computed tomography (SPECT).

  13. NUCLEAR REACTOR

    DOEpatents

    Treshow, M.

    1961-09-01

    A boiling-water nuclear reactor is described wherein control is effected by varying the moderator-to-fuel ratio in the reactor core. This is accomplished by providing control tubes containing a liquid control moderator in the reactor core and providing means for varying the amount of control moderatcr within the control tubes.

  14. Nuclear Science.

    ERIC Educational Resources Information Center

    Pennsylvania State Dept. of Education, Harrisburg. Bureau of Curriculum Services.

    This document is a report on a course in nuclear science for the high school curriculum. The course is designed to provide a basic but comprehensive understanding of the atom in the light of modern knowledge, and to show how people attempt to harness the tremendous energy liberated through fission and fusion reactions. The course crosses what are…

  15. Nuclear energy.

    PubMed

    Wilson, Peter D

    2010-01-01

    The technical principles and practices of the civil nuclear industry are described with particular reference to fission and its products, natural and artificial radioactivity elements principally concerned and their relationships, main types of reactor, safety issues, the fuel cycle, waste management, issues related to weapon proliferation, environmental considerations and possible future developments.

  16. The Fission Yeast Nup107-120 Complex Functionally Interacts with the Small GTPase Ran/Spi1 and Is Required for mRNA Export, Nuclear Pore Distribution, and Proper Cell Division

    PubMed Central

    Baï, Siau Wei; Rouquette, Jacques; Umeda, Makoto; Faigle, Wolfgang; Loew, Damarys; Sazer, Shelley; Doye, Valérie

    2004-01-01

    We have characterized Schizosaccharomyces pombe open reading frames encoding potential orthologues of constituents of the evolutionarily conserved Saccharomyces cerevisiae Nup84 vertebrate Nup107-160 nuclear pore subcomplex, namely Nup133a, Nup133b, Nup120, Nup107, Nup85, and Seh1. In spite of rather weak sequence conservation, in vivo analyses demonstrated that these S. pombe proteins are localized at the nuclear envelope. Biochemical data confirmed the organization of these nucleoporins within conserved complexes. Although examination of the S. cerevisiae and S. pombe deletion mutants revealed different viability phenotypes, functional studies indicated that the involvement of this complex in nuclear pore distribution and mRNA export has been conserved between these highly divergent yeasts. Unexpectedly, microscopic analyses of some of the S. pombe mutants revealed cell division defects at the restrictive temperature (abnormal septa and mitotic spindles and chromosome missegregation) that were reminiscent of defects occurring in several S. pombe GTPase Ran (RanSp)/Spi1 cycle mutants. Furthermore, deletion of nup120 moderately altered the nuclear location of RanSp/Spi1, whereas overexpression of a nonfunctional RanSp/Spi1-GFP allele was specifically toxic in the Δnup120 and Δnup133b mutant strains, indicating a functional and genetic link between constituents of the S. pombe Nup107-120 complex and of the RanSp/Spi1 pathway. PMID:15226438

  17. Nuclear Scattering from Transition Metals

    NASA Astrophysics Data System (ADS)

    Hira, Ajit; McKeough, James; Valerio, Mario; Cathey, Tommy

    2016-03-01

    In view of the continued interest in the scattering of light projectiles by metallic nuclei, we present a computational study of the interactions between different nuclear species of atoms such as H through F (Z <= 9) and the nuclei of Silver, Palladium and other metals. Recent work has shown that neutron scattering can be used to record holographic images of materials. We have developed a FORTRAN computer program to compute stopping cross sections and scattering angles in Ag and other metals for the small nuclear projectiles, using Monte Carlo calculation. This code allows for different angles of incidence. Next, simulations were done in the energy interval from 50 to 210 keV. The computational results thus obtained are compared with relevant experimental data. The data are further analyzed to identify periodic trends in terms of the atomic number of the projectile. Such studies also have potential applications in nuclear physics and in nuclear medicine. Funding from National Science Foundation.

  18. NUCLEAR REACTOR

    DOEpatents

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  19. NUCLEAR REACTORS

    DOEpatents

    Long, E.; Ashby, J.W.

    1958-09-16

    ABS>A graphite moderator structure is presented for a nuclear reactor compriscd of an assembly of similarly orientated prismatic graphite blocks arranged on spaced longitudinal axes lying in common planes wherein the planes of the walls of the blocks are positioned so as to be twisted reintive to the planes of said axes so thatthe unlmpeded dtrect paths in direction wholly across the walls of the blocks are limited to the width of the blocks plus spacing between the blocks.

  20. Learning Nuclear Science with Marbles

    ERIC Educational Resources Information Center

    Constan, Zach

    2010-01-01

    Nuclei are "small": if an atom was the size of a football field, the nucleus would be an apple sitting on the 50-yd line. At the same time, nuclei are "dense": the Earth, compressed to nuclear density, could fit inside four Sears Towers. The subatomic level is strange and exotic. For that reason, it's not hard to get young minds excited about…

  1. Nuclear waste

    SciTech Connect

    Not Available

    1991-09-01

    Radioactive waste is mounting at U.S. nuclear power plants at a rate of more than 2,000 metric tons a year. Pursuant to statute and anticipating that a geologic repository would be available in 1998, the Department of Energy (DOE) entered into disposal contracts with nuclear utilities. Now, however, DOE does not expect the repository to be ready before 2010. For this reason, DOE does not want to develop a facility for monitored retrievable storage (MRS) by 1998. This book is concerned about how best to store the waste until a repository is available, congressional requesters asked GAO to review the alternatives of continued storage at utilities' reactor sites or transferring waste to an MRS facility, GAO assessed the likelihood of an MRSA facility operating by 1998, legal implications if DOE is not able to take delivery of wastes in 1998, propriety of using the Nuclear Waste Fund-from which DOE's waste program costs are paid-to pay utilities for on-site storage capacity added after 1998, ability of utilities to store their waste on-site until a repository is operating, and relative costs and safety of the two storage alternatives.

  2. Nuclear Energy Policy

    DTIC Science & Technology

    2009-12-10

    Small Modular Reactors Rising cost estimates for large conventional nuclear power plants—widely projected to be $6 billion or more—have contributed to growing interest in proposals for smaller, modular reactors. Ranging from about 40 to 350 megawatts of electrical capacity, such reactors would be only a fraction of the size of current commercial reactors. Several modular reactors would be installed together to make up a power block with a single control room, under most concepts. Modular reactor concepts would use a variety of technologies,

  3. Small Reactor for Deep Space Exploration

    ScienceCinema

    none,

    2016-07-12

    This is the first demonstration of a space nuclear reactor system to produce electricity in the United States since 1965, and an experiment demonstrated the first use of a heat pipe to cool a small nuclear reactor and then harvest the heat to power a Stirling engine at the Nevada National Security Site's Device Assembly Facility confirms basic nuclear reactor physics and heat transfer for a simple, reliable space power system.

  4. Small Reactor for Deep Space Exploration

    SciTech Connect

    none,

    2012-11-29

    This is the first demonstration of a space nuclear reactor system to produce electricity in the United States since 1965, and an experiment demonstrated the first use of a heat pipe to cool a small nuclear reactor and then harvest the heat to power a Stirling engine at the Nevada National Security Site's Device Assembly Facility confirms basic nuclear reactor physics and heat transfer for a simple, reliable space power system.

  5. Magnetic fusion driventransmutation of nuclear waste (FTW)

    SciTech Connect

    Peng, Yueng Kay Martin; Cheng, E.T.

    1993-01-01

    The possibility of magnetic Fusion driven Transmutation of Waste (FTW) was revisted and discussed recently. Nuclear wastes include all transuranium elements: Pu isotopes, minor actinides separated from the spent fission fuel, and fissile products. Elimination of thse long-life nuclear wastes is necessary for the long-term viability of fission power. A Small Business Innovative Research program has been initiated under the leadership of TSI Research to examine the efficacy of fusion transmutation of waste utilizing small fusion drivers.

  6. Nuclear photonics

    NASA Astrophysics Data System (ADS)

    Habs, D.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.

    2012-07-01

    With the planned new γ-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 1013 γ/s and a band width of ΔEγ/Eγ≈10-3, a new era of γ beams with energies up to 20MeV comes into operation, compared to the present world-leading HIγS facility at Duke University (USA) with 108 γ/s and ΔEγ/Eγ≈3ṡ10-2. In the long run even a seeded quantum FEL for γ beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused γ beams. Here we describe a new experiment at the γ beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for γ beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for γ beams are being developed. Thus, we have to optimize the total system: the γ-beam facility, the γ-beam optics and γ detectors. We can trade γ intensity for band width, going down to ΔEγ/Eγ≈10-6 and address individual nuclear levels. The term "nuclear photonics" stresses the importance of nuclear applications. We can address with γ-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, γ beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to μm resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

  7. Nuclear photonics

    SciTech Connect

    Habs, D.; Guenther, M. M.; Jentschel, M.; Thirolf, P. G.

    2012-07-09

    With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here we describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of

  8. High-content screening identifies small molecules that remove nuclear foci, affect MBNL distribution and CELF1 protein levels via a PKC-independent pathway in myotonic dystrophy cell lines.

    PubMed

    Ketley, Ami; Chen, Catherine Z; Li, Xin; Arya, Sukrat; Robinson, Thelma E; Granados-Riveron, Javier; Udosen, Inyang; Morris, Glenn E; Holt, Ian; Furling, Denis; Chaouch, Soraya; Haworth, Ben; Southall, Noel; Shinn, Paul; Zheng, Wei; Austin, Christopher P; Hayes, Christopher J; Brook, J David

    2014-03-15

    Myotonic dystrophy (DM) is a multi-system neuromuscular disorder for which there is no treatment. We have developed a medium throughput phenotypic assay, based on the identification of nuclear foci in DM patient cell lines using in situ hybridization and high-content imaging to screen for potentially useful therapeutic compounds. A series of further assays based on molecular features of DM have also been employed. Two compounds that reduce and/or remove nuclear foci have been identified, Ro 31-8220 and chromomycin A3. Ro 31-8220 is a PKC inhibitor, previously shown to affect the hyperphosphorylation of CELF1 and ameliorate the cardiac phenotype in a DM1 mouse model. We show that the same compound eliminates nuclear foci, reduces MBNL1 protein in the nucleus, affects ATP2A1 alternative splicing and reduces steady-state levels of CELF1 protein. We demonstrate that this effect is independent of PKC activity and conclude that this compound may be acting on alternative kinase targets within DM pathophysiology. Understanding the activity profile for this compound is key for the development of targeted therapeutics in the treatment of DM.

  9. The Nuclear Power and Nuclear Weapons Connection.

    ERIC Educational Resources Information Center

    Leventhal, Paul

    1990-01-01

    Explains problems enforcing the Nuclear Non-Proliferation Treaty (NPT) of 1968. Provides factual charts and details concerning the production of nuclear energy and arms, the processing and disposal of waste products, and outlines the nuclear fuel cycle. Discusses safeguards, the risk of nuclear terrorism, and ways to deal with these problems. (NL)

  10. The Nuclear Power/Nuclear Weapons Connection.

    ERIC Educational Resources Information Center

    Totten, Sam; Totten, Martha Wescoat

    1985-01-01

    Once they have nuclear power, most countries will divert nuclear materials from commercial to military programs. In excerpts from the book "Facing the Danger" (by Totten, S. and M. W., Crossing Press, 1984), five anti-nuclear activists explain how and why they have been addressing the nuclear connection. (RM)

  11. Nuclear hybrid energy infrastructure

    SciTech Connect

    Agarwal, Vivek; Tawfik, Magdy S.

    2015-02-01

    The nuclear hybrid energy concept is becoming a reality for the US energy infrastructure where combinations of the various potential energy sources (nuclear, wind, solar, biomass, and so on) are integrated in a hybrid energy system. This paper focuses on challenges facing a hybrid system with a Small Modular Reactor at its core. The core of the paper will discuss efforts required to develop supervisory control center that collects data, supports decision-making, and serves as an information hub for supervisory control center. Such a center will also be a model for integrating future technologies and controls. In addition, advanced operations research, thermal cycle analysis, energy conversion analysis, control engineering, and human factors engineering will be part of the supervisory control center. Nuclear hybrid energy infrastructure would allow operators to optimize the cost of energy production by providing appropriate means of integrating different energy sources. The data needs to be stored, processed, analyzed, trended, and projected at right time to right operator to integrate different energy sources.

  12. Nuclear energy.

    PubMed

    Grandin, Karl; Jagers, Peter; Kullander, Sven

    2010-01-01

    Nuclear energy can play a role in carbon free production of electrical energy, thus making it interesting for tomorrow's energy mix. However, several issues have to be addressed. In fission technology, the design of so-called fourth generation reactors show great promise, in particular in addressing materials efficiency and safety issues. If successfully developed, such reactors may have an important and sustainable part in future energy production. Working fusion reactors may be even more materials efficient and environmental friendly, but also need more development and research. The roadmap for development of fourth generation fission and fusion reactors, therefore, asks for attention and research in these fields must be strengthened.

  13. NUCLEAR REACTORS

    DOEpatents

    Long, E.; Ashley, J.W.

    1958-12-16

    A graphite moderator structure is described for a gas-cooled nuclear reactor having a vertical orlentation wherein the structure is physically stable with regard to dlmensional changes due to Wigner growth properties of the graphite, and leakage of coolant gas along spaces in the structure is reduced. The structure is comprised of stacks of unlform right prismatic graphite blocks positioned in layers extending in the direction of the lengths of the blocks, the adjacent end faces of the blocks being separated by pairs of tiles. The blocks and tiles have central bores which are in alignment when assembled and are provided with cooperatlng keys and keyways for physical stability.

  14. Nuclear security

    SciTech Connect

    Dingell, J.D.

    1991-02-01

    The Department of Energy's (DOE) Lawrence Livermore National Laboratory, located in Livermore, California, generates and controls large numbers of classified documents associated with the research and testing of nuclear weapons. Concern has been raised about the potential for espionage at the laboratory and the national security implications of classified documents being stolen. This paper determines the extent of missing classified documents at the laboratory and assesses the adequacy of accountability over classified documents in the laboratory's custody. Audit coverage was limited to the approximately 600,000 secret documents in the laboratory's custody. The adequacy of DOE's oversight of the laboratory's secret document control program was also assessed.

  15. Nuclear dualism.

    PubMed

    Karrer, Kathleen M

    2012-01-01

    Nuclear dualism is a characteristic feature of the ciliated protozoa. Tetrahymena have two different nuclei in each cell. The larger, polyploid, somatic macronucleus (MAC) is the site of transcriptional activity in the vegetatively growing cell. The smaller, diploid micronucleus (MIC) is transcriptionally inactive in vegetative cells, but is transcriptionally active in mating cells and responsible for the genetic continuity during sexual reproduction. Although the MICs and MACs develop from mitotic products of a common progenitor and reside in a common cytoplasm, they are different from one another in almost every respect.

  16. Applications of nuclear physics.

    PubMed

    Hayes, A C

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  17. Applications of nuclear physics

    DOE PAGES

    Hayes-Sterbenz, Anna Catherine

    2017-01-10

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applicationsmore » of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Lastly, each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.« less

  18. Applications of nuclear physics

    NASA Astrophysics Data System (ADS)

    Hayes, A. C.

    2017-02-01

    Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion. The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos. The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article unto itself, which is not the intention of the current review; rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

  19. Nuclear gastroenterology

    SciTech Connect

    Robinson, P.

    1986-01-01

    This book contains the following chapters: Scintigraphy of the oesopohagus; Gastric emptying; Bile dynamics; Scintigraphy in diffuse liver disease; Scintigraphic diagnosis of liver tumors; Acute cholecystitis; Radiolabelled white cells in inflammatory disease; Scintigraphy in gastrointestinal bleeding; Radiolabelled antibodies for imaging of gastrointestinal tumors; Assessment of the small intestine; and Gastrointestinal scintigraphy in pediatrics.

  20. NUCLEAR REACTOR

    DOEpatents

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  1. NUCLEAR REACTOR

    DOEpatents

    Christy, R.F.

    1958-07-15

    A nuclear reactor of the homogeneous liquid fuel type is described wherein the fissionable isotope is suspended or dissolved in a liquid moderator such as water. The reactor core is comprised essentially of a spherical vessel for containing the reactive composition surrounded by a reflector, preferably of beryllium oxide. The reactive composition may be an ordinary water solution of a soluble salt of uranium, the quantity of fissionable isotope in solution being sufficient to provide a critical mass in the vessel. The liquid fuel is stored in a tank of non-crtttcal geometry below the reactor vessel and outside of the reflector and is passed from the tank to the vessel through a pipe connecting the two by air pressure means. Neutron absorbing control and safety rods are operated within slots in the reflector adjacent to the vessel.

  2. NUCLEAR REACTOR

    DOEpatents

    Grebe, J.J.

    1959-12-15

    A reactor which is particularly adapted tu serve as a heat source for a nuclear powered alrcraft or rocket is described. The core of this reactor consists of a porous refractory modera;or body which is impregnated with fissionable nuclei. The core is designed so that its surface forms tapered inlet and outlet ducts which are separated by the porous moderator body. In operation a gaseous working fluid is circulated through the inlet ducts to the surface of the moderator, enters and passes through the porous body, and is heated therein. The hot gas emerges into the outlet ducts and is available to provide thrust. The principle advantage is that tremendous quantities of gas can be quickly heated without suffering an excessive pressure drop.

  3. Metabonomics for detection of nuclear materials processing.

    SciTech Connect

    Alam, Todd Michael; Luxon, Bruce A.; Neerathilingam, Muniasamy; Ansari, S.; Volk, David; Sarkar, S.; Alam, Mary Kathleen

    2010-08-01

    Tracking nuclear materials production and processing, particularly covert operations, is a key national security concern, given that nuclear materials processing can be a signature of nuclear weapons activities by US adversaries. Covert trafficking can also result in homeland security threats, most notably allowing terrorists to assemble devices such as dirty bombs. Existing methods depend on isotope analysis and do not necessarily detect chronic low-level exposure. In this project, indigenous organisms such as plants, small mammals, and bacteria are utilized as living sensors for the presence of chemicals used in nuclear materials processing. Such 'metabolic fingerprinting' (or 'metabonomics') employs nuclear magnetic resonance (NMR) spectroscopy to assess alterations in organismal metabolism provoked by the environmental presence of nuclear materials processing, for example the tributyl phosphate employed in the processing of spent reactor fuel rods to extract and purify uranium and plutonium for weaponization.

  4. Effective citizen advocacy of beneficial nuclear technologies

    SciTech Connect

    Wood, S.; McKibben, Ph.D.

    2007-07-01

    In 1991, a small group of citizens from communities near the Savannah River Site (SRS) formed a pro-nuclear education and advocacy group, Citizens for Nuclear Technology Awareness (CNTA). Their purpose was to: (1) counter nuclear misinformation that dominated the nation's news outlets, (2) provide education on nuclear subjects to area citizens, students, elected officials, and (3) provide informed citizen support for potential new missions for SRS when needed. To effectively accomplish these objectives it is also essential to establish and maintain good relations with community leaders and reporters that cover energy and nuclear subjects. The organization has grown considerably since its inception and has expanded its sphere of influence. We believe that our experiences over these fifteen years are a good model for effectively communicating nuclear subjects with the public. This paper describes the structure, operation and some of the results of CNTA. (authors)

  5. The spread of nuclear-weapon-free zones: Building a new nuclear bargain

    SciTech Connect

    Davis, Z.S.

    1996-02-01

    The United States (US), France and Britain took a small step in the direction of nuclear disarmament when they announced they would ratify the protocols of the Treaty of Rarotonga, also called the South Pacific nuclear-free-zone treaty. The author examines the protocols of this treaty and the implications for its adoption.

  6. NUCLEAR FLASH TYPE STEAM GENERATOR

    DOEpatents

    Johns, F.L.; Gronemeyer, E.C.; Dusbabek, M.R.

    1962-09-01

    A nuclear steam generating apparatus is designed so that steam may be generated from water heated directly by the nuclear heat source. The apparatus comprises a pair of pressure vessels mounted one within the other, the inner vessel containing a nuclear reactor heat source in the lower portion thereof to which water is pumped. A series of small ports are disposed in the upper portion of the inner vessel for jetting heated water under pressure outwardly into the atmosphere within the interior of the outer vessel, at which time part of the jetted water flashes into steam. The invention eliminates the necessity of any intermediate heat transfer medium and components ordinarily required for handling that medium. (AEC)

  7. Small Families

    MedlinePlus

    ... more emphasis on careers for women, more effective methods of contraception, and the rising cost of rearing and educating children. There are some very clear benefits to having a small family; Each child receives more parental attention and educational advantages, which generally raise her self- ...

  8. Nuclear war: Opposing viewpoints

    SciTech Connect

    Szumski, B.

    1985-01-01

    This book presents opposing viewpoints on nuclear war. Topics discussed include: how nuclear would begin; would humanity survive; would civil defense work; will an arms agreement work; and can space weapons reduce the risk of nuclear war.

  9. Nuclear analytical chemistry

    SciTech Connect

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

  10. Nuclear Quadrupole Moments and Nuclear Shell Structure

    DOE R&D Accomplishments Database

    Townes, C. H.; Foley, H. M.; Low, W.

    1950-06-23

    Describes a simple model, based on nuclear shell considerations, which leads to the proper behavior of known nuclear quadrupole moments, although predictions of the magnitudes of some quadrupole moments are seriously in error.

  11. Nuclear South Asia

    DTIC Science & Technology

    2007-11-02

    inseparable from the history of nuclear developments in both India and Pakistan. The timing of India’s tests was determined by the pronuclear stance of the...Rawalpindi, 2001), 17-18. 53 3Robert Boardman, The Politics of Fading Dreams: Britain and the Nuclear Export Business, Nuclear Exports and World Politics (New...disasters of nuclear arms race. 61 BIBLIOGRAPHY Books Boardman, Robert. The Politics of Fading Dreams: Britain and the Nuclear Export Business, Nuclear

  12. Nuclear Fuel Cycle & Vulnerabilities

    SciTech Connect

    Boyer, Brian D.

    2012-06-18

    The objective of safeguards is the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection. The safeguards system should be designed to provide credible assurances that there has been no diversion of declared nuclear material and no undeclared nuclear material and activities.

  13. Nuclear reactor

    DOEpatents

    Thomson, Wallace B.

    2004-03-16

    A nuclear reactor comprising a cylindrical pressure vessel, an elongated annular core centrally disposed within and spaced from the pressure vessel, and a plurality of ducts disposed longitudinally of the pressure vessel about the periphery thereof, said core comprising an annular active portion, an annular reflector just inside the active portion, and an annular reflector just outside the active a portion, said annular active portion comprising rectangular slab, porous fuel elements radially disposed around the inner reflector and extending the length of the active portion, wedge-shaped, porous moderator elements disposed adjacent one face of each fuel element and extending the length of the fuel element, the fuel and moderator elements being oriented so that the fuel elements face each other and the moderator elements do likewise, adjacent moderator elements being spaced to provide air inlet channels, and adjacent fuel elements being spaced to provide air outlet channels which communicate with the interior of the peripheral ducts, and means for introducing air into the air inlet channels which passes through the porous moderator elements and porous fuel elements to the outlet channel.

  14. Nuclear Proliferation: A Global Nuclear Strategy

    DTIC Science & Technology

    2007-03-30

    thinking about nuclear weapons as a “ Wild Card ” in this case. Finally, just as North Korea is using nuclear weapons as a “bargaining chip,” we...definite disadvantage for non-nuclear nations not to have a nuclear” Wild Card ”. So some misguided Japanese politicians are attracted to the “ Wild Card ” advantage

  15. Nuclear weapons modernizations

    SciTech Connect

    Kristensen, Hans M.

    2014-05-09

    This article reviews the nuclear weapons modernization programs underway in the world's nine nuclear weapons states. It concludes that despite significant reductions in overall weapons inventories since the end of the Cold War, the pace of reductions is slowing - four of the nuclear weapons states are even increasing their arsenals, and all the nuclear weapons states are busy modernizing their remaining arsenals in what appears to be a dynamic and counterproductive nuclear competition. The author questions whether perpetual modernization combined with no specific plan for the elimination of nuclear weapons is consistent with the nuclear Non-Proliferation Treaty and concludes that new limits on nuclear modernizations are needed.

  16. Nuclear weapons modernizations

    NASA Astrophysics Data System (ADS)

    Kristensen, Hans M.

    2014-05-01

    This article reviews the nuclear weapons modernization programs underway in the world's nine nuclear weapons states. It concludes that despite significant reductions in overall weapons inventories since the end of the Cold War, the pace of reductions is slowing - four of the nuclear weapons states are even increasing their arsenals, and all the nuclear weapons states are busy modernizing their remaining arsenals in what appears to be a dynamic and counterproductive nuclear competition. The author questions whether perpetual modernization combined with no specific plan for the elimination of nuclear weapons is consistent with the nuclear Non-Proliferation Treaty and concludes that new limits on nuclear modernizations are needed.

  17. Special nuclear material simulation device

    DOEpatents

    Leckey, John H.; DeMint, Amy; Gooch, Jack; Hawk, Todd; Pickett, Chris A.; Blessinger, Chris; York, Robbie L.

    2014-08-12

    An apparatus for simulating special nuclear material is provided. The apparatus typically contains a small quantity of special nuclear material (SNM) in a configuration that simulates a much larger quantity of SNM. Generally the apparatus includes a spherical shell that is formed from an alloy containing a small quantity of highly enriched uranium. Also typically provided is a core of depleted uranium. A spacer, typically aluminum, may be used to separate the depleted uranium from the shell of uranium alloy. A cladding, typically made of titanium, is provided to seal the source. Methods are provided to simulate SNM for testing radiation monitoring portals. Typically the methods use at least one primary SNM spectral line and exclude at least one secondary SNM spectral line.

  18. Phase transitions in nuclear matter

    SciTech Connect

    Glendenning, N.K.

    1984-11-01

    The rather general circumstances under which a phase transition in hadronic matter at finite temperature to an abnormal phase in which baryon effective masses become small and in which copious baryon-antibaryon pairs appear is emphasized. A preview is also given of a soliton model of dense matter, in which at a density of about seven times nuclear density, matter ceases to be a color insulator and becomes increasingly color conducting. 22 references.

  19. Photodetectors for Nuclear Medical Imaging

    PubMed Central

    Moses, William W.

    2009-01-01

    There have been a number of recent advances in photodetector technology, notably in photomultiplier tubes with high quantum efficiency (up to ~50%), hybrid photodetectors, and silicon-based Geiger-mode photodetectors. This paper looks at the potential benefits that these technologies can bring to nuclear medicine, notably SPECT and PET. We find that while the potential benefits to SPECT are relatively small, they can bring performance improvements in many areas for PET. PMID:20161403

  20. Volumetric direct nuclear pumped laser

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.; Hohl, F.; Deyoung, R. J.; Williams, M. D. (Inventor)

    1978-01-01

    A volumetric direct nuclear pumped laser was developed in which the gas is a mixture of He-3 and a minority gas from the group of argon, krypton, xenon, chlorine and fluorine. The mixture of He-3 and the minority gas produces lasing with a minority gas concentration of from 0.01 to 10 percent argon, 1 percent krypton, 0.01 to 5 percent xenon and small concentrations of chlorine or fluorine.

  1. Nuclear track membranes: Production in nuclear reactors and prospects of application

    SciTech Connect

    Fursov, B.I.; Kryuchkov, E.A.; Mironov, N.N.

    1993-12-31

    Nuclear track membranes are produced by a physico-chemical treatment of polymeric films exposed to fission fragments in nuclear reactors or to heavy ion beams. Heavy charged particles form in the solids along their trajectories regions of high ionization density where polymer destruction takes place. Selective dissolution of damaged material converts the initial film into a microfiltration membrane with cylindrical through pores. The main feature of nuclear membranes are a small thickness and uniformity of pore size. The qualities of the nuclear membranes promise good prospects for applications in many areas.

  2. Nuclear Thermal Propulsion Development Risks

    NASA Technical Reports Server (NTRS)

    Kim, Tony

    2015-01-01

    There are clear advantages of development of a Nuclear Thermal Propulsion (NTP) for a crewed mission to Mars. NTP for in-space propulsion enables more ambitious space missions by providing high thrust at high specific impulse ((is) approximately 900 sec) that is 2 times the best theoretical performance possible for chemical rockets. Missions can be optimized for maximum payload capability to take more payload with reduced total mass to orbit; saving cost on reduction of the number of launch vehicles needed. Or missions can be optimized to minimize trip time significantly to reduce the deep space radiation exposure to the crew. NTR propulsion technology is a game changer for space exploration to Mars and beyond. However, 'NUCLEAR' is a word that is feared and vilified by some groups and the hostility towards development of any nuclear systems can meet great opposition by the public as well as from national leaders and people in authority. The public often associates the 'nuclear' word with weapons of mass destruction. The development NTP is at risk due to unwarranted public fears and clear honest communication of nuclear safety will be critical to the success of the development of the NTP technology. Reducing cost to NTP development is critical to its acceptance and funding. In the past, highly inflated cost estimates of a full-scale development nuclear engine due to Category I nuclear security requirements and costly regulatory requirements have put the NTP technology as a low priority. Innovative approaches utilizing low enriched uranium (LEU). Even though NTP can be a small source of radiation to the crew, NTP can facilitate significant reduction of crew exposure to solar and cosmic radiation by reducing trip times by 3-4 months. Current Human Mars Mission (HMM) trajectories with conventional propulsion systems and fuel-efficient transfer orbits exceed astronaut radiation exposure limits. Utilizing extra propellant from one additional SLS launch and available

  3. Theoretical nuclear physics

    SciTech Connect

    Kunz, P.D.

    1990-10-01

    This report contains small papers on the following topics: ground state correlations of nuclei in relativistic random phase approximation; instability of infinite nuclear matter in the relativistic hartree approximation; charge density differences for nuclei near {sup 208}Pb in relativistic models; meson exchange current corrections to magnetic moments in quantum hadro-dynamics; analysis of the O{sup +} {yields} O{sup {minus}} reaction at intermediate energies; contributions of reaction channels to the {sup 6}Li(p,{gamma}){sup 7}Be Reaction; deformed chiral nucleons; vacuum polarization in a finite system; second order processes in the (e,e{prime}d) reaction; sea contributions in Dirac RPA for finite nuclei; and momentum cutoffs in the sea.

  4. Nuclear Physicists in Finance

    NASA Astrophysics Data System (ADS)

    Mattoni, Carlo

    2017-01-01

    The financial services industry presents an interesting alternative career path for nuclear physicists. Careers in finance typically offer intellectual challenge, a fast pace, high caliber colleagues, merit-based compensation with substantial upside, and an opportunity to deploy skills learned as a physicist. Physicists are employed at a wide range of financial institutions on both the ``buy side'' (hedge fund managers, private equity managers, mutual fund managers, etc.) and the ``sell side'' (investment banks and brokerages). Historically, physicists in finance were primarily ``quants'' tasked with applying stochastic calculus to determine the price of financial derivatives. With the maturation of the field of derivative pricing, physicists in finance today find work in a variety of roles ranging from quantification and management of risk to investment analysis to development of sophisticated software used to price, trade, and risk manage securities. Only a small subset of today's finance careers for physicists require the use of advanced math and practically none provide an opportunity to tinker with an apparatus, yet most nevertheless draw on important skills honed during the training of a nuclear physicist. Intellectually rigorous critical thinking, sophisticated problem solving, an attention to minute detail and an ability to create and test hypotheses based on incomplete information are key to both disciplines.

  5. Multinational underground nuclear parks

    SciTech Connect

    Myers, C.W.; Giraud, K.M.

    2013-07-01

    Newcomer countries expected to develop new nuclear power programs by 2030 are being encouraged by the International Atomic Energy Agency to explore the use of shared facilities for spent fuel storage and geologic disposal. Multinational underground nuclear parks (M-UNPs) are an option for sharing such facilities. Newcomer countries with suitable bedrock conditions could volunteer to host M-UNPs. M-UNPs would include back-end fuel cycle facilities, in open or closed fuel cycle configurations, with sufficient capacity to enable M-UNP host countries to provide for-fee waste management services to partner countries, and to manage waste from the M-UNP power reactors. M-UNP potential advantages include: the option for decades of spent fuel storage; fuel-cycle policy flexibility; increased proliferation resistance; high margin of physical security against attack; and high margin of containment capability in the event of beyond-design-basis accidents, thereby reducing the risk of Fukushima-like radiological contamination of surface lands. A hypothetical M-UNP in crystalline rock with facilities for small modular reactors, spent fuel storage, reprocessing, and geologic disposal is described using a room-and-pillar reference-design cavern. Underground construction cost is judged tractable through use of modern excavation technology and careful site selection. (authors)

  6. [Nuclear medicine and radiopharmaceuticals].

    PubMed

    Sopena Novales, P; Plancha Mansanet, M C; Martinez Carsi, C; Sopena Monforte, R

    2014-06-01

    Nuclear Medicine is a medical specialty that allows modern diagnostics and treatments using radiopharmaceuticals original radiotracers (drugs linked to a radioactive isotope). In Europe, radiopharmaceuticals are considered a special group of drugs and thus their preparation and use are regulated by a set of policies that have been adopted by individual member countries. The radiopharmaceuticals used in diagnostic examinations are administered in very small doses. So, in general, they have no pharmacological action, side effects or serious adverse reactions. The biggest problem associated with their use are the alterations in their biodistribution that may cause diagnostic errors. Nuclear Medicine is growing considerably influenced by the appearance and development of new radiopharmaceuticals in both the diagnostic and therapeutic fields and primarily to the impact of new multimodality imaging techniques (SPECT-CT, PET-CT, PET-MRI, etc.). It's mandatory to know the limitations of these techniques, distribution and eventual physiological alterations of radiopharmaceuticals, contraindications and adverse reactions of radiological contrasts, and the possible interference of both.

  7. Nuclear Power in China

    NASA Astrophysics Data System (ADS)

    Zhou, Yun

    2012-02-01

    In response to the Fukushima accident, China is strengthening its nuclear safety at reactors in operation, under construction and in preparation, including efforts to improve nuclear safety regulations and guidelines based on lessons learned from the accident. Although China is one of the major contributors in the global nuclear expansion, China's nuclear power industry is relatively young. Its nuclear safety regulators are less experienced compared to those in other major nuclear power countries. To realize China's resolute commitment to rapid growth of safe nuclear energy, detailed analyses of its nuclear safety regulatory system are required. This talk explains China's nuclear energy program and policy at first. It also explores China's governmental activities and future nuclear development after Fukushima accidents. At last, an overview of China's nuclear safety regulations and practices are provided. Issues and challenges are also identified for police makers, regulators, and industry professionals.

  8. Nuclear reactor

    DOEpatents

    Pennell, William E.; Rowan, William J.

    1977-01-01

    A nuclear reactor in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assmblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters and the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters and the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance.

  9. Nuclear reactor

    DOEpatents

    Yant, Howard W.; Stinebiser, Karl W.; Anzur, Gregory C.

    1977-01-01

    A nuclear reactor, particularly a liquid-metal breeder reactor, whose upper internals include outlet modules for channeling the liquid-metal coolant from selected areas of the outlet of the core vertically to the outlet plenum. The modules are composed of a highly-refractory, high corrosion-resistant alloy, for example, INCONEL-718. Each module is disposed to confine and channel generally vertically the coolant emitted from a subplurality of core-component assemblies. Each module has a grid with openings, each opening disposed to receive the coolant from an assembly of the subplurality. The grid in addition serves as a holdown for the assemblies of the corresponding subplurality preventing their excessive ejection upwardly from the core. In the region directly over the core the outlet modules are of such peripheral form that they nest forming a continuum over the core-component assemblies whose outlet coolant they confine. Each subassembly includes a chimney which confines the coolant emitted by its corresponding subassemblies to generally vertical flow between the outlet of the core and the outlet plenum. Each subplurality of assemblies whose emitted coolant is confined by an outlet module includes assemblies which emit lower-temperature coolant, for example, a control-rod assembly, or fertile assemblies, and assemblies which emit coolant of substantially higher temperature, for example, fuel-rod assemblies. The coolants of different temperatures are mixed in the chimneys reducing the effect of stripping (hot-cold temperature fluctuations) on the remainder of the upper internals which are composed typically of AISI-304 or AISI-316 stainless steel.

  10. Nuclear data relevant to the production of medically important {beta}{sup +} emitting radioisotopes {sup 75}Br, {sup 86}Y, {sup 94m}Tc and {sup 124}I at a small cyclotron

    SciTech Connect

    Qaim, S.M.; Roesch, F.; Scholten, B.; Stoecklin, G.; Kovacs, Z.; Tarkanyi, F.

    1994-12-31

    Excitation functions were measured for the formation of medically important positron emitting radioisotopes {sup 75}Br, {sup 86}Y, {sup 94m}Tc and {sup 124}I at a small cyclotron. The reactions investigated up to about 20 MeV included {sup 78}Kr(p,{alpha}){sup 75}Br, {sup 74}Se(d,n){sup 75}Br, {sup 86}Sr(p,n){sup 86}Y, {sup 94}Mo(p,n){sup 94m}Tc and {sup 124}Te(p,n){sup 124}I. In each case the well-known stacked-foil (in case of {sup 78}Kr gas stacked-cylinder) technique was used and the target material was isotopically enriched. From the cross section data the optimum production conditions for various radioisotopes were deduced. Whereas {sup 86}Y, {sup 94m}Tc, and {sup 124}I can be produced at a small cyclotron in quantities and purity sufficient for medical applications, the achievable batch yields of {sup 75}Br at such a cyclotron are limited.

  11. Adamantyl-Substituted Retinoid-Derived Molecules That Interact with the Orphan Nuclear Receptor Small Heterodimer Partner: Effects of Replacing the 1-Adamantyl or Hydroxyl Group on Inhibition of Cancer Cell Growth, Induction of Cancer Cell Apoptosis, and Inhibition of Src Homology 2 Domain-Containing Protein Tyrosine Phosphatase-2 Activity

    PubMed Central

    Dawson, Marcia I.; Xia, Zebin; Jiang, Tao; Ye, Mao; Fontana, Joseph A.; Farhana, Lulu; Patel, Bhaumik; Xue, Li Ping; Bhuiyan, Mohammad; Pellicciari, Roberto; Macchiarulo, Antonio; Nuti, Roberto; Zhang, Xiao-Kun; Han, Young-Hoon; Tautz, Lutz; Hobbs, Peter D.; Jong, Ling; Waleh, Nahid; Chao, Wan-ru; Feng, Gen-Sheng; Pang, Yuhong; Su, Ying

    2014-01-01

    (E)-4-[3-(1-Adamantyl)-4′-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC) induces the cell-cycle arrest and apoptosis of leukemia and cancer cells. Studies demonstrated that 3-Cl-AHPC bound to the atypical orphan nuclear receptor small heterodimer partner (SHP). Although missing a DNA-binding domain, SHP heterodimerizes with the ligand-binding domains of other nuclear receptors to repress their abilities to induce or inhibit gene expression. 3-Cl-AHPC analogues having the 1-adamantyl and phenolic hydroxyl pharmacophoric elements replaced with isosteric groups were designed, synthesized, and evaluated for their inhibition of proliferation and induction of human cancer cell apoptosis. Structure–anticancer activity relationship studies indicated the importance of both groups to apoptotic activity. Docking of 3-Cl-AHPC and its analogues to an SHP computational model that was based on the crystal structure of ultraspiracle complexed with 1-stearoyl-2-palmitoylglycero-3-phosphoethanolamine suggested why these 3-Cl-AHPC groups could influence SHP activity. Inhibitory activity against Src homology 2 domain-containing protein tyrosine phosphatase 2 (Shp-2) was also assessed. The most active Shp-2 inhibitor was found to be the 3′-(3,3-dimethylbutynyl) analogue of 3-Cl-AHPC. PMID:18759424

  12. Small Business Innovations (Robotic Wrist)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Under a Langley Research Center Small Business Innovation Research (SBIR) contract, Ross-Hime Designs, Inc. Minneapolis, MN, developed the Omni-Wrist actuator, which has a 25-pound capacity, 180 degrees of pitch/yaw, and 360 degrees of roll. Company literature calls it "the first successful singularity-free high-precision (robotic) wrist." Applications include spray painting, sealing, ultrasonic testing, welding and a variety of nuclear industry, aerospace and military uses.

  13. The New Nuclear Nations.

    ERIC Educational Resources Information Center

    Spector, Leonard S.

    1990-01-01

    Explores the issue of nuclear proliferation, noting that the countries with nuclear capability now include Israel, South Africa, India, and Pakistan. Describes the role and problems of the United States in halting nuclearization. Supplies charts, maps, and information concerning the state of nuclear capability in each country. (NL)

  14. Nuclear air cushion vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    The state-of-the-art of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant is identified. Using mission studies and cost estimates, some of the advantages of nuclear power for large air cushion vehicles are described. The technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies are summarized.

  15. Nuclear energy and security

    SciTech Connect

    BLEJWAS,THOMAS E.; SANDERS,THOMAS L.; EAGAN,ROBERT J.; BAKER,ARNOLD B.

    2000-01-01

    Nuclear power is an important and, the authors believe, essential component of a secure nuclear future. Although nuclear fuel cycles create materials that have some potential for use in nuclear weapons, with appropriate fuel cycles, nuclear power could reduce rather than increase real proliferation risk worldwide. Future fuel cycles could be designed to avoid plutonium production, generate minimal amounts of plutonium in proliferation-resistant amounts or configurations, and/or transparently and efficiently consume plutonium already created. Furthermore, a strong and viable US nuclear infrastructure, of which nuclear power is a large element, is essential if the US is to maintain a leadership or even participatory role in defining the global nuclear infrastructure and controlling the proliferation of nuclear weapons. By focusing on new fuel cycles and new reactor technologies, it is possible to advantageously burn and reduce nuclear materials that could be used for nuclear weapons rather than increase and/or dispose of these materials. Thus, the authors suggest that planners for a secure nuclear future use technology to design an ideal future. In this future, nuclear power creates large amounts of virtually atmospherically clean energy while significantly lowering the threat of proliferation through the thoughtful use, physical security, and agreed-upon transparency of nuclear materials. The authors must develop options for policy makers that bring them as close as practical to this ideal. Just as Atoms for Peace became the ideal for the first nuclear century, they see a potential nuclear future that contributes significantly to power for peace and prosperity.

  16. Terrorists and Nuclear Technology

    ERIC Educational Resources Information Center

    Krieger, David

    1975-01-01

    This essay explores the ways terrorist groups may gain possession of nuclear materials; the way in which they may use nuclear weapons and other nuclear technologies to their benefit; and various courses of action designed to minimize the possibilities of terrorists utilizing nuclear technology to their benefit and society's detriment. (BT)

  17. Frontiers of Nuclear Structure

    SciTech Connect

    Nazarewicz, Witold

    1997-12-31

    Current developments in nuclear structure at the `limits` are discussed. The studies of nuclear behavior at extreme conditions provide us with invaluable information about the nature of the nuclear interaction and nucleonic correlations at various energy-distance scales. In this talk frontiers of nuclear structure are briefly reviewed from a theoretical perspective, mainly concentrating on medium-mass and heavy nuclei.

  18. Nuclear medicine annual, 1984

    SciTech Connect

    Freeman, L.M.; Weissmann, H.S.

    1984-01-01

    The following topics are reviewed in this work: nuclear physicians role in planning for and handling radiation accidents; the role of nuclear medicine in evaluating the hypertensive patient; studies of the heart with radionuclides; role of radionuclide imaging in the patient undergoing chemotherapy; hematologic nuclear medicine; the role of nuclear medicine in sports related injuries; radionuclide evaluation of hepatic function with emphasis on cholestatis.

  19. The nuclear freeze controversy

    SciTech Connect

    Payne, K.B.; Gray, C.S.

    1984-01-01

    This book presents papers on nuclear arms control. Topics considered include the background and rationale behind the nuclear freeze proposal, nuclear deterrence, national defense, arms races, arms buildup, warfare, the moral aspects of nuclear deterrence, treaty verification, the federal budget, the economy, a historical perspective on Soviet policy toward the freeze, the other side of the Soviet peace offensive, and making sense of the nuclear freeze debate.

  20. A new perspective on severe nuclear accidents.

    PubMed

    Lee, Jaiki

    2012-03-01

    The reactions of the public in Korea to the nuclear accident at the Fukushima Daiichi plants in Japan, particularly over-reactions, are reviewed, with the conclusion that significant radioactive contamination of a small country could lead to a severe national crisis. The most important factor is the socio-economic damage caused by stigma, which in turn is caused by a misunderstanding of the radiation risk. Given that nuclear power is an important choice in the face of the threat of climate change, the public's perceptions need to be changed at any cost, not only in those countries operating nuclear power plants but globally as well.

  1. Effects of macromolecular crowding on nuclear size.

    PubMed

    Rosania, G R; Swanson, J A

    1995-05-01

    The concentration of macromolecules inside cells is high, and the resultant crowding of cytoplasm can be expected to affect many interactions involving macromolecular assemblies. Here, we have examined the effect of solute size and concentration on nuclear volume in saponin-permeabilized macrophages. Nuclei swelled in the presence of small solutes and shrank reversibly in the presence of larger permeant solutes. Remarkably, the smallest solutes capable of shrinking the nucleus were not excluded by the pores in the nuclear envelope. Indeed, nuclei shrank in the presence of such solutes even after the nuclear envelope had been sheared mechanically or permeabilized with detergent. Nuclei extracted with 1% Triton X-100 shrank in the presence of very high concentrations of small solute molecules (30% w/v) as well as in lower concentrations of larger solutes. Consistent with a macromolecular crowding effect, changes in nuclear volume were dependent on solute size and not simply dependent on the colligative properties of solutes or the exclusion of solutes by the nuclear envelope. Solute size-dependent changes in nuclear volume were independent of the chemical nature of the solutes and of the activity of the ions in the buffer. Together, these observations indicate that high concentrations of macromolecules such as those found inside cells can influence the size of the nucleus by directly affecting nuclear structure.

  2. A genome-wide small interfering RNA (siRNA) screen reveals nuclear factor-κB (NF-κB)-independent regulators of NOD2-induced interleukin-8 (IL-8) secretion.

    PubMed

    Warner, Neil; Burberry, Aaron; Pliakas, Maria; McDonald, Christine; Núñez, Gabriel

    2014-10-10

    NOD2 encodes an intracellular multidomain pattern recognition receptor that is the strongest known genetic risk factor in the pathogenesis of Crohn disease (CD), a chronic relapsing inflammatory disorder of the intestinal tract. NOD2 functions as a sensor for bacterial cell wall components and activates proinflammatory and antimicrobial signaling pathways. Here, using a genome-wide small interfering RNA (siRNA) screen, we identify numerous genes that regulate secretion of the proinflammatory cytokine IL-8 in response to NOD2 activation. Moreover, many of the identified IL-8 regulators are linked by protein-protein interactions, revealing subnetworks of highly connected IL-8 regulators implicated in processes such as vesicle formation, mRNA stability, and protein ubiquitination and trafficking. A TNFα counterscreen to induce IL-8 secretion in an NOD2-independent manner reveals that the majority of the identified regulators affect IL-8 secretion irrespective of the initiating stimuli. Using immortalized macrophages, we validate the ubiquitin protease, USP8, and the endosomal sorting protein, VPS28, as negative regulators of NOD2-induced cytokine secretion. Interestingly, several genes that affect NOD2-induced IL-8 secretion are present in loci associated with CD risk by genome-wide association studies, supporting a role for the NOD2/IL-8 pathway, and not just NOD2, in the pathogenesis of CD. Overall, this screen provides a valuable resource in the advancement of our understanding of the genes that regulate the secretion of IL-8.

  3. When lamins go bad: nuclear structure and disease.

    PubMed

    Schreiber, Katherine H; Kennedy, Brian K

    2013-03-14

    Mutations in nuclear lamins or other proteins of the nuclear envelope are the root cause of a group of phenotypically diverse genetic disorders known as laminopathies, which have symptoms that range from muscular dystrophy to neuropathy to premature aging syndromes. Although precise disease mechanisms remain unclear, there has been substantial progress in our understanding of not only laminopathies, but also the biological roles of nuclear structure. Nuclear envelope dysfunction is associated with altered nuclear activity, impaired structural dynamics, and aberrant cell signaling. Building on these findings, small molecules are being discovered that may become effective therapeutic agents.

  4. A Monte Carlo approach to small-scale dosimetry of solid tumour microvasculature for nuclear medicine therapies with (223)Ra-, (131)I-, (177)Lu- and (111)In-labelled radiopharmaceuticals.

    PubMed

    Amato, Ernesto; Leotta, Salvatore; Italiano, Antonio; Baldari, Sergio

    2015-07-01

    The small-scale dosimetry of radionuclides in solid-tumours is directly related to the intra-tumoral distribution of the administered radiopharmaceutical, which is affected by its egress from the vasculature and dispersion within the tumour. The aim of the present study was to evaluate the combined dosimetric effects of radiopharmaceutical distribution and range of the emitted radiation in a model of tumour microvasculature. We developed a computational model of solid-tumour microenvironment around a blood capillary vessel, and we simulated the transport of radiation emitted by (223)Ra, (111)In, (131)I and (177)Lu using the GEANT4 Monte Carlo. For each nuclide, several models of radiopharmaceutical dispersion throughout the capillary vessel were considered. Radial dose profiles around the capillary vessel, the Initial Radioactivity (IR) necessary to deposit 100 Gy of dose at the edge of the viable tumour-cell region, the Endothelial Cell Mean Dose (ECMD) and the Tumour Edge Mean Dose (TEMD), i.e. the mean dose imparted at the 250-μm layer of tissue, were computed. The results for beta and Auger emitters demonstrate that the photon dose is about three to four orders of magnitude lower than that deposited by electrons. For (223)Ra, the beta emissions of its progeny deliver a dose about three orders of magnitude lower than that delivered by the alpha emissions. Such results may help to characterize the dose inhomogeneities in solid tumour therapies with radiopharmaceuticals, taking into account the interplay between drug distribution from vasculature and range of ionizing radiations.

  5. Global Security, Medical Isotopes, and Nuclear Science

    SciTech Connect

    Ahle, Larry

    2007-10-26

    Over the past century basic nuclear science research has led to the use of radioactive isotopes into a wide variety of applications that touch our lives everyday. Some are obvious, such as isotopes for medical diagnostics and treatment. Others are less so, such as National/Global security issues. And some we take for granted, like the small amount of 241 Am that is in every smoke detector. At the beginning of this century, we are in a position where the prevalence and importance of some applications of nuclear science are pushing the basic nuclear science community for improved models and nuclear data. Yet, at the same time, the push by the basic nuclear science community to study nuclei that are farther and farther away from stability also offer new opportunities for many applications. This talk will look at several global security applications of nuclear science, summarizing current R and D and need for improved nuclear data It will also look at how applications of nuclear science, such as to medicine, will benefit from the push for more and more powerful radioactive ion beam facilities.

  6. Global Security, Medical Isotopes, and Nuclear Science

    SciTech Connect

    Ahle, L E

    2007-09-17

    Over the past century basic nuclear science research has led to the use of radioactive isotopes into a wide variety of applications that touch our lives everyday. Some are obvious, such as isotopes for medical diagnostics and treatment. Others are less so, such as National/Global security issues. And some we take for granted, like the small amount of 241Am that is in every smoke detector. At the beginning of this century, we are in a position where the prevalence and importance of some applications of nuclear science are pushing the basic nuclear science community for improved models and nuclear data. Yet, at the same time, the push by the basic nuclear science community to study nuclei that are farther and farther away from stability also offer new opportunities for many applications. This talk will look at several global security applications of nuclear science, summarizing current R&D and need for improved nuclear data It will also look at how applications of nuclear science, such as to medicine, will benefit from the push for more and more powerful radioactive ion beam facilities.

  7. Nuclear data for criticality safety - current issues

    SciTech Connect

    Leal, L.C.; Jordan, W.C.; Wright, R.Q.

    1995-06-01

    Traditionally, nuclear data evaluations have been performed in support of the analysis and design of thermal and fast reactors. In general, the neutron spectra characteristic of the thermal and fast systems used for data testing are predominantly in the low- and high-energy range with a relatively small influence from the intermediate-energy range. In the area of nuclear criticality safety, nuclear systems arising from applications involving fissionable materials outside reactors can lead to situations very different from those most commonly found in reactor analysis and design. These systems are not limited to thermal or fast and may have significant influence from the intermediate energy range. The extension of the range of applicability of the nuclear data evaluation beyond thermal and fast systems is therefore needed to cover problems found in nuclear criticality safety. Before criticality safety calculations are performed, the bias and uncertainties of the codes and cross sections that are used must be determined. The most common sources of uncertainties, in general, are the calculational methodologies and the uncertainties related to the nuclear data, such as the microscopic cross sections, entering into the calculational procedure. The aim here is to focus on the evaluated nuclear data pertaining to applications in nuclear criticality safety.

  8. Nuclear Waste Disposal

    SciTech Connect

    Gee, Glendon W.; Meyer, Philip D.; Ward, Andy L.

    2005-01-12

    Nuclear wastes are by-products of nuclear weapons production and nuclear power generation, plus residuals of radioactive materials used by industry, medicine, agriculture, and academia. Their distinctive nature and potential hazard make nuclear wastes not only the most dangerous waste ever created by mankind, but also one of the most controversial and regulated with respect to disposal. Nuclear waste issues, related to uncertainties in geologic disposal and long-term protection, combined with potential misuse by terrorist groups, have created uneasiness and fear in the general public and remain stumbling blocks for further development of a nuclear industry in a world that may soon be facing a global energy crisis.

  9. Generation of Gravitational Waves with Nuclear Reactions

    SciTech Connect

    Fontana, Giorgio; Baker, Robert M. L. Jr.

    2006-01-20

    The problem of efficient generation of High Frequency Gravitational Waves (HFGWs) and pulses of Gravitational Radiation might find a reasonably simple solution by employing nuclear matter, especially isomers. A fissioning isomer not only rotates at extremely high frequency ({approx} 3.03x1024 s-1), but is also highly deformed in the first stages of fission (the nucleus is rotating and made asymmetric 'before' fission). Thus one achieves significant impulsive forces (e.g., 3.67x108 N) acting over extremely short time spans (e.g., 3.3x10-22 s). Alternatively, a pulsed particle beam, which could include antimatter, could trigger nuclear reactions and build up a coherent GW as the particles move through a target mass. The usual difficulty with HFGWs generated by nuclear reactions is the small dimensions of their nuclear-reaction volumes, that is, the small moment of inertia and submicroscopic radii of gyration (e.g., 10-16 m) of the nuclear-mass system. Such a difficulty is overcome by utilizing clusters of nuclear material, whose nuclear reactions are in synchronization (through the use of a computer controlled logic system) and are at a large distance apart, e.g., meters, kilometers, etc. The effective radius of gyration of the overall nuclear mass system is enormous and if the quadrupole formalism holds even approximately, then significant HFGW is generated, for example up to 8.5x1010 W to 1.64x1025 W bursts for the transient asymmetrical spinning nucleus case. In this preliminary analysis, possible conceptual designs of reactors suitable for the generation of HFGWs are discussed as well as applications to space technology. In an optimized dual-beam design, GW amplitudes on the order of A {approx} 0.005 are theoretically achieved in the laboratory, which might have interesting general-relativity and nuclear-physics consequences.

  10. A simple sperm nuclear vacuole assay with propidium iodide.

    PubMed

    Zhu, W-J; Li, J

    2015-09-01

    Our aim was to develop a new simple sperm nuclear vacuole assay (SNVA) with propidium iodide (PI) to determine the status of nuclear vacuole (NV) of individual spermatozoa. After PI staining, sperm nuclei were classified into the 14 categories according to both nuclear morphology and the status of NV. The incidence was 57.8% (range 28-84%) in fertile controls (n = 40), and 85.1% (range 67-99%) in men with varicocele (n = 40). In the fertile group, normal nuclear-shaped spermatozoa without NV or with one small NV located in the ante-nuclear region were significantly more in comparison with the varicocele group. In the varicocele group, abnormal nuclear-shaped spermatozoa with one large NV and with multiple NVs located in the ante-nuclear region were most frequent findings. Besides, spermatozoa with NVs in both ante- and post-nuclear regions in the varicocele group were significantly more than those in the fertile group. In both fertile and varicocele groups, normal or abnormal nuclear-shaped spermatozoa with one or more vacuoles only located in the post-nuclear region occurred sparingly. The SNVA provides a useful additional approach to identify the status of NV in human spermatozoa for diagnostic purposes. A good sperm sample would have more spermatozoa without NV or with one small NV located in the ante-nuclear region.

  11. Countering the Nuclear Terrorist Threat

    SciTech Connect

    Vantine, H C

    2002-10-04

    The nuclear/radioactive threat to homeland security posed by terrorists can be broken into four categories. Of highest concern is the use of an improvised nuclear device (IND). An IND, as its name implies, is a nuclear explosive device. It produces nuclear yield, and this nuclear yield has catastrophic effects. An IND is the ultimate terrorist weapon, and terrorist groups are actively attempting to acquire nuclear weapons. Detonation of an IND could dwarf the devastation of the September 11 attack on the World Trade Center. Dealing with the aftermath of an IND would be horrific. Rescue efforts and cleanup would be hazardous and difficult. Workers would have to wear full protection suits and self-contained breathing apparatus. Because of the residual radioactivity, in certain locations they could only work short times before acquiring their ''lifetime'' dose. As with the Chernobyl event, some rescue workers might well expose themselves to lethal doses of radiation, adding to the casualty toll. Enormous volumes of contaminated debris would have to be removed and disposed. If a terrorist group decides not to pursue an actual nuclear device, it might well turn to Radiological Dispersal Devices (RDDs) or ''dirty bombs'' as they are often called. RDDs spread radioactivity but they do not generate nuclear yield. The fabrication of an RDD requires radioactive material and a dispersal mechanism. Radioactive materials are used all over the world for medical, industrial, and research applications. Standards for safe handling and accountability of radioactive material vary around the world. Stories in the press suggest inadequate controls on radiological materials in parts of the world. The effects of an RDD vary widely, and are measured in terms of contamination area, health effects to the exposed population, and economic consequences. Even a negligible, but measurable, exposure would exploit the general public's fear of things radioactive and would have significant

  12. Nuclear radiation actuated valve

    DOEpatents

    Christiansen, David W.; Schively, Dixon P.

    1985-01-01

    A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

  13. Nuclear Thermal Propulsion (NTP)

    NASA Video Gallery

    NASA's history with nuclear thermal propulsion (NTP) technology goes back to the earliest days of the Agency. The Manned Lunar Rover Vehicle and the Nuclear Engine for Rocket Vehicle Applications p...

  14. Nuclear disarmament verification

    SciTech Connect

    DeVolpi, A.

    1993-12-31

    Arms control treaties, unilateral actions, and cooperative activities -- reflecting the defusing of East-West tensions -- are causing nuclear weapons to be disarmed and dismantled worldwide. In order to provide for future reductions and to build confidence in the permanency of this disarmament, verification procedures and technologies would play an important role. This paper outlines arms-control objectives, treaty organization, and actions that could be undertaken. For the purposes of this Workshop on Verification, nuclear disarmament has been divided into five topical subareas: Converting nuclear-weapons production complexes, Eliminating and monitoring nuclear-weapons delivery systems, Disabling and destroying nuclear warheads, Demilitarizing or non-military utilization of special nuclear materials, and Inhibiting nuclear arms in non-nuclear-weapons states. This paper concludes with an overview of potential methods for verification.

  15. Nuclear fear revisited

    NASA Astrophysics Data System (ADS)

    Crease, Robert P.

    2010-10-01

    In 1988 the science historian Spencer Weart published a groundbreaking book called Nuclear Fear: A History of Images, which examined visions of radiation damage and nuclear disaster in newspapers, television, film, literature, advertisements and popular culture.

  16. Triangle Universities Nuclear Laboratory

    SciTech Connect

    Not Available

    1991-01-01

    This report contains brief papers that discusses the following topics: Fundamental Symmetries in the Nucleus; Internucleon Interactions; Dynamics of Very Light Nuclei; Facets of the Nuclear Many-Body Problem; and Nuclear Instruments and Methods.

  17. Teaching "The Nuclear Predicament."

    ERIC Educational Resources Information Center

    Carman, Philip; Kneeshaw, Stephen

    1987-01-01

    Contends that courses on nuclear war must help students examine the political, social, religious, philosophical, economic, and moral assumptions which characterized the dilemma of nuclear armament/disarmament. Describes the upper level undergraduate course taught by the authors. (JDH)

  18. JPRS Report, Nuclear Developments

    DTIC Science & Technology

    2016-03-24

    of efforts to improve the safety of nuclear reactors that were started together with the USSR. These efforts are focused in particular on...characteristics of these reactors are quite encouraging. With their improved safety and low radiation effect on environment they ensure the possi...Nuclear Power [KYODO] 3 Fukushima Nuclear Reactor Reports Leak [KYODO] 3 NORTH KOREA Nuclear Weapons Capability Discussed by ROK Paper

  19. Nuclear power browning out

    SciTech Connect

    Flavin, C.; Lenssen, N.

    1996-05-01

    When the sad history of nuclear power is written, April 26, 1986, will be recorded as the day the dream died. The explosion at the Chernobyl plant was a terrible human tragedy- and it delivered a stark verdict on the hope that nuclear power will one day replace fossil fuel-based energy systems. Nuclear advocates may soldier on, but a decade after Chernobyl it is clear that nuclear power is no longer a viable energy option for the twenty-first century.

  20. JPRS Report Nuclear Developments

    DTIC Science & Technology

    2007-11-02

    release; Distribution Unlimited | -—fb 40 Nuclear Developments JPRS-TND-88-016 CONTENTS 2 SEPTEMBER 1988 CHINA Nuclear Power Chief Seeks...Foreign Cooperation [Yuan Zhou; CHINA DAILY (BUSINESS WEEKLY) 1 Aug 88] 1 Nuclear Fusion Study Reaches Advanced Level [Xiao Longlian; Beijing...Government ’Welcomes’ Group [Beijing XINHUA 12 Aug 88] 4 No Decision on Disposal of Daya Nuclear Waste [Andy Ho; Hong Kong SOUTH CHINA MORNING POST

  1. Nuclear air cushion vehicles.

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    This paper serves several functions. It identifies the 'state-of-the-art' of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant. Using mission studies and cost estimates, the report describes some of the advantages of nuclear power for large air cushion vehicles. The paper also summarizes the technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies that have been performed at NASA Lewis Research Center.

  2. Anomalies in the Decay of Particular Nuclear Isotopes (Briefing charts)

    DTIC Science & Technology

    2014-05-08

    AFRL-OSR-VA-TR-2014-0109 ANOMALIES IN THE DECAY OF PARTICULAR NUCLEAR ISOTOPES Juan Klein Comision Chilena De Enlgia Nuclea Final Report 05/08/2014...Anomalies in the Decay of Particular Nuclear Isotopes 5b. GRANT NUMBER FA9550-12-1-0027 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...small annual oscillations in many of the same isotopes as the aforementioned 15. SUBJECT TERMS Nuclear Decay , Periodic Variations 16

  3. Xenon monitoring and the Comprehensive Nuclear-Test-Ban Treaty

    SciTech Connect

    Bowyer, Theodore W.

    2014-05-09

    How do you monitor (verify) a CTBT? It is a difficult challenge to monitor the entire world for nuclear tests, regardless of size. Nuclear tests 'normally' occur underground, above ground or underwater. Setting aside very small tests (let's limit our thinking to 1 kiloton or more), nuclear tests shake the ground, emit large amounts of radioactivity, and make loud noises if in the atmosphere (or hydroacoustic waves if underwater)

  4. NUCLEAR REACTOR CONTROL SYSTEM

    DOEpatents

    Epler, E.P.; Hanauer, S.H.; Oakes, L.C.

    1959-11-01

    A control system is described for a nuclear reactor using enriched uranium fuel of the type of the swimming pool and other heterogeneous nuclear reactors. Circuits are included for automatically removing and inserting the control rods during the course of normal operation. Appropriate safety circuits close down the nuclear reactor in the event of emergency.

  5. Revitalizing Nuclear Safety Research.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC.

    This report covers the general issues involved in nuclear safety research and points out the areas needing detailed consideration. Topics included are: (1) "Principles of Nuclear Safety Research" (examining who should fund, who should conduct, and who should set the agenda for nuclear safety research); (2) "Elements of a Future…

  6. Nuclear energy technology

    NASA Technical Reports Server (NTRS)

    Buden, David

    1992-01-01

    An overview of space nuclear energy technologies is presented. The development and characteristics of radioisotope thermoelectric generators (RTG's) and space nuclear power reactors are discussed. In addition, the policy and issues related to public safety and the use of nuclear power sources in space are addressed.

  7. JPRS Report, Nuclear Developments

    DTIC Science & Technology

    2016-03-24

    a new generation of nuclear Because of the significant improvements in radiation read- reactors with an increased degree of safety are developed...With USSR [Moscow PRA VDA 14 Aug] ...................... 14 Future Nuclear Reactor Plans Detailed fIslamnahad Radio...July Stoppages /Moscow International] ........................................... 19 Suspension of Nuclear Reactor Construction Urged ITASS

  8. JPRS Report, Nuclear Developments

    DTIC Science & Technology

    2016-03-24

    extraction plant in collaboration with the Fer- Prototype Fast Breeder Reactor (PFBR). tilizers and Chemicals , Travancore (FACT) at Eloor near Cochin...Nuclear Reactor Shut Down After Malfunction [KYODO] ................................................................ 8 PHILIPPINES Proposal To Operate...Nuclear Reactor in Algeria [TELAM] .............................................................. 10 Nuclear Official Returns From Algeria [TELAM

  9. Teaching Nuclear History.

    ERIC Educational Resources Information Center

    Holl, Jack M.; Convis, Sheila C.

    1991-01-01

    Presents results of a survey of the teaching about nuclear history at U.S. colleges and universities. Reports the existence of a well-established and extensive literature, a focus on nuclear weapons or warfare, and a concentration on nuclear citizenship, therapy, or eschatology for courses outside of history departments. Discusses individual…

  10. Nuclear Medicine Imaging

    MedlinePlus

    ... necesita saber acerca de... Estudios de Imagen de Medicina Nuclear Un procedimiento de medicina nuclear se describe algunas veces como unos rayos- ... través del cuerpo del paciente. Los procedimientos de medicina nuclear utilizan pequeñas cantidades de mate- riales radiactivos, ...

  11. Nuclear fact book

    SciTech Connect

    Hill, O. F.; Platt, A. M.; Robinson, J. V.

    1983-05-01

    This reference provides significant highlights and summary facts in the following areas: general energy; nuclear energy; nuclear fuel cycle; uranium supply and enrichment; nuclear reactors; spent fuel and advanced repacking concepts; reprocessing; high-level waste; gaseous waste; transuranic waste; low-level waste; remedial action; transportation; disposal; radiation information; environment; legislation; socio-political aspects; conversion factors; and a glossary. (GHT)

  12. Effects of Nuclear Weapons.

    ERIC Educational Resources Information Center

    Sartori, Leo

    1983-01-01

    Fundamental principles governing nuclear explosions and their effects are discussed, including three components of a nuclear explosion (thermal radiation, shock wave, nuclear radiation). Describes how effects of these components depend on the weapon's yield, its height of burst, and distance of detonation point. Includes effects of three…

  13. Basic Nuclear Physics.

    ERIC Educational Resources Information Center

    Bureau of Naval Personnel, Washington, DC.

    Basic concepts of nuclear structures, radiation, nuclear reactions, and health physics are presented in this text, prepared for naval officers. Applications to the area of nuclear power are described in connection with pressurized water reactors, experimental boiling water reactors, homogeneous reactor experiments, and experimental breeder…

  14. Manned space flight nuclear system safety. Volume 1: Executive summary. Part 2: Space shuttle nuclear system safety

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The nuclear safety integration and operational aspects of transporting nuclear payloads to and from an earth orbiting space base by space shuttle are discussed. The representative payloads considered were: (1) zirconium hydride-Brayton power module, (2) isotope-Brayton power module, and (3) small isotope power systems or heat sources. Areas of investigation also include nuclear safety related integration and packaging as well as operational requirements for the shuttle and payload systems for all phases of the mission.

  15. Global warming and nuclear power

    SciTech Connect

    Wood, L., LLNL

    1998-07-10

    Nuclear fission power reactors represent a potential solution to many aspects of global change possibly induced by inputting of either particulate or carbon or sulfur oxides into the Earth`s atmosphere. Of proven technological feasibility, they presently produce high-grade heat for large-scale electricity generation, space heating and industrial process-energizing around the world, without emitting greenhouse gases or atmospheric particulates; importantly, electricity production costs from the best nuclear plants presently are closely comparable with those of the best fossil-fired plants. However, a substantial number of issues currently stand between nuclear power and widespread substitution for large stationary fossil fuel-fired systems. These include perceptual ones regarding both long-term and acute operational safety, plant decommissioning, fuel reprocessing, radwaste disposal, fissile materials diversion to military purposes and - perhaps most seriously- readily quantifiable concerns regarding long-term fuel supply and total unit electrical energy cost. We sketch a road-map for proceeding from the present situation toward a nuclear power-intensive world, addressing along the way each of the concerns which presently impede widespread nuclear substitution for fossil fuels, particularly for coal in the most populous and rapidly developing portions of the world, e.g., China and India. This `design to societal specifications` approach to large-scale nuclear fission power systems may lead to energy sources meeting essentially all stationary demands for high-temperature heat. Such advanced options offer a human population of ten billion the electricity supply levels currently enjoyed by Americans for 10,000 years. Nuclear power systems tailored to local needs-and-interests and having a common advanced technology base could reduce present-day world-wide C0{sub 2} emissions by two-fold, if universally employed. By application to small mobile demands, a second two

  16. History of Nuclear India

    NASA Astrophysics Data System (ADS)

    Chaturvedi, Ram

    2000-04-01

    India emerged as a free and democratic country in 1947, and entered into the nuclear age in 1948 by establishing the Atomic Energy Commission (AEC), with Homi Bhabha as the chairman. Later on the Department of Atomic Energy (DAE) was created under the Office of the Prime Minister Jawahar Lal Nehru. Initially the AEC and DAE received international cooperation, and by 1963 India had two research reactors and four nuclear power reactors. In spite of the humiliating defeat in the border war by China in 1962 and China's nuclear testing in 1964, India continued to adhere to the peaceful uses of nuclear energy. On May 18, 1974 India performed a 15 kt Peaceful Nuclear Explosion (PNE). The western powers considered it nuclear weapons proliferation and cut off all financial and technical help, even for the production of nuclear power. However, India used existing infrastructure to build nuclear power reactors and exploded both fission and fusion devices on May 11 and 13, 1998. The international community viewed the later activity as a serious road block for the Non-Proliferation Treaty and the Comprehensive Test Ban Treaty; both deemed essential to stop the spread of nuclear weapons. India considers these treaties favoring nuclear states and is prepared to sign if genuine nuclear disarmament is included as an integral part of these treaties.

  17. Commercial nuclear power 1990

    SciTech Connect

    Not Available

    1990-09-28

    This report presents the status at the end of 1989 and the outlook for commercial nuclear capacity and generation for all countries in the world with free market economies (FME). The report provides documentation of the US nuclear capacity and generation projections through 2030. The long-term projections of US nuclear capacity and generation are provided to the US Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) for use in estimating nuclear waste fund revenues and to aid in planning the disposal of nuclear waste. These projections also support the Energy Information Administration's annual report, Domestic Uranium Mining and Milling Industry: Viability Assessment, and are provided to the Organization for Economic Cooperation and Development. The foreign nuclear capacity projections are used by the DOE uranium enrichment program in assessing potential markets for future enrichment contracts. The two major sections of this report discuss US and foreign commercial nuclear power. The US section (Chapters 2 and 3) deals with (1) the status of nuclear power as of the end of 1989; (2) projections of nuclear capacity and generation at 5-year intervals from 1990 through 2030; and (3) a discussion of institutional and technical issues that affect nuclear power. The nuclear capacity projections are discussed in terms of two projection periods: the intermediate term through 2010 and the long term through 2030. A No New Orders case is presented for each of the projection periods, as well as Lower Reference and Upper Reference cases. 5 figs., 30 tabs.

  18. The nuclear symmetry energy

    NASA Astrophysics Data System (ADS)

    Baldo, M.; Burgio, G. F.

    2016-11-01

    The nuclear symmetry energy characterizes the variation of the binding energy as the neutron to proton ratio of a nuclear system is varied. This is one of the most important features of nuclear physics in general, since it is just related to the two component nature of the nuclear systems. As such it is one of the most relevant physical parameters that affect the physics of many phenomena and nuclear processes. This review paper presents a survey of the role and relevance of the nuclear symmetry energy in different fields of research and of the accuracy of its determination from the phenomenology and from the microscopic many-body theory. In recent years, a great interest was devoted not only to the Nuclear Matter symmetry energy at saturation density but also to its whole density dependence, which is an essential ingredient for our understanding of many phenomena. We analyze the nuclear symmetry energy in different realms of nuclear physics and astrophysics. In particular we consider the nuclear symmetry energy in relation to nuclear structure, astrophysics of Neutron Stars and supernovae, and heavy ion collision experiments, trying to elucidate the connections of these different fields on the basis of the symmetry energy peculiarities. The interplay between experimental and observational data and theoretical developments is stressed. The expected future developments and improvements are schematically addressed, together with most demanded experimental and theoretical advances for the next few years.

  19. Tracing nuclear elements released by Fukushima Nuclear Power Plant accident

    NASA Astrophysics Data System (ADS)

    Tsujimura, M.; Onda, Y.; Abe, Y.; Hada, M.; Pun, I.

    2011-12-01

    Radioactive contamination has been detected in Fukushima and the neighboring regions due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami occurred on 11th March 2011. The small experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima Prefecture, located approximately 35 km west from the Fukushima NPP. The tritium (3H) concentration and stable isotopic compositions of deuterium and oxygen-18 have been determined on the water samples of precipitation, soil water at the depths of 10 to 30 cm, groundwater at the depths of 5 m to 50 m, spring water and stream water taken at the watersheds in the recharge and discharge zones from the view point of the groundwater flow system. The tritium concentration of the rain water fell just a few days after the earthquake showed a value of approximately 17 Tritium Unit (T.U.), whereas the average concentration of the tritium in the precipitation was less than 5 T.U. before the Fukushima accident. The spring water in the recharge zone showed a relatively high tritium concentration of approximately 12 T.U., whereas that of the discharge zone showed less than 5 T.U. Thus, the artificial tritium was apparently injected in the groundwater flow system due to the Fukushima NPP accident, whereas that has not reached at the discharge zone yet. The monitoring of the nuclear elements is now on going from the view points of the hydrological cycles and the drinking water security.

  20. Nuclear constriction segregates mobile nuclear proteins away from chromatin

    PubMed Central

    Irianto, Jerome; Pfeifer, Charlotte R.; Bennett, Rachel R.; Xia, Yuntao; Ivanovska, Irena L.; Liu, Andrea J.; Greenberg, Roger A.; Discher, Dennis E.

    2016-01-01

    As a cell squeezes its nucleus through adjacent tissue, penetrates a basement membrane, or enters a small blood capillary, chromatin density and nuclear factors could in principle be physically perturbed. Here, in cancer cell migration through rigid micropores and in passive pulling into micropipettes, local compaction of chromatin is observed coincident with depletion of mobile factors. Heterochromatin/euchromatin was previously estimated from molecular mobility measurements to occupy a volume fraction f of roughly two-thirds of the nuclear volume, but based on the relative intensity of DNA and histones in several cancer cell lines drawn into narrow constrictions, f can easily increase locally to nearly 100%. By contrast, mobile proteins in the nucleus, including a dozen that function as DNA repair proteins (e.g., BRCA1, 53BP1) or nucleases (e.g., Cas9, FokI), are depleted within the constriction, approaching 0%. Such losses—compounded by the occasional rupture of the nuclear envelope—can have important functional consequences. Studies of a nuclease that targets a locus in chromosome-1 indeed show that constricted migration delays DNA damage. PMID:27798234

  1. 75 FR 30078 - Entergy Nuclear Operations, Inc.; Entergy Nuclear Vermont Yankee, LLC; Vermont Yankee Nuclear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... Office of Nuclear Reactor Regulation (NRR). By letter dated May 20, 2010, the Director denied the... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc.; Entergy Nuclear Vermont Yankee, LLC; Vermont Yankee...

  2. Uranium-mediated activation of small molecules.

    PubMed

    Arnold, Polly L

    2011-08-28

    Molecular complexes of uranium are capable of activating a range of industrially and economically important small molecules such as CO, CO(2), and N(2); new and often unexpected reactions provide insight into an element that needs to be well-understood if future clean-energy solutions are to involve nuclear power.

  3. Microcoil nuclear magnetic resonance spectroscopy.

    PubMed

    Webb, A G

    2005-08-10

    In comparison with most analytical chemistry techniques, nuclear magnetic resonance has an intrinsically low sensitivity, and many potential applications are therefore precluded by the limited available quantity of certain types of sample. In recent years, there has been a trend, both commercial and academic, towards miniaturization of the receiver coil in order to increase the mass sensitivity of NMR measurements. These small coils have also proved very useful in coupling NMR detection with commonly used microseparation techniques. A further development enabled by small detectors is parallel data acquisition from many samples simultaneously, made possible by incorporating multiple receiver coils into a single NMR probehead. This review article summarizes recent developments and applications of "microcoil" NMR spectroscopy.

  4. Small Active Radiation Monitor

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.

    2004-01-01

    A device, named small active radiation monitor, allows on-orbit evaluations during periods of increased radiation, after extravehicular activities, or at predesignated times for crews on such long-duration space missions as on the International Space Station. It also permits direct evaluation of biological doses, a task now performed using a combination of measurements and potentially inaccurate simulations. Indeed the new monitor can measure a full array of radiation levels, from soft x-rays to hard galactic cosmic-ray particles. With refinement, it will benefit commercial (nuclear power-plant workers, airline pilots, medical technicians, physicians/dentists, and others) and military personnel as well as the astronauts for whom thermoluminescent dosimeters are inadequate. Civilian and military personnel have long since graduated from film badges to thermoluminescent dosimeters. Once used, most dosimeters must be returned to a central facility for processing, a step that can take days or even weeks. While this suffices for radiation workers for whom exposure levels are typically very low and of brief duration, it does not work for astronauts. Even in emergencies and using express mail, the results can often be delayed by as much as 24 hours. Electronic dosimeters, which are the size of electronic oral thermometers, and tattlers, small electronic dosimeters that sound an alarm when the dose/dose rate exceeds preset values, are also used but suffer disadvantages similar to those of thermoluminescent dosimeters. None of these devices fully answers the need of rapid monitoring during the space missions. Instead, radiation is monitored by passive detectors, which are read out after the missions. Unfortunately, these detectors measure only the absorbed dose and not the biologically relevant dose equivalent. The new monitor provides a real-time readout, a time history of radiation exposures (both absorbed dose and biologically relevant dose equivalent), and a count of the

  5. Apparatus for blending small particles

    DOEpatents

    Bradley, R.A.; Reese, C.R.; Sease, J.D.

    1975-08-26

    An apparatus is described for blending small particles and uniformly loading the blended particles in a receptacle. Measured volumes of various particles are simultaneously fed into a funnel to accomplish radial blending and then directed onto the apex of a conical splitter which collects the blended particles in a multiplicity of equal subvolumes. Thereafter the apparatus sequentially discharges the subvolumes for loading in a receptacle. A system for blending nuclear fuel particles and loading them into fuel rod molds is described in a preferred embodiment. (auth)

  6. British nuclear policymaking

    SciTech Connect

    Bowie, C.J.; Platt, A.

    1984-01-01

    This study analyzes the domestic political, economic, and bureaucratic factors that affect the nuclear policymaking process in Great Britain. Its major conclusion is that, although there have been changes in that process in recent years (notably the current involvement of a segment of the British public in the debate about the deployment of intermediate-range nuclear forces), future British nuclear policymaking will remain much what it has been in the past. Three ideas are central to understanding British thinking on the subject: (1) Britain's long-standing resolve to have her own national nuclear force is largely traceable to her desire to maintain first-rank standing among the nations of the world in spite of loss of empire. (2) Financial considerations have always been important--so much so that they have usually dominated issues of nuclear policy. (3) The executive branch of government dominates the nuclear policymaking process but does not always present a united front. The United States heavily influences British nuclear policy through having supplied Britain since the late 1950s with nuclear data and components of nuclear weapon systems such as Polaris and Trident. The relationship works both ways since the U.S. depends on Britain as a base for deployment of both conventional and nuclear systems.

  7. Nonlinear Tunneling and Nuclear Decay

    NASA Astrophysics Data System (ADS)

    Labadorf, Christa; Chaffin, Eugene

    2008-10-01

    Recent astrophysical data have indicated a possible variation of the proton-electron mass ratio μ = mp/me. Attributing the variation to a change in the strength of the nuclear force, we take into account nonlinear inteactions, such as those originally proposed in 1955 by Johnson and Teller, and examine the resulting change in nuclear half lives. Our Mathematica calculations show the effect of the nonlinear terms by solving the three-dimensional nonlinear Schrodinger equation in a model applied to a typical nucleus. We match the radial wavefunction and its derivative for the interior of the nucleus to the Coulomb wavefunctions on the exterior of the nucleus in a generalization of the procedure originally used by Pieronne and Marquez, 1978, but without the nonlinear interactions. The results indicate that the nonlinear interactions, in cases where the number of nodes in the radial wavefunction is poised on a change from one value to another, can cause a large change in half-life for a small change in the strength of the nuclear force.

  8. Genes for Xenopus laevis U3 small nuclear RNA.

    PubMed Central

    Savino, R; Hitti, Y; Gerbi, S A

    1992-01-01

    Genomic Southern blots showed there are only 14 to 20 copies of U3 snRNA genes per somatic genome in Xenopus laevis, unlike the highly repetitive, tandem arrangement of other snRNA genes in this organism. Sequencing of two U3 snRNA genes from lambda clones of a genomic library revealed striking similarity upstream, but much more divergence downstream. Consensus motifs common to other U snRNA genes were also found: a distal sequence element (DSE, octamer motif at -222 to -215), a proximal sequence element (PSE, at -62 to -52) and a 3' Box (15 or 16 bp downstream of the U3 genes). The DSE of mammals also has an inverted CCAAT motif specific for U3 snRNA genes, and we find this is conserved in the amphibian U3 snRNA genes. The Xenopus inverted CCAAT motif is exactly one helical turn further upstream of the octamer motif than its mammalian counterpart, suggesting interaction of putative transcription factors bound to these motifs. Mutation of the inverted CCAAT motif and part of an adjacent Sp1 site greatly depresses transcription of the mutant U3 snRNA gene in Xenopus oocytes, implying a role in transcriptional efficiency. Electrophoretic mobility shift assays implicate transcription factor binding to this region. Images PMID:1437561

  9. Curved Waveguide Based Nuclear Fission for Small, Lightweight Reactors

    NASA Technical Reports Server (NTRS)

    Coker, Robert; Putnam, Gabriel

    2012-01-01

    The focus of the presented work is on the creation of a system of grazing incidence, supermirror waveguides for the capture and reuse of fission sourced neutrons. Within research reactors, neutron guides are a well known tool for directing neutrons from the confined and hazardous central core to a more accessible testing or measurement location. Typical neutron guides have rectangular, hollow cross sections, which are crafted as thin, mirrored waveguides plated with metal (commonly nickel). Under glancing angles with incoming neutrons, these waveguides can achieve nearly lossless transport of neutrons to distant instruments. Furthermore, recent developments have created supermirror surfaces which can accommodate neutron grazing angles up to four times as steep as nickel. A completed system will form an enclosing ring or spherical resonator system to a coupled neutron source for the purpose of capturing and reusing free neutrons to sustain and/or accelerate fission. While grazing incidence mirrors are a known method of directing and safely using neutrons, no method has been disclosed for capture and reuse of neutrons or sustainment of fission using a circular waveguide structure. The presented work is in the process of fabricating a functional, highly curved, neutron supermirror using known methods of Ni-Ti layering capable of achieving incident reflection angles up to four times steeper than nickel alone. Parallel work is analytically investigating future geometries, mirror compositions, and sources for enabling sustained fission with applicability to the propulsion and energy goals of NASA and other agencies. Should research into this concept prove feasible, it would lead to development of a high energy density, low mass power source potentially capable of sustaining fission with a fraction of the standard critical mass for a given material and a broadening of feasible materials due to reduced rates of release, absorption, and non-fission for neutrons. This advance could be applied to direct propulsion through guided fission products or as a secondary energy source for high impulse electric propulsion. It would help meet national needs for highly efficient energy sources with limited dependence on fossil fuels or conflict materials, and it would improve the use of low grade fissile materials which would help reduce national stockpiles and waste.

  10. Transcriptional regulation of human small nuclear RNA genes

    PubMed Central

    Jawdekar, Gauri W.; Henry, R. William

    2009-01-01

    The products of human snRNA genes have been frequently described as performing housekeeping functions and their synthesis refractory to regulation. However, recent studies have emphasized that snRNA and other related non-coding RNA molecules control multiple facets of the central dogma, and their regulated expression is critical to cellular homeostasis during normal growth and in response to stress. Human snRNA genes contain compact and yet powerful promoters that are recognized by increasingly well-characterized transcription factors, thus providing a premier model system to study gene regulation. This review summarizes many recent advances deciphering the mechanism by which the transcription of human snRNA and related genes are regulated. PMID:18442490

  11. PREFACE: XXXIV Symposium on Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Barrón-Palos, Libertad; Bijker, Roelof

    2011-10-01

    In the present volume of the Journal of Physics: Conference Series we publish the proceedings of the 'XXXIV Symposium on Nuclear Physics', which was held from 4-7 January 2011 at the Hacienda Cocoyoc, Morelos, Mexico. The proceedings consist of 19 contributions that were presented as invited talks at the meeting. The abstracts of all contributions, plenary talks and posters were published in the Conference Handbook. The Symposium on Nuclear Physics has a long and distinguished history. From the beginning it was intended to be a relatively small meeting designed to bring together some of the leading nuclear scientists in the field. Its most distinctive feature is to provide a forum for specialists in different areas of nuclear physics, both theorists and experimentalists, students, postdocs and senior scientists, in a relaxed and informal environment providing them with a unique opportunity to exchange ideas. From the first meeting in Oaxtepec in 1978, the Symposium has been organized every year without interruption, which makes the present Symposium the 34th in a row. The scientific program consisted of 27 invited talks and 17 posters on a wide variety of hot topics in contemporary nuclear physics, ranging from the traditional fields of nuclear structure (Draayer, Pittel, Van Isacker, Fraser, Lerma, Cejnar, Hirsch, Stránský and Rath) and nuclear reactions (Aguilera, Gómez-Camacho, Scheid, Navrátil and Yennello) to radioactive beams (Padilla-Rodal and Galindo-Uribarri), nuclear astrophysics (Aprahamian, Civitarese and Escher), hadronic physics (Bijker, Valcarce and Hess), fundamental symmetries (Liu, Barrón-Palos and Baessler) and LHC physics (Menchaca-Rocha and Paic). The high quality of the talks, the prestige of the speakers and the broad spectrum of subjects covered in the meeting, shows that nuclear physics is a very active area at the frontier of scientific research which establishes bridges between many different disciplines. Libertad Barr

  12. Marginally Stable Nuclear Burning

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  13. Atmospheric effects and societal consequences of regional scale nuclear conflicts and acts of individual nuclear terrorism

    NASA Astrophysics Data System (ADS)

    Toon, O. B.; Turco, R. P.; Robock, A.; Bardeen, C.; Oman, L.; Stenchikov, G. L.

    2007-04-01

    We assess the potential damage and smoke production associated with the detonation of small nuclear weapons in modern megacities. While the number of nuclear warheads in the world has fallen by about a factor of three since its peak in 1986, the number of nuclear weapons states is increasing and the potential exists for numerous regional nuclear arms races. Eight countries are known to have nuclear weapons, 2 are constructing them, and an additional 32 nations already have the fissile material needed to build substantial arsenals of low-yield (Hiroshima-sized) explosives. Population and economic activity worldwide are congregated to an increasing extent in megacities, which might be targeted in a nuclear conflict. We find that low yield weapons, which new nuclear powers are likely to construct, can produce 100 times as many fatalities and 100 times as much smoke from fires per kt yield as previously estimated in analyses for full scale nuclear wars using high-yield weapons, if the small weapons are targeted at city centers. A single "small" nuclear detonation in an urban center could lead to more fatalities, in some cases by orders of magnitude, than have occurred in the major historical conflicts of many countries. We analyze the likely outcome of a regional nuclear exchange involving 100 15-kt explosions (less than 0.1% of the explosive yield of the current global nuclear arsenal). We find that such an exchange could produce direct fatalities comparable to all of those worldwide in World War II, or to those once estimated for a "counterforce" nuclear war between the superpowers. Megacities exposed to atmospheric fallout of long-lived radionuclides would likely be abandoned indefinitely, with severe national and international implications. Our analysis shows that smoke from urban firestorms in a regional war would rise into the upper troposphere due to pyro-convection. Robock et al. (2007) show that the smoke would subsequently rise deep into the stratosphere due

  14. Nuclear transport erupts on the slopes of Mount Etna.

    PubMed

    Powers, Maureen A; Dasso, Mary

    2004-02-01

    Nuclear pore complexes (NPCs) mediate the active transport of large substrates and allow the passive diffusion of small molecules into the nucleus of eukaryotic cells. The EMBO Workshop on the Mechanisms of Nuclear Transport focused on NPCs and on the soluble nucleocytoplasmic transport machinery. This meeting, organized by Valérie Doye (Institut Curie, Paris) and Ed Hurt (University of Heidelberg), was held within view of Mount Etna at Taormina, Sicily (November 1-5, 2003). Presentations emphasized the dynamic properties of the nuclear trafficking machinery, and demonstrated the continuity of nuclear transport with processes in the nucleus and cytoplasm.

  15. Economics of nuclear power.

    PubMed

    Rossin, A D; Rieck, T A

    1978-08-18

    With 12 percent of U.S. electricity now being supplied by nuclear power, Commonwealth Edison has found nuclear plants to be good investments relative to other base load energy sources. The country's largest user of nuclear power, Commonwealth Edison, estimates that its commitment to nuclear saved its customers about 10 percent on their electric bills in 1977, compared to the cost with the next best alternative, coal. This advantage is seen as continuing, contrary to criticisms of the economics and reliability of nuclear power and claims that it has hidden subsidies. It is concluded that there is a need for both nuclear and coal and that government policy precluding or restricting either would be unwise.

  16. Nuclear Science References Database

    SciTech Connect

    Pritychenko, B.; Běták, E.; Singh, B.; Totans, J.

    2014-06-15

    The Nuclear Science References (NSR) database together with its associated Web interface, is the world's only comprehensive source of easily accessible low- and intermediate-energy nuclear physics bibliographic information for more than 210,000 articles since the beginning of nuclear science. The weekly-updated NSR database provides essential support for nuclear data evaluation, compilation and research activities. The principles of the database and Web application development and maintenance are described. Examples of nuclear structure, reaction and decay applications are specifically included. The complete NSR database is freely available at the websites of the National Nuclear Data Center (http://www.nndc.bnl.gov/nsr) and the International Atomic Energy Agency (http://www-nds.iaea.org/nsr)

  17. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  18. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  19. Nuclear Fabrication Consortium

    SciTech Connect

    Levesque, Stephen

    2013-04-05

    This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. Supporting industry in helping to create a larger qualified nuclear supplier network. Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium

  20. Pakistans Nuclear Weapons

    DTIC Science & Technology

    2016-02-12

    2004 revelations about a procurement network run by former Pakistani nuclear official A. Q. Khan, Islamabad has taken a number of steps to improve ...strengthened export control laws, improved personnel security, and international nuclear security cooperation programs, have improved Pakistan’s...context where these broader tensions and conflicts are present. 1 Pakistani efforts to improve the security of its nuclear weapons have been ongoing

  1. Nuclear Proliferation Challenges

    SciTech Connect

    Professor William Potter

    2005-11-28

    William C. Potter, Director of the Center for Non Proliferation Studies and the Center for Russian and Eurasian Studies at the Monterey Institute of International Studies, will present nuclear proliferation challenges following the 2005 Nuclear Non-Proliferation Treaty (NPT) Review Conference. In addition to elucidating reasons for, and implications of, the conference’s failure, Dr. Potter will discuss common ground between nuclear proliferation and terrorism issues and whether corrective action can be taken.

  2. Nuclear imaging in pediatrics

    SciTech Connect

    Siddiqui, A.R.

    1985-01-01

    The author's intent is to familiarize practicing radiologists with the technical aspects and interpretation of nuclear medicine procedures in children and to illustrate the indications for nuclear medicine procedures in pediatric problems. Pediatric doses, dosimetry, sedation, and injection techniques, organ systems, oncology and infection, testicular scanning and nuclear crystography, pediatric endocrine and skeletal systems, ventilation and perfusion imaging of both congenital and acquired pediatric disorders, cardiovascular problems, gastrointestinal, hepatobiliary, reticuloendothelial studies, and central nervous system are all topics which are included and discussed.

  3. Nuclear Politics in Iran

    DTIC Science & Technology

    2010-05-01

    system. States with prestige are recognized by other actors as having a high 21 Nuclear Politics in Iran standing either generally or with regard to...Nuclear Politics in Iran Edited by Judith S. Yaphe MIDDLE EAST STRATEGIC PERSPECTIVES 1 Center for Strategic Research Institute for National...OMB control number. 1. REPORT DATE MAY 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Nuclear Politics in

  4. Nonstrategic Nuclear Weapons

    DTIC Science & Technology

    2014-01-03

    William Potter , and Nikolai Sokov, Reducing and Regulating Tactical (Nonstrategic) Nuclear Weapons in Europe, The James Martin Center For...See William C. Potter and Nikolai Sokov, “Nuclear Weapons that People Forget,” International Herald Tribune, May 31, 2000. 87 Sam Nunn, Igor...their security.97 94 Kent Harris , “NATO Allies Want U.S. Nuclear Weapons out of Europe

  5. Steady Nuclear Combustion in Rockets

    NASA Technical Reports Server (NTRS)

    Saenger, E.

    1957-01-01

    The astrophysical theory of stationary nuclear reactions in stars is applied to the conditions that would be met in the practical engineering cases that would differ from the former, particularly with respect to the much lower combustion pressures, dimensions of the reacting volume, and burnup times. This application yields maximum rates of hear production per unit volume of reacting gas occurring at about 10(exp 8) K in the cases of reactions between the hydrogen isotopes, but yields higher rates for heavier atoms. For the former, with chamber pressures of the order of 100 atmospheres, the energy production for nuclear combustion reaches values of about 10(exp 4) kilocalories per cubic meter per second, which approaches the magnitude for the familiar chemical fuels. The values are substantially lower for heavier atoms, and increase with the square of the combustion pressure. The half-life of the burnup in the fastest reactions may drop to values as low as those for chemical fuels so that, despite the high temperature, the radiated energy can remain smaller than the energy produced, particularly if an inefficiently radiating (i.e., easily completely ionized reacting material like hydrogen), is used. On the other hand, the fraction of completely ionized particles in the gases undergoing nuclear combustion must not exceed a certain upper limit because the densities (approximately 10(exp -10) grams per cubic centimeter)) lie in the range of high vacua and only for the previously mentioned fraction of nonionized particles can mean free paths be retained small enough so that the chamber diameters of several dozen meters will suffice. Under these conditions it appears that continuously maintained stable nuclear reactions at practical pressures and dimensions are fundamentally possible and their application can be visualized as energy sources for power plants and propulsion units.

  6. Nuclear reactor apparatus

    DOEpatents

    Wade, Elman E.

    1978-01-01

    A lifting, rotating and sealing apparatus for nuclear reactors utilizing rotating plugs above the nuclear reactor core. This apparatus permits rotation of the plugs to provide under the plug refueling of a nuclear core. It also provides a means by which positive top core holddown can be utilized. Both of these operations are accomplished by means of the apparatus lifting the top core holddown structure off the nuclear core while stationary, and maintaining this structure in its elevated position during plug rotation. During both of these operations, the interface between the rotating member and its supporting member is sealingly maintained.

  7. Comprehensive Nuclear Materials

    SciTech Connect

    Konings, Dr. Rudy J. M.; Allen, Todd R.; Stoller, Roger E; Yamanaka, Prof. Shinsuke

    2012-01-01

    This book encompasses a rich seam of current information on the vast and multidisciplinary field of nuclear materials employed in fission and prototype fusion systems. Discussion includes both historical and contemporary international research in nuclear materials, from Actinides to Zirconium alloys, from the worlds leading scientists and engineers. Synthesizes pertinent current science to support the selection, assessment, validation and engineering of materials in extreme nuclear environments. The work discusses the major classes of materials suitable for usage in nuclear fission, fusion reactors and high power accelerators, and for diverse functions in fuels, cladding, moderator and control materials, structural, functional, and waste materials.

  8. [Nuclear families in Turkey].

    PubMed

    Unalan, T

    1988-01-01

    This study examines the household or family types in Turkey in 1983, especially nuclear families. Nuclear families constitute 61.6% of all households in Turkey, and the majority of them are in the West and the Central regions. The highest % of nuclear families was found in the Mediterranean regions, and the lowest in the Black Sea region. Among all nuclear families, 87% of them consist of husband, wife and children, whereas 13% of them have only husband and wife. Nuclear families without children are common in urban areas and in the West while nuclear families with children are mostly found in rural areas and in the East and the Black Sea regions. Nuclear families with 3 or more children constitute 32% of all nuclear households in the West. On the other hand, the corresponding % is 73 for the Eastern region. As a result, it is concluded that nuclear families have significant regional and residential differentiations and households with the same formation in a developed and a less developed region should have different social, economic, and cultural characteristics.

  9. Technologists for Nuclear Medicine

    ERIC Educational Resources Information Center

    Barnett, Huey D.

    1974-01-01

    Physicians need support personnel for work with radioisotopes in diagnosing dangerous diseases. The Nuclear Medicine Technology (NMT) Program at Hillsborough Community College in Tampa, Florida, is described. (MW)

  10. Nuclear criticality safety guide

    SciTech Connect

    Pruvost, N.L.; Paxton, H.C.

    1996-09-01

    This technical reference document cites information related to nuclear criticality safety principles, experience, and practice. The document also provides general guidance for criticality safety personnel and regulators.

  11. The role of commercial nuclear pharmacy in the future practice of nuclear medicine.

    PubMed

    Callahan, R J

    1996-04-01

    It has been estimated that today 70% to 80% of all radiopharmaceutical doses are dispensed through commercial nuclear pharmacy channels. These services are provided by the approximately 250 facilities in the United States, with some multisite corporations dispensing in excess of 20,000 unit-dose prescriptions per day. As pressures mount within health care institutions to reduce manpower, increase cost-effectiveness, increase participation in managed care contracts, and to seek outside vendors for many services that were previously provided in-house, the future role of the commercial nuclear pharmacy in the practice of nuclear medicine will only continue to increase. The essence of nuclear pharmacy practice is the dispensing of a full range of high quality radiopharmaceuticals in patient-specific unit doses. These doses must be delivered in a timely and cost effective manner, without compromising quality or patient safety. Commercial nuclear pharmacies have expanded to provide such varied functions as radiation safety and waste management, as well as consultative and marketing activities directed towards clinicians within a nuclear medicine practitioners own facility. In-service continuing education programs directed towards physicians and technologists are frequently offered by many commercial nuclear pharmacies. Changes in health care economics, merging and down-sizing in the hospital industry, and the overall impact of managed care on the viability of hospitals in general has resulted in slow growth, or even a small decline in the number of institutionally based nuclear pharmacists. As a result, nuclear medicine practitioners will be looking to the commercial nuclear pharmacies to meet a larger portion of their radiopharmaceutical needs, as well as to value added services, such as education and research and development. Specialized practice settings, such as nuclear cardiology and free-standing nuclear medicine clinics, are especially well suited to the services

  12. Remote nuclear screening system for hostile environments

    SciTech Connect

    Addleman, R.S.; Beck, M.A.; Blewett, G.R.; Selle, E.R.; McClellan, C.S.; Dodd, D.A.; Troyer, G.L.; Keele, B.D.

    1996-02-27

    A remote measurement system has been constructed for in situ gamma and beta isotopic characterization of highly radioactive nuclear material in hostile environments. A small collimated, planar CdZnTe detector is used for gamma-ray spectroscopy. Spectral resolution of 2% full width at half maximum at 662 kiloelectronvolts has been obtained remotely using rise time compensation and limited pulse shape discrimination, Isotopc measurement of high-energy beta emitters was accomplished with a ruggedized, deeply depleted, surface barrier silicon dictator. The primary function of the remote nuclear screening system is to provide fast qualitative and quantitative isotopic assessment of high-level radioactive material.

  13. Analysis of nuclear power plant component failures

    SciTech Connect

    Not Available

    1984-01-01

    Items are shown that have caused 90% of the nuclear unit outages and/or deratings between 1971 and 1980 and the magnitude of the problem indicated by an estimate of power replacement cost when the units are out of service or derated. The funding EPRI has provided on these specific items for R and D and technology transfer in the past and the funding planned in the future (1982 to 1986) are shown. EPRI's R and D may help the utilities on only a small part of their nuclear unit outage problems. For example, refueling is the major cause for nuclear unit outages or deratings and the steam turbine is the second major cause for nuclear unit outages; however, these two items have been ranked fairly low on the EPRI priority list for R and D funding. Other items such as nuclear safety (NRC requirements), reactor general, reactor and safety valves and piping, and reactor fuel appear to be receiving more priority than is necessary as determined by analysis of nuclear unit outage causes.

  14. Reconstitution of Nuclear Import in Permeabilized Cells

    PubMed Central

    Cassany, Aurelia; Gerace, Larry

    2012-01-01

    The trafficking of protein and RNA cargoes between the cytoplasm and the nucleus of eukaryotic cells, which is a major pathway involved in cell regulation, is mediated by nuclear transport sequences in the cargoes and by shuttling transport factors. The latter include receptors (karyopherins) that recognize the cargoes and carry them across the nuclear pore complex (NPC), and the small GTPase Ran, which modulates karyopherin–cargo binding. Nuclear import can be studied in vitro using digitonin-permeabilized cells, which are depleted of shuttling transport factors. Nuclear import can be reconstituted in the permeabilized cells with exogenous cytosol or with purified recombinant transport factors, and can be quantified by light microscopy of fluorescently labeled cargoes or by immunofluorescence staining. Here we describe procedures for in vitro nuclear import in permeabilized mammalian cells, and for the preparation of recombinant transport factors (importin α, importin β, importin 7, transportin, Ran, NTF2) and other reagents commonly used in the assay. This assay provides means to characterize the molecular mechanisms of nuclear import and to study the import requirements of specific cargoes. PMID:18951186

  15. Reconstitution of nuclear import in permeabilized cells.

    PubMed

    Cassany, Aurelia; Gerace, Larry

    2009-01-01

    The trafficking of protein and RNA cargoes between the cytoplasm and the nucleus of eukaryotic cells, which is a major pathway involved in cell regulation, is mediated by nuclear transport sequences in the cargoes and by shuttling transport factors. The latter include receptors (karyopherins) that recognize the cargoes and carry them across the nuclear pore complex (NPC), and the small GTPase Ran, which modulates karyopherin-cargo binding. Nuclear import can be studied in vitro using digitonin-permeabilized cells, which are depleted of shuttling transport factors. Nuclear import can be reconstituted in the permeabilized cells with exogenous cytosol or with purified recombinant transport factors, and can be quantified by light microscopy of fluorescently labeled cargoes or by immunofluorescence staining. Here we describe procedures for in vitro nuclear import in permeabilized mammalian cells, and for the preparation of recombinant transport factors (importin alpha, importin beta, importin 7, transportin, Ran, NTF2) and other reagents commonly used in the assay. This assay provides means to characterize the molecular mechanisms of nuclear import and to study the import requirements of specific cargoes.

  16. Advanced nuclear precleaner

    SciTech Connect

    Wright, S.R.

    1997-10-01

    This Phase II Small Business Innovation Research (SBIR) program`s goal is to develop a dynamic, self-cleaning air precleaner for high-efficiency particulate air (HEPA) filtration systems that would extend significantly the life of HEPA filter banks by reducing the particulate matter that causes filter fouling and increased pack pressure. HEPA filters are widely used in DOE, Department of Defense, and a variety of commercial facilities. InnovaTech, Inc. (Formerly Micro Composite materials Corporation) has developed a proprietary dynamic separation device using a concept called Boundary Layer Momentum Transfer (BLMT) to extract particulate matter from fluid process streams. When used as a prefilter in the HVAC systems or downstream of waste vitrifiers in nuclear power plants, fuel processing facilities, and weapons decommissioning factories, the BLMT filter will dramatically extend the service life and increase the operation efficiency of existing HEPA filtration systems. The BLMT filter is self cleaning, so there will be no degraded flow or increased pressure drop. Because the BLMT filtration process is independent of temperature, it can be designed to work in ambient, medium, or high-temperature applications. During Phase II, the authors are continuing development of the computerized flow simulation model to include turbulence and incorporate expansion into a three-dimensional model that includes airflow behavior inside the filter housing before entering the active BLMT device. A full-scale (1000 ACFM) prototype filter is being designed to meet existing HEPA filter standards and will be fabricated for subsequent testing. Extensive in-house testing will be performed to determine a full range of performance characteristics. Final testing and evaluation of the prototype filter will be conducted at a DOE Quality Assurance Filter Test Station.

  17. Strategies on the nuclear-targeted delivery of genes

    PubMed Central

    Yao, Jing; Fan, Ying; Li, Yuanke; Huang, Leaf

    2016-01-01

    To improve the nuclear-targeted delivery of non-viral vectors, extensive effort has been carried out on the development of smart vectors which could overcome multiple barriers. The nuclear envelope presents a major barrier to transgene delivery. Viruses are capable of crossing the nuclear envelope to efficiently deliver their genome into the nucleus through the specialized protein components. However, non-viral vectors are preferred over viral ones because of the safety concerns associated with the latter. Non-viral delivery systems have been designed to include various types of components to enable nuclear translocation at the periphery of the nucleus. This review summarizes the progress of research regarding nuclear transport mechanisms. “Smart” non-viral vectors that have been modified by peptides and other small molecules are able to facilitate the nuclear translocation and enhance the efficacy of gene expression. The resulting technology may also enhance delivery of other macromolecules to the nucleus. PMID:23964565

  18. Nuclear Energy and the Environment.

    ERIC Educational Resources Information Center

    International Atomic Energy Agency, Vienna (Austria).

    "Nuclear Energy and the Environment" is a pocket folder of removable leaflets concerned with two major topics: Nuclear energy and Nuclear Techniques. Under Nuclear Energy, leaflets concerning the topics of "Radiation--A Fact of Life,""The Impact of a Fact: 1963 Test Ban Treaty,""Energy Needs and Nuclear Power,""Power Reactor Safety,""Transport,"…

  19. Gordon Conference on Nuclear Research

    SciTech Connect

    Austin, S.M.

    1983-09-01

    Session topics were: quarks and nuclear physics; anomalons and anti-protons; the independent particle structure of nuclei; relativistic descriptions of nuclear structure and scattering; nuclear structure at high excitation; advances in nuclear astrophysics; properties of nuclear material; the earliest moments of the universe; and pions and spin excitations in nuclei.

  20. Nuclear fuel cycle information workshop

    SciTech Connect

    Not Available

    1983-01-01

    This overview of the nuclear fuel cycle is divided into three parts. First, is a brief discussion of the basic principles of how nuclear reactors work; second, is a look at the major types of nuclear reactors being used and world-wide nuclear capacity; and third, is an overview of the nuclear fuel cycle and the present industrial capability in the US.

  1. Under the Nuclear Umbrella.

    ERIC Educational Resources Information Center

    Williams, Leon F.

    1987-01-01

    Entertains the thesis that social work has a stake in the technological-humanistic debate and should greet the recent and spectacular technological failures with protest and alarm. Discusses relationship of nuclear issue and social work, effects of nuclear issue on children, and Chernobyl. Advocates pacifism, activism, and a coherent conception of…

  2. Nuclear physics and cosmology

    SciTech Connect

    Coc, Alain

    2014-05-09

    There are important aspects of Cosmology, the scientific study of the large scale properties of the universe as a whole, for which nuclear physics can provide insights. Here, we will focus on Standard Big-Bang Nucleosynthesis and we refer to the previous edition of the School [1] for the aspects concerning the variations of constants in nuclear cosmo-physics.

  3. Nuclear Taskforce Summation.

    ERIC Educational Resources Information Center

    1979

    At the end of 1978, there were approximately 230 nuclear-fueled electric generating plants around the world; 72 of these were in the United States. Each plant requires an operations-and-maintenance workforce of 92 people, and attrition occurs at a rate of 8% per year. Requirements for a nuclear taskforce and job training, in view of current…

  4. JPRS Report, Nuclear Developments

    DTIC Science & Technology

    2016-03-24

    7 Scientists Term Nuclear Reactor ’Satisfactory’ [XINHUA] ............................................................... 7 Neutron Velocity...PAULO 29 Oct] .................................... 14 Details of Secret Army Graphite Reactor Disclosed [FOLHA DE SAO PAULO 24 Oct] .............. 14...Corporation Plans To Expand Production [THE HINDU 2 Oct] .................................. 28 ISRAEL Request for Canadian Nuclear Reactor Confirmed

  5. Nuclear-Powered Debate.

    ERIC Educational Resources Information Center

    Arce, Gary

    1992-01-01

    Describes an exercise to develop interest and understanding about nuclear energy in which students make presentations regarding a proposal to build a hypothetical nuclear power plant. Students spend two weeks researching the topic; give testimony before a "Senate Energy Committee"; and vote on the proposal. Background information is…

  6. Talk About Nuclear Power

    ERIC Educational Resources Information Center

    Tremlett, Lewis

    1976-01-01

    Presents an overview of the relation of nuclear power to human health and the environment, and discusses the advantages and disadvantages of nuclear power as an energy source urging technical educators to inculcate an awareness of the problems associated with the production of energy. Describes the fission reaction process, the hazards of…

  7. Nuclear Age Education Curriculum.

    ERIC Educational Resources Information Center

    Oregon State Dept. of Education, Salem.

    The primary goal of the Oregon nuclear age education curriculum is to develop in students the knowledge and skills needed to meet the challenges of living in a nuclear age. This curriculum is developed around five general themes, each corresponding to a specific unit. The general goals for the units are: (Unit 1) to increase students' exposure to…

  8. Nuclear Power Plants. Revised.

    ERIC Educational Resources Information Center

    Lyerly, Ray L.; Mitchell, Walter, III

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: Why Use Nuclear Power?; From Atoms to Electricity; Reactor Types; Typical Plant Design Features; The Cost of Nuclear Power; Plants in the United States; Developments in Foreign…

  9. Nuclear Shuttle Logistics Configuration

    NASA Technical Reports Server (NTRS)

    1971-01-01

    This 1971 artist's concept shows the Nuclear Shuttle in both its lunar logistics configuraton and geosynchronous station configuration. As envisioned by Marshall Space Flight Center Program Development persornel, the Nuclear Shuttle would deliver payloads to lunar orbits or other destinations then return to Earth orbit for refueling and additional missions.

  10. High energy nuclear structures

    SciTech Connect

    Boguta, J.; Kunz, J.

    1984-03-09

    In conventional nuclear physics the nucleus is described as a non-relativistic many-body system, which is governed by the Schroedinger equation. Nucleons interact in this framework via static two-body potentials, mesonic degrees of freedom are neglected. An alternative description of nuclear physics in terms of a relativistic field theory has been developed by Walecka. The model Lagrangian containing baryons, sigma-mesons and ..omega..-mesons was subsequently extended to include also ..pi..-mesons and rho-mesons. An essential feature of such a nuclear Lagrangian is its renormalizability. In addition to the description of known nuclear structure the field theoretical approach may reveal entirely new nuclear phenomena, based on the explicit treatment of mesonic degrees of freedom. The existence of such abnormal nuclear states was proposed by Lee and Wick employing the sigma-model Lagrangian. There the non-linearity of the meson field equations allows for soliton solutions in the presence of nucleons, in particular the sigma-field may exhibit a kink. Different types of soliton solutions occur in gauge theories with hidden symmetries. In the phenomenological Lagrangian the rho-meson is described by a non-abelian gauge field, that acquires its mass spontaneously due to the non-vanishing vacuum expectation value of a Higgs field. A general ansatz for soliton solutions of such a gauge theory was given by Dashen et al. A specific solution and its possible implications for nuclear physics like anomalous nuclear states were discussed by Boguta.

  11. Nuclear Weapons and Schools.

    ERIC Educational Resources Information Center

    Howie, David I.

    1984-01-01

    The growing debate on nuclear weapons in recent years has begun to make inroads into school curricula. Elementary and secondary school teachers now face the important task of educating their students on issues relating to nuclear war without indoctrinating them to a particular point of view. (JBM)

  12. Nuclear effects at HERA

    SciTech Connect

    Brodsky, S.J.

    1996-07-01

    The development of a nuclear beam facility at HERA would allow the study of fundamental features of quark and gluon interactions in QCD. I briefly review the physics underlying nuclear shadowing and anti-shadowing as well as other diffractive and jet fragmentation processes that can be studies in high energy electron-nucleus collisions.

  13. TRAINING NUCLEAR TECHNICIANS.

    ERIC Educational Resources Information Center

    KOVNER, EDGAR A.

    PROBLEMS CONFRONTED BY PLANNERS OF NUCLEAR PROGRAMS AT THE TECHNICIAN LEVEL INCLUDE (1) LACK OF PRECEDENT IN CURRICULUM, COURSE OUTLINES, AND GRADUATE PLACEMENT, (2) DIFFICULTY IN DETERMINING COSTS OF LABORATORY CONSTRUCTION, EQUIPMENT, AND OPERATION, AND (3) REQUIREMENT OF ATOMIC ENERGY COMMISSION LICENSES IN NUCLEAR OCCUPATIONS. A 92-SEMESTER…

  14. Nuclear Power Plant Technician

    ERIC Educational Resources Information Center

    Randall, George A.

    1975-01-01

    The author recognizes a body of basic knowledge in nuclear power plant technoogy that can be taught in school programs, and lists the various courses, aiming to fill the anticipated need for nuclear-trained manpower--persons holding an associate degree in engineering technology. (Author/BP)

  15. Nuclear energy related research

    NASA Astrophysics Data System (ADS)

    Rintamaa, R.

    1992-05-01

    The annual Research Program Plan describes publicly funded nuclear energy related research to be carried out mainly at the Technical Research Center of Finland (VTT) in 1992. The research is financed primarily by the Ministry of Trade and Industry (KTM), the Finnish Center for Radiation and Nuclear Safety (STUK), and VTT itself. Other research institutes, utilities, and industry also contribute to many projects.

  16. Concerted evolution of the tandemly repeated genes encoding primate U2 small nuclear RNA (the RNU2 locus) does not prevent rapid diversification of the (CT){sub n} {center_dot} (GA){sub n} microsatellite embedded within the U2 repeat unit

    SciTech Connect

    Liao, D.; Weiner, A.M.

    1995-12-10

    The RNU2 locus encoding human U2 small nuclear RNA (snRNA) is organized as a nearly perfect tandem array containing 5 to 22 copies of a 5.8-kb repeat unit. Just downstream of the U2 snRNA gene in each 5.8-kb repeat unit lies a large (CT){sub n}{center_dot}(GA){sub n} dinucleotide repeat (n {approx} 70). This form of genomic organization, in which one repeat is embedded within another, provides an unusual opportunity to study the balance of forces maintaining the homogeneity of both kinds of repeats. Using a combination of field inversion gel electrophoresis and polymerase chain reaction, we have been able to study the CT microsatellites within individual U2 tandem arrays. We find that the CT microsatellites within an RNU2 allele exhibit significant length polymorphism, despite the remarkable homogeneity of the surrounding U2 repeat units. Length polymorphism is due primarily to loss or gain of CT dinucleotide repeats, but other types of deletions, insertions, and substitutions are also frequent. Polymorphism is greatly reduced in regions where pure (CT){sub n} tracts are interrupted by occasional G residues, suggesting that irregularities stabilize both the length and the sequence of the dinucleotide repeat. We further show that the RNU2 loci of other catarrhine primates (gorilla, chimpanzee, ogangutan, and baboon) contain orthologous CT microsatellites; these also exhibit length polymorphism, but are highly divergent from each other. Thus, although the CT microsatellite is evolving far more rapidly than the rest of the U2 repeat unit, it has persisted through multiple speciation events spanning >35 Myr. The persistence of the CT microsatellite, despite polymorphism and rapid evolution, suggests that it might play a functional role in concerted evolution of the RNU2 loci, perhaps as an initiation site for recombination and/or gene conversion. 70 refs., 5 figs.

  17. World nuclear outlook 1994

    SciTech Connect

    1994-12-01

    As part of the EIA program to provide energy information, this analysis report presents the current status and projections through 2010 of nuclear capacity, generation, and fuel cycle requirements for all countries in the world using nuclear power to generate electricity for commercial use. It also contains information and forecasts of developments in the uranium market. Long-term projections of US nuclear capacity, generation, and spent fuel discharges for three different scenarios through 2040 are developed for the Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM). In turn, the OCRWM provides partial funding for preparation of this report. The projections of uranium requirements are provided to the Organization for Economic Cooperation and Development (OECD) for preparation of the Nuclear Energy Agency/OECD report, Summary of Nuclear Power and Fuel Cycle Data in OECD Member Countries.

  18. World nuclear outlook 1995

    SciTech Connect

    1995-09-29

    As part of the EIA program to provide energy information, this analysis report presents the current status and projections through 2015 of nuclear capacity, generation, and fuel cycle requirements for all countries in the world using nuclear power to generate electricity for commercial use. It also contains information and forecasts of developments in the uranium market. Long-term projections of US nuclear capacity, generation, and spent fuel discharges for two different scenarios through 2040 are developed for the Department of Energy`s Office of Civilian Radioactive Waste Management (OCRWM). In turn, the OCRWM provides partial funding for preparation of this report. The projections of uranium requirements are provided to the Organization for Economic Cooperation and Development (OECD) for preparation of the Nuclear Energy Agency/OECD report, Summary of Nuclear Power and Fuel Cycle Data in OECD Member Countries.

  19. Nuclear transfer in rodents.

    PubMed

    Mullins, Linda J; Wilmut, Ian; Mullins, John J

    2004-01-01

    Cloning is the asexual reproduction of an individual, such that the offspring have an essentially identical nuclear genome. Nuclear transfer and cloning have been achieved in a number of species, namely sheep, cows, goats, rabbits, cats and mice, but have been largely unsuccessful, so far, in dogs, primates and rats. Clearly, contributory factors which affect the outcome of successful cloning experiments are not universally applicable to all species. One theme common to all cloning experiments, however, is the overall inefficiency of the process, typically 0-4%. A number of factors contribute to nuclear transfer inefficiency, and we will review mouse cloning experiments, which address these problems, highlighting the importance of donor nucleus choice (somatic or ES cell, fetal or adult, quiescent or actively dividing). Finally, we will summarize the emerging principles which appear to govern nuclear reprogramming and production of clones, and will consider the application of nuclear transfer to the rat.

  20. Nuclear physics: Macroscopic aspects

    SciTech Connect

    Swiatecki, W.J.

    1993-12-01

    A systematic macroscopic, leptodermous approach to nuclear statics and dynamics is described, based formally on the assumptions {h_bar} {yields} 0 and b/R << 1, where b is the surface diffuseness and R the nuclear radius. The resulting static model of shell-corrected nuclear binding energies and deformabilities is accurate to better than 1 part in a thousand and yields a firm determination of the principal properties of the nuclear fluid. As regards dynamics, the above approach suggests that nuclear shape evolutions will often be dominated by dissipation, but quantitative comparisons with experimental data are more difficult than in the case of statics. In its simplest liquid drop version the model exhibits interesting formal connections to the classic astronomical problem of rotating gravitating masses.

  1. Nuclear Powerplant Safety: Source Terms. Nuclear Energy.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Nuclear Energy Office.

    There has been increased public interest in the potential effects of nuclear powerplant accidents since the Soviet reactor accident at Chernobyl. People have begun to look for more information about the amount of radioactivity that might be released into the environment as a result of such an accident. When this issue is discussed by people…

  2. Nuclear war, nuclear proliferation, and their consequences

    SciTech Connect

    Sanruddin, A.K.

    1986-01-01

    The proceedings of a colloquium convened by the Groupe de Bellerive offers the contributions of Carl Sagan, Gabriel Garcia Marquez, Kenneth Galbraith, Pierre Trudeau, Edward Kennedy, and other eminent scientists, politicians, and strategists on the subject of the proliferation of nuclear weaponry and its potential ramifications.

  3. Nuclear excitation and precompound nuclear reactions

    SciTech Connect

    De, A.; Ray, S.; Ghosh, S.K.

    1988-06-01

    The angular distribution of nucleons emitted in nucleon-induced precompound nuclear reactions are calculated taking into account the effect of excitation on the kinematics of nucleon-nucleon scattering inside the target-plus-projectile system. The results are compared with quantum mechanical calculations and those of reaction models based on a pure nucleon-nucleon collision picture.

  4. A mitotic nuclear envelope tether for Gle1 also affects nuclear and nucleolar architecture

    PubMed Central

    Chemudupati, Mahesh; Osmani, Aysha H.; Osmani, Stephen A.

    2016-01-01

    During Aspergillus nidulans mitosis, peripheral nuclear pore complex (NPC) proteins (Nups) disperse from the core NPC structure. Unexpectedly, one predicted peripheral Nup, Gle1, remains at the mitotic nuclear envelope (NE) via an unknown mechanism. Gle1 affinity purification identified mitotic tether for Gle1 (MtgA), which tethers Gle1 to the NE during mitosis but not during interphase when Gle1 is at NPCs. MtgA is the orthologue of the Schizosaccharomyces pombe telomere-anchoring inner nuclear membrane protein Bqt4. Like Bqt4, MtgA has meiotic roles, but it is functionally distinct from Bqt4 because MtgA is not required for tethering telomeres to the NE. Domain analyses showed that MtgA targeting to the NE requires its C-terminal transmembrane domain and a nuclear localization signal. Of importance, MtgA functions beyond Gle1 mitotic targeting and meiosis and affects nuclear and nucleolar architecture when deleted or overexpressed. Deleting MtgA generates small, round nuclei, whereas overexpressing MtgA generates larger nuclei with altered nuclear compartmentalization resulting from NE expansion around the nucleolus. The accumulation of MtgA around the nucleolus promotes a similar accumulation of the endoplasmic reticulum (ER) protein Erg24, reducing its levels in the ER. This study extends the functions of Bqt4-like proteins to include mitotic Gle1 targeting and modulation of nuclear and nucleolar architecture. PMID:27630260

  5. Assessment of nuclear reactor concepts for low power space applications

    NASA Technical Reports Server (NTRS)

    Klein, Andrew C.; Gedeon, Stephen R.; Morey, Dennis C.

    1988-01-01

    The results of a preliminary small reactor concepts feasibility and safety evaluation designed to provide a first order validation of the nuclear feasibility and safety of six small reactor concepts are given. These small reactor concepts have potential space applications for missions in the 1 to 20 kWe power output range. It was concluded that low power concepts are available from the U.S. nuclear industry that have the potential for meeting both the operational and launch safety space mission requirements. However, each design has its uncertainties, and further work is required. The reactor concepts must be mated to a power conversion technology that can offer safe and reliable operation.

  6. US nuclear weapons policy

    SciTech Connect

    May, M.

    1990-12-05

    We are closing chapter one'' of the nuclear age. Whatever happens to the Soviet Union and to Europe, some of the major determinants of nuclear policy will not be what they have been for the last forty-five years. Part of the task for US nuclear weapons policy is to adapt its nuclear forces and the oganizations managing them to the present, highly uncertain, but not urgently competitive situation between the US and the Soviet Union. Containment is no longer the appropriate watchword. Stabilization in the face of uncertainty, a more complicated and politically less readily communicable goal, may come closer. A second and more difficult part of the task is to deal with what may be the greatest potential source of danger to come out of the end of the cold war: the breakup of some of the cooperative institutions that managed the nuclear threat and were created by the cold war. These cooperative institutions, principally the North Atlantic Treaty Organization (NATO), the Warsaw Pact, the US-Japan alliance, were not created specifically to manage the nuclear threat, but manage it they did. A third task for nuclear weapons policy is that of dealing with nuclear proliferation under modern conditions when the technologies needed to field effective nuclear weapons systems and their command and control apparatus are ever more widely available, and the leverage over some potential proliferators, which stemmed from superpower military support, is likely to be on the wane. This paper will make some suggestions regarding these tasks, bearing in mind that the unsettled nature of that part of the world most likely to become involved in nuclear weapons decisions today must make any suggestions tentative and the allowance for surprise more than usually important.

  7. Economics of nuclear power and climate change mitigation policies

    PubMed Central

    Bauer, Nico; Brecha, Robert J.; Luderer, Gunnar

    2012-01-01

    The events of March 2011 at the nuclear power complex in Fukushima, Japan, raised questions about the safe operation of nuclear power plants, with early retirement of existing nuclear power plants being debated in the policy arena and considered by regulators. Also, the future of building new nuclear power plants is highly uncertain. Should nuclear power policies become more restrictive, one potential option for climate change mitigation will be less available. However, a systematic analysis of nuclear power policies, including early retirement, has been missing in the climate change mitigation literature. We apply an energy economy model framework to derive scenarios and analyze the interactions and tradeoffs between these two policy fields. Our results indicate that early retirement of nuclear power plants leads to discounted cumulative global GDP losses of 0.07% by 2020. If, in addition, new nuclear investments are excluded, total losses will double. The effect of climate policies imposed by an intertemporal carbon budget on incremental costs of policies restricting nuclear power use is small. However, climate policies have much larger impacts than policies restricting the use of nuclear power. The carbon budget leads to cumulative discounted near term reductions of global GDP of 0.64% until 2020. Intertemporal flexibility of the carbon budget approach enables higher near-term emissions as a result of increased power generation from natural gas to fill the emerging gap in electricity supply, while still remaining within the overall carbon budget. Demand reductions and efficiency improvements are the second major response strategy. PMID:23027963

  8. Economics of nuclear power and climate change mitigation policies.

    PubMed

    Bauer, Nico; Brecha, Robert J; Luderer, Gunnar

    2012-10-16

    The events of March 2011 at the nuclear power complex in Fukushima, Japan, raised questions about the safe operation of nuclear power plants, with early retirement of existing nuclear power plants being debated in the policy arena and considered by regulators. Also, the future of building new nuclear power plants is highly uncertain. Should nuclear power policies become more restrictive, one potential option for climate change mitigation will be less available. However, a systematic analysis of nuclear power policies, including early retirement, has been missing in the climate change mitigation literature. We apply an energy economy model framework to derive scenarios and analyze the interactions and tradeoffs between these two policy fields. Our results indicate that early retirement of nuclear power plants leads to discounted cumulative global GDP losses of 0.07% by 2020. If, in addition, new nuclear investments are excluded, total losses will double. The effect of climate policies imposed by an intertemporal carbon budget on incremental costs of policies restricting nuclear power use is small. However, climate policies have much larger impacts than policies restricting the use of nuclear power. The carbon budget leads to cumulative discounted near term reductions of global GDP of 0.64% until 2020. Intertemporal flexibility of the carbon budget approach enables higher near-term emissions as a result of increased power generation from natural gas to fill the emerging gap in electricity supply, while still remaining within the overall carbon budget. Demand reductions and efficiency improvements are the second major response strategy.

  9. The nuclear dynamo; Can a nuclear tornado annihilate nations

    SciTech Connect

    McNally, J.R. Jr.

    1991-01-01

    This paper reports on the development of the hypothesis of a nuclear dynamo for a controlled nuclear fusion reactor. This dynamo hypothesis suggests properties for a nuclear tornado that could annihilate nations if accidentally triggered by a single high yield to weight nuclear weapon detonation. The formerly classified reports on ignition of the atmosphere, the properties of a nuclear dynamo, methods to achieve a nuclear dynamo in the laboratory, and the analogy of a nuclear dynamo to a nuclear tornado are discussed. An unclassified international study of this question is urged.

  10. 75 FR 39057 - Entergy Nuclear Operations, Inc.; Entergy Nuclear Vermont Yankee, LLC; Vermont Yankee Nuclear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc.; Entergy Nuclear Vermont Yankee, LLC; Vermont Yankee Nuclear... CFR), Section 2.206, ``Requests for Action under this Subpart,'' the U.S. Nuclear...

  11. 77 FR 7184 - Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations, Inc.; Indian Point Nuclear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-10

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Indian Point 2, LLC; Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit No. 2; Exemption 1.0 Background Entergy Nuclear Operations, Inc. (Entergy or the licensee)...

  12. 75 FR 3497 - Entergy Nuclear Operations, Inc., Entergy Nuclear Indian Point 2, LLC, Entergy Nuclear Indian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-21

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc., Entergy Nuclear Indian Point 2, LLC, Entergy Nuclear Indian Point 3, LLC,: Indian Point Nuclear Generating Unit Nos. 2 and 3; Notice of Consideration of Issuance of Amendment to Facility Operating License...

  13. 76 FR 15001 - Entergy Nuclear Operations, Inc,. Entergy Nuclear Vermont Yankee, LLC, Vermont Yankee Nuclear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-18

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc,. Entergy Nuclear Vermont Yankee, LLC, Vermont Yankee Nuclear... Regulations (10 CFR) 2.206, ``Requests for Action under this Subpart,'' the U.S. Nuclear Regulatory...

  14. Nuclear drug delivery for cancer chemotherapy.

    PubMed

    Sui, Meihua; Liu, Wenwen; Shen, Youqing

    2011-10-30

    Nanosystems with unique physical and biological properties have been extensively explored for cancer targeted intracellular delivery of small-molecular chemotherapeutic drugs to increase their therapeutic efficacies and to minimize their side effects. A large number of anticancer drugs are DNA-toxins that bind nuclear DNA or its associated enzymes to exert their cytotoxicity to cancer cells. After entering tumor cells, they need to be further delivered to the nucleus for actions. Herein, we discuss the biological barriers and summarize recent progress of nuclear drug delivery for cancer chemotherapy, emphasizing strategies that appear useful for design of vehicles capable of delivering drugs to the nucleus, particularly for in vivo applications. The existing obstacles or problems that need to be overcome before successful applications of nuclear drug delivery for cancer chemotherapy are also discussed.

  15. A Roadmap of Innovative Nuclear Energy System

    NASA Astrophysics Data System (ADS)

    Sekimoto, Hiroshi

    2017-01-01

    Nuclear is a dense energy without CO2 emission. It can be used for more than 100,000 years using fast breeder reactors with uranium from the sea. However, it raises difficult problems associated with severe accidents, spent fuel waste and nuclear threats, which should be solved with acceptable costs. Some innovative reactors have attracted interest, and many designs have been proposed for small reactors. These reactors are considered much safer than conventional large reactors and have fewer technical obstructions. Breed-and-burn reactors have high potential to solve all inherent problems for peaceful use of nuclear energy. However, they have some technical problems with materials. A roadmap for innovative reactors is presented herein.

  16. Your Radiologist Explains Nuclear Medicine

    MedlinePlus

    ... Sponsored by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org ... I’d like to talk to you about nuclear medicine. Nuclear medicine offers the potential to identify ...

  17. Supporting Our Nation's Nuclear Industry

    ScienceCinema

    Lyons, Peter

    2016-07-12

    On the 60th anniversary of the world's first nuclear power plant to produce electricity, Assistant Secretary for Nuclear Energy Peter Lyons discusses the Energy Department's and the Administration's commitment to promoting a nuclear renaissance in the United States.

  18. Your Radiologist Explains Nuclear Medicine

    MedlinePlus Videos and Cool Tools

    ... by Image/Video Gallery Your Radiologist Explains Nuclear Medicine Transcript Welcome to Radiology Info dot org Hello! ... d like to talk to you about nuclear medicine. Nuclear medicine offers the potential to identify disease ...

  19. Supporting Our Nation's Nuclear Industry

    SciTech Connect

    Lyons, Peter

    2011-01-01

    On the 60th anniversary of the world's first nuclear power plant to produce electricity, Assistant Secretary for Nuclear Energy Peter Lyons discusses the Energy Department's and the Administration's commitment to promoting a nuclear renaissance in the United States.

  20. Radiological Effects of Nuclear War.

    ERIC Educational Resources Information Center

    Shapiro, Charles S.

    1988-01-01

    Described are the global effects of nuclear war. Discussed are radiation dosages, limited nuclear attacks, strategic arms reductions, and other results reported at the workshop on nuclear war issues in Moscow in March 1988. (CW)

  1. Lung cancer - small cell

    MedlinePlus

    Cancer - lung - small cell; Small cell lung cancer; SCLC ... About 15% of all lung cancer cases are SCLC. Small cell lung cancer is slightly more common in men than women. Almost all cases of SCLC are ...

  2. Small Scale Organic Techniques

    ERIC Educational Resources Information Center

    Horak, V.; Crist, DeLanson R.

    1975-01-01

    Discusses the advantages of using small scale experimentation in the undergraduate organic chemistry laboratory. Describes small scale filtration techniques as an example of a semi-micro method applied to small quantities of material. (MLH)

  3. The new nuclear nations

    SciTech Connect

    Spector, L.

    1985-01-01

    Using 251 pages of text, 66 pages of references and 26 pages of appendixes, Spector delves into a world of new nuclear suppliers whose voracious hunger for profits may lead them to provide unwise assistance to countries that are unduly interested in nuclear weaponry. He assails a new dragon, a 'nuclear netherworld' that would illicitly supply such items for profit or political gain. Spector's book tells of covert dealings in nuclear technologies and materials. For him, the buyers have but one goal: '... to gain possession of the knowledge and materials necessary for development of nuclear weapons'. He warns of dangers from this illicit trade, of the loopholes in existing controls and the need to close them. His warnings come wrapped in stories of undercover transactions, many about Pakistan's efforts to get what it needs for its centrifuge enrichment plant. Recognizing the tightening of controls over nuclear trade since the 1970s, including those for dual-use items, Spector is nonetheless pessimistic that these efforts are sufficient to irradicate the nuclear netherworld or to deter newcomers from it.

  4. Nuclear forensics: Soil content

    SciTech Connect

    Beebe, Merilyn Amy

    2015-08-31

    Nuclear Forensics is a growing field that is concerned with all stages of the process of creating and detonating a nuclear weapon. The main goal is to prevent nuclear attack by locating and securing nuclear material before it can be used in an aggressive manner. This stage of the process is mostly paperwork; laws, regulations, treaties, and declarations made by individual countries or by the UN Security Council. There is some preliminary leg work done in the form of field testing detection equipment and tracking down orphan materials; however, none of these have yielded any spectacular or useful results. In the event of a nuclear attack, the first step is to analyze the post detonation debris to aid in the identification of the responsible party. This aspect of the nuclear forensics process, while reactive in nature, is more scientific. A rock sample taken from the detonation site can be dissolved into liquid form and analyzed to determine its chemical composition. The chemical analysis of spent nuclear material can provide valuable information if properly processed and analyzed. In order to accurately evaluate the results, scientists require information on the natural occurring elements in the detonation zone. From this information, scientists can determine what percentage of the element originated in the bomb itself rather than the environment. To this end, element concentrations in soils from sixty-nine different cities are given, along with activity concentrations for uranium, thorium, potassium, and radium in various building materials. These data are used in the analysis program Python.

  5. Evaluated Nuclear Data

    SciTech Connect

    Oblozinsky, P.; Oblozinsky,P.; Herman,M.; Mughabghab,S.F.

    2010-10-01

    This chapter describes the current status of evaluated nuclear data for nuclear technology applications. We start with evaluation procedures for neutron-induced reactions focusing on incident energies from the thermal energy up to 20 MeV, though higher energies are also mentioned. This is followed by examining the status of evaluated neutron data for actinides that play dominant role in most of the applications, followed by coolants/moderators, structural materials and fission products. We then discuss neutron covariance data that characterize uncertainties and correlations. We explain how modern nuclear evaluated data libraries are validated against an extensive set of integral benchmark experiments. Afterwards, we briefly examine other data of importance for nuclear technology, including fission yields, thermal neutron scattering and decay data. A description of three major evaluated nuclear data libraries is provided, including the latest version of the US library ENDF/B-VII.0, European JEFF-3.1 and Japanese JENDL-3.3. A brief introduction is made to current web retrieval systems that allow easy access to a vast amount of up-to-date evaluated nuclear data for nuclear technology applications.

  6. Perspectives of Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Faessler, Amand

    2003-04-01

    The organizers of this meeting have asked me to present perspectives of nuclear physics. This means to identify the areas where nuclear physics will be expanding in the next future. In six chapters a short overview of these areas will be given, where I expect that nuclear physics will develop quite fast: (1) Quantum Chromodynamics and effective field theories in the confinement region. (2) Nuclear structure at the limits. (3) High energy heavy ion collisions. (4) Nuclear astrophysics. (5) Neutrino physics. (6) Test of physics beyond the standard model by rare processes. After a survey over these six points I will pick out a few topics where I will go more in details. There is no time to give for all six points detailed examples. I shall discuss the following examples of the six topics mentionned above: (1) The perturbative chiral quark model and the nucleon Σ-term. (2) VAMPIR (Variation After Mean field Projection In Realistic model spaces and with realistic forces) as an example of the nuclear structure renaissance. (3) Measurement of important astrophysical nuclear reactions in the Gamow peak. (4) The solar neutrino problem. As examples for testing new physics beyond the standard model by rare processes I had prepared to speak about the measurement of the electric neutron dipole moment and of the neutrinoless double beta decay. But the time is limited and so I have to skip these points, although they are extremely interesting.

  7. Virtual nuclear weapons

    SciTech Connect

    Pilat, J.F.

    1997-08-01

    The term virtual nuclear weapons proliferation and arsenals, as opposed to actual weapons and arsenals, has entered in recent years the American lexicon of nuclear strategy, arms control, and nonproliferation. While the term seems to have an intuitive appeal, largely due to its cyberspace imagery, its current use is still vague and loose. The author believes, however, that if the term is clearly delineated, it might offer a promising approach to conceptualizing certain current problems of proliferation. The first use is in a reference to an old problem that has resurfaced recently: the problem of growing availability of weapon-usable nuclear materials in civilian nuclear programs along with materials made `excess` to defense needs by current arms reduction and dismantlement. It is argued that the availability of these vast materials, either by declared nuclear-weapon states or by technologically advanced nonweapon states, makes it possible for those states to rapidly assemble and deploy nuclear weapons. The second use has quite a different set of connotations. It is derived conceptually from the imagery of computer-generated reality. In this use, one thinks of virtual proliferation and arsenals not in terms of the physical hardware required to make the bomb but rather in terms of the knowledge/experience required to design, assemble, and deploy the arsenal. Virtual weapons are a physics reality and cannot be ignored in a world where knowledge, experience, materials, and other requirements to make nuclear weapons are widespread, and where dramatic army reductions and, in some cases, disarmament are realities. These concepts are useful in defining a continuum of virtual capabilities, ranging from those at the low end that derive from general technology diffusion and the existence of nuclear energy programs to those at the high end that involve conscious decisions to develop or maintain militarily significant nuclear-weapon capabilities.

  8. Small bowel bacterial overgrowth

    MedlinePlus

    Overgrowth - intestinal bacteria; Bacterial overgrowth - intestine; Small intestinal bacterial overgrowth; SIBO ... intestine does not have a high number of bacteria. Excess bacteria in the small intestine may use ...

  9. Nuclear Cryogenic Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2012-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced NEP.

  10. Nuclear Regulatory Commission issuances

    SciTech Connect

    1996-03-01

    This document is the March 1996 listing of NRC issuances. Included are: (1) NRC orders granting Cleveland Electric Illuminating Company`s petition for review of the ASLB order LBP-95-17, (2) NRC orders relating to the potential disqualification of two commissioners in the matter of the decommissioning of Yankee Nuclear Power Station, (3) ASLB orders pertaining to the Oncology Services Corporation, (4) ASLB orders pertaining to the Radiation Oncology Center, (5) ASLB orders pertaining to the Yankee Nuclear Power Station, and (6) Director`s decision pertaining to the Yankee Nuclear Power Station.

  11. The nuclear option

    SciTech Connect

    Herken, G.

    1992-03-01

    A development history and current status evaluation are presented for nuclear-thermal rocket propulsion systems applicable to interplanetary flight. While the most advanced current chemical rocket engines, such as the SSMEs of the Space Shuttle, produce specific impulses of the order of 450 secs, a nuclear-thermal rocket engine tested at Los Alamos in 1969 generated 845 secs; such specific impulse improvements could represent weeks or months of interplanetary travel time. Attention is given to the achievements of the historical Nuclear Engine for Rocket Vehicle Application, Helios, and Orion design programs, as well as to the current Vehicle for Interplanetary Space Transportation Applications, which is fusion-based.

  12. Fictions of nuclear disaster

    SciTech Connect

    Dowling, D.

    1987-01-01

    This work is critical study of literary interpretations of the nuclear holocaust. The author examines more than 250 stories and novels dealing with the theme of nuclear power and its devastating potential implications. Addressing such topics as the scientist and Armageddon, the role of religion, future evolution and mutation, and the postnuclear society, the author assesses the response of Bradbury, Lessing, Malamud, Shute, Huxley, Vonnegut, Heinlein, and others to the threat of nuclear apocalypse, with in-depth analyses of Alter Miller's A canticle for Leibowitz and Russell Hoban's Riddley Walker.

  13. Monitoring international nuclear activity

    SciTech Connect

    Firestone, R.B.

    2006-05-19

    The LBNL Table of Isotopes website provides primary nuclearinformation to>150,000 different users annually. We have developedthe covert technology to identify users by IP address and country todetermine the kinds of nuclear information they are retrieving. Wepropose to develop pattern recognition software to provide an earlywarning system to identify Unusual nuclear activity by country or regionSpecific nuclear/radioactive material interests We have monitored nuclearinformation for over two years and provide this information to the FBIand LLNL. Intelligence is gleaned from the website log files. Thisproposal would expand our reporting capabilities.

  14. Nuclear Medicine Annual, 1989

    SciTech Connect

    Freeman, L.M.; Weissmann, H.S.

    1989-01-01

    Among the highlights of Nuclear Medicine Annual, 1989 are a status report on the thyroid scan in clinical practice, a review of functional and structural brain imaging in dementia, an update on radionuclide renal imaging in children, and an article outlining a quality assurance program for SPECT instrumentation. Also included are discussions on current concepts in osseous sports and stress injury scintigraphy and on correlative magnetic resonance and radionuclide imaging of bone. Other contributors assess the role of nuclear medicine in clinical decision making and examine medicolegal and regulatory aspects of nuclear medicine.

  15. A brief history of design studies on innovative nuclear reactors

    SciTech Connect

    Sekimoto, Hiroshi

    2014-09-30

    In a short period after the success of CP1, many types of nuclear reactors were proposed and investigated. However, soon only a small number of reactors were selected for practical use. Around 1970, only LWRs with small number of CANDUs were operated in the western world, and FBRs were under development. It was about the time when Apollo moon landing was accomplished. However, at the same time, the future of human being was widely considered pessimistic and Limits to Growth was published. In the end of 1970’s the TMI accident occurred and many nuclear reactor contracts were cancelled in USA and any more contracts had not been concluded until recent years. From the reflection of this accident, many Inherent Safe Reactors (ISRs) were proposed, though none of them were constructed. A common idea of ISRs is smallness of their size. Tokyo Institute of Technology (TokyoTech) held a symposium on small reactors, SR/TIT, in 1991, where many types of small ISRs were presented. Recently small reactors attract interest again. The most ideas employed in these reactors were the same discussed in SR/TIT. In 1980’s the radioactive wastes from fuel cycle became a severe problem around the world. In TokyoTech, this issue was discussed mainly from the viewpoint of nuclear transmutations. The neutron economy became inevitable for these innovative nuclear reactors especially small long-life reactors and transmutation reactors.

  16. A synthetic snRNA m3G-CAP enhances nuclear delivery of exogenous proteins and nucleic acids.

    PubMed

    Moreno, Pedro M D; Wenska, Malgorzata; Lundin, Karin E; Wrange, Orjan; Strömberg, Roger; Smith, C I Edvard

    2009-04-01

    Accessing the nucleus through the surrounding membrane poses one of the major obstacles for therapeutic molecules large enough to be excluded due to nuclear pore size limits. In some therapeutic applications the large size of some nucleic acids, like plasmid DNA, hampers their access to the nuclear compartment. However, also for small oligonucleotides, achieving higher nuclear concentrations could be of great benefit. We report on the synthesis and possible applications of a natural RNA 5'-end nuclear localization signal composed of a 2,2,7-trimethylguanosine cap (m(3)G-CAP). The cap is found in the small nuclear RNAs that are constitutive part of the small nuclear ribonucleoprotein complexes involved in nuclear splicing. We demonstrate the use of the m(3)G signal as an adaptor that can be attached to different oligonucleotides, thereby conferring nuclear targeting capabilities with capacity to transport large-size cargo molecules. The synthetic capping of oligos interfering with splicing may have immediate clinical applications.

  17. The role of nuclear shapes in nuclear structure (from the perspective of the Daresbury Tandem)

    SciTech Connect

    Nazarewicz, W.

    1993-06-01

    In specific regions of the nuclear periodic chart, large multipole moments are observed and the low-lying excitations have a rotational character. These features are understood if the nuclei in question are assumed to have a stable deformation, i.e., a non-spherical distribution of the nuclear matter. In other (transitional) regions the quasi-rotational bands are present; they are strongly coupled to low-lying vibrational modes. Those nuclei are best understood in terms of small static deformations but large dynamic fluctuations around local equilibria. As a matter of fact, the vast majority of nuclei are deformed; even in those which are spherical or almost spherical, the dynamical couplings to shape vibrations are crucial. The issue of nuclear deformation is many-faceted. If the nuclear shape (nuclear mean field) is deformed, characteristic excitation modes are present, such as rotations and vibrations built upon the non-spherical equilibrium. Through the particle-core coupling, nuclear deformations can dramatically influence the single-particle properties of nucleons moving in the average nuclear potential. Many experimental investigations using the Daresbury Tandem were related in one way or another to the physics of nuclear shapes. Fundamental discoveries from Daresbury include the observation of superdeformed structures in rapidly rotating nuclei, the observation of identical ({open_quotes}twinned{close_quotes}) rotational bands, various studies of structural changes induced by very fast rotation (band-crossings, band-terminations), the observation of the oblate-deformed {open_quotes}dipole{close_quotes} bands, studies of reflection-asymmetric shapes, studies of (quasimolecular) cluster configurations in light nuclei, and many, many others. The author reviews the forefront research at Daresbury from the global perspective; the common denominator being the nuclear shape deformation.

  18. Nuclear charge and neutron radii and nuclear matter: Trend analysis in Skyrme density-functional-theory approach

    NASA Astrophysics Data System (ADS)

    Reinhard, P.-G.; Nazarewicz, W.

    2016-05-01

    with two-nucleon and three-nucleon forces optimized simultaneously to binding energies and radii of selected nuclei. Second, since the neutron skin uncertainty primarily depends on the slope of the symmetry energy, imposing constraints on both ρ0 and L practically determines the nuclear size, modulo small variations due to shell effects.

  19. Nuclear receptors in transgenerational epigenetic inheritance.

    PubMed

    Ozgyin, Lilla; Erdős, Edina; Bojcsuk, Dóra; Balint, Balint L

    2015-07-01

    Nuclear Receptors are ligand-activated transcription factors that translate information about the lipid environment into specific genetic programs, a property that renders them good candidates to be mediators of rapid adaptation changes of a species. Lipid-based morphogens, endocrine hormones, fatty acids and xenobiotics might act through this class of transcription factors making them regulators able to fine-tune physiological processes. Here we review the basic concepts and current knowledge on the process whereby small molecules act through nuclear receptors and contribute to transgenerational changes. Several molecules shown to cause transgenerational changes like phthalates, BPA, nicotine, tributylin bind and activate nuclear receptors like ERs, androgen receptors, glucocorticoid receptors or PPARγ. A specific subset of observations involving nuclear receptors has focused on the effects of environmental stress or maternal behaviour on the development of transgenerational traits. While these effects do not involve environmental ligands, they change the expression levels of Estrogen and glucocorticoid receptors of the second generation and consequently initiate an altered genetic program in the second generation. In this review we summarize the available literature about the role of nuclear receptors in transgenerational inheritance.

  20. Neutron contribution to nuclear DVCS asymmetries

    SciTech Connect

    Vadim Guzey

    2008-01-22

    Using a simple model for nuclear GPDs, we study the role of the neutron contribution to nuclear DVCS observables. As an example, we use the beam-spin asymmetry $A_{LU}^A$ measured in coherent and incoherent DVCS on a wide range of nuclear targets in the HERMES and JLab kinematics. We find that at small values of the momentum transfer $t$, $A_{LU}^A$ is dominated by the coherent-enriched contribution, which enhances $A_{LU}^A$ compared to the free proton asymmetry $A_{LU}^p$, $A_{LU}^A(\\phi)/A_{LU}^p(\\phi)=1.8-2.2$. At large values of $t$, the nuclear asymmetry is dominated by the incoherent contribution and $A_{LU}^A/(\\phi)A_{LU}^p(\\phi)=0.66-0.74$. The deviation of $A_{LU}^A(\\phi)/A_{LU}^p(\\phi)$ from unity at large $t$ is a result of the neutron contribution, which gives a possibility to constain neutron GPDs in incoherent nuclear DVCS. A similar trend is expected for other DVCS asymmetries.

  1. International nuclear waste management fact book

    SciTech Connect

    Abrahms, C W; Patridge, M D; Widrig, J E

    1995-11-01

    The International Nuclear Waste Management Fact Book has been compiled to provide current data on fuel cycle and waste management facilities, R and D programs, and key personnel in 24 countries, including the US; four multinational agencies; and 20 nuclear societies. This document, which is in its second year of publication supersedes the previously issued International Nuclear Fuel Cycle Fact Book (PNL-3594), which appeared annually for 12 years. The content has been updated to reflect current information. The Fact Book is organized as follows: National summaries--a section for each country that summarizes nuclear policy, describes organizational relationships, and provides addresses and names of key personnel and information on facilities. International agencies--a section for each of the international agencies that has significant fuel cycle involvement and a list of nuclear societies. Glossary--a list of abbreviations/acronyms of organizations, facilities, and technical and other terms. The national summaries, in addition to the data described above, feature a small map for each country and some general information that is presented from the perspective of the Fact Book user in the US.

  2. Nuclear component horizontal seismic restraint

    DOEpatents

    Snyder, Glenn J.

    1988-01-01

    A nuclear component horizontal seismic restraint. Small gaps limit horizontal displacement of components during a seismic occurrence and therefore reduce dynamic loadings on the free lower end. The reactor vessel and reactor guard vessel use thicker section roll-forged rings welded between the vessel straight shell sections and the bottom hemispherical head sections. The inside of the reactor guard vessel ring forging contains local vertical dovetail slots and upper ledge pockets to mount and retain field fitted and installed blocks. As an option, the horizontal displacement of the reactor vessel core support cone can be limited by including shop fitted/installed local blocks in opposing alignment with the reactor vessel forged ring. Beams embedded in the wall of the reactor building protrude into apertures in the thermal insulation shell adjacent the reactor guard vessel ring and have motion limit blocks attached thereto to provide to a predetermined clearance between the blocks and reactor guard vessel ring.

  3. What are Nuclear Receptor Ligands?

    PubMed Central

    Sladek, Frances M.

    2010-01-01

    Nuclear receptors (NRs) are a family of highly conserved transcription factors that regulate transcription in response to small lipophilic compounds. They play a role in every aspect of development, physiology and disease in humans. They are also ubiquitous in and unique to the animal kingdom suggesting that they may have played an important role in their evolution. In contrast to the classical endocrine receptors that originally defined the family, recent studies suggest that the first NRs might have been sensors of their environment, binding ligands that were external to the host organism. The purpose of this review is to provide a broad perspective on NR ligands and address the issue of exactly what constitutes a NR ligand from historical, biological and evolutionary perspectives. This discussion will lay the foundation for subsequent reviews in this issue as well as pose new questions for future investigation. PMID:20615454

  4. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, Kevin M.; Doyle, Barney L.

    1996-01-01

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue.

  5. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, K.M.; Doyle, B.L.

    1996-08-20

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue. 25 figs.

  6. Nuclear Fuel Reprocessing

    SciTech Connect

    Michael F. Simpson; Jack D. Law

    2010-02-01

    This is an a submission for the Encyclopedia of Sustainable Technology on the subject of Reprocessing Spent Nuclear Fuel. No formal abstract was required for the article. The full article will be attached.

  7. Nuclear Explosion Monitoring

    SciTech Connect

    Fagan, Deborah K.; Anderson, Dale N.; Shumway, Robert

    2008-09-15

    Teleseismic events (earthquakes or explosions) generate strong seismic energy waves that propagate largely in the mantle. For example, the Threshold Test Ban Treaty restricted nuclear tests to be less that 150 kilotons in size, and explosions of this size generate seismic energy waves that are observed teleseismically. Teleseismic monitoring for explosions answers three questions: Where is the seismic event located? Is the event an explosion or natural (event identification)? If an explosion, how large was it? Resolving whether an explosion is chemical or nuclear can require additional analysis (e.g., analysis of atmospherically observed chemical and nuclear spectra). Because of the political ramifications of event identification errors, risk analysis in the context of nuclear explosion monitoring is unique.

  8. 2011 Japanese Nuclear Incident

    EPA Pesticide Factsheets

    EPA’s RadNet system monitored the environmental radiation levels in the United States and parts of the Pacific following the Japanese Nuclear Incident. Learn about EPA’s response and view historical laboratory data and news releases.

  9. Desalting and Nuclear Energy

    ERIC Educational Resources Information Center

    Burwell, Calvin C.

    1971-01-01

    Future use of nuclear energy to produce electricity and desalted water is outlined. Possible desalting processes are analyzed to show economic feasibility and the place in planning in world's economic growth. (DS)

  10. Nuclear Heart Scan

    MedlinePlus

    ... into your blood and travels to your heart. Nuclear heart scans use single photon emission computed tomography (SPECT) or cardiac positron emission tomography (PET) to detect the energy from the tracer to make pictures of your ...

  11. International Nuclear Security

    SciTech Connect

    Doyle, James E.

    2012-08-14

    This presentation discusses: (1) Definitions of international nuclear security; (2) What degree of security do we have now; (3) Limitations of a nuclear security strategy focused on national lock-downs of fissile materials and weapons; (4) What do current trends say about the future; and (5) How can nuclear security be strengthened? Nuclear security can be strengthened by: (1) More accurate baseline inventories; (2) Better physical protection, control and accounting; (3) Effective personnel reliability programs; (4) Minimize weapons-usable materials and consolidate to fewer locations; (5) Consider local threat environment when siting facilities; (6) Implement pledges made in the NSS process; and (7) More robust interdiction, emergency response and special operations capabilities. International cooperation is desirable, but not always possible.

  12. The nuclear weapons world

    SciTech Connect

    Burke, P.

    1988-01-01

    This book presents insight into the technical world of weapons production. It discusses accountability in nuclear weapons decisionmaking. Nuclear decisions and the weapons and strategy they concern are too mammoth, too complex and too intimidating a subject for most of us to grapple with. The more so because informed debate is rare, and because information is difficult to obtain. In Britain, Parliamentary questions receive evasive answers or no answers at all, and the rationale of official secrecy is used as a reason to reveal less and less about decisions on national defense: between 1981 and 1987, for example, the number of open government documents published on defence fell from fifty-seven to two. In the case of NATO, decisions on nuclear strategy into the next century are taken in secret by defence ministers meeting in the Nuclear Planning Group.

  13. Physics and nuclear power

    NASA Astrophysics Data System (ADS)

    Buttery, N. E.

    2008-03-01

    Nuclear power owes its origin to physicists. Fission was demonstrated by physicists and chemists and the first nuclear reactor project was led by physicists. However as nuclear power was harnessed to produce electricity the role of the engineer became stronger. Modern nuclear power reactors bring together the skills of physicists, chemists, chemical engineers, electrical engineers, mechanical engineers and civil engineers. The paper illustrates this by considering the Sizewell B project and the role played by physicists in this. This covers not only the roles in design and analysis but in problem solving during the commissioning of first of a kind plant. Looking forward to the challenges to provide sustainable and environmentally acceptable energy sources for the future illustrates the need for a continuing synergy between physics and engineering. This will be discussed in the context of the challenges posed by Generation IV reactors.

  14. Nuclear energy: moving ahead

    SciTech Connect

    Not Available

    1983-01-01

    Electricity is assuming a larger role despite conservation efforts because it can be generated from a variety of fuels, it is essential for many industrial processes, and it is easier to control the environmental impacts from centralized power plants. The growth in electricity use over the next 10 years is expected to match that of productivity and the gross national product. After examining available energy sources and concluding that nuclear energy is necessary for an adequate and reliable supply, this booklet goes on to examine the risks, accidents and accident control, safety research, nuclear waste management, and the economics of nuclear energy. It concludes that nuclear energy is needed for both the transition period as fossil fuels are used up and in the long term when demand may increase as much as 50%. 24 references, 5 figures, 1 table.

  15. Nuclear data interface retrospective

    SciTech Connect

    Gray, Mark G

    2008-01-01

    The Nuclear Data Interface (NDI) code library and data formats are the standards for multigroup nuclear data at Los Alamos National Laboratory. NDI's analysis, design, implementation, testing, integration, and maintenance required a ten person-year and ongoing effort by the Nuclear Data Team. Their efforts provide a unique, contemporary experience in producing a standard component library. In reflection upon that experience at NDI's decennial, we have identified several factors critical to NDI's success: it addressed real problems with appropriate simplicity, it fully supported all users, it added extra value through the code to the raw nuclear data, and its team went the distance from analysis through maintenance. In this report we review these critical success factors and discuss their implications for future standardization projects.

  16. JPRS report, nuclear developments

    SciTech Connect

    1991-03-28

    This report contains articles concerning the nuclear developments of the following countries: (1) China; (2) Japan, North Korea, South Korea; (3) Bulgaria; (4) Argentina, Brazil, Honduras; (5) India, Iran, Pakistan, Syria; (6) Soviet Union; and (7) France, Germany, Turkey.

  17. Nuclear material operations manual

    SciTech Connect

    Tyler, R.P.

    1981-02-01

    This manual provides a concise and comprehensive documentation of the operating procedures currently practiced at Sandia National Laboratories with regard to the management, control, and accountability of nuclear materials. The manual is divided into chapters which are devoted to the separate functions performed in nuclear material operations-management, control, accountability, and safeguards, and the final two chapters comprise a document which is also issued separately to provide a summary of the information and operating procedures relevant to custodians and users of radioactive and nuclear materials. The manual also contains samples of the forms utilized in carrying out nuclear material activities. To enhance the clarity of presentation, operating procedures are presented in the form of playscripts in which the responsible organizations and necessary actions are clearly delineated in a chronological fashion from the initiation of a transaction to its completion.

  18. Direct nuclear pumped laser

    DOEpatents

    Miley, George H.; Wells, William E.; DeYoung, Russell J.

    1978-01-01

    There is provided a direct nuclear pumped gas laser in which the lasing mechanism is collisional radiated recombination of ions. The gas laser active medium is a mixture of the gases, with one example being neon and nitrogen.

  19. Nuclear Clusters in Astrophysics

    NASA Astrophysics Data System (ADS)

    Kubono, S.; Binh, Dam N.; Hayakawa, S.; Hashimoto, H.; Kahl, D.; Wakabayashi, Y.; Yamaguchi, H.; Teranishi, T.; Iwasa, N.; Komatsubara, T.; Kato, S.; Khiem, Le H.

    2010-03-01

    The role of nuclear clustering is discussed for nucleosynthesis in stellar evolution with Cluster Nucleosynthesis Diagram (CND) proposed before. Special emphasis is placed on α-induced stellar reactions together with molecular states for O and C burning.

  20. Western Nuclear Science Alliance

    SciTech Connect

    Steve Reese; George Miller; Stephen Frantz; Denis Beller; Denis Beller; Ed Morse; Melinda Krahenbuhl; Bob Flocchini; Jim Elliston

    2010-12-07

    The primary objective of the INIE program is to strengthen nuclear science and engineering programs at the member institutions and to address the long term goal of the University Reactor Infrastructure and Education Assistance Program.

  1. Nuclear-Rocket Propulsion

    NASA Technical Reports Server (NTRS)

    Rom, Frank E.

    1968-01-01

    The three basic types of nuclear power-plants (solid, liquid, and gas core) are compared on the bases of performance potential and the status of current technology. The solid-core systems are expected to have impulses in the range of 850 seconds, any thrust level (as long as it is greater than 10,000 pounds (44,480 newtons)), and thrust-to-engine-weight ratios of 2 to 20 pounds per pound (19.7 to 197 newtons per kilogram). There is negligible or no fuel loss from the solid-core system. The solid-core system, of course, has had the most work done on it. Large-scale tests have been performed on a breadboard engine that has produced specific impulses greater than 700 seconds at thrust levels of about 50,000 pounds (222,000 newtons). The liquid-core reactor would be interesting in the specific impulse range of 1200 to 1500 seconds. Again, any thrust level can be obtained depending on how big or small the reactor is made. The thrust-to-engine weight ratio for these systems would be in the range of 1 to 10. The discouraging feature of the liquid-core system is the high fuel-loss ratio anticipated. Values of 0.01 to 0.1 pound (0.00454 to 0.0454 kilograms) or uranium loss per pound (0.454 kilograms) of hydrogen are expected, if impulses in the range of 1200 to 1500 seconds are desired. The gas-core reactor shows specific impulses in the range of 1500 to 2500 seconds. The thrust levels should be at least as high as the weight so that the thrust-to-weight ratio does not go below 1. Because the engine weight is not expected to be under 100,000 pounds (444,800 newtons), thrust levels higher than 100,000 pounds (448,000 newtons) are of interest. The thrust-to-engine weights, in that case, would run from 1 to 20 pounds per pound (9.8 to 19.7 kilograms). Gas-core reactors tend to be very large, and can have high thrust-to-weight ratios. As in the case of the liquid-core system, the fuel loss that will be attendant with gas cores as envisioned today will be rather high. The loss

  2. Nuclear DNA Amounts in Macaronesian Angiosperms

    PubMed Central

    SUDA, JAN; KYNCL, TOMÁŠ; FREIOVÁ, RADKA

    2003-01-01

    Nuclear DNA contents for 104 Macaronesian angiosperms, with particular attention on Canary Islands endemics, were analysed using propidium iodide flow cytometry. Prime estimates for more than one‐sixth of the whole Canarian endemic flora (including representatives of 11 endemic genera) were obtained. The resulting 1C DNA values ranged from 0·19 to 7·21 pg for Descurainia bourgeauana and Argyranthemum frutescens, respectively (about 38‐fold difference). The majority of species, however, possessed (very) small genomes, with C‐values <1·6 pg. The tendency towards small nuclear DNA contents and genome sizes was confirmed by comparing average values for Macaronesian and non‐Macaronesian representatives of individual families, genera and major phylogenetic lineages. Our data support the hypothesis that the insular selection pressures in Macaronesia favour small C‐values and genome sizes. Both positive and negative correlations between infrageneric nuclear DNA amount variation and environmental conditions on Tenerife were also found in several genera. PMID:12824074

  3. Nuclear Technology Series. Course 5: Introduction to Nuclear Systems.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  4. Nuclear Technology Series. Course 24: Nuclear Systems and Safety.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  5. Nuclear Technology Series. Course 23: Nuclear Chemical Processes.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  6. Nuclear fuel element

    DOEpatents

    Meadowcroft, Ronald Ross; Bain, Alastair Stewart

    1977-01-01

    A nuclear fuel element wherein a tubular cladding of zirconium or a zirconium alloy has a fission gas plenum chamber which is held against collapse by the loops of a spacer in the form of a tube which has been deformed inwardly at three equally spaced, circumferential positions to provide three loops. A heat resistant disc of, say, graphite separates nuclear fuel pellets within the cladding from the plenum chamber. The spacer is of zirconium or a zirconium alloy.

  7. UNISOR Nuclear Orientation Facility

    SciTech Connect

    Girit, I.C.

    1988-01-01

    The combination of an on-line isotope separator and a dilution refrigerator has increased the applicability of the nuclear orientation technique to a wide range of nuclei, especially those very far from stability. The UNISOR Nuclear Orientation Facility (UNISOR/NOF) is among the two (the other being NICOLE at CERN) that have recently become operational. The following is an overall view of the UNISOR system and recent results. 24 refs., 3 figs.

  8. Nuclear magnetic resonance gyroscope

    SciTech Connect

    Grover, B.C.

    1984-02-07

    A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor.

  9. Keeping Nuclear Materials Secure

    SciTech Connect

    2016-10-19

    For 50 years, Los Alamos National Laboratory has been helping to keep nuclear materials secure. We do this by developing instruments and training inspectors that are deployed to other countries to make sure materials such as uranium are being used for peaceful purposes and not diverted for use in weapons. These measures are called “nuclear safeguards,” and they help make the world a safer place.

  10. Nuclear Warfare Water Contamination.

    DTIC Science & Technology

    1982-05-01

    Products x Applied Health Physics, Inc x Applied Physical Technology, Inc x Aptec Nuclear Inc x The Aston Company x Baird Corp x Berthold-Beta...15, Department of the Army, Washington, D. C., June 1966. 61 26. Private Communication, D. C. Lindsten (USAMERADCOM) to John C.Phillips (SA[-Chicago...Detection and Measurement," John Wiley & Sons, New York, 1919. 29. Lichholz, G. G., "Environmental Aspects of Nuclear Power," Ann Arbor, Science, Ann Arbor

  11. Nuclear Plant Inspection

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Engineers from the Power Authority of the State of New York use a Crack Growth Analysis Program supplied by COSMIC (Computer Software Management and Information Center) in one stage of nuclear plant inspection. Welds of the nuclear steam supply system are checked for cracks; radiographs, dye penetration and visual inspections are performed to locate cracks in the metal structure and welds. The software package includes three separate crack growth analysis models and enables necessary repairs to be planned before serious problems develop.

  12. Nuclear Rocket Technology Conference

    NASA Technical Reports Server (NTRS)

    1966-01-01

    The Lewis Research Center has a strong interest in nuclear rocket propulsion and provides active support of the graphite reactor program in such nonnuclear areas as cryogenics, two-phase flow, propellant heating, fluid systems, heat transfer, nozzle cooling, nozzle design, pumps, turbines, and startup and control problems. A parallel effort has also been expended to evaluate the engineering feasibility of a nuclear rocket reactor using tungsten-matrix fuel elements and water as the moderator. Both of these efforts have resulted in significant contributions to nuclear rocket technology. Many successful static firings of nuclear rockets have been made with graphite-core reactors. Sufficient information has also been accumulated to permit a reasonable Judgment as to the feasibility of the tungsten water-moderated reactor concept. We therefore consider that this technoIogy conference on the nuclear rocket work that has been sponsored by the Lewis Research Center is timely. The conference has been prepared by NASA personnel, but the information presented includes substantial contributions from both NASA and AEC contractors. The conference excludes from consideration the many possible mission requirements for nuclear rockets. Also excluded is the direct comparison of nuclear rocket types with each other or with other modes of propulsion. The graphite reactor support work presented on the first day of the conference was partly inspired through a close cooperative effort between the Cleveland extension of the Space Nuclear Propulsion Office (headed by Robert W. Schroeder) and the Lewis Research Center. Much of this effort was supervised by Mr. John C. Sanders, chairman for the first day of the conference, and by Mr. Hugh M. Henneberry. The tungsten water-moderated reactor concept was initiated at Lewis by Mr. Frank E. Rom and his coworkers. The supervision of the recent engineering studies has been shared by Mr. Samuel J. Kaufman, chairman for the second day of the

  13. JPRS Report, Nuclear Developments.

    DTIC Science & Technology

    2007-11-02

    COMERCIO 21 Aug] 23 NEAR EAST & SOUTH ASIA EGYPT Agreements Signed to Develop Domestic Uranium [AL-JUMHURIYAH 2 Aug] 24 INDIA Two Large...Empresas Nucleares Brasileiras S.A. (Nuclebras) to Industrias Nucleares do Brasil S.A. (INB), and trans- ferred the shares of its capital stock...96.622 authorizes the establishment of Uranium of Brasil S.A. as a subsidiary of INB, with headquarters in the city of Caldas, Minas Gerais State

  14. Nuclear Energy Policy

    DTIC Science & Technology

    2007-07-12

    Generation IV Program will also focus on developing a sodium-cooled fast reactor ( SFR ). Existing U.S. commercial nuclear reactors use water to slow...Nevada. The UREX+ process also would reduce the heat generated by nuclear waste — the major limit on the repository’s capacity — by removing cesium ...significantly contaminated by radioactive cesium .17 Greenpeace issued a report in 2006 estimating that 200,000 deaths in Belarus, Russia, and Ukraine resulted

  15. A Nuclear Energy Renaissance: Challenges to Nuclear Weapon Nonproliferation

    DTIC Science & Technology

    2009-03-30

    civilian nuclear power infrastructure. Light water reactors require enriched uranium to operate, albeit at much lower enrichment percentages...the horizon. Twenty-two years after the Chernobyl nuclear reactor accident the world’s nuclear energy industry is booming.1 Nuclear energy is...experiencing a strong revival around the world and in the United States. There are currently 439 nuclear reactors operating worldwide, in 30 countries. Thirty

  16. Analysis of nuclear reconstitution, nuclear envelope assembly, and nuclear pore assembly using Xenopus in vitro assays.

    PubMed

    Bernis, Cyril; Forbes, Douglass J

    2014-01-01

    The large and complex eukaryotic nucleus is the arbiter of DNA replication, RNA transcription, splicing, and ribosome assembly. With the advent of in vitro nuclear reconstitution extracts derived from Xenopus eggs in the 1980s, it became possible to assemble multiple nuclei in vitro around added DNA or chromatin substrates. Such reconstituted nuclei contain a nuclear lamina, double nuclear membranes, nuclear pores, and are competent for DNA replication and nuclear import. In vitro nuclear reconstitution has allowed the assembly of "wild-type" and "biochemically mutant" nuclei in which the impact of individual components can be assessed. Here, we describe protocols for preparation of the nuclear reconstitution extract, nuclear reconstitution in vitro, assessment of nuclear membrane integrity, and a more specialized assay for nuclear pore assembly into preformed pore-free nuclear intermediates.

  17. Analysis of Nuclear Reconstitution, Nuclear Envelope Assembly, and Nuclear Pore Assembly Using Xenopus In Vitro Assays

    PubMed Central

    Bernis, Cyril; Forbes, Douglass J.

    2015-01-01

    The large and complex eukaryotic nucleus is the arbiter of DNA replication, RNA transcription, splicing, and ribosome assembly. With the advent of in vitro nuclear reconstitution extracts derived from Xenopus eggs in the 1980s, it became possible to assemble multiple nuclei in vitro around added DNA or chromatin substrates. Such reconstituted nuclei contain a nuclear lamina, double nuclear membranes, nuclear pores, and are competent for DNA replication and nuclear import. In vitro nuclear reconstitution has allowed the assembly of “wild-type” and “biochemically mutant” nuclei in which the impact of individual components can be assessed. Here, we describe protocols for preparation of the nuclear reconstitution extract, nuclear reconstitution in vitro, assessment of nuclear membrane integrity, and a more specialized assay for nuclear pore assembly into preformed pore-free nuclear intermediates. PMID:24857730

  18. Panel report: nuclear physics

    SciTech Connect

    Carlson, Joseph A; Hartouni, Edward P

    2010-01-01

    Nuclear science is at the very heart of the NNSA program. The energy produced by nuclear processes is central to the NNSA mission, and nuclear reactions are critical in many applications, including National Ignition Facility (NIF) capsules, energy production, weapons, and in global threat reduction. Nuclear reactions are the source of energy in all these applications, and they can also be crucial in understanding and diagnosing the complex high-energy environments integral to the work of the NNSA. Nuclear processes are complex quantum many-body problems. Modeling and simulation of nuclear reactions and their role in applications, coupled tightly with experiments, have played a key role in NNSA's mission. The science input to NNSA program applications has been heavily reliant on experiment combined with extrapolations and physical models 'just good enough' to provide a starting point to extensive engineering that generated a body of empirical information. This body of information lacks the basic science underpinnings necessary to provide reliable extrapolations beyond the domain in which it was produced and for providing quantifiable error bars. Further, the ability to perform additional engineering tests is no longer possible, especially those tests that produce data in the extreme environments that uniquely characterize these applications. The end of testing has required improvements to the predictive capabilities of codes simulating the reactions and associated applications for both well known and well characterized cases as well as incompletely known cases. Developments in high performance computing, computational physics, applied mathematics and nuclear theory have combined to make spectacular advances in the theory of fission, fusion and nuclear reactions. Current research exploits these developments in a number of Office of Science and NNSA programs, and in joint programs such as the SciDAC (Science Discovery through Advanced Computing) that supports the

  19. Thinking About Preventing Nuclear War.

    ERIC Educational Resources Information Center

    Ground Zero, Washington, DC.

    Potential paths to nuclear war and the available means of prevention of nuclear war are discussed. Presented is a detailed description of six nuclear war scenarios, and brief examples of types of potential deterrents to nuclear war (firebreaks) which are relevant for each. To be effective, the right combination of firebreaks must be used, the…

  20. Nuclear War and Science Teaching.

    ERIC Educational Resources Information Center

    Hobson, Art

    1983-01-01

    Suggests that science-related material on nuclear war be included in introductory courses. Lists nuclear war topics for physics, psychology, sociology, biology/ecology, chemistry, geography, geology/meteorology, mathematics, and medical science. Also lists 11 lectures on nuclear physics which include nuclear war topics. (JN)