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Sample records for suprachiasmatic nuclei scn

  1. In vivo metabolic activity of hamster suprachiasmatic nuclei: use of anesthesia

    International Nuclear Information System (INIS)

    Schwartz, W.J.

    1987-01-01

    In vivo glucose utilization was measured in the suprachiasmatic nuclei (SCN) of Golden hamsters using the 14 C-labeled deoxyglucose technique. A circadian rhythm of SCN metabolic activity could be measured in this species, but only during pentobarbital sodium anesthesia when the surrounding background activity of adjacent hypothalamus was suppressed. Both the SCN's metabolic oscillation and its time-keeping ability are resistant to general anesthesia

  2. Clock-dependent and system-driven oscillators interact in the suprachiasmatic nuclei to pace mammalian circadian rhythms.

    Directory of Open Access Journals (Sweden)

    Karine Abitbol

    Full Text Available Circadian clocks drive biological rhythms with a period of approximately 24 hours and keep in time with the outside world through daily resetting by environmental cues. While this external entrainment has been extensively investigated in the suprachiasmatic nuclei (SCN, the role of internal systemic rhythms, including daily fluctuations in core temperature or circulating hormones remains debated. Here, we show that lactating mice, which exhibit dampened systemic rhythms, possess normal molecular clockwork but impaired rhythms in both heat shock response gene expression and electrophysiological output in their SCN. This suggests that body rhythms regulate SCN activity downstream of the clock. Mathematical modeling predicts that systemic feedback upon the SCN functions as an internal oscillator that accounts for in vivo and ex vivo observations. Thus we are able to propose a new bottom-up hierarchical organization of circadian timekeeping in mammals, based on the interaction in the SCN between clock-dependent and system-driven oscillators.

  3. The opioid fentanyl affects light input, electrical activity and Per gene expression in the hamster suprachiasmatic nuclei.

    Science.gov (United States)

    Vansteensel, Mariska J; Magnone, Maria Chiara; van Oosterhout, Floor; Baeriswyl, Stéphanie; Albrecht, Urs; Albus, Henk; Dahan, Albert; Meijer, Johanna H

    2005-06-01

    The suprachiasmatic nuclei (SCN) contain a major circadian pacemaker, which is regulated by photic and nonphotic stimuli. Although enkephalins are present in the SCN, their role in phase regulation of the pacemaker is largely unknown. The opioid agonist fentanyl, a homologue of morphine, is an addictive drug that induces phase shifts of circadian rhythms in hamsters. We observed that these phase shifts are blocked by naloxone, which is a critical test for true opioid receptor involvement, and conclude that opioid receptors are the sole mediators of the actions of fentanyl on the circadian timing system. A strong interaction between opioids and light input was shown by the ability of fentanyl and light to completely block each other's phase shifts of behavioural activity rhythms. Neuronal ensemble recordings in vitro provide first evidence that SCN cells show direct responses to fentanyl and react with a suppression of firing rate. Moreover, we show that fentanyl induces a strong attenuation of light-induced Syrian hamster Period 1 (shPer1) gene expression during the night. During the subjective day, we found no evidence for a role of shPer1 in mediation of fentanyl-induced phase shifts. Based on the present results, however, we cannot exclude the involvement of shPer2. Our data indicate that opioids can strongly modify the photic responsiveness of the circadian pacemaker and may do so via direct effects on SCN electrical activity and regulation of Per genes. This suggests that the pathways regulating addictive behaviour and the circadian clock intersect.

  4. In Vivo Initiation of Clock Gene Expression Rhythmicity in Fetal Rat Suprachiasmatic Nuclei

    Czech Academy of Sciences Publication Activity Database

    Houdek, Pavel; Sumová, Alena

    2014-01-01

    Roč. 9, č. 9 (2014), e107360 E-ISSN 1932-6203 R&D Projects: GA ČR(CZ) GAP303/12/1108 Institutional support: RVO:67985823 Keywords : circadian * suprachiasmatic nuclei * ontogenesis * clock gene * entrainment * rat Subject RIV: FH - Neurology Impact factor: 3.234, year: 2014

  5. Daily and circadian rhythms of neurotransmitters and related compounds in the hypothalamic suprachiasmatic nuclei of a diurnal vertebrate.

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    Magnone, Maria Chiara; Bertolucci, Cristiano; Piazza, Francesca; Foà, Augusto

    2003-05-23

    By using immunocytochemistry we tested whether neurotransmitters, and enzymes specific to neurotransmitters synthesis are rhythmically expressed in the suprachiasmatic nuclei of the hypothalamus of Ruin lizards Podarcis sicula either kept in light-dark cycles or constant darkness. Within the suprachiasmatic nuclei, prominent 24 h rhythms under 12:12 light-dark cycles were found for vasoactive intestinal polypeptide (VIP) and for tyrosine hydroxylase (TH). Peaks of both VIP and TH fell in the light phase of the cycle. Rhythmic expression of TH persisted under constant temperature and darkness, demonstrating the existence of circadian rhythms of TH in the suprachiasmatic nuclei. No rhythmic expression of neurotransmitters and related compounds was found in the periventricular nuclei, the supraoptic nuclei, and the rest of the hypothalamus. Our data are the first demonstration of rhythmic expression of neurotransmitters and related compounds in the suprachiasmatic nuclei of a non-mammalian vertebrate. The demonstration of a diurnal peak of VIP in a diurnal reptile-vs. nocturnal peak of VIP typical of nocturnal mammals-provides new information for comparative studies on the circadian physiology of the suprachiasmatic nuclei across vertebrate classes and their adaptation strategies to different temporal niches.

  6. In Vivo Imaging of the Central and Peripheral Effects of Sleep Deprivation and Suprachiasmatic Nuclei Lesion on PERIOD-2 Protein in Mice.

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    Curie, Thomas; Maret, Stephanie; Emmenegger, Yann; Franken, Paul

    2015-09-01

    That sleep deprivation increases the brain expression of various clock genes has been well documented. Based on these and other findings we hypothesized that clock genes not only underlie circadian rhythm generation but are also implicated in sleep homeostasis. However, long time lags have been reported between the changes in the clock gene messenger RNA levels and their encoded proteins. It is therefore crucial to establish whether also protein levels increase within the time frame known to activate a homeostatic sleep response. We report on the central and peripheral effects of sleep deprivation on PERIOD-2 (PER2) protein both in intact and suprachiasmatic nuclei-lesioned mice. In vivo and in situ PER2 imaging during baseline, sleep deprivation, and recovery. Mouse sleep-recording facility. Per2::Luciferase knock-in mice. N/A. Six-hour sleep deprivation increased PER2 not only in the brain but also in liver and kidney. Remarkably, the effects in the liver outlasted those observed in the brain. Within the brain the increase in PER2 concerned the cerebral cortex mainly, while leaving suprachiasmatic nuclei (SCN) levels unaffected. Against expectation, sleep deprivation did not increase PER2 in the brain of arrhythmic SCN-lesioned mice because of higher PER2 levels in baseline. In contrast, liver PER2 levels did increase in these mice similar to the sham and partially lesioned controls. Our results stress the importance of considering both sleep-wake dependent and circadian processes when quantifying clock-gene levels. Because sleep deprivation alters PERIOD-2 in the brain as well as in the periphery, it is tempting to speculate that clock genes constitute a common pathway mediating the shared and well-known adverse effects of both chronic sleep loss and disrupted circadian rhythmicity on metabolic health. © 2015 Associated Professional Sleep Societies, LLC.

  7. The suprachiasmatic nucleus regulates sleep timing and amount in mice

    NARCIS (Netherlands)

    Easton, Amy; Meerlo, Peter; Bergmann, Bernard; Turek, Fred W.

    2004-01-01

    Context: Sleep is regulated by circadian and homeostatic processes. The circadian pacemaker, located in the suprachiasmatic nuclei (SCN), regulates the timing and consolidation of the sleep-wake cycle, while a homeostatic mechanism governs the accumulation of sleep debt and sleep, recovery. Recent

  8. Aging does not compromise in vitro oscillation of the suprachiasmatic nuclei but makes it more vulnerable to constant light

    Czech Academy of Sciences Publication Activity Database

    Polidarová, Lenka; Sládek, Martin; Novosadová, Zuzana; Sumová, Alena

    2017-01-01

    Roč. 34, č. 1 (2017), s. 105-117 ISSN 0742-0528 R&D Projects: GA ČR(CZ) GA14-07711S Institutional support: RVO:67985823 Keywords : aging * circadian clock * constant light * suprachiasmatic nuclei * mPer2Luc mice Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 2.562, year: 2016

  9. Comparative anatomy of the mammalian hypothalamic suprachiasmatic nucleus.

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    Cassone, V M; Speh, J C; Card, J P; Moore, R Y

    1988-01-01

    A detailed analysis of the cytoarchitecture, retinohypothalamic tract (RHT) projections, and immunohistochemical localization of major cell and fiber types within the hypothalamic suprachiasmatic nuclei (SCN) was conducted in five mammalian species: two species of opossum, the domestic cat, the guinea pig, and the house mouse. Cytoarchitectural and immunohistochemical studies were conducted in three additional species of marsupial mammals and in the domestic pig. The SCN in this diverse transect of mammalian taxonomy bear striking similarities. First, the SCN are similar in location, lying close to the third ventricle (3V) dorsal to the optic chiasm (OC), with a cytoarchitecture characterized by small, tightly packed neurons. Second, in all groups studied, the SCN receive bilateral retinal input. Third, the SCN contain immunohistochemically similar elements. These similarities suggest that the SCN developed characteristic features early in mammalian phylogeny. Some details of SCN organization vary among the species studied. In marsupials, vasopressin-like immunoreactive (VP-LI) and vasoactive intestinal polypeptide-like immunoreactive (VIP-LI) cells codistribute primarily in the dorsomedial aspects of the SCN, while in eutherians, VP-LI and VIP-LI cells are separated into SCN subnuclei. Furthermore, the marsupial RHT projects to the periventricular dorsomedial region, whereas the eutherian RHT projects more ventrally in the SCN into the zone that typically contains VIP-LI perikarya.

  10. Potentiation of Inhibitory Synaptic Transmission by Extracellular ATP in Rat Suprachiasmatic Nuclei

    Czech Academy of Sciences Publication Activity Database

    Bhattacharya, Anirban; Vávra, Vojtěch; Svobodová, Irena; Bendová, Z.; Vereb, G.; Zemková, Hana

    2013-01-01

    Roč. 33, č. 18 (2013), s. 8035-8044 ISSN 0270-6474 R&D Projects: GA AV ČR(CZ) IAA500110910; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : suprachiasmatic nucleus * P2X receptors * P2Y receptors * ATP * GABA * spontaneous inhibitory synaptic currents Subject RIV: ED - Physiology Impact factor: 6.747, year: 2013

  11. Circadian Tick-Talking Across the Neuroendocrine System and Suprachiasmatic Nuclei Circuits: The Enigmatic Communication Between the Molecular and Electrical Membrane Clocks.

    Science.gov (United States)

    Belle, M D C

    2015-07-01

    As with many processes in nature, appropriate timing in biological systems is of paramount importance. In the neuroendocrine system, the efficacy of hormonal influence on major bodily functions, such as reproduction, metabolism and growth, relies on timely communication within and across many of the brain's homeostatic systems. The activity of these circuits is tightly orchestrated with the animal's internal physiological demands and external solar cycle by a master circadian clock. In mammals, this master clock is located in the hypothalamic suprachiasmatic nucleus (SCN), where the ensemble activity of thousands of clock neurones generates and communicates circadian time cues to the rest of the brain and body. Many regions of the brain, including areas with neuroendocrine function, also contain local daily clocks that can provide feedback signals to the SCN. Although much is known about the molecular processes underpinning endogenous circadian rhythm generation in SCN neurones and, to a lesser extent, extra-SCN cells, the electrical membrane clock that acts in partnership with the molecular clockwork to communicate circadian timing across the brain is poorly understood. The present review focuses on some circadian aspects of reproductive neuroendocrinology and processes involved in circadian rhythm communication in the SCN, aiming to identify key gaps in our knowledge of cross-talk between our daily master clock and neuroendocrine function. The intention is to highlight our surprisingly limited understanding of their interaction in the hope that this will stimulate future work in these areas. © 2015 The Author. Journal of Neuroendocrinology published by John Wiley & Sons Ltd on behalf of The British Society for Neuroendocrinology.

  12. Delayed Cryptochrome Degradation Asymmetrically Alters the Daily Rhythm in Suprachiasmatic Clock Neuron Excitability.

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    Wegner, Sven; Belle, Mino D C; Hughes, Alun T L; Diekman, Casey O; Piggins, Hugh D

    2017-08-16

    Suprachiasmatic nuclei (SCN) neurons contain an intracellular molecular circadian clock and the Cryptochromes (CRY1/2), key transcriptional repressors of this molecular apparatus, are subject to post-translational modification through ubiquitination and targeting for proteosomal degradation by the ubiquitin E3 ligase complex. Loss-of-function point mutations in a component of this ligase complex, Fbxl3, delay CRY1/2 degradation, reduce circadian rhythm strength, and lengthen the circadian period by ∼2.5 h. The molecular clock drives circadian changes in the membrane properties of SCN neurons, but it is unclear how alterations in CRY1/2 stability affect SCN neurophysiology. Here we use male and female Afterhours mice which carry the circadian period lengthening loss-of-function Fbxl3 Afh mutation and perform patch-clamp recordings from SCN brain slices across the projected day/night cycle. We find that the daily rhythm in membrane excitability in the ventral SCN (vSCN) was enhanced in amplitude and delayed in timing in Fbxl3 Afh/Afh mice. At night, vSCN cells from Fbxl3 Afh/Afh mice were more hyperpolarized, receiving more GABAergic input than their Fbxl3 +/+ counterparts. Unexpectedly, the progression to daytime hyperexcited states was slowed by Afh mutation, whereas the decline to hypoexcited states was accelerated. In long-term bioluminescence recordings, GABA A receptor blockade desynchronized the Fbxl3 +/+ but not the Fbxl3 Afh/Afh vSCN neuronal network. Further, a neurochemical mimic of the light input pathway evoked larger shifts in molecular clock rhythms in Fbxl3 Afh/Afh compared with Fbxl3 +/+ SCN slices. These results reveal unanticipated consequences of delaying CRY degradation, indicating that the Afh mutation prolongs nighttime hyperpolarized states of vSCN cells through increased GABAergic synaptic transmission. SIGNIFICANCE STATEMENT The intracellular molecular clock drives changes in SCN neuronal excitability, but it is unclear how mutations

  13. The suprachiasmatic nucleus-paraventricular nucleus interactions: a bridge to the neuroendocrine and autonomic nervous system

    NARCIS (Netherlands)

    Buijs, R. M.; Hermes, M. H.; Kalsbeek, A.

    1998-01-01

    Vasopressin (VP) is one of the principal neurotransmitters of the suprachiasmatic nucleus (SCN). By means of anatomical, physiological and electrophysiological techniques we have demonstrated that VP containing pathways from the SCN serve to affect neuroendocrine and 'autonomic' neurons in the

  14. Suprachiasmatic Nucleus Interaction with the Arcuate Nucleus; Essential for Organizing Physiological Rhythms

    NARCIS (Netherlands)

    Buijs, Frederik N.; Guzmán-Ruiz, Mara; León-Mercado, Luis; Basualdo, Mari Carmen; Escobar, Carolina; Kalsbeek, Andries; Buijs, Ruud M.

    2017-01-01

    The suprachiasmatic nucleus (SCN) is generally considered the master clock, independently driving all circadian rhythms. We recently demonstrated the SCN receives metabolic and cardiovascular feedback adeptly altering its neuronal activity. In the present study, we show that microcuts effectively

  15. Mitochondrial calcium signaling mediates rhythmic extracellular ATP accumulation in suprachiasmatic nucleus astrocytes.

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    Burkeen, Jeff F; Womac, Alisa D; Earnest, David J; Zoran, Mark J

    2011-06-08

    The master circadian pacemaker located within the suprachiasmatic nuclei (SCN) controls neural and neuroendocrine rhythms in the mammalian brain. Astrocytes are abundant in the SCN, and this cell type displays circadian rhythms in clock gene expression and extracellular accumulation of ATP. Still, the intracellular signaling pathways that link the SCN clockworks to circadian rhythms in extracellular ATP accumulation remain unclear. Because ATP release from astrocytes is a calcium-dependent process, we investigated the relationship between intracellular Ca(2+) and ATP accumulation and have demonstrated that intracellular Ca(2+) levels fluctuate in an antiphase relationship with rhythmic ATP accumulation in rat SCN2.2 cell cultures. Furthermore, mitochondrial Ca(2+) levels were rhythmic and maximal in precise antiphase with the peak in cytosolic Ca(2+). In contrast, our finding that peak mitochondrial Ca(2+) occurred during maximal extracellular ATP accumulation suggests a link between these cellular rhythms. Inhibition of the mitochondrial Ca(2+) uniporter disrupted the rhythmic production and extracellular accumulation of ATP. ATP, calcium, and the biological clock affect cell division and have been implicated in cell death processes. Nonetheless, rhythmic extracellular ATP accumulation was not disrupted by cell cycle arrest and was not correlated with caspase activity in SCN2.2 cell cultures. Together, these results demonstrate that mitochondrial Ca(2+) mediates SCN2.2 rhythms in extracellular ATP accumulation and suggest a role for circadian gliotransmission in SCN clock function.

  16. Increased glutamic acid decarboxylase expression in the hypothalamic suprachiasmatic nucleus in depression

    NARCIS (Netherlands)

    Wu, Xueyan; Balesar, R.A.; Lu, Jing; Farajnia, Sahar; Zhu, Qiongbin; Huang, Manli; Bao, Ai-Min; Swaab, D.F.

    2017-01-01

    In depression, disrupted circadian rhythms reflect abnormalities in the central circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN). Although many SCN neurons are said to be GABAergic, it was not yet known whether and how SCN GABA changes occur in the SCN in depression. We,

  17. Retinal ganglion cell projections to the hamster suprachiasmatic nucleus, intergeniculate leaflet, and visual midbrain: bifurcation and melanopsin immunoreactivity

    Science.gov (United States)

    Morin, Lawrence P.; Blanchard, Jane H.; Provencio, Ignacio

    2003-01-01

    The circadian clock in the suprachiasmatic nucleus (SCN) receives direct retinal input via the retinohypothalamic tract (RHT), and the retinal ganglion cells contributing to this projection may be specialized with respect to direct regulation of the circadian clock. However, some ganglion cells forming the RHT bifurcate, sending axon collaterals to the intergeniculate leaflet (IGL) through which light has secondary access to the circadian clock. The present studies provide a more extensive examination of ganglion cell bifurcation and evaluate whether ganglion cells projecting to several subcortical visual nuclei contain melanopsin, a putative ganglion cell photopigment. The results showed that retinal ganglion cells projecting to the SCN send collaterals to the IGL, olivary pretectal nucleus, and superior colliculus, among other places. Melanopsin-immunoreactive (IR) ganglion cells are present in the hamster retina, and some of these cells project to the SCN, IGL, olivary pretectal nucleus, or superior colliculus. Triple-label analysis showed that melanopsin-IR cells bifurcate and project bilaterally to each SCN, but not to the other visual nuclei evaluated. The melanopsin-IR cells have photoreceptive characteristics optimal for circadian rhythm regulation. However, the presence of moderately widespread bifurcation among ganglion cells projecting to the SCN, and projection by melanopsin-IR cells to locations distinct from the SCN and without known rhythm function, suggest that this ganglion cell type is generalized, rather than specialized, with respect to the conveyance of photic information to the brain. Copyright 2003 Wiley-Liss, Inc.

  18. Functionally Complete Excision of Conditional Alleles in the Mouse Suprachiasmatic Nucleus by Vgat-ires-Cre.

    Science.gov (United States)

    Weaver, David R; van der Vinne, Vincent; Giannaris, E Lela; Vajtay, Thomas J; Holloway, Kristopher L; Anaclet, Christelle

    2018-04-01

    Mice with targeted gene disruption have provided important information about the molecular mechanisms of circadian clock function. A full understanding of the roles of circadian-relevant genes requires manipulation of their expression in a tissue-specific manner, ideally including manipulation with high efficiency within the suprachiasmatic nuclei (SCN). To date, conditional manipulation of genes within the SCN has been difficult. In a previously developed mouse line, Cre recombinase was inserted into the vesicular GABA transporter (Vgat) locus. Since virtually all SCN neurons are GABAergic, this Vgat-Cre line seemed likely to have high efficiency at disrupting conditional alleles in SCN. To test this premise, the efficacy of Vgat-Cre in excising conditional (fl, for flanked by LoxP) alleles in the SCN was examined. Vgat-Cre-mediated excision of conditional alleles of Clock or Bmal1 led to loss of immunostaining for products of the targeted genes in the SCN. Vgat-Cre + ; Clock fl/fl ; Npas2 m/m mice and Vgat-Cre + ; Bmal1 fl/fl mice became arrhythmic immediately upon exposure to constant darkness, as expected based on the phenotype of mice in which these genes are disrupted throughout the body. The phenotype of mice with other combinations of Vgat-Cre + , conditional Clock, and mutant Npas2 alleles also resembled the corresponding whole-body knockout mice. These data indicate that the Vgat-Cre line is useful for Cre-mediated recombination within the SCN, making it useful for Cre-enabled technologies including gene disruption, gene replacement, and opto- and chemogenetic manipulation of the SCN circadian clock.

  19. Control of the Estradiol-Induced Prolactin Surge by the Suprachiasmatic Nucleus

    NARCIS (Netherlands)

    Palm, Inge F.; van der Beek, Eline M.; Swarts, Hans J. M.; van der Vliet, Jan; Wiegant, Victor M.; Buijs, Ruud M.; Kalsbeek, Andries

    2001-01-01

    In the present study we investigated how the suprachiasmatic nucleus (SCN) controls the E(2)-induced PRL surge in female rats. First, the role of vasopressin (VP), a SCN transmitter present in medial preoptic area (MPO) projections and rhythmically released by SCN neurons, as a circadian signal for

  20. Effects of melatonin on 2-deoxy-[1-14C]glucose uptake within rat suprachiasmatic nucleus

    International Nuclear Information System (INIS)

    Cassone, V.M.; Roberts, M.H.; Moore, R.Y.

    1988-01-01

    Previously, we have demonstrated that metabolic activity, shown by autoradiographic determination of 2-deoxy-[1- 14 C]glucose (2-DG) uptake, within the rat hypothalamic suprachiasmatic nuclei (SCN) was inhibited by subcutaneous injection of 1 mg/kg melatonin. To determine whether this effect was specific to a particular time of day, the effects of melatonin on 2-DG uptake were studied in several hypothalamic areas, including the SCN, supraoptic nuclei (SON), lateral hypothalamic area (LHA), and anterior hypothalamic area (AHA) every 4 h throughout the circadian day. In a second experiment, the effects of different melatonin doses were studied at the time of day at which melatonin had its maximal effect to determine the dose-response relationship of melatonin-induced inhibition of SCN 2-DG uptake. The data indicate that melatonin inhibited 2-DG uptake in the SCN alone at one time of day, primarily at circadian time (CT) 6 and CT10, 2-6 h before subjective dusk, and secondarily at CT22, just before subjective dawn. This effect was dose dependent with a 50% effective dose of 1.49 +/- 2.30 micrograms/kg. The temporal and dose-response characteristics of these effects are similar to those characterizing the entraining effects of melatonin on circadian patterns of locomotion and drinking

  1. Direct and specific effect of sevoflurane anesthesia on rat Per2 expression in the suprachiasmatic nucleus.

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    Megumi Anzai

    Full Text Available BACKGROUND: Our previous studies revealed that application of the inhalation anesthetic, sevoflurane, reversibly repressed the expression of Per2 in the mouse suprachiasmatic nucleus (SCN. We aimed to examine whether sevoflurane directly affects the SCN. METHODS: We performed in vivo and in vitro experiments to investigate rat Per2 expression under sevoflurane-treatment. The in vivo effects of sevoflurane on rPer2 expression were examined by quantitative in situ hybridization with a radioactively-labeled cRNA probe. Additionally, we examined the effect of sevoflurane anesthesia on rest/activity rhythms in the rat. In the in vitro experiments, we applied sevoflurane to SCN explant cultures from Per2-dLuc transgenic rats, and monitored luciferase bioluminescence, representing Per2 promoter activity. Bioluminescence from two peripheral organs, the kidney cortex and the anterior pituitary gland, were also analyzed. RESULTS: Application of sevoflurane in rats significantly suppressed Per2 expression in the SCN compared with untreated animals. We observed no sevoflurane-induced phase-shift in the rest/activity rhythms. In the in vitro experiments, the intermittent application of sevoflurane repressed the increase of Per2-dLuc luminescence and led to a phase delay in the Per2-dLuc luminescence rhythm. Sevoflurane treatment did not suppress bioluminescence in the kidney cortex or the anterior pituitary gland. CONCLUSION: The suppression of Per2-dLuc luminescence by sevoflurane in in vitro SCN cultures isolated from peripheral inputs and other nuclei suggest a direct action of sevoflurane on the SCN itself. That sevoflurane has no such effect on peripheral organs suggests that this action might be mediated through a neuron-specific cellular mechanism or a regulation of the signal transduction between neurons.

  2. Effects of Photoperiod Extension on Clock Gene and Neuropeptide RNA Expression in the SCN of the Soay Sheep.

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    Hugues Dardente

    Full Text Available In mammals, changing daylength (photoperiod is the main synchronizer of seasonal functions. The photoperiodic information is transmitted through the retino-hypothalamic tract to the suprachiasmatic nuclei (SCN, site of the master circadian clock. To investigate effects of day length change on the sheep SCN, we used in-situ hybridization to assess the daily temporal organization of expression of circadian clock genes (Per1, Per2, Bmal1 and Fbxl21 and neuropeptides (Vip, Grp and Avp in animals acclimated to a short photoperiod (SP; 8h of light and at 3 or 15 days following transfer to a long photoperiod (LP3, LP15, respectively; 16h of light, achieved by an acute 8-h delay of lights off. We found that waveforms of SCN gene expression conformed to those previously seen in LP acclimated animals within 3 days of transfer to LP. Mean levels of expression for Per1-2 and Fbxl21 were nearly 2-fold higher in the LP15 than in the SP group. The expression of Vip was arrhythmic and unaffected by photoperiod, while, in contrast to rodents, Grp expression was not detectable within the sheep SCN. Expression of the circadian output gene Avp cycled robustly in all photoperiod groups with no detectable change in phasing. Overall these data suggest that synchronizing effects of light on SCN circadian organisation proceed similarly in ungulates and in rodents, despite differences in neuropeptide gene expression.

  3. Cardiovascular control by the suprachiasmatic nucleus: neural and neuroendocrine mechanisms in human and rat

    NARCIS (Netherlands)

    Scheer, Frank A.; Kalsbeek, Andries; Buijs, Ruud M.

    2003-01-01

    The risk for cardiovascular incidents is highest in the early morning, which seems partially due to endogenous factors. Endogenous circadian rhythms in mammalian physiology and behavior are regulated by the suprachiasmatic nucleus (SCN). Recently, anatomical evidence has been provided that SCN

  4. Circadian modulation of GABA function in the rat suprachiasmatic nucleus: excitatory effects during the night phase.

    NARCIS (Netherlands)

    De Jeu, M.T.G.; Pennartz, C.M.A.

    2002-01-01

    Gramicidin-perforated patch-clamp recordings were made from slices of the suprachiasmatic nucleus (SCN) of adult rats to characterize the role of gamma-amino butyric acid (GABA) in the circadian timing system. During the day, activation of GABA(A) receptors hyperpolarized the membrane of SCN

  5. Functional network inference of the suprachiasmatic nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Abel, John H.; Meeker, Kirsten; Granados-Fuentes, Daniel; St. John, Peter C.; Wang, Thomas J.; Bales, Benjamin B.; Doyle, Francis J.; Herzog, Erik D.; Petzold, Linda R.

    2016-04-04

    In the mammalian suprachiasmatic nucleus (SCN), noisy cellular oscillators communicate within a neuronal network to generate precise system-wide circadian rhythms. Although the intracellular genetic oscillator and intercellular biochemical coupling mechanisms have been examined previously, the network topology driving synchronization of the SCN has not been elucidated. This network has been particularly challenging to probe, due to its oscillatory components and slow coupling timescale. In this work, we investigated the SCN network at a single-cell resolution through a chemically induced desynchronization. We then inferred functional connections in the SCN by applying the maximal information coefficient statistic to bioluminescence reporter data from individual neurons while they resynchronized their circadian cycling. Our results demonstrate that the functional network of circadian cells associated with resynchronization has small-world characteristics, with a node degree distribution that is exponential. We show that hubs of this small-world network are preferentially located in the central SCN, with sparsely connected shells surrounding these cores. Finally, we used two computational models of circadian neurons to validate our predictions of network structure.

  6. Vasopressin immunoreactivity and release in the suprachiasmatic nucleus of wild-type and tau mutant Syrian hamsters

    NARCIS (Netherlands)

    Van der Zee, EA; Oklejewicz, M; Jansen, K; Daan, S; Gerkema, MP

    2002-01-01

    Despite the prominent role of the Syrian hamster (Mesocricetus auratus) in studies of circadian rhythms, there are no data available on the temporal dynamics of the neuropeptide vasopressin (AVP), a major output system of the suprachiasmatic nucleus (SCN). We studied the hamster SCN-AVP system in

  7. Combined Pharmacological and Genetic Manipulations Unlock Unprecedented Temporal Elasticity and Reveal Phase-Specific Modulation of the Molecular Circadian Clock of the Mouse Suprachiasmatic Nucleus

    OpenAIRE

    Patton, Andrew P.; Chesham, Johanna E.; Hastings, Michael H.

    2016-01-01

    The suprachiasmatic nucleus (SCN) is the master circadian oscillator encoding time-of-day information. SCN timekeeping is sustained by a cell-autonomous transcriptional–translational feedback loop, whereby expression of the Period and Cryptochrome genes is negatively regulated by their protein products. This loop in turn drives circadian oscillations in gene expression that direct SCN electrical activity and thence behavior. The robustness of SCN timekeeping is further enhanced by interneuron...

  8. Sensitivity of housekeeping genes in the suprachiasmatic nucleus of the mouse brain to diet and the daily light-dark cycle.

    Science.gov (United States)

    Cleal, Jane K; Shepherd, James N; Shearer, Jasmine L; Bruce, Kimberley D; Cagampang, Felino R

    2014-08-05

    The endogenous timing system within the suprachiasmatic nuclei (SCN) of the hypothalamus drives the cyclic expression of the clock molecules across the 24h day-night cycle controlling downstream molecular pathways and physiological processes. The developing fetal clock system is sensitive to the environment and physiology of the pregnant mother and as such disruption of this system could lead to altered physiology in the offspring. Characterizing the gene profiles of the endogenous molecular clock system by quantitative reverse transcription polymerase chain reaction is dependent on normalization by appropriate housekeeping genes (HKGs). However, many HKGs commonly used as internal controls, although stably expressed under control conditions, can vary significantly in their expression under certain experimental conditions. Here we analyzed the expression of 10 classic HKG across the 24h light-dark cycle in the SCN of mouse offspring exposed to normal chow or a high fat diet during early development and in postnatal life. We found that the HKGs glyceraldehyde-3-phosphate dehydrogenase, beta actin and adenosine triphosphate synthase subunit to be the most stably expressed genes in the SCN regardless of diet or time within the 24h light-dark cycle, and are therefore suitable to be used as internal controls. However SCN samples collected during the light and dark periods did show differences in expression and as such the timing of collection should be considered when carrying out gene expression studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Suprachiasmatic modulation of noradrenaline release in the ventrolateral preoptic nucleus.

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    Saint-Mleux, Benoît; Bayer, Laurence; Eggermann, Emmanuel; Jones, Barbara E; Mühlethaler, Michel; Serafin, Mauro

    2007-06-13

    As the major brain circadian pacemaker, the suprachiasmatic nucleus (SCN) is known to influence the timing of sleep and waking. We thus investigated here the effect of SCN stimulation on neurons of the ventrolateral preoptic nucleus (VLPO) thought to be involved in promoting sleep. Using an acute in vitro preparation of the rat anterior hypothalamus/preoptic area, we found that whereas single-pulse stimulations of the SCN evoked standard fast ionotropic IPSPs and EPSPs, train stimulations unexpectedly evoked a long-lasting inhibition (LLI). Such LLIs could also be evoked in VLPO neurons by pressure application of NMDA within the SCN, indicating the specific activation of SCN neurons. This LLI was shown to result from the presynaptic facilitation of noradrenaline release, because it was suppressed in presence of yohimbine, a selective antagonist of alpha2-adrenoreceptors. The LLI depended on the opening of a potassium conductance, because it was annulled at E(K) and could be reversed below E(K). These results show that the SCN can provide an LLI of the sleep-promoting VLPO neurons that could play a role in the circadian organization of the sleep-waking cycle.

  10. The Suprachiasmatic nucleus balances sympathetic and parasympathetic output to peripheral organs through separate preautonomic neurons

    NARCIS (Netherlands)

    Buijs, Ruud M.; la Fleur, Susanne E.; Wortel, Joke; van Heyningen, Caroline; Zuiddam, Laura; Mettenleiter, Thomas C.; Kalsbeek, Andries; Nagai, Katsuya; Niijima, Akira

    2003-01-01

    Opposing parasympathetic and sympathetic signals determine the autonomic output of the brain to the body and the change in balance over the sleep-wake cycle. The suprachiasmatic nucleus (SCN) organizes the activity/inactivity cycle and the behaviors that go along with it, but it is unclear how the

  11. Grafted fetal suprachiasmatic nucleus cells survive much better in tissue pieces than in suspension

    NARCIS (Netherlands)

    Boer, G. J.; Griffioen, H. A.; Saeed, P.

    1992-01-01

    A comparison was made between the survival of fetal suprachiasmatic nucleus (SCN) grafted either in tissue pieces or as tissue suspension. Donor tissue was obtained from day 15, 16 or 17 Wistar fetuses, and stereotaxically placed in the dorsal thalamus of the brain of vasopressin(VP)-deficient

  12. Environmental light and suprachiasmatic nucleus interact in the regulation of body temperature.

    NARCIS (Netherlands)

    Scheer, F.A.J.L.; Pirovano, C.; Someren, E.J.W. van; Buijs, R.M.

    2005-01-01

    The mammalian biological clock, located in the suprachiasmatic nucleus (SCN), is crucial for circadian rhythms in physiology and behavior. However, equivocal findings have been reported on its role in the circadian regulation of body temperature. The goal of the present studies was to investigate

  13. Cognitive performance as a zeitgeber: cognitive oscillators and cholinergic modulation of the SCN entrain circadian rhythms.

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    Howard J Gritton

    Full Text Available The suprachiasmatic nucleus (SCN is the primary circadian pacemaker in mammals that can synchronize or entrain to environmental cues. Although light exerts powerful influences on SCN output, other non-photic stimuli can modulate the SCN as well. We recently demonstrated that daily performance of a cognitive task requiring sustained periods of attentional effort that relies upon basal forebrain (BF cholinergic activity dramatically alters circadian rhythms in rats. In particular, normally nocturnal rats adopt a robust diurnal activity pattern that persists for several days in the absence of cognitive training. Although anatomical and pharmacological data from non-performing animals support a relationship between cholinergic signaling and circadian rhythms, little is known about how endogenous cholinergic signaling influences SCN function in behaving animals. Here we report that BF cholinergic projections to the SCN provide the principal signal allowing for the expression of cognitive entrainment in light-phase trained animals. We also reveal that oscillator(s outside of the SCN drive cognitive entrainment as daily timed cognitive training robustly entrains SCN-lesioned arrhythmic animals. Ablation of the SCN, however, resulted in significant impairments in task acquisition, indicating that SCN-mediated timekeeping benefits new learning and cognitive performance. Taken together, we conclude that cognition entrains non-photic oscillators, and cholinergic signaling to the SCN serves as a temporal timestamp attenuating SCN photic-driven rhythms, thereby permitting cognitive demands to modulate behavior.

  14. The Suprachiasmatic Nucleus of the Dromedary Camel (Camelus dromedarius: Cytoarchitecture and Neurochemical Anatomy

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    Khalid El Allali

    2017-11-01

    Full Text Available In mammals, biological rhythms are driven by a master circadian clock located in the suprachiasmatic nucleus (SCN of the hypothalamus. Recently, we have demonstrated that in the camel, the daily cycle of environmental temperature is able to entrain the master clock. This raises several questions about the structure and function of the SCN in this species. The current work is the first neuroanatomical investigation of the camel SCN. We carried out a cartography and cytoarchitectural study of the nucleus and then studied its cell types and chemical neuroanatomy. Relevant neuropeptides involved in the circadian system were investigated, including arginine-vasopressin (AVP, vasoactive intestinal polypeptide (VIP, met-enkephalin (Met-Enk, neuropeptide Y (NPY, as well as oxytocin (OT. The neurotransmitter serotonin (5-HT and the enzymes tyrosine hydroxylase (TH and aromatic L-amino acid decarboxylase (AADC were also studied. The camel SCN is a large and elongated nucleus, extending rostrocaudally for 9.55 ± 0.10 mm. Based on histological and immunofluorescence findings, we subdivided the camel SCN into rostral/preoptic (rSCN, middle/main body (mSCN and caudal/retrochiasmatic (cSCN divisions. Among mammals, the rSCN is unusual and appears as an assembly of neurons that protrudes from the main mass of the hypothalamus. The mSCN exhibits the triangular shape described in rodents, while the cSCN is located in the retrochiasmatic area. As expected, VIP-immunoreactive (ir neurons were observed in the ventral part of mSCN. AVP-ir neurons were located in the rSCN and mSCN. Results also showed the presence of OT-ir and TH-ir neurons which seem to be a peculiarity of the camel SCN. OT-ir neurons were either scattered or gathered in one isolated cluster, while TH-ir neurons constituted two defined populations, dorsal parvicellular and ventral magnocellular neurons, respectively. TH colocalized with VIP in some rSCN neurons. Moreover, a high density of Met

  15. Effects of SCN lesions on circadian blood pressure rhythm in normotensive and transgenic hypertensive rats

    NARCIS (Netherlands)

    Witte, K.; Schnecko, A.; Buijs, R. M.; van der Vliet, J.; Scalbert, E.; Delagrange, P.; Guardiola-Lemaître, B.; Lemmer, B.

    1998-01-01

    Transgenic hypertensive TGR(mREN2)27 (TGR) rats, carrying an additional mouse renin gene, have been found to show inverse circadian blood pressure profiles compared to normotensive Sprague-Dawley rats. In order to evaluate the contributions of the suprachiasmatic nucleus (SCN) and the neurohormone

  16. Biological Rhythms Workshop IB: neurophysiology of SCN pacemaker function.

    Science.gov (United States)

    Kuhlman, S J

    2007-01-01

    Pacemakers are functional units capable of generating oscillations that synchronize downstream rhythms. In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus is a circadian pacemaker composed of individual neurons that intrinsically express a near 24-hour rhythm in gene expression. Rhythmic gene expression is tightly coupled to a rhythm in spontaneous firing rate via intrinsic daily regulation of potassium current. Recent progress in the field indicates that SCN pacemaking is a specialized property that emerges from intrinsic features of single cells, structural connectivity among cells, and activity dynamics within the SCN. The focus of this chapter is on how Nature built a functional pacemaker from many individual oscillators that is capable of coordinating the daily timing of essential brain and physiological processes.

  17. Phase preference for the display of activity is associated with the phase of extra-SCN oscillators within and between species

    OpenAIRE

    Ramanathan, Chidambaram; Stowie, Adam; Smale, Laura; Nunez, Antonio A.

    2010-01-01

    Many features of the suprachiasmatic nucleus (SCN) are the same in diurnal and nocturnal animals, suggesting that differences in phase preference are determined by mechanisms downstream from the SCN. Here, we examined this hypothesis by characterizing rhythmic expression of PER1 and PER2 in several extra-SCN areas in the brains of a diurnal murid rodent, Arvicanthis niloticus (grass rats). In the shell of the nucleus accumbens, dorsal striatum, piriform cortex, and CA1 of the hippocampus, bot...

  18. The suprachiasmatic nucleus: age-related decline in biological rhythms.

    Science.gov (United States)

    Nakamura, Takahiro J; Takasu, Nana N; Nakamura, Wataru

    2016-09-01

    Aging is associated with changes in sleep duration and quality, as well as increased rates of pathologic/disordered sleep. While several factors contribute to these changes, emerging research suggests that age-related changes in the mammalian central circadian clock within the suprachiasmatic nucleus (SCN) may be a key factor. Prior work from our group suggests that circadian output from the SCN declines because of aging. Furthermore, we have previously observed age-related infertility in female mice, caused by a mismatch between environmental light-dark cycles and the intrinsic, internal biological clocks. In this review, we address regulatory mechanisms underlying circadian rhythms in mammals and summarize recent literature describing the effects of aging on the circadian system.

  19. Distribution of AVP and Ca2+-dependent PKC-isozymes in the suprachiasmatic nucleus of the mouse and rabbit

    NARCIS (Netherlands)

    Zee, Eddy A. van der; Bult, Abel

    1995-01-01

    The suprachiasmatic nucleus (SCN) is the circadian pacemaker in mammals and contains a network of arginine-vasopressin-immunoreactive (AVP-ir) neurons. AVP-recipient cells contain the V1a class of receptors linked to phosphoinositol turnover and protein kinase C (PKC). The present study describes

  20. Study of SCN Neurochemistry using In Vivo Microdialysis in the Conscious Brain: Correlation with Circadian Activity Rhythms.

    Science.gov (United States)

    1992-12-29

    Hydroxyindole -acetic acid In vivo brain microdialysis was used to characterize the daily pattern of 5 -hy- Suprachiasmatic nucleus droxyindole-acetic acid...principal serotonin metabolite, 5 - hydroxyindole - SCN is comprised of cells that exhibit a self-generating acetic acid ( 5 -HIAA), in the SCN. The...significance of pacemaker activity [3, 4] and is richly innervated by amino the 5 -HIAA rhythm is not certain, however, because acid, peptidergic and

  1. Intracellular calcium spikes in rat suprachiasmatic nucleus neurons induced by BAPTA-based calcium dyes.

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    Jin Hee Hong

    Full Text Available BACKGROUND: Circadian rhythms in spontaneous action potential (AP firing frequencies and in cytosolic free calcium concentrations have been reported for mammalian circadian pacemaker neurons located within the hypothalamic suprachiasmatic nucleus (SCN. Also reported is the existence of "Ca(2+ spikes" (i.e., [Ca(2+](c transients having a bandwidth of 10 approximately 100 seconds in SCN neurons, but it is unclear if these SCN Ca(2+ spikes are related to the slow circadian rhythms. METHODOLOGY/PRINCIPAL FINDINGS: We addressed this issue based on a Ca(2+ indicator dye (fluo-4 and a protein Ca(2+ sensor (yellow cameleon. Using fluo-4 AM dye, we found spontaneous Ca(2+ spikes in 18% of rat SCN cells in acute brain slices, but the Ca(2+ spiking frequencies showed no day/night variation. We repeated the same experiments with rat (and mouse SCN slice cultures that expressed yellow cameleon genes for a number of different circadian phases and, surprisingly, spontaneous Ca(2+ spike was barely observed (<3%. When fluo-4 AM or BAPTA-AM was loaded in addition to the cameleon-expressing SCN cultures, however, the number of cells exhibiting Ca(2+ spikes was increased to 13 approximately 14%. CONCLUSIONS/SIGNIFICANCE: Despite our extensive set of experiments, no evidence of a circadian rhythm was found in the spontaneous Ca(2+ spiking activity of SCN. Furthermore, our study strongly suggests that the spontaneous Ca(2+ spiking activity is caused by the Ca(2+ chelating effect of the BAPTA-based fluo-4 dye. Therefore, this induced activity seems irrelevant to the intrinsic circadian rhythm of [Ca(2+](c in SCN neurons. The problems with BAPTA based dyes are widely known and our study provides a clear case for concern, in particular, for SCN Ca(2+ spikes. On the other hand, our study neither invalidates the use of these dyes as a whole, nor undermines the potential role of SCN Ca(2+ spikes in the function of SCN.

  2. Calcium Circadian Rhythmicity in the Suprachiasmatic Nucleus: Cell Autonomy and Network Modulation.

    Science.gov (United States)

    Noguchi, Takako; Leise, Tanya L; Kingsbury, Nathaniel J; Diemer, Tanja; Wang, Lexie L; Henson, Michael A; Welsh, David K

    2017-01-01

    Circadian rhythms of mammalian physiology and behavior are coordinated by the suprachiasmatic nucleus (SCN) in the hypothalamus. Within SCN neurons, various aspects of cell physiology exhibit circadian oscillations, including circadian clock gene expression, levels of intracellular Ca 2+ ([Ca 2+ ] i ), and neuronal firing rate. [Ca 2+ ] i oscillates in SCN neurons even in the absence of neuronal firing. To determine the causal relationship between circadian clock gene expression and [Ca 2+ ] i rhythms in the SCN, as well as the SCN neuronal network dependence of [Ca 2+ ] i rhythms, we introduced GCaMP3, a genetically encoded fluorescent Ca 2+ indicator, into SCN neurons from PER2::LUC knock-in reporter mice. Then, PER2 and [Ca 2+ ] i were imaged in SCN dispersed and organotypic slice cultures. In dispersed cells, PER2 and [Ca 2+ ] i both exhibited cell autonomous circadian rhythms, but [Ca 2+ ] i rhythms were typically weaker than PER2 rhythms. This result matches the predictions of a detailed mathematical model in which clock gene rhythms drive [Ca 2+ ] i rhythms. As predicted by the model, PER2 and [Ca 2+ ] i rhythms were both stronger in SCN slices than in dispersed cells and were weakened by blocking neuronal firing in slices but not in dispersed cells. The phase relationship between [Ca 2+ ] i and PER2 rhythms was more variable in cells within slices than in dispersed cells. Both PER2 and [Ca 2+ ] i rhythms were abolished in SCN cells deficient in the essential clock gene Bmal1 . These results suggest that the circadian rhythm of [Ca 2+ ] i in SCN neurons is cell autonomous and dependent on clock gene rhythms, but reinforced and modulated by a synchronized SCN neuronal network.

  3. Glutamatergic induction of CREB phosphorylation and Fos expression in primary cultures of the suprachiasmatic hypothalamus in vitro is mediated by co-ordinate activity of NMDA and non-NMDA receptors.

    Science.gov (United States)

    Schurov, I L; McNulty, S; Best, J D; Sloper, P J; Hastings, M H

    1999-01-01

    Exposure of Syrian hamsters to light 1 h after lights-off rapidly (10 min) induced nuclear immunoreactivity (-ir) to the phospho-Ser133 form of the Ca2+/cAMP response element (CRE) binding protein (pCREB) in the retinorecipient zone of the suprachiasmatic nuclei (SCN). Light also induced nuclear Fos-ir in the same region of the SCN after 1 h. The glutamatergic N-methyl-D-aspartate (NMDA) receptor blocker MK801 attenuated the photic induction of both factors. To investigate glutamatergic regulation of pCREB and Fos further, tissue blocks and primary cultures of neonatal hamster SCN were examined by Western blotting and immunocytochemistry in vitro. On Western blots of SCN tissue, the pCREB-ir signal at 45 kDa was enhanced by glutamate or a mixture of glutamatergic agonists (NMDA, amino-methyl proprionic acid (AMPA), and Kainate (KA)), whereas total CREB did not change. Glutamate or the mixture of agonists also induced a 56 kDa band identified as Fos protein in SCN tissue. In dissociated cultures of SCN, glutamate caused a rapid (15 min) induction of nuclear pCREB-ir and Fos-ir (after 60 min) exclusively in neurones, both GABA-ir and others. Treatment with NMDA alone had no effect on pCREB-ir. AMPA alone caused a slight increase in pCREB-ir. However, kainate alone or in combination with NMDA and AMPA induced nuclear pCREB-ir equal to that induced by glutamate. The effects of glutamate on pCREB-ir and Fos-ir were blocked by antagonists of both NMDA (MK801) and AMPA/KA (NBQX) receptors. In the absence of extracellular Mg2+, MK801 blocked glutamatergic induction of Fos-ir. However, the AMPA/KA receptor antagonist was no longer effective at blocking glutamatergic induction of either Fos-ir or pCREB-ir, consistent with the model that glutamate regulates gene expression in the SCN by a co-ordinate action through both NMDA and AMPA/KA receptors. Glutamatergic induction of nuclear pCREB-ir in GABA-ir neurones was blocked by KN-62 an inhibitor of Ca2+/Calmodulin (Ca

  4. Flank-marking behavior and the neural distribution of vasopressin innervation in golden hamsters with suprachiasmatic lesions.

    Science.gov (United States)

    Delville, Y; De Vries, G J; Schwartz, W J; Ferris, C F

    1998-12-01

    In golden hamsters, microinjections of arginine-vasopressin (AVP) within the anterior hypothalamus trigger a stereotyped scent-marking behavior, flank marking. Our experiment was carried out to test the contribution of AVP neurons within the suprachiasmatic nucleus (SCN) in the control of this behavior. Our results suggest that the SCN does not contribute to flank-marking behavior. Whereas SCN lesions disrupted circadian rhythms of wheel running, the same lesions did not disrupt flank-marking. The results also suggest that neurons located outside the SCN contribute significantly to the vasopressinergic innervation of the brain and the expression of AVP-dependent behaviors, such as flank-marking behavior. Although AVP-immunoreactive fibers were severely (ca. 95%) depleted from several forebrain areas in SCN-lesioned hamsters, the effect of the lesions was much more limited within the forebrain areas involved in flank-marking behavior as well as within the midbrain and hindbrain.

  5. Cholecystokinin (CCK)-expressing neurons in the suprachiasmatic nucleus: innervation, light responsiveness and entrainment in CCK-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hundahl, Christian; Fahrenkrug, Jan

    2010-01-01

    of the mammalian SCN, but its role in circadian timing is not known. In the present study, CCK was demonstrated in a distinct population of neurons located in the shell region of the SCN and in a few cells in the core region. The CCK neurons did not express vasopressin or vasoactive intestinal peptide. However......The suprachiasmatic nucleus (SCN) is the principal pacemaker driving circadian rhythms of physiology and behaviour. Neurons within the SCN express both classical and neuropeptide transmitters which regulate clock functions. Cholecyctokinin (CCK) is a potent neurotransmitter expressed in neurons......, CCK-containing processes make synaptic contacts with both groups of neurons and some CCK cell bodies were innervated by VIPergic neurons. The CCK neurons received no direct input from the three major pathways to the SCN, and the CCK neurons were not light-responsive as evaluated by induction of c...

  6. Development of SCN connectivity and the circadian control of arousal: a diminishing role for humoral factors?

    Directory of Open Access Journals (Sweden)

    Andrew J Gall

    Full Text Available The suprachiasmatic nucleus (SCN is part of a wake-promoting circuit comprising the dorsomedial hypothalamus (DMH and locus coeruleus (LC. Although widely considered a "master clock," the SCN of adult rats is also sensitive to feedback regarding an animal's behavioral state. Interestingly, in rats at postnatal day (P2, repeated arousing stimulation does not increase neural activation in the SCN, despite doing so in the LC and DMH. Here we show that, by P8, the SCN is activated by arousing stimulation and that selective destruction of LC terminals with DSP-4 blocks this activational effect. We next show that bidirectional projections among the SCN, DMH, and LC are nearly absent at P2 but present at P8. Despite the relative lack of SCN connectivity with downstream structures at P2, day-night differences in sleep-wake activity are observed, suggesting that the SCN modulates behavior at this age via humoral factors. To test this hypothesis, we lesioned the SCN at P1 and recorded sleep-wake behavior at P2: Day-night differences in sleep and wake were eliminated. We next performed precollicular transections at P2 and P8 that isolate the SCN and DMH from the brainstem and found that day-night differences in sleep-wake behavior were retained at P2 but eliminated at P8. Finally, the SCN or DMH was lesioned at P8: When recorded at P21, rats with either lesion exhibited similarly fragmented wake bouts and no evidence of circadian modulation of wakefulness. These results suggest an age-related decline in the SCN's humoral influence on sleep-wake behavior that coincides with the emergence of bidirectional connectivity among the SCN, DMH, and LC.

  7. BK channels regulate spontaneous action potential rhythmicity in the suprachiasmatic nucleus.

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    Jack Kent

    Full Text Available BACKGROUND: Circadian ( approximately 24 hr rhythms are generated by the central pacemaker localized to the suprachiasmatic nucleus (SCN of the hypothalamus. Although the basis for intrinsic rhythmicity is generally understood to rely on transcription factors encoded by "clock genes", less is known about the daily regulation of SCN neuronal activity patterns that communicate a circadian time signal to downstream behaviors and physiological systems. Action potentials in the SCN are necessary for the circadian timing of behavior, and individual SCN neurons modulate their spontaneous firing rate (SFR over the daily cycle, suggesting that the circadian patterning of neuronal activity is necessary for normal behavioral rhythm expression. The BK K(+ channel plays an important role in suppressing spontaneous firing at night in SCN neurons. Deletion of the Kcnma1 gene, encoding the BK channel, causes degradation of circadian behavioral and physiological rhythms. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis that loss of robust behavioral rhythmicity in Kcnma1(-/- mice is due to the disruption of SFR rhythms in the SCN, we used multi-electrode arrays to record extracellular action potentials from acute wild-type (WT and Kcnma1(-/- slices. Patterns of activity in the SCN were tracked simultaneously for up to 3 days, and the phase, period, and synchronization of SFR rhythms were examined. Loss of BK channels increased arrhythmicity but also altered the amplitude and period of rhythmic activity. Unexpectedly, Kcnma1(-/- SCNs showed increased variability in the timing of the daily SFR peak. CONCLUSIONS/SIGNIFICANCE: These results suggest that BK channels regulate multiple aspects of the circadian patterning of neuronal activity in the SCN. In addition, these data illustrate the characteristics of a disrupted SCN rhythm downstream of clock gene-mediated timekeeping and its relationship to behavioral rhythms.

  8. Topological specificity and hierarchical network of the circadian calcium rhythm in the suprachiasmatic nucleus.

    Science.gov (United States)

    Enoki, Ryosuke; Kuroda, Shigeru; Ono, Daisuke; Hasan, Mazahir T; Ueda, Tetsuo; Honma, Sato; Honma, Ken-ichi

    2012-12-26

    The circadian pacemaker in the hypothalamic suprachiasmatic nucleus (SCN) is a hierarchical multioscillator system in which neuronal networks play crucial roles in expressing coherent rhythms in physiology and behavior. However, our understanding of the neuronal network is still incomplete. Intracellular calcium mediates the input signals, such as phase-resetting stimuli, to the core molecular loop involving clock genes for circadian rhythm generation and the output signals from the loop to various cellular functions, including changes in neurotransmitter release. Using a unique large-scale calcium imaging method with genetically encoded calcium sensors, we visualized intracellular calcium from the entire surface of SCN slice in culture including the regions where autonomous clock gene expression was undetectable. We found circadian calcium rhythms at a single-cell level in the SCN, which were topologically specific with a larger amplitude and more delayed phase in the ventral region than the dorsal. The robustness of the rhythm was reduced but persisted even after blocking the neuronal firing with tetrodotoxin (TTX). Notably, TTX dissociated the circadian calcium rhythms between the dorsal and ventral SCN. In contrast, a blocker of gap junctions, carbenoxolone, had only a minor effect on the calcium rhythms at both the single-cell and network levels. These results reveal the topological specificity of the circadian calcium rhythm in the SCN and the presence of coupled regional pacemakers in the dorsal and ventral regions. Neuronal firings are not necessary for the persistence of the calcium rhythms but indispensable for the hierarchical organization of rhythmicity in the SCN.

  9. SCN2A encephalopathy

    Science.gov (United States)

    Howell, Katherine B.; McMahon, Jacinta M.; Carvill, Gemma L.; Tambunan, Dimira; Mackay, Mark T.; Rodriguez-Casero, Victoria; Webster, Richard; Clark, Damian; Freeman, Jeremy L.; Calvert, Sophie; Olson, Heather E.; Mandelstam, Simone; Poduri, Annapurna; Mefford, Heather C.; Harvey, A. Simon

    2015-01-01

    Objective: De novo SCN2A mutations have recently been associated with severe infantile-onset epilepsies. Herein, we define the phenotypic spectrum of SCN2A encephalopathy. Methods: Twelve patients with an SCN2A epileptic encephalopathy underwent electroclinical phenotyping. Results: Patients were aged 0.7 to 22 years; 3 were deceased. Seizures commenced on day 1–4 in 8, week 2–6 in 2, and after 1 year in 2. Characteristic features included clusters of brief focal seizures with multiple hourly (9 patients), multiple daily (2), or multiple weekly (1) seizures, peaking at maximal frequency within 3 months of onset. Multifocal interictal epileptiform discharges were seen in all. Three of 12 patients had infantile spasms. The epileptic syndrome at presentation was epilepsy of infancy with migrating focal seizures (EIMFS) in 7 and Ohtahara syndrome in 2. Nine patients had improved seizure control with sodium channel blockers including supratherapeutic or high therapeutic phenytoin levels in 5. Eight had severe to profound developmental impairment. Other features included movement disorders (10), axial hypotonia (11) with intermittent or persistent appendicular spasticity, early handedness, and severe gastrointestinal symptoms. Mutations arose de novo in 11 patients; paternal DNA was unavailable in one. Conclusions: Review of our 12 and 34 other reported cases of SCN2A encephalopathy suggests 3 phenotypes: neonatal-infantile–onset groups with severe and intermediate outcomes, and a childhood-onset group. Here, we show that SCN2A is the second most common cause of EIMFS and, importantly, does not always have a poor developmental outcome. Sodium channel blockers, particularly phenytoin, may improve seizure control. PMID:26291284

  10. Circadian waves of cytosolic calcium concentration and long-range network connections in rat suprachiasmatic nucleus.

    Science.gov (United States)

    Hong, Jin Hee; Jeong, Byeongha; Min, Cheol Hong; Lee, Kyoung J

    2012-05-01

    The suprachiasmatic nucleus (SCN) is the master clock in mammals governing the daily physiological and behavioral rhythms. It is composed of thousands of clock cells with their own intrinsic periods varying over a wide range (20-28 h). Despite this heterogeneity, an intact SCN maintains a coherent 24 h periodic rhythm through some cell-to-cell coupling mechanisms. This study examined how the clock cells are connected to each other and how their phases are organized in space by monitoring the cytosolic free calcium ion concentration ([Ca(2+)](c)) of clock cells using the calcium-binding fluorescent protein, cameleon. Extensive analysis of 18 different organotypic slice cultures of the SCN showed that the SCN calcium dynamics is coordinated by phase-synchronizing networks of long-range neurites as well as by diffusively propagating phase waves. The networks appear quite extensive and far-reaching, and the clock cells connected by them exhibit heterogeneous responses in their amplitudes and periods of oscillation to tetrodotoxin treatments. Taken together, our study suggests that the network of long-range cellular connectivity has an important role for the SCN in achieving its phase and period coherence. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  11. The Role of the Suprachiasmatic Nucleus in Cardiac Autonomic Control during Sleep.

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    S D Joustra

    Full Text Available The suprachiasmatic nucleus (SCN may play an important role in central autonomic control, since its projections connect to (parasympathetic relay stations in the brainstem and spinal cord. The cardiac autonomic modifications during nighttime may therefore not only result from direct effects of the sleep-related changes in the central autonomic network, but also from endogenous circadian factors as directed by the SCN. To explore the influence of the SCN on autonomic fluctuations during nighttime, we studied heart rate and its variability (HRV in a clinical model of SCN damage.Fifteen patients in follow-up after surgical treatment for nonfunctioning pituitary macroadenoma (NFMA compressing the optic chiasm (8 females, 26-65 years old and fifteen age-matched healthy controls (5 females, 30-63 years underwent overnight ambulatory polysomnography. Eleven patients had hypopituitarism and received adequate replacement therapy. HRV was calculated for each 30-second epoch and corrected for sleep stage, arousals, and gender using mixed effect regression models.Compared to controls, patients spent more time awake after sleep onset and in NREM1-sleep, and less in REM-sleep. Heart rate, low (LF and high frequency (HF power components and the LF/HF ratio across sleep stages were not significantly different between groups.These findings suggest that the SCN does not play a dominant role in cardiac autonomic control during sleep.

  12. Genetic Disruption of Circadian Rhythms in the Suprachiasmatic Nucleus Causes Helplessness, Behavioral Despair, and Anxiety-like Behavior in Mice.

    Science.gov (United States)

    Landgraf, Dominic; Long, Jaimie E; Proulx, Christophe D; Barandas, Rita; Malinow, Roberto; Welsh, David K

    2016-12-01

    Major depressive disorder is associated with disturbed circadian rhythms. To investigate the causal relationship between mood disorders and circadian clock disruption, previous studies in animal models have employed light/dark manipulations, global mutations of clock genes, or brain area lesions. However, light can impact mood by noncircadian mechanisms; clock genes have pleiotropic, clock-independent functions; and brain lesions not only disrupt cellular circadian rhythms but also destroy cells and eliminate important neuronal connections, including light reception pathways. Thus, a definitive causal role for functioning circadian clocks in mood regulation has not been established. We stereotactically injected viral vectors encoding short hairpin RNA to knock down expression of the essential clock gene Bmal1 into the brain's master circadian pacemaker, the suprachiasmatic nucleus (SCN). In these SCN-specific Bmal1-knockdown (SCN-Bmal1-KD) mice, circadian rhythms were greatly attenuated in the SCN, while the mice were maintained in a standard light/dark cycle, SCN neurons remained intact, and neuronal connections were undisturbed, including photic inputs. In the learned helplessness paradigm, the SCN-Bmal1-KD mice were slower to escape, even before exposure to inescapable stress. They also spent more time immobile in the tail suspension test and less time in the lighted section of a light/dark box. The SCN-Bmal1-KD mice also showed greater weight gain, an abnormal circadian pattern of corticosterone, and an attenuated increase of corticosterone in response to stress. Disrupting SCN circadian rhythms is sufficient to cause helplessness, behavioral despair, and anxiety-like behavior in mice, establishing SCN-Bmal1-KD mice as a new animal model of depression. Copyright © 2016 Society of Biological Psychiatry. All rights reserved.

  13. Cholecystokinin (CCK)-expressing neurons in the suprachiasmatic nucleus: innervation, light responsiveness and entrainment in CCK-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hundahl, Christian; Fahrenkrug, Jan

    2010-01-01

    The suprachiasmatic nucleus (SCN) is the principal pacemaker driving circadian rhythms of physiology and behaviour. Neurons within the SCN express both classical and neuropeptide transmitters which regulate clock functions. Cholecyctokinin (CCK) is a potent neurotransmitter expressed in neurons......, CCK-containing processes make synaptic contacts with both groups of neurons and some CCK cell bodies were innervated by VIPergic neurons. The CCK neurons received no direct input from the three major pathways to the SCN, and the CCK neurons were not light-responsive as evaluated by induction of c......FOS, and did not express the core clock protein PER1. Accordingly, CCK-deficient mice showed normal entrainment and had similar t, light-induced phase shift and negative masking behaviour as wild-type animals. In conclusion, CCK signalling seems not to be involved directly in light-induced resetting...

  14. Neonatal exposure to monosodium glutamate induces morphological alterations in suprachiasmatic nucleus of adult rat.

    Science.gov (United States)

    Rojas-Castañeda, Julio César; Vigueras-Villaseñor, Rosa María; Chávez-Saldaña, Margarita; Rojas, Patricia; Gutiérrez-Pérez, Oscar; Rojas, Carolina; Arteaga-Silva, Marcela

    2016-02-01

    Neonatal exposure to monosodium glutamate (MSG) induces circadian disorders in several physiological and behavioural processes regulated by the suprachiasmatic nucleus (SCN). The objective of this study was to evaluate the effects of neonatal exposure to MSG on locomotor activity, and on morphology, cellular density and expression of proteins, as evaluated by optical density (OD), of vasopressin (VP)-, vasoactive intestinal polypeptide (VIP)- and glial fibrillary acidic protein (GFAP)-immunoreactive cells in the SCN. Male Wistar rats were used: the MSG group was subcutaneously treated from 3 to 10 days of age with 3.5 mg/g/day. Locomotor activity was evaluated at 90 days of age using 'open-field' test, and the brains were processed for immunohistochemical studies. MSG exposure induced a significant decrease in locomotor activity. VP- and VIP-immunoreactive neuronal densities showed a significant decrease, while the somatic OD showed an increase. Major axes and somatic area were significantly increased in VIP neurons. The cellular and optical densities of GFAP-immunoreactive sections of SCN were significantly increased. These results demonstrated that newborn exposure to MSG induced morphological alterations in SCN cells, an alteration that could be the basis for behavioural disorders observed in the animals. © 2016 The Authors. International Journal of Experimental Pathology © 2016 International Journal of Experimental Pathology.

  15. Neural Damage in Experimental Trypanosoma brucei gambiense Infection: The Suprachiasmatic Nucleus

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    Chiara Tesoriero

    2018-02-01

    Full Text Available Trypanosoma brucei (T. b. gambiense is the parasite subspecies responsible for most reported cases of human African trypanosomiasis (HAT or sleeping sickness. This severe infection leads to characteristic disruption of the sleep-wake cycle, recalling attention on the circadian timing system. Most animal models of the disease have been hitherto based on infection of laboratory rodents with the T. b. brucei subspecies, which is not infectious to humans. In these animal models, functional, rather than structural, alterations of the master circadian pacemaker, the hypothalamic suprachiasmatic nucleus (SCN, have been reported. Information on the SCN after infection with the human pathogenic T. b. gambiense is instead lacking. The present study was aimed at the examination of the SCN after T. b. gambiense infection of a susceptible rodent, the multimammate mouse, Mastomys natalensis, compared with T. b. brucei infection of the same host species. The animals were examined at 4 and 8 weeks post-infection, when parasites (T. b. gambiense or T. b. brucei were detected in the brain parenchyma, indicating that the disease was in the encephalitic stage. Neuron and astrocyte changes were examined with Nissl staining, immunophenotyping and quantitative analyses. Interestingly, significant neuronal loss (about 30% reduction was documented in the SCN during the progression of T. b. gambiense infection. No significant neuronal density changes were found in the SCN of T. b. brucei-infected animals. Neuronal cell counts in the hippocampal dentate gyrus of T. b. gambiense-infected M. natalensis did not point out significant changes, indicating that no widespread neuron loss had occurred in the brain. Marked activation of astrocytes was detected in the SCN after both T. b. gambiense and T. b. brucei infections. Altogether the findings reveal that neurons of the biological clock are highly susceptible to the infection caused by human pathogenic African trypanosomes

  16. Effects of damage to the suprachiasmatic area of the anterior hypothalamus on the daily melatonin and cortisol rhythms in the rhesus monkey

    International Nuclear Information System (INIS)

    Reppert, S.M.; Perlow, M.J.; Ungerleider, L.G.; Mishkin, M.; Tamarkin, L.; Orloff, D.G.; Hoffman, H.J.; Klein, D.C.

    1981-01-01

    The effects of lesions of the suprachiasmatic nucleus (SCN) on the circadian rhythms in melatonin and cortisol were examined in the rhesus monkey. The concentrations of the two hormones were monitored in cerebrospinal fluid (CSF) withdrawn from two sham-operated animals, two animals with complete bilateral SCN lesions, and two animals with partial SCN damage at 4 and 8 months after surgery. In the sham-operated animals, as in the intact animal, the daily melatonin rhythm was entrained to the daily light-dark cycle, was suppressed in constant light, and persisted in constant darkness. In contrast, neither animal with complete SCN ablation exhibited a daily pattern of CSF melatonin in diurnal lighting at 4 months after surgery nor were their melatonin levels at constant low values. Furthermore, CSF melatonin concentrations were not suppressed in either animal by constant light. Surprisingly, at 8 months after surgery, spectral analysis revealed a 24-hr component to the melatonin patterns for each animal with complete SCN ablation in both diurnal lighting and constant darkness. The two animals with partial SCN damage exhibited a daily melatonin rhythm in diurnal lighting, but constant light did not suppress CSF melatonin concentrations consistently. Daily rhythms persisted in both for a 6 1/2-d period of study in constant darkness. In contrast to the alterations in the melatonin rhythm after SCN damage, there was no apparent effect of either partial or complete SCN ablation on the daily CSF cortisol rhythm. These data indicate that, in the rhesus monkey, the SCN is important for the generation, photic entrainment, and photic suppression of the melatonin rhythm. However, circadian oscillators located outside of the SCN region may control the normal daily cortisol rhythm and perhaps the melatonin rhythm in the absence of the SCN

  17. Effects of damage to the suprachiasmatic area of the anterior hypothalamus on the daily melatonin and cortisol rhythms in the rhesus monkey

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    Reppert, S.M.; Perlow, M.J.; Ungerleider, L.G.; Mishkin, M.; Tamarkin, L.; Orloff, D.G.; Hoffman, H.J.; Klein, D.C.

    1981-12-01

    The effects of lesions of the suprachiasmatic nucleus (SCN) on the circadian rhythms in melatonin and cortisol were examined in the rhesus monkey. The concentrations of the two hormones were monitored in cerebrospinal fluid (CSF) withdrawn from two sham-operated animals, two animals with complete bilateral SCN lesions, and two animals with partial SCN damage at 4 and 8 months after surgery. In the sham-operated animals, as in the intact animal, the daily melatonin rhythm was entrained to the daily light-dark cycle, was suppressed in constant light, and persisted in constant darkness. In contrast, neither animal with complete SCN ablation exhibited a daily pattern of CSF melatonin in diurnal lighting at 4 months after surgery nor were their melatonin levels at constant low values. Furthermore, CSF melatonin concentrations were not suppressed in either animal by constant light. Surprisingly, at 8 months after surgery, spectral analysis revealed a 24-hr component to the melatonin patterns for each animal with complete SCN ablation in both diurnal lighting and constant darkness. The two animals with partial SCN damage exhibited a daily melatonin rhythm in diurnal lighting, but constant light did not suppress CSF melatonin concentrations consistently. Daily rhythms persisted in both for a 6 1/2-d period of study in constant darkness. In contrast to the alterations in the melatonin rhythm after SCN damage, there was no apparent effect of either partial or complete SCN ablation on the daily CSF cortisol rhythm. These data indicate that, in the rhesus monkey, the SCN is important for the generation, photic entrainment, and photic suppression of the melatonin rhythm. However, circadian oscillators located outside of the SCN region may control the normal daily cortisol rhythm and perhaps the melatonin rhythm in the absence of the SCN.

  18. Effect of network architecture on synchronization and entrainment properties of the circadian oscillations in the suprachiasmatic nucleus.

    Science.gov (United States)

    Hafner, Marc; Koeppl, Heinz; Gonze, Didier

    2012-01-01

    In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus constitutes the central circadian pacemaker. The SCN receives light signals from the retina and controls peripheral circadian clocks (located in the cortex, the pineal gland, the liver, the kidney, the heart, etc.). This hierarchical organization of the circadian system ensures the proper timing of physiological processes. In each SCN neuron, interconnected transcriptional and translational feedback loops enable the circadian expression of the clock genes. Although all the neurons have the same genotype, the oscillations of individual cells are highly heterogeneous in dispersed cell culture: many cells present damped oscillations and the period of the oscillations varies from cell to cell. In addition, the neurotransmitters that ensure the intercellular coupling, and thereby the synchronization of the cellular rhythms, differ between the two main regions of the SCN. In this work, a mathematical model that accounts for this heterogeneous organization of the SCN is presented and used to study the implication of the SCN network topology on synchronization and entrainment properties. The results show that oscillations with larger amplitude can be obtained with scale-free networks, in contrast to random and local connections. Networks with the small-world property such as the scale-free networks used in this work can adapt faster to a delay or advance in the light/dark cycle (jet lag). Interestingly a certain level of cellular heterogeneity is not detrimental to synchronization performances, but on the contrary helps resynchronization after jet lag. When coupling two networks with different topologies that mimic the two regions of the SCN, efficient filtering of pulse-like perturbations in the entrainment pattern is observed. These results suggest that the complex and heterogeneous architecture of the SCN decreases the sensitivity of the network to short entrainment perturbations while, at the same time

  19. Melatonin administered during the fetal stage affects circadian clock in the suprachiasmatic nucleus but not in the liver

    Czech Academy of Sciences Publication Activity Database

    Houdek, Pavel; Polidarová, Lenka; Nováková, Marta; Matějů, Kristýna; Kubík, Štěpán; Sumová, Alena

    2015-01-01

    Roč. 75, č. 2 (2015), s. 131-144 ISSN 1932-8451 R&D Projects: GA ČR(CZ) GAP303/12/1108 Institutional support: RVO:67985823 Keywords : ontogenesis * circadian system * suprachiasmatic nuclei * clock gene * melatonin Subject RIV: FH - Neurology Impact factor: 2.529, year: 2015

  20. Expression profiles and functional annotation analysis of mRNAs in suprachiasmatic nucleus of Clock mutant mice.

    Science.gov (United States)

    Wang, Yanli; Lv, Ke; Zhao, Mei; Liang, Fengji; Chen, Hailong; Ji, Guohua; Wang, Tingmei; Zhang, Yongliang; Cao, Hongqing; Li, Yinghui; Qu, Lina

    2018-03-20

    The core circadian clock gene, Clock, is a positive component of the transcription/translation feedback loop in the master pacemaker suprachiasmatic nucleus (SCN) in mammals. The robust daytime peak of some clock genes in the wild-type SCN is absent in Clock mutant mice. However, very little is known about the impact of Clock mutation on the expression of other functional genes in SCN. Here, we performed cDNA microarray and found 799 differentially expressed genes (DEGs) at zeitgeber time 2 (ZT2) and 1289 DEGs at ZT14 in SCN of Clock △19/△19 mutant mice. KEGG pathway analysis showed that the changed mRNAs were highly associated with hedgehog signaling pathway, retinol metabolism, allograft rejection, drug metabolism, hematopoietic cell lineage and neuroactive ligand-receptor interaction. The top 14 and 71 hub genes were identified from the protein-protein interaction (PPI) network at ZT2 and ZT14, respectively. The sub-networks revealed hub genes were involved in olfactory transduction and neuroactive ligand-receptor interaction pathways. These results demonstrate the Clock △19/△19 mutation alters the expression of various genes involved in a wide spectrum of biological function in mouse SCN, which are helpful for better understanding the function of Clock and potential regulatory mechanisms. Copyright © 2017. Published by Elsevier B.V.

  1. The Circadian Clock Gene Period1 Connects the Molecular Clock to Neural Activity in the Suprachiasmatic Nucleus.

    Science.gov (United States)

    Kudo, Takashi; Block, Gene D; Colwell, Christopher S

    2015-01-01

    The neural activity patterns of suprachiasmatic nucleus (SCN) neurons are dynamically regulated throughout the circadian cycle with highest levels of spontaneous action potentials during the day. These rhythms in electrical activity are critical for the function of the circadian timing system and yet the mechanisms by which the molecular clockwork drives changes in the membrane are not well understood. In this study, we sought to examine how the clock gene Period1 (Per1) regulates the electrical activity in the mouse SCN by transiently and selectively decreasing levels of PER1 through use of an antisense oligodeoxynucleotide. We found that this treatment effectively reduced SCN neural activity. Direct current injection to restore the normal membrane potential partially, but not completely, returned firing rate to normal levels. The antisense treatment also reduced baseline [Ca(2+)]i levels as measured by Fura2 imaging technique. Whole cell patch clamp recording techniques were used to examine which specific potassium currents were altered by the treatment. These recordings revealed that the large conductance [Ca(2+)]i-activated potassium currents were reduced in antisense-treated neurons and that blocking this current mimicked the effects of the anti-sense on SCN firing rate. These results indicate that the circadian clock gene Per1 alters firing rate in SCN neurons and raise the possibility that the large conductance [Ca(2+)]i-activated channel is one of the targets. © The Author(s) 2015.

  2. Effect of Mefloquine, a Gap Junction Blocker, on Circadian Period2 Gene Oscillation in the Mouse Suprachiasmatic Nucleus

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    Jinmi Koo

    2015-09-01

    Full Text Available BackgroundIn mammals, the master circadian pacemaker is localized in an area of the ventral hypothalamus known as the suprachiasmatic nucleus (SCN. Previous studies have shown that pacemaker neurons in the SCN are highly coupled to one another, and this coupling is crucial for intrinsic self-sustainability of the SCN central clock, which is distinguished from peripheral oscillators. One plausible mechanism underlying the intercellular communication may involve direct electrical connections mediated by gap junctions.MethodsWe examined the effect of mefloquine, a neuronal gap junction blocker, on circadian Period 2 (Per2 gene oscillation in SCN slice cultures prepared from Per2::luciferase (PER2::LUC knock-in mice using a real-time bioluminescence measurement system.ResultsAdministration of mefloquine causes instability in the pulse period and a slight reduction of amplitude in cyclic PER2::LUC expression. Blockade of gap junctions uncouples PER2::LUC-expressing cells, in terms of phase transition, which weakens synchrony among individual cellular rhythms.ConclusionThese findings suggest that neuronal gap junctions play an important role in synchronizing the central pacemaker neurons and contribute to the distinct self-sustainability of the SCN master clock.

  3. Effects of irradiation on the circadian rhythm in the release of peptides in the suprachiasmatic nucleus culture

    International Nuclear Information System (INIS)

    Saito, Kimihiko

    2000-01-01

    Mammalian circadian rhythms are regulated by the circadian clock which is located in the hypothalamic suprachiasmatic nucleus (SCN). In the present study, we examined the effect of irradiation on the circadian rhythm in the release of arginine-vasopressin (AVP) and vasoactive intestinal polypeptide (VIP) in slice cultures of the rat SCN. The effect of irradiation on the glial cell proliferation in the SCN culture was also examined by the immunohistochemical method. In SCN cultures which received irradiation, circadian rhythms in the release of AVP and VIP were detected, as observed in the SCN culture not irradiated. However, the AVP and VIP rhythms showed various phase angle differences in some cultures irradiated, which suggested that irradiation caused a looseness of coupling between AVP and VIP oscillators. On the other hand, the number of glial cells was decreased by irradiation. These results suggested that the dissociation of the two peptide rhythms after irradiation might be due to the inhibition of glial cell proliferation. Furthermore, the radiation changed the amplitude of AVP and VIP rhythms, suggesting that couplings within both AVP and VIP oscillators were influenced by irradiation. (author)

  4. Bmal1 is an essential regulator for circadian cytosolic Ca²⁺ rhythms in suprachiasmatic nucleus neurons.

    Science.gov (United States)

    Ikeda, Masayuki; Ikeda, Masaaki

    2014-09-03

    The hypothalamic suprachiasmatic nucleus (SCN) plays a pivotal role in the mammalian circadian clock system. Bmal1 is a clock gene that drives transcriptional-translational feedback loops (TTFLs) for itself and other genes, and is expressed in nearly all SCN neurons. Despite strong evidence that Bmal1-null mutant mice display arrhythmic behavior under constant darkness, the function of Bmal1 in neuronal activity is unknown. Recently, periodic changes in the levels of intracellular signaling messengers, such as cytosolic Ca(2+) and cAMP, were suggested to regulate TTFLs. However, the opposite aspect of how clock gene TTFLs regulate cytosolic signaling remains unclear. To investigate intracellular Ca(2+) dynamics under Bmal1 perturbations, we cotransfected some SCN neurons with yellow cameleon together with wild-type or dominant-negative Bmal1 using a gene-gun applied for mouse organotypic cultures. Immunofluorescence staining for a tag protein linked to BMAL1 showed nuclear expression of wild-type BMAL1 and its degradation within 1 week after transfection in SCN neurons. However, dominant-negative BMAL1 did not translocate into the nucleus and the cytosolic signals persisted beyond 1 week. Consistently, circadian Ca(2+) rhythms in SCN neurons were inhibited for longer periods by dominant-negative Bmal1 overexpression. Furthermore, SCN neurons transfected with a Bmal1 shRNA lengthened, whereas those overexpressing wild-type Bmal1 shortened, the periods of Ca(2+) rhythms, with a significant reduction in their amplitude. BMAL1 expression was intact in the majority of neighboring neurons in organotypic cultures. Therefore, we conclude that proper intrinsic Bmal1 expression, but not passive signaling via cell-to-cell interactions, is the determinant of circadian Ca(2+) rhythms in SCN neurons. Copyright © 2014 the authors 0270-6474/14/3412029-10$15.00/0.

  5. Control of Circadian Behavior by Transplanted Suprachiasmatic Nuclei.

    Science.gov (United States)

    1994-09-02

    Ihara NL (in press) The tau mutation destabilizes the circadian system of golden hamste,’s Fifth Sapporo Symposium on Biological Rhythms Hokkaido...Shimomura K and Ihara NL (in press) The tau mutation destabilizes the circadian system of golden hamsters Fifth Sapporo Symposium oh Biological Rhythms...Switzerland, April 5 University of Pisa, Dipartimento di Scienze del Comportamento Animale e dell’Uomo, invited lecture: "Circadian Organization in the

  6. Retinohypothalamic Tract Synapses in the Rat Suprachiasmatic Nucleus Demonstrate Short-Term Synaptic Plasticity

    Science.gov (United States)

    Moldavan, Mykhaylo G.

    2010-01-01

    The master circadian pacemaker located in the suprachiasmatic nucleus (SCN) is entrained by light intensity–dependent signals transmitted via the retinohypothalamic tract (RHT). Short-term plasticity at glutamatergic RHT–SCN synapses was studied using stimulus frequencies that simulated the firing of light sensitive retinal ganglion cells. The evoked excitatory postsynaptic current (eEPSC) was recorded from SCN neurons located in hypothalamic brain slices. The eEPSC amplitude was stable during 0.08 Hz stimulation and exhibited frequency-dependent short-term synaptic depression (SD) during 0.5 to 100 Hz stimulus trains in 95 of 99 (96%) recorded neurons. During SD the steady-state eEPSC amplitude decreased, whereas the cumulative charge transfer increased in a frequency-dependent manner and saturated at 20 Hz. SD was similar during subjective day and night and decreased with increasing temperature. Paired-pulse stimulation (PPS) and voltage-dependent Ca2+ channel (VDCC) blockers were used to characterize a presynaptic release mechanism. Facilitation was present in 30% and depression in 70% of studied neurons during PPS. Synaptic transmission was reduced by blocking both N- and P/Q-type presynaptic VDCCs, but only the N-type channel blocker significantly relieved SD. Aniracetam inhibited AMPA receptor desensitization but did not alter SD. Thus we concluded that SD is the principal form of short-term plasticity at RHT synapses, which presynaptically and frequency-dependently attenuates light-induced glutamatergic RHT synaptic transmission protecting SCN neurons against excessive excitation. PMID:20220078

  7. Identification of PAC1 receptor isoform mRNAs by real-time PCR in rat suprachiasmatic nucleus.

    Science.gov (United States)

    Ajpru, Supaporn; McArthur, Angela J; Piggins, Hugh D; Sugden, David

    2002-09-30

    The pituitary adenylate cyclase-activating polypeptide (PACAP) has been implicated in the photic resetting of the rodent circadian clock in the suprachiasmatic nucleus (SCN). PACAP can exert its effects via VPAC1, VPAC2 and PAC1 G-protein coupled receptors. PAC1 and VPAC2, but not VPAC1, mRNA is expressed in rat SCN. A variety of PAC1 receptor splice variants have been described showing differences in ligand binding affinity and selectivity, G-protein coupling and ability to activate signal transduction pathways. The present experiments used PCR with isoform specific primers to determine which PAC1 variants are expressed in rat SCN. The PAC1(null) isoform and a variant containing a single 28-amino acid insert in the third intracellular (IC3) loop (hop1/2) were detected. No other IC3 variants (hip, hip-hop), N-terminal variants (PAC1(short), PAC1(very short) and PAC1(3a)) or the variant differing in transmembrane II and IV (PAC1TM4) were detected in SCN obtained at any time of day. A quantitative real-time PCR assay was established which measured combined expression of the PAC1(null/hop) variants in rat SCN during a 12:12-h light:dark (L:D) cycle. There was no significant variation of PAC1 mRNA expression (PAC1(null)+PAC1(hop)) with time of day. Nor was there a significant difference in the proportion of these two variants with time of day. These results indicate that the phase-dependency of the actions of PACAP on SCN firing and circadian behaviour are not mediated by changes in the level of expression of PAC1 receptor mRNA, nor by phase-dependent expression of PAC1 receptor variants with altered ligand binding, G-protein coupling or signalling characteristics. Copyright 2002 Elsevier Science B.V.

  8. Time-of-day- and light-dependent expression of ubiquitin protein ligase E3 component N-recognin 4 (UBR4 in the suprachiasmatic nucleus circadian clock.

    Directory of Open Access Journals (Sweden)

    Harrod H Ling

    Full Text Available Circadian rhythms of behavior and physiology are driven by the biological clock that operates endogenously but can also be entrained to the light-dark cycle of the environment. In mammals, the master circadian pacemaker is located in the suprachiasmatic nucleus (SCN, which is composed of individual cellular oscillators that are driven by a set of core clock genes interacting in transcriptional/translational feedback loops. Light signals can trigger molecular events in the SCN that ultimately impact on the phase of expression of core clock genes to reset the master pacemaker. While transcriptional regulation has received much attention in the field of circadian biology in the past, other mechanisms including targeted protein degradation likely contribute to the clock timing and entrainment process. In the present study, proteome-wide screens of the murine SCN led to the identification of ubiquitin protein ligase E3 component N-recognin 4 (UBR4, a novel E3 ubiquitin ligase component of the N-end rule pathway, as a time-of-day-dependent and light-inducible protein. The spatial and temporal expression pattern of UBR4 in the SCN was subsequently characterized by immunofluorescence microscopy. UBR4 is expressed across the entire rostrocaudal extent of the SCN in a time-of-day-dependent fashion. UBR4 is localized exclusively to arginine vasopressin (AVP-expressing neurons of the SCN shell. Upon photic stimulation in the early subjective night, the number of UBR4-expressing cells within the SCN increases. This study is the first to identify a novel E3 ubiquitin ligase component, UBR4, in the murine SCN and to implicate the N-end rule degradation pathway as a potential player in regulating core clock mechanisms and photic entrainment.

  9. Stress affects expression of the clock gene Bmal1 in the suprachiasmatic nucleus of neonatal rats via glucocorticoid‐dependent mechanism

    Czech Academy of Sciences Publication Activity Database

    Olejníková, Lucie; Polidarová, Lenka; Sumová, Alena

    2018-01-01

    Roč. 223, č. 1 (2018), č. článku e13020. ISSN 1748-1708 R&D Projects: GA ČR(CZ) GA16-03932S Institutional support: RVO:67985823 Keywords : clock genes * development * glucocorticoids * mifepristone * restricted feeding * stress * suprachiasmatic nuclei Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) Impact factor: 4.867, year: 2016

  10. Facilitation of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate receptor transmission in the suprachiasmatic nucleus by aniracetam enhances photic responses of the biological clock in rodents.

    Science.gov (United States)

    Moriya, Takahiro; Ikeda, Masayuki; Teshima, Koji; Hara, Reiko; Kuriyama, Koji; Yoshioka, Tohru; Allen, Charles N; Shibata, Shigenobu

    2003-05-01

    This study was designed to test whether the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor-facilitating drug, aniracetam, could potentiate photic responses of the biological clock in the suprachiasmatic nucleus (SCN) of rodents. Using the whole-cell patch technique, we first demonstrated that AMPA currents elicited by either local AMPA application or optic chiasm stimulation were augmented by aniracetam in the neurons of the SCN. The AMPA application-elicited increase of intracellular Ca2+ concentration in SCN slices was also enhanced by aniracetam treatment. The systemic injection of aniracetam dose-dependently (10-100 mg/kg) potentiated the phase delay in behavioral rhythm induced by brief light exposure of low intensity (3 lux) but not high intensity (10 or 60 lux) during early subjective night. Under the blockade of NMDA receptors by (+) MK801, aniracetam failed to potentiate a light (3 lux)-induced phase delay in behavioral rhythm. Aniracetam increased the photic induction of c-Fos protein in the SCN that was elicited by low intensity light exposure (3 lux). These results suggest that AMPA receptor-mediated responses facilitated by aniracetam can explain enhanced photic responses of the biological clock in the SCN of rodents.

  11. Day-night variations in zinc sensitivity of GABA(A) receptor-channels in rat suprachiasmatic nucleus

    Czech Academy of Sciences Publication Activity Database

    Kretschmannová, Karla; Svobodová, Irena; Zemková, Hana

    2003-01-01

    Roč. 120, č. 1 (2003), s. 46-51 ISSN 0169-328X R&D Projects: GA ČR GA309/02/1519; GA AV ČR IAA5011103; GA AV ČR IAA5011105 Institutional research plan: CEZ:AV0Z5011922 Keywords : GABA * circadian rhythm * suprachiasmatic nuclei Subject RIV: ED - Physiology Impact factor: 2.107, year: 2003

  12. Circadian ATP Release in Organotypic Cultures of the Rat Suprachiasmatic Nucleus Is Dependent on P2X7 and P2Y Receptors

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    Irena Svobodova

    2018-03-01

    Full Text Available The circadian rhythms in physiological and behavioral functions are driven by a pacemaker located in the suprachiasmatic nucleus (SCN. The rhythms continue in constant darkness and depend on cell-cell communication between neurons and glia. The SCN astrocytes generate also a circadian rhythm in extracellular adenosine 5′-triphosphate (ATP accumulation, but molecular mechanisms that regulate ATP release are poorly understood. Here, we tested the hypothesis that ATP is released via the plasma membrane purinergic P2X7 receptors (P2X7Rs and P2Y receptors (P2YRs which have been previously shown to be expressed in the SCN tissue at transcriptional level. We have investigated this hypothesis using SCN organotypic cultures, primary cultures of SCN astrocytes, ATP bioluminescent assays, immunohistochemistry, patch-clamping, and calcium imaging. We found that extracellular ATP accumulation in organotypic cultures followed a circadian rhythm, with a peak between 24:00 and 04:00 h, and the trough at ~12:00 h. ATP rhythm was inhibited by application of AZ10606120, A438079, and BBG, specific blockers of P2X7R, and potentiated by GW791343, a positive allosteric modulator of this receptor. Double-immunohistochemical staining revealed high expression of the P2X7R protein in astrocytes of SCN slices. PPADS, a non-specific P2 antagonist, and MRS2179, specific P2Y1R antagonist, also abolished ATP rhythm, whereas the specific P2X4R blocker 5-BDBD was not effective. The pannexin-1 hemichannel blocker carbenoxolone displayed a partial inhibitory effect. The P2Y1R agonist MRS2365, and the P2Y2R agonist MRS2768 potentiated ATP release in organotypic cultures and increase intracellular Ca2+ level in cultured astrocytes. Thus, SCN utilizes multiple purinergic receptor systems and pannexin-1 hemichannels to release ATP.

  13. Combined Pharmacological and Genetic Manipulations Unlock Unprecedented Temporal Elasticity and Reveal Phase-Specific Modulation of the Molecular Circadian Clock of the Mouse Suprachiasmatic Nucleus.

    Science.gov (United States)

    Patton, Andrew P; Chesham, Johanna E; Hastings, Michael H

    2016-09-07

    The suprachiasmatic nucleus (SCN) is the master circadian oscillator encoding time-of-day information. SCN timekeeping is sustained by a cell-autonomous transcriptional-translational feedback loop, whereby expression of the Period and Cryptochrome genes is negatively regulated by their protein products. This loop in turn drives circadian oscillations in gene expression that direct SCN electrical activity and thence behavior. The robustness of SCN timekeeping is further enhanced by interneuronal, circuit-level coupling. The aim of this study was to combine pharmacological and genetic manipulations to push the SCN clockwork toward its limits and, by doing so, probe cell-autonomous and emergent, circuit-level properties. Circadian oscillation of mouse SCN organotypic slice cultures was monitored as PER2::LUC bioluminescence. SCN of three genetic backgrounds-wild-type, short-period CK1ε(Tau/Tau) mutant, and long-period Fbxl3(Afh/Afh) mutant-all responded reversibly to pharmacological manipulation with period-altering compounds: picrotoxin, PF-670462 (4-[1-Cyclohexyl-4-(4-fluorophenyl)-1H-imidazol-5-yl]-2-pyrimidinamine dihydrochloride), and KNK437 (N-Formyl-3,4-methylenedioxy-benzylidine-gamma-butyrolactam). This revealed a remarkably wide operating range of sustained periods extending across 25 h, from ≤17 h to >42 h. Moreover, this range was maintained at network and single-cell levels. Development of a new technique for formal analysis of circadian waveform, first derivative analysis (FDA), revealed internal phase patterning to the circadian oscillation at these extreme periods and differential phase sensitivity of the SCN to genetic and pharmacological manipulations. For example, FDA of the CK1ε(Tau/Tau) mutant SCN treated with the CK1ε-specific inhibitor PF-4800567 (3-[(3-Chlorophenoxy)methyl]-1-(tetrahydro-2H-pyran-4-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine hydrochloride) revealed that period acceleration in the mutant is due to inappropriately phased

  14. Sustained activation of GABAA receptors in the suprachiasmatic nucleus mediates light-induced phase delays of the circadian clock: a novel function of ionotropic receptors.

    Science.gov (United States)

    Hummer, Daniel L; Ehlen, J Christopher; Larkin, Tony E; McNeill, John K; Pamplin, John R; Walker, Colton A; Walker, Phillip V; Dhanraj, Daryl R; Albers, H Elliott

    2015-07-01

    The suprachiasmatic nucleus (SCN) contains a circadian clock that generates endogenous rhythmicity and entrains that rhythmicity with the day-night cycle. The neurochemical events that transduce photic input within the SCN and mediate entrainment by resetting the molecular clock have yet to be defined. Because GABA is contained in nearly all SCN neurons we tested the hypothesis that GABA serves as this signal in studies employing Syrian hamsters (Mesocricetus auratus). Activation of GABAA receptors was found to be necessary and sufficient for light to induce phase delays of the clock. Remarkably, the sustained activation of GABAA receptors for more than three consecutive hours was necessary to phase-delay the clock. The duration of GABAA receptor activation required to induce phase delays would not have been predicted by either the prevalent theory of circadian entrainment or by expectations regarding the duration of ionotropic receptor activation necessary to produce functional responses. Taken together, these data identify a novel neurochemical mechanism essential for phase-delaying the 'master' circadian clock within the SCN as well as identifying an unprecedented action of an amino acid neurotransmitter involving the sustained activation of ionotropic receptors. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  15. Dispersion of the intrinsic neuronal periods affects the relationship of the entrainment range to the coupling strength in the suprachiasmatic nucleus

    Science.gov (United States)

    Gu, Changgui; Yang, Huijie; Wang, Man

    2017-11-01

    Living beings on the Earth are subjected to and entrained (synchronized) to the natural 24-h light-dark cycle. Interestingly, they can also be entrained to an external artificial cycle of non-24-h periods. The range of these periods is called the entrainment range and it differs among species. In mammals, the entrainment range is regulated by a main clock located in the suprachiasmatic nucleus (SCN) which is composed of 10 000 neurons in the brain. Previous works have found that the entrainment range depends on the cellular coupling strength in the SCN. In particular, the entrainment range decreases with the increase of the cellular coupling strength, provided that all the neuronal oscillators are identical. However, the SCN neurons differ in the intrinsic periods that follow a normal distribution in a range from 22 to 28 h. In the present study, taking the dispersion of the intrinsic neuronal periods into account, we examined the relationship between the entrainment range and the coupling strength. Results from numerical simulations and theoretical analyses both show that the relationship is altered to be paraboliclike if the intrinsic neuronal periods are nonidentical, and the maximal entrainment range is obtained with a suitable coupling strength. Our results shed light on the role of the cellular coupling in the entrainment ability of the SCN network.

  16. Histamine 1 receptor-Gβγ-cAMP/PKA-CFTR pathway mediates the histamine-induced resetting of the suprachiasmatic circadian clock.

    Science.gov (United States)

    Kim, Yoon Sik; Kim, Young-Beom; Kim, Woong Bin; Lee, Seung Won; Oh, Seog Bae; Han, Hee-Chul; Lee, C Justin; Colwell, Christopher S; Kim, Yang In

    2016-05-06

    Recent evidence indicates that histamine, acting on histamine 1 receptor (H1R), resets the circadian clock in the mouse suprachiasmatic nucleus (SCN) by increasing intracellular Ca(2+) concentration ([Ca(2+)]i) through the activation of CaV1.3 L-type Ca(2+) channels and Ca(2+)-induced Ca(2+) release from ryanodine receptor-mediated internal stores. In the current study, we explored the underlying mechanisms with various techniques including Ca(2+)- and Cl(-)-imaging and extracellular single-unit recording. Our hypothesis was that histamine causes Cl(-) efflux through cystic fibrosis transmembrane conductance regulator (CFTR) to elicit membrane depolarization needed for the activation of CaV1.3 Ca(2+) channels in SCN neurons. We found that histamine elicited Cl(-) efflux and increased [Ca(2+)]i in dissociated mouse SCN cells. Both of these events were suppressed by bumetanide [Na(+)-K(+)-2Cl(-) cotransporter isotype 1 (NKCC1) blocker], CFTRinh-172 (CFTR inhibitor), gallein (Gβγ protein inhibitor) and H89 [protein kinase A (PKA) inhibitor]. By itself, H1R activation with 2-pyridylethylamine increased the level of cAMP in the SCN and this regulation was prevented by gallein. Finally, histamine-evoked phase shifts of the circadian neural activity rhythm in the mouse SCN slice were blocked by bumetanide, CFTRinh-172, gallein or H89 and were not observed in NKCC1 or CFTR KO mice. Taken together, these results indicate that histamine recruits the H1R-Gβγ-cAMP/PKA pathway in the SCN neurons to activate CaV1.3 channels through CFTR-mediated Cl(-) efflux and ultimately to phase-shift the circadian clock. This pathway and NKCC1 may well be potential targets for agents designed to treat problems resulting from the disturbance of the circadian system.

  17. Histamine resets the circadian clock in the suprachiasmatic nucleus through the H1R-CaV 1.3-RyR pathway in the mouse.

    Science.gov (United States)

    Kim, Yoon Sik; Kim, Young-Beom; Kim, Woong Bin; Yoon, Bo-Eun; Shen, Feng-Yan; Lee, Seung Won; Soong, Tuck-Wah; Han, Hee-Chul; Colwell, Christopher S; Lee, C Justin; Kim, Yang In

    2015-10-01

    Histamine, a neurotransmitter/neuromodulator implicated in the control of arousal state, exerts a potent phase-shifting effect on the circadian clock in the rodent suprachiasmatic nucleus (SCN). In this study, the mechanisms by which histamine resets the circadian clock in the mouse SCN were investigated. As a first step, Ca(2+) -imaging techniques were used to demonstrate that histamine increases intracellular Ca(2+) concentration ([Ca(2+) ]i ) in acutely dissociated SCN neurons and that this increase is blocked by the H1 histamine receptor (H1R) antagonist pyrilamine, the removal of extracellular Ca(2+) and the L-type Ca(2+) channel blocker nimodipine. The histamine-induced Ca(2+) transient is reduced, but not blocked, by application of the ryanodine receptor (RyR) blocker dantrolene. Immunohistochemical techniques indicated that CaV 1.3 L-type Ca(2+) channels are expressed mainly in the somata of SCN cells along with the H1R, whereas CaV 1.2 channels are located primarily in the processes. Finally, extracellular single-unit recordings demonstrated that the histamine-elicited phase delay of the circadian neural activity rhythm recorded from SCN slices is blocked by pyrilamine, nimodipine and the knockout of CaV 1.3 channel. Again, application of dantrolene reduced but did not block the histamine-induced phase delays. Collectively, these results indicate that, to reset the circadian clock, histamine increases [Ca(2+) ]i in SCN neurons by activating CaV 1.3 channels through H1R, and secondarily by causing Ca(2+) -induced Ca(2+) release from RyR-mediated internal stores. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. Phase preference for the display of activity is associated with the phase of extra-suprachiasmatic nucleus oscillators within and between species.

    Science.gov (United States)

    Ramanathan, C; Stowie, A; Smale, L; Nunez, A A

    2010-10-27

    Many features of the suprachiasmatic nucleus (SCN) are the same in diurnal and nocturnal animals, suggesting that differences in phase preference are determined by mechanisms downstream from the SCN. Here, we examined this hypothesis by characterizing rhythmic expression of Period 1 (PER1) and Period 2 (PER2) in several extra-SCN areas in the brains of a diurnal murid rodent, Arvicanthis niloticus (grass rats). In the shell of the nucleus accumbens, dorsal striatum, piriform cortex, and CA1 of the hippocampus, both PER1 and PER2 were rhythmic, with peak expression occurring at ZT10. PER1 in the dentate gyrus also peaked at ZT10, but PER2 was arrhythmic in this region. In general, these patterns are 180 degrees out of phase with those reported for nocturnal species. In a second study, we examined inter-individual differences in the multioscillator system of grass rats. Here, we housed grass rats in cages with running wheels, under which conditions some individuals spontaneously adopt a day active (DA) and others a night active (NA) phase preference. In the majority of the extra-SCN regions sampled, the patterns of PER1 and PER2 expression of NA grass rats resembled those of nocturnal species, while those of DA grass rats were similar to the ones seen in grass without access to running wheels. In contrast, the rhythmic expression of both PER proteins was identical in the SCN and ventral subparaventricular zone (vSPZ) of DA and NA animals. Differences in the phase of oscillators downstream from the SCN, and perhaps the vSPZ, appear to determine the phase preference of particular species, as well as that of members of a diurnal species that show voluntary phase reversals. The latter observation has important implications for the understanding of health problems associated with human shift work. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. A common genetic variant within SCN10A modulates cardiac SCN5A expression

    NARCIS (Netherlands)

    van den Boogaard, Malou; Smemo, Scott; Burnicka-Turek, Ozanna; Arnolds, David E.; van de Werken, Harmen J. G.; Klous, Petra; McKean, David; Muehlschlegel, Jochen D.; Moosmann, Julia; Toka, Okan; Yang, Xinan H.; Koopmann, Tamara T.; Adriaens, Michiel E.; Bezzina, Connie R.; de Laat, Wouter; Seidman, Christine; Seidman, J. G.; Christoffels, Vincent M.; Nobrega, Marcelo A.; Barnett, Phil; Moskowitz, Ivan P.

    2014-01-01

    Variants in SCN10A, which encodes a voltage-gated sodium channel, are associated with alterations of cardiac conduction parameters and the cardiac rhythm disorder Brugada syndrome; however, it is unclear how SCN10A variants promote dysfunctional cardiac conduction. Here we showed by high-resolution

  20. Melatonin Signal Transduction Pathways Require E-Box-Mediated Transcription of Per1 and Per2 to Reset the SCN Clock at Dusk.

    Directory of Open Access Journals (Sweden)

    Patty C Kandalepas

    Full Text Available Melatonin is released from the pineal gland into the circulatory system at night in the absence of light, acting as "hormone of darkness" to the brain and body. Melatonin also can regulate circadian phasing of the suprachiasmatic nucleus (SCN. During the day-to-night transition, melatonin exposure advances intrinsic SCN neural activity rhythms via the melatonin type-2 (MT2 receptor and downstream activation of protein kinase C (PKC. The effects of melatonin on SCN phasing have not been linked to daily changes in the expression of core genes that constitute the molecular framework of the circadian clock. Using real-time RT-PCR, we found that melatonin induces an increase in the expression of two clock genes, Period 1 (Per1 and Period 2 (Per2. This effect occurs at CT 10, when melatonin advances SCN phase, but not at CT 6, when it does not. Using anti-sense oligodeoxynucleotides (α ODNs to Per 1 and Per 2, as well as to E-box enhancer sequences in the promoters of these genes, we show that their specific induction is necessary for the phase-altering effects of melatonin on SCN neural activity rhythms in the rat. These effects of melatonin on Per1 and Per2 were mediated by PKC. This is unlike day-active non-photic signals that reset the SCN clock by non-PCK signal transduction mechanisms and by decreasing Per1 expression. Rather, this finding extends roles for Per1 and Per2, which are critical to photic phase-resetting, to a nonphotic zeitgeber, melatonin, and suggest that the regulation of these clock gene transcripts is required for clock resetting by diverse regulatory cues.

  1. Distribution of N-methyl D-aspartate (NMDA) receptor mRNAs in the rat suprachiasmatic nucleus

    DEFF Research Database (Denmark)

    Mikkelsen, J.D.; Larsen, Philip J.; Ebling, Francis J.P.

    1993-01-01

    Anatomi, neurobiologi, glutamate receptor, circadian rhythms, suprachiasmatic nucleus, in situ hybridization, rat......Anatomi, neurobiologi, glutamate receptor, circadian rhythms, suprachiasmatic nucleus, in situ hybridization, rat...

  2. Intracellular Na(+) and metabolic modulation of Na/K pump and excitability in the rat suprachiasmatic nucleus neurons.

    Science.gov (United States)

    Wang, Yi-Chi; Yang, Jyh-Jeen; Huang, Rong-Chi

    2012-10-01

    Na/K pump activity and metabolic rate are both higher during the day in the suprachiasmatic nucleus (SCN) that houses the circadian clock. Here we investigated the role of intracellular Na(+) and energy metabolism in regulating Na/K pump activity and neuronal excitability. Removal of extracellular K(+) to block the Na/K pump excited SCN neurons to fire at higher rates and return to normal K(+) to reactivate the pump produced rebound hyperpolarization to inhibit firing. In the presence of tetrodotoxin to block the action potentials, both zero K(+)-induced depolarization and rebound hyperpolarization were blocked by the cardiac glycoside strophanthidin. Ratiometric Na(+) imaging with a Na(+)-sensitive fluorescent dye indicated saturating accumulation of intracellular Na(+) in response to pump blockade with zero K(+). The Na(+) ionophore monensin also induced Na(+) loading and hyperpolarized the membrane potential, with the hyperpolarizing effect of monensin abolished in zero Na(+) or by pump blockade. Conversely, Na(+) depletion with Na(+)-free pipette solution depolarized membrane potential but retained residual Na/K pump activity. Cyanide inhibition of oxidative phosphorylation blocked the Na/K pump to depolarize resting potential and increase spontaneous firing in most cells, and to raise intracellular Na(+) levels in all cells. Nonetheless, the Na/K pump was incompletely blocked by cyanide but completely blocked by iodoacetate to inhibit glycolysis, indicating the involvement of both oxidative phosphorylation and glycolysis in fueling the Na/K pump. Together, the results indicate the importance of intracellular Na(+) and energy metabolism in regulating Na/K pump activity as well as neuronal excitability in the SCN neurons.

  3. Prenatal administration of letrozole reduces SDN and SCN volume and cell number independent of partner preference in the male rat.

    Science.gov (United States)

    Olvera-Hernández, Sandra; Tapia-Rodríguez, Miguel; Swaab, Dick F; Fernández-Guasti, Alonso

    2017-03-15

    During development, the exposure to testosterone, and its conversion to estradiol by an enzyme complex termed aromatase, appears to be essential in adult male rats for the expression of typical male sexual behavior and female-sex preference. Some hypothalamic areas are the supposed neural bases of sexual preference/orientation; for example, male-oriented rams have a reduced volume of the sexually dimorphic nucleus (oSDN), while in homosexual men this nucleus does not differ from that of heterosexual men. In contrast, homosexual men showed a larger number of vasopressinergic cells in the suprachiasmatic nucleus (SCN). Interestingly, male rats perinatally treated with an aromatase inhibitor, 1,4,6-androstatriene-3,17-dione (ATD), also showed bisexual preference and an increased number of vasopressinergic neurons in the SCN. However, this steroidal aromatase inhibitor has affinity for all three steroid receptors. Recently, we reported that the prenatal administration of the selective aromatase inhibitor, letrozole, produced a subpopulation of males with same-sex preference. The aim of this study was to compare the volume and number of cells of the SDN and SCN (the latter nucleus was immunohistochemically stained for vasopressin) between males treated with letrozole with same-sex preference, males treated with letrozole with female preference and control males with female preference. Results showed that all males prenatally treated with letrozole have a reduced volume and estimated cell number in the SDN and SCN, independent of their partner preference. These results indicate that the changes in these brain areas are not related to sexual preference, but rather to the effects of letrozole. The divergent results may be explained by species differences as well as by the critical windows during which the aromatase inhibitor was administered. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Photic induction of Fos in the suprachiasmatic nucleus of African mole-rats: responses to increasing irradiance.

    Science.gov (United States)

    Oosthuizen, Maria K; Bennett, Nigel C; Cooper, Howard M

    2010-09-01

    African mole-rats (family Bathyergidae) are strictly subterranean rodent species that are rarely exposed to environmental light. Morphological and physiological adaptations to the underground environment include a severely reduced eye size and regressed visual system. Responses of the circadian system to light, however, appear to be intact, since mole-rats are able to entrain their circadian activity rhythms to the light-dark cycle and light induces Fos expression in the suprachiasmatic nucleus (SCN). Social organization varies from solitary species to highly elaborated eusocial structures, characterized by a distinct division of labor and in which one reproductive female regulates the behavior and reproductive physiology of other individuals in the colony. The authors studied light-induced Fos expression in the SCN to increasing light intensities in four mole-rat species, ranging from strictly solitary to highly social. In the solitary Cape mole-rat, light induces significant Fos expression in the SCN, and the number of Fos-immunopositive cells increases with increasing light intensity. In contrast, Fos induction in the SCN of social species was slightly greater than, but not statistically different from, the dark-control animals as is typical of most rodents. One species showed a trend for an increase in expression with increased light, whereas a second species showed no trend in expression. In the naked mole-rat, Fos expression appeared higher in the dark-controls than in the animals exposed to light, although the differences in Fos expression were not significant. These results suggest a gradient in the sensitivity of the circadian system to light in mole-rats, with a higher percentage of individuals that are unresponsive to light in correlation with the degree of sociality. In highly social species, such as the naked mole-rat that live in a relatively stable subterranean milieu in terms of food availability, temperature, constant darkness, and devoid of 24-h

  5. Novel description of ionic currents recorded with the action potential clamp technique: application to excitatory currents in suprachiasmatic nucleus neurons.

    Science.gov (United States)

    Clay, John R

    2015-07-01

    The traditional method of recording ionic currents in neurons has been with voltage-clamp steps. Other waveforms such as action potentials (APs) can be used. The AP clamp method reveals contributions of ionic currents that underlie excitability during an AP (Bean BP. Nat Rev Neurosci 8: 451-465, 2007). A novel usage of the method is described in this report. An experimental recording of an AP from the literature is digitized and applied computationally to models of ionic currents. These results are compared with experimental AP-clamp recordings for model verification or, if need be, alterations to the model. The method is applied to the tetrodotoxin-sensitive sodium ion current, INa, and the calcium ion current, ICa, from suprachiasmatic nucleus (SCN) neurons (Jackson AC, Yao GL, Bean BP. J Neurosci 24: 7985-7998, 2004). The latter group reported voltage-step and AP-clamp results for both components. A model of INa is constructed from their voltage-step results. The AP clamp computational methodology applied to that model compares favorably with experiment, other than a modest discrepancy close to the peak of the AP that has not yet been resolved. A model of ICa was constructed from both voltage-step and AP-clamp results of this component. The model employs the Goldman-Hodgkin-Katz equation for the current-voltage relation rather than the traditional linear dependence of this aspect of the model on the Ca(2+) driving force. The long-term goal of this work is a mathematical model of the SCN AP. The method is general. It can be applied to any excitable cell.

  6. Exotic nuclei

    International Nuclear Information System (INIS)

    Villari, A.C.C.

    1990-01-01

    The actual tendencies to study exotic nuclei; applications of exotic nuclei beams in material study and medicine; recent results obtained by GANIL and Berkeley Laboratories of measurements of binding energy and radii of light nuclei; the future experiences to be carry out in several international laboratories and; proposal of studies in Brazil using Pelletron-USP accelerator and the LINAC superconductor accelerator, in construction in the same laboratory, are presented. (M.C.K.)

  7. The neuronal transition probability (NTP model for the dynamic progression of non-REM sleep EEG: the role of the suprachiasmatic nucleus.

    Directory of Open Access Journals (Sweden)

    Helli Merica

    Full Text Available Little attention has gone into linking to its neuronal substrates the dynamic structure of non-rapid-eye-movement (NREM sleep, defined as the pattern of time-course power in all frequency bands across an entire episode. Using the spectral power time-courses in the sleep electroencephalogram (EEG, we showed in the typical first episode, several moves towards-and-away from deep sleep, each having an identical pattern linking the major frequency bands beta, sigma and delta. The neuronal transition probability model (NTP--in fitting the data well--successfully explained the pattern as resulting from stochastic transitions of the firing-rates of the thalamically-projecting brainstem-activating neurons, alternating between two steady dynamic-states (towards-and-away from deep sleep each initiated by a so-far unidentified flip-flop. The aims here are to identify this flip-flop and to demonstrate that the model fits well all NREM episodes, not just the first. Using published data on suprachiasmatic nucleus (SCN activity we show that the SCN has the information required to provide a threshold-triggered flip-flop for TIMING the towards-and-away alternations, information provided by sleep-relevant feedback to the SCN. NTP then determines the PATTERN of spectral power within each dynamic-state. NTP was fitted to individual NREM episodes 1-4, using data from 30 healthy subjects aged 20-30 years, and the quality of fit for each NREM measured. We show that the model fits well all NREM episodes and the best-fit probability-set is found to be effectively the same in fitting all subject data. The significant model-data agreement, the constant probability parameter and the proposed role of the SCN add considerable strength to the model. With it we link for the first time findings at cellular level and detailed time-course data at EEG level, to give a coherent picture of NREM dynamics over the entire night and over hierarchic brain levels all the way from the SCN

  8. Role of common and rare variants in SCN10A

    DEFF Research Database (Denmark)

    Behr, Elijah R.; Savio-Galimberti, Eleonora; Barc, Julien

    2015-01-01

    , CASQ2, TKT, TBX3, and TBX5) in 156 Caucasian SCN5A mutation-negative BrS patients (80% male; mean age 48) with symptoms (64%) and/or a family history of sudden death (47%) or BrS (18%). Forty-nine variants were identified: 18 were rare (MAF ..., were predicted as pathogenic using multiple bioinformatics tools. Allele frequencies were compared with the Exome Sequencing and UK10K Projects. SKAT methods tested rare variation in SCN10A finding no statistically significant difference between cases and controls. Co-segregation analysis was possible.......8 were performed for SCN10A common variants V1073, A1073, and rare variants of interest: A200V and I671V. V1073, A200V and I671V, demonstrated significant reductions in peak INa compared with ancestral allele A1073 (rs6795970). CONCLUSION: Rare variants in the screened QRS-associated genes (including SCN...

  9. A new sodium channel {alpha}-subunit gene (Scn9a) from Schwann cells maps to the Scn1a, Scn2a, Scn3a cluster of mouse chromosome 2

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, M.C.; Ernst, E.; Gros, P. [McGill Univ., Montreal (Canada)

    1996-08-15

    We have used a total of 27 AXB/BXA recombinant inbred mouse strains to determine the chromosomal location of a newly identified gene encoding an {alpha}-subunit isoform of the sodium channel from Schwann cells, Scn9a. Linkage analysis established that Scn9a mapped to the proximal segment of mouse chromosome 2. The segregation of restriction fragment length polymorphisms in 145 progeny from a Mus spretus x C57BL/6J backcross indicates that Scn9a is very tightly linked to Scn1a (gene encoding the type I sodium channel {alpha}-subunit of the brain) and forms part of a cluster of four Scna genes located on mouse chromosome 2. 17 refs., 1 fig., 3 tabs.

  10. SCN Neurochemistry using In Vivo, Microdialysis in the Conscious Brain

    Science.gov (United States)

    1993-12-27

    related to the the activities of serotonergic and excitatory amino acid activities in the SCN. Specifically, it was found that 1) serotonin inhibits...pacemaker activity. These involved direct application of a reversible inhibitor of glial cell metabolism ( fluorocitrate ) to the SCN via a microdialysis...extraneuronal concentration of the excitatory amino acid (EAA), glutamate. The present experiments were undertaken to extend these findings by characterizing the

  11. Projections from the raphe nuclei to the suprachiasmatic nucleus of the rat

    DEFF Research Database (Denmark)

    Hay-Schmidt, Anders; Vrang, N.; Larsen, P.J.

    2003-01-01

    Hypothalamus, Circadian rhythm, Serotonin, Nucleus, Neuronal connections, Phaseolus vulgaris-leucoagglutinin (PHA-L), Cholera toxin (ChB)......Hypothalamus, Circadian rhythm, Serotonin, Nucleus, Neuronal connections, Phaseolus vulgaris-leucoagglutinin (PHA-L), Cholera toxin (ChB)...

  12. Control of Circadian Behavior by Transplanted Suprachiasmatic Nuclei and by the Tau Gene

    National Research Council Canada - National Science Library

    Menaker, Micahel

    1997-01-01

    The mammalian retina was found to contain an independent circadian oscillator which regulates the synthesis of melatonin and has effects, through a presently unknown pathway, on the circadian rhythm...

  13. Early programming of astrocyte organization in the mouse suprachiasmatic nuclei by light

    Czech Academy of Sciences Publication Activity Database

    Canal, M. M.; Mohammed, N. M.; Rodríguez Arellano, Jose Julio

    2009-01-01

    Roč. 26, č. 8 (2009), s. 1545-1558 ISSN 0742-0528 Institutional research plan: CEZ:AV0Z50390512 Keywords : Development * GFAP * Circadian rhythm Subject RIV: FH - Neurology Impact factor: 3.987, year: 2009

  14. Primary erythermalgia as a sodium channelopathy: screening for SCN9A mutations: exclusion of a causal role of SCN10A and SCN11A.

    NARCIS (Netherlands)

    Drenth, J.P.H.; Morsche, R.H.M. te; Mansour, S.; Mortimer, P.S.

    2008-01-01

    OBJECTIVES: To elucidate the rate of missense mutations in the SCN9A gene (which encodes sodium channel Na(v)1.7) (OMIM 603415) among patients with primary erythermalgia and to examine the possibility that other sodium channels can cause the disease. DESIGN: Case series. SETTING: Department of

  15. Altered energy intake and the amplitude of the body temperature rhythm are associated with changes in phase, but not amplitude, of clock gene expression in the rat suprachiasmatic nucleus in vivo.

    Science.gov (United States)

    Goh, Grace H; Mark, Peter J; Maloney, Shane K

    2016-01-01

    Circadian rhythms in mammals are driven by a central clock in the suprachiasmatic nucleus (SCN). In vitro, temperature cycles within the physiological range can act as potent entraining cues for biological clocks. We altered the body temperature (Tc) rhythm in rats by manipulating energy intake (EI) to determine whether EI-induced changes in Tc oscillations are associated with changes in SCN clock gene rhythms in vivo. Male Wistar rats (n = 16 per diet) were maintained on either an ad libitum diet (CON), a high energy cafeteria diet (CAF), or a calorie restricted diet (CR), and Tc was recorded every 30 min for 6-7 weeks. SCN tissue was harvested from rats at zeitgeber time (ZT) 0, ZT6, ZT12, or ZT18. Expression of the clock genes Bmal1, Per2, Cry1, and Rev-erbα, the heat shock transcription factor Hsf1, and the heat shock protein Hsp90aa1, were determined using qPCR. The circadian profile of gene expression for each gene was characterized using cosinor analysis. Compared to the CON rats, the amplitude of Tc was decreased in CAF rats by 0.1 °C (p  0.25). Compared to CON, phase advances of the Tc, Bmal1, and Per2 rhythms were observed with CR feeding (p < 0.05), but CAF feeding elicited no significant changes in phase. The present results indicate that in vivo, the SCN is largely resistant to entrainment by EI-induced changes in the Tc rhythm, although some phase entrainment may occur.

  16. Compensation of native donor doping in ScN: Carrier concentration control and p-type ScN

    Science.gov (United States)

    Saha, Bivas; Garbrecht, Magnus; Perez-Taborda, Jaime A.; Fawey, Mohammed H.; Koh, Yee Rui; Shakouri, Ali; Martin-Gonzalez, Marisol; Hultman, Lars; Sands, Timothy D.

    2017-06-01

    Scandium nitride (ScN) is an emerging indirect bandgap rocksalt semiconductor that has attracted significant attention in recent years for its potential applications in thermoelectric energy conversion devices, as a semiconducting component in epitaxial metal/semiconductor superlattices and as a substrate material for high quality GaN growth. Due to the presence of oxygen impurities and native defects such as nitrogen vacancies, sputter-deposited ScN thin-films are highly degenerate n-type semiconductors with carrier concentrations in the (1-6) × 1020 cm-3 range. In this letter, we show that magnesium nitride (MgxNy) acts as an efficient hole dopant in ScN and reduces the n-type carrier concentration, turning ScN into a p-type semiconductor at high doping levels. Employing a combination of high-resolution X-ray diffraction, transmission electron microscopy, and room temperature optical and temperature dependent electrical measurements, we demonstrate that p-type Sc1-xMgxN thin-film alloys (a) are substitutional solid solutions without MgxNy precipitation, phase segregation, or secondary phase formation within the studied compositional region, (b) exhibit a maximum hole-concentration of 2.2 × 1020 cm-3 and a hole mobility of 21 cm2/Vs, (c) do not show any defect states inside the direct gap of ScN, thus retaining their basic electronic structure, and (d) exhibit alloy scattering dominating hole conduction at high temperatures. These results demonstrate MgxNy doped p-type ScN and compare well with our previous reports on p-type ScN with manganese nitride (MnxNy) doping.

  17. Re-determination of succinonitrile (SCN) camphor phase diagram

    Science.gov (United States)

    Teng, Jing; Liu, Shan

    2006-04-01

    Low-melting temperature transparent organic materials have been extensively used to study the pattern formation and microstructure evolution. It proves to be very challenging to accurately determine the phase diagram since there is no viable way to measure the composition microscopically. In this paper, we presented the detailed experimental characterization of the phase diagram of succinonitrile (SCN)-camphor binary system. Differential scanning calorimetry, a ring-heater, and the directional solidification technique have been combined to determine the details of the phase diagram by using the purified materials. The advantages and disadvantages have been discussed for the different experimental techniques. SCN and camphor constitute a simple binary eutectic system with the eutectic composition at 23.6 wt% camphor and eutectic temperature at 37.65 °C. The solidus and the solubility of the SCN base solid solution have been precisely determined for the first time in this binary system.

  18. Circadian and pharmacological regulation of casein kinase I in the ...

    Indian Academy of Sciences (India)

    In mammals, the mechanism for the generation of circadian rhythms and entrainment by light–dark (LD) cycles resides in the hypothalamic suprachiasmatic nuclei (SCN), and the principal signal that adjusts this biological clock with environmental timing is the light:dark cycle. Within the SCN, rhythms are generated by a ...

  19. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    In mammals, the mechanism for the generation of circadian rhythms and entrainment by light–dark (LD) cycles resides in the hypothalamic suprachiasmatic nuclei (SCN), and the principal signal that adjusts this biological clock with environmental timing is the light:dark cycle. Within the SCN, rhythms are generated by a ...

  20. Insulin-regulated aminopeptidase immunoreactivity is abundantly present in human hypothalamus and posterior pituitary gland, with reduced expression in paraventricular and suprachiasmatic neurons in chronic schizophrenia.

    Science.gov (United States)

    Bernstein, Hans-Gert; Müller, Susan; Dobrowolny, Hendrik; Wolke, Carmen; Lendeckel, Uwe; Bukowska, Alicja; Keilhoff, Gerburg; Becker, Axel; Trübner, Kurt; Steiner, Johann; Bogerts, Bernhard

    2017-08-01

    The vasopressin- and oxytocin-degrading enzyme insulin-regulated aminopeptidase (IRAP) is expressed in various organs including the brain. However, knowledge about its presence in human hypothalamus is fragmentary. Functionally, for a number of reasons (genetic linkage, hydrolysis of oxytocin and vasopressin, its role as angiotensin IV receptor in learning and memory and others) IRAP might play a role in schizophrenia. We studied the regional and cellular localization of IRAP in normal human brain with special emphasis on the hypothalamus and determined numerical densities of IRAP-expressing cells in the paraventricular, supraoptic and suprachiasmatic nuclei in schizophrenia patients and controls. By using immunohistochemistry and Western blot analysis, IRAP was immunolocalized in postmortem human brains. Cell countings were performed to estimate numbers and numerical densities of IRAP immunoreactive hypothalamic neurons in schizophrenia patients and control cases. Shape, size and regional distribution of IRAP-expressing cells, as well the lack of co-localization with the glia marker glutamine synthetase, show that IRAP is expressed in neurons. IRAP immunoreactive cells were observed in the hippocampal formation, cerebral cortex, thalamus, amygdala and, abundantly, hypothalamus. Double labeling experiments (IRAP and oxytocin/neurophysin 1, IRAP with vasopressin/neurophysin 2) revealed that IRAP is present in oxytocinergic and in vasopressinergic neurons. In schizophrenia patients, the numerical density of IRAP-expressing neurons in the paraventricular and the suprachiasmatic nuclei is significantly reduced, which might be associated with the reduction in neurophysin-containing neurons in these nuclei in schizophrenia. The pathophysiological role of lowered hypothalamic IRAP expression in schizophrenia remains to be established.

  1. Colliding nuclei

    International Nuclear Information System (INIS)

    Balian, Roger; Remaud, Bernard; Suraud, E.; Durand, Dominique; Tamain, Bernard; Gobbi, A.; Cugnon, J.; Drapier, Olivier; Govaerts, Jan; Prieels, Rene

    1995-09-01

    This 14. international school Joliot-Curie of nuclear physic deals with nuclei in collision at high energy. Nine lectures are included in the proceedings of this summer school: 1 - From statistical mechanics outside equilibrium to transport equations (Balian, R.); 2 - Modeling of heavy ions reactions (Remaud, B.); 3 - Kinetic equations in heavy ions physics (Suraud, E.); 4 - Colliding nuclei near the Fermi energy (Durand, D.; Tamain, B.); 5 - From the Fermi to the relativistic energy domain: which observable? For which physics? (Gobbi, A.); 6 - Collisions at relativistic and ultra relativistic energies, Theoretical aspects (Cugnon, J.); 7 - Quark-gluon plasma: experimental signatures (Drapier, O.); 8 - Electroweak interaction: a window on physics beyond the standard model (Govaerts, J.); 9 - Symmetry tests in β nuclear process: polarization techniques (Prieels, R.)

  2. NO and SCN -intercalated layered double hydroxides: structure and ...

    Indian Academy of Sciences (India)

    2018-02-05

    Feb 5, 2018 ... Nitrite ion; thiocyanate ion; layered double hydroxide; structure refinement. 1. Introduction. The layered .... the synthesis. The [Zn−Al−NO2] and [Zn–Al–SCN] LDHs were synthe- sized by coprecipitation at constant pH = 8 and temperature of 60 ... were obtained by the difference Fourier method embedded in.

  3. The Neuronal Transition Probability (NTP) Model for the Dynamic Progression of Non-REM Sleep EEG: The Role of the Suprachiasmatic Nucleus

    CERN Document Server

    Merica, H

    2011-01-01

    Little attention has gone into linking to its neuronal substrates the dynamic structure of non-rapid-eye-movement (NREM) sleep, defined as the pattern of time-course power in all frequency bands across an entire episode. Using the spectral power time-courses in the sleep electroencephalogram (EEG), we showed in the typical first episode, several moves towards-and-away from deep sleep, each having an identical pattern linking the major frequency bands beta, sigma and delta. The neuronal transition probability model (NTP) - in fitting the data well - successfully explained the pattern as resulting from stochastic transitions of the firing-rates of the thalamically-projecting brainstem-activating neurons, alternating between two steady dynamic-states (towards-and-away from deep sleep) each initiated by a so-far unidentified flip-flop. The aims here are to identify this flip-flop and to demonstrate that the model fits well all NREM episodes, not just the first. Using published data on suprachiasmatic nucleus (SCN...

  4. Primordial nuclei

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The recent detection of intergalactic helium by NASA's Astro-2 mission backs up two earlier measurements by ESA and the University of California, San Diego, using instruments aboard the Hubble Space Telescope. Taken together, these results give strong evidence that this helium is primordial, confirming a key prediction of the Big Bang theory. The amount of helium the results imply could also account for some of the Universe's invisible dark matter - material which affects galactic motion but is otherwise undetectable. According to theory, helium nuclei formed at around 100 seconds after the Big Bang, but the amount of helium depended on even earlier events. Initially, protons turned into neutrons with the same probability that neutrons turned into protons. But after about one second, the Universe had cooled down enough for the weak interaction to freeze out. Neutrons continued to decay into the slightly lighter protons, whilst the opposite reaction became much more scarce. At around 100 seconds, thermonuclear fusion reactions could begin, and all the neutrons that were left became absorbed into helium nuclei, leaving the remaining protons locked up in hydrogen. The ratio of helium to hydrogen was therefore determined by events occurring when the Universe was just one second old. Standard models of primordial nucleosynthesis fix this ratio at slightly less than 2 5% by mass. All heavier elements were cooked up much later in the stars, and amount to less than 1 % of the Universe's mass. These predictions have been borne out remarkably well by observation, although proof of the primordial origins of hydrogen and helium has remained elusive until now. Big Bang nucleosynthesis goes on to estimate that primordial baryonic matter in the form of light nuclei could account for around 10% of the Universe's dark matter. All three recent measurements used the same technique of looking at distant quasars, some of the most luminous objects in the Universe, to

  5. Direct projection from the suprachiasmatic nucleus to hypophysiotrophic corticotropin-releasing factor immunoreactive cells in the paraventricular nucleus of the hypothalamus demonstrated...

    DEFF Research Database (Denmark)

    Vrang, N.; Larsen, P.J.; Mikkelsen, J.D.

    1995-01-01

    Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry......Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry...

  6. Common variants at SCN5A-SCN10A and HEY2 are associated with Brugada syndrome, a rare disease with high risk of sudden cardiac death

    DEFF Research Database (Denmark)

    Bezzina, Connie; Barc, Julien; Mizusawa, Yuka

    2013-01-01

    Brugada syndrome is a rare cardiac arrhythmia disorder, causally related to SCN5A mutations in around 20% of cases. Through a genome-wide association study of 312 individuals with Brugada syndrome and 1,115 controls, we detected 2 significant association signals at the SCN10A locus (rs10428132) a...

  7. Improved CuSCN–ZnO diode performance with spray deposited CuSCN

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, S.M., E-mail: s.c.dunn@qmul.ac.uk; Briscoe, J.; Dunn, S.

    2013-03-01

    P-type copper(I) thiocyanate (β-CuSCN) was deposited using a pneumatic micro-spray gun from a saturated solution in propyl sulphide. An as-produced 6 μm CuSCN film exhibited a hole mobility of 70 cm {sup 2}/V·s and conductivity of 0.02 S·m{sup −1}. A zinc oxide (ZnO) nanorod array was filled with CuSCN, demonstrating the capability of the process for filling nanostructured materials. This produced a diode with a n-type ZnO and p-type CuSCN junction. The best performing diodes exhibited rectifications of 3550 at ± 3 V. The electronic characteristics exhibited by the diode were attributed to a compact grain structure of the β-CuSCN giving increased carrier mobility and an absence of cracks preventing electrical shorts between electrode contacts that are typically associated with β-CuSCN films. - Highlights: ► CuSCN depositions using impregnation and a spray technique are compared. ► ZnO nanorod–CuSCN diodes were fabricated to demonstrate device performance. ► Hall mobility measurements show good conductivity of CuSCN films. ► Spray deposition improved film morphology and reduced device production time. ► Device rectifications are higher than previously reported for ZnO–CuSCN diodes.

  8. Synthesis and characterizations of AgSCN nanospheres using AgCl as the precursor

    International Nuclear Information System (INIS)

    Yang Ming; Ma Jing

    2009-01-01

    Nanospheres of AgSCN with an average radius of 30-80 nm have been prepared by a simple reaction between AgCl suspension and KSCN in the presence of gelatin. Gelatin played a decisive role as an inhibitor of the direct attack of SCN - ions to AgCl surfaces and coagulation of the growing AgSCN in producing the spherical AgSCN nanoparticles. The products were characterized by X-ray powder diffraction, transmission electron microscopy and X-ray photoelectron spectra techniques. The electrical conductivity of thin films of as-prepared AgSCN nanoparticles and polyethylene oxide (PEO) at room temperature was measured. The maximum value of electrical conductivity of as-prepared AgSCN-PEO was 1.53 x 10 -5 S cm -1 .

  9. Efficient modeling of chiral media using SCN-TLM method

    Directory of Open Access Journals (Sweden)

    Yaich M.I.

    2004-01-01

    Full Text Available An efficient approach allowing to include linear bi-isotropic chiral materials in time-domain transmission line matrix (TLM calculations by employing recursive evaluation of the convolution of the electric and magnetic fields and susceptibility functions is presented. The new technique consists to add both voltage and current sources in supplementary stubs of the symmetrical condensed node (SCN of the TLM method. In this article, the details and the complete description of this approach are given. A comparison of the obtained numerical results with those of the literature reflects its validity and efficiency.

  10. Cellular Neurophysiology of the Rat Suprachiasmatic Nucleus: Electrical Properties, Neurotransmission, and Mechanisms of Synchronization

    Science.gov (United States)

    1994-07-29

    activity in rabbit mino -atrial node. Journal of Physiology 308, 331-351. CAHILL. (.M. & MFtNAKER. M. (1987). Kynurenic acid blocks suprachiasmatic nucleus...E. (1987) The Retina: An Approachable Part of* the Brain. Harvard University Press. Cambridge. MA. 35. Drucker-Colin R., Aguilar -Roblero R., Garcia

  11. Chronic ethanol consumption disrupts the core molecular clock and diurnal rhythms of metabolic genes in the liver without affecting the suprachiasmatic nucleus.

    Directory of Open Access Journals (Sweden)

    Ashley N Filiano

    Full Text Available Chronic ethanol consumption disrupts several metabolic pathways including β-oxidation and lipid biosynthesis, facilitating the development of alcoholic fatty liver disease. Many of these same metabolic pathways are directly regulated by cell autonomous circadian clocks, and recent studies suggest that disruption of daily rhythms in metabolism contributes to multiple common cardiometabolic diseases (including non-alcoholic fatty liver disease. However, it is not known whether ethanol disrupts the core molecular clock in the liver, nor whether this, in turn, alters rhythms in lipid metabolism. Herein, we tested the hypothesis that chronic ethanol consumption disrupts the molecular circadian clock in the liver and potentially changes the diurnal expression patterns of lipid metabolism genes. Consistent with previous studies, male C57BL/6J mice fed an ethanol-containing diet exhibited higher levels of liver triglycerides compared to control mice, indicating hepatic steatosis. Further, the diurnal oscillations of core clock genes (Bmal1, Clock, Cry1, Cry2, Per1, and Per2 and clock-controlled genes (Dbp, Hlf, Nocturnin, Npas2, Rev-erbα, and Tef were altered in livers from ethanol-fed mice. In contrast, ethanol had only minor effects on the expression of core clock genes in the suprachiasmatic nucleus (SCN. These results were confirmed in Per2(Luciferase knock-in mice, in which ethanol induced a phase advance in PER2::LUC bioluminescence oscillations in liver, but not SCN. Further, there was greater variability in the phase of PER2::LUC oscillations in livers from ethanol-fed mice. Ethanol consumption also affected the diurnal oscillations of metabolic genes, including Adh1, Cpt1a, Cyp2e1, Pck1, Pdk4, Ppargc1a, Ppargc1b and Srebp1c, in the livers of C57BL/6J mice. In summary, chronic ethanol consumption alters the function of the circadian clock in liver. Importantly, these results suggest that chronic ethanol consumption, at levels sufficient to

  12. Resonance Raman Spectrum of the Transient (SCN)2 Free Radical Anion

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N. H.; Pagsberg, Palle Bjørn

    1979-01-01

    The resonance Raman spectrum of the transient species (λmax = 475 nm, τ½ = 1.6 μs) formed by pulse radiolysis of aqueous solutions of thiocyanate, SCN2−, is reported. The spectrum is discussed in terms of the previous assignment of this transient to the radical anion, (SCN)−2. The observed...

  13. Evaluation of Presumably Disease Causing SCN1A Variants in a Cohort of Common Epilepsy Syndromes

    DEFF Research Database (Denmark)

    Lal, Dennis; Reinthaler, Eva M; Dejanovic, Borislav

    2016-01-01

    OBJECTIVE: The SCN1A gene, coding for the voltage-gated Na+ channel alpha subunit NaV1.1, is the clinically most relevant epilepsy gene. With the advent of high-throughput next-generation sequencing, clinical laboratories are generating an ever-increasing catalogue of SCN1A variants. Variants...

  14. Complex SCN8A DNA-abnormalities in an individual with therapy resistant absence epilepsy

    NARCIS (Netherlands)

    Berghuis, Bianca; de Kovel, Carolien G F; van Iterson, Loretta; Lamberts, Robert J.; Sander, Josemir W.; Lindhout, Dick; Koeleman, Bobby P. C.

    Background: De novo SCN8A missense mutations have been identified as a rare dominant cause of epileptic encephalopathy. We described a person with epileptic encephalopathy associated with a mosaic deletion of the SCN8A gene. Methods: Array comparative genome hybridization was used to identify

  15. Ab initio study of structural, electronic and optical properties of MnHg(SCN)4 and FeHg(SCN)4

    International Nuclear Information System (INIS)

    He, K.H.; Zheng, G.; Chen, G.; Lue, T.; Wan, M.; Ji, G.F.

    2007-01-01

    The structural, electronic and optical properties of MnHg(SCN) 4 and FeHg(SCN) 4 were studied by means of quantum-mechanical calculations based on the density-functional theory and pseudopotential method. The lattice constants can be compared with the experimental values when the effects of temperature are considered. The peaks of partial density of states of S, C, N and Hg of FeHg(SCN) 4 have a tendency of shifting to the higher energy levels relative to those of MnHg(SCN) 4 . The distributions of the 3d electronic states in the transition metal atoms show quite large difference and decide different optical properties. We found that absorptional peaks of FeHg(SCN) 4 lag behind those of MnHg(SCN) 4 and the peak in the infrared range has a higher absorptional intensity, which are in accord with the experimental results. By analyzing the distributions and transitions of the 3d electronic states, we explained the different absorption phenomena

  16. Ab initio study of structural, electronic and optical properties of MnHg(SCN){sub 4} and FeHg(SCN){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    He, K.H. [College of Maths and Physics, China University of Geosciences, Wuhan 430074 (China)]. E-mail: he23981006@126.com; Zheng, G. [College of Maths and Physics, China University of Geosciences, Wuhan 430074 (China)]. E-mail: gzheng25@yahoo.com; Chen, G. [College of Maths and Physics, China University of Geosciences, Wuhan 430074 (China); Lue, T. [College of Maths and Physics, China University of Geosciences, Wuhan 430074 (China); Wan, M. [College of Maths and Physics, China University of Geosciences, Wuhan 430074 (China); Ji, G.F. [Laboratory for Shock Wave and Detonation Physics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2007-03-01

    The structural, electronic and optical properties of MnHg(SCN){sub 4} and FeHg(SCN){sub 4} were studied by means of quantum-mechanical calculations based on the density-functional theory and pseudopotential method. The lattice constants can be compared with the experimental values when the effects of temperature are considered. The peaks of partial density of states of S, C, N and Hg of FeHg(SCN){sub 4} have a tendency of shifting to the higher energy levels relative to those of MnHg(SCN){sub 4}. The distributions of the 3d electronic states in the transition metal atoms show quite large difference and decide different optical properties. We found that absorptional peaks of FeHg(SCN){sub 4} lag behind those of MnHg(SCN){sub 4} and the peak in the infrared range has a higher absorptional intensity, which are in accord with the experimental results. By analyzing the distributions and transitions of the 3d electronic states, we explained the different absorption phenomena.

  17. Ovarian steroid regulation of monoamine oxidase-A and -B mRNAs in the macaque dorsal raphe and hypothalamic nuclei.

    Science.gov (United States)

    Gundlah, Chrisana; Lu, Nick Z; Bethea, Cynthia L

    2002-03-01

    The serotonin neural system plays a pivotal role in mood, affective regulation and integrative cognition, as well as numerous autonomic functions. We have shown that ovarian steroids alter the expression of several genes in the dorsal raphe of macaques, which may increase serotonin synthesis and decrease serotonin autoinhibition. Another control point in aminergic neurotransmission involves degradation by MAO. This enzyme occurs in two isoforms, A and B, which have different substrate preferences. We questioned the effect of ovarian steroid hormones on MAO-A and MAO-B mRNA expression in the dorsal raphe nucleus and hypothalamus using in situ hybridization in non-human primates. Rhesus monkeys ( Macaca mulatta; n=5/group) were spayed and either placebo treated (controls), estrogen (E) treated (28 days), progesterone (P) treated (14 days placebo+14 days P), or E+P treated (14 days E+14 days E+P). Perfusion-fixed sections (25 microm) were hybridized with a 233 bp MAO-A, or a 373 bp MAO-B, radiolabeled-antisense monkey specific probes. Autoradiographic films were analyzed by densitometry, which was performed with NIH Image Software. MAO-A and -B mRNAs were detected in the dorsal raphe nucleus (DRN) and in the hypothalamic suprachiasmatic nucleus (SCN), preoptic area (POA), paraventricular nucleus (PVN), supraoptic nucleus (SON), lateral hypothalamus (LH) and ventromedial nucleus (VMN). MAO-A mRNA optical density was significantly decreased by E, P, and E+P in the DRN and in the hypothalamic PVN, LH and VMN. Ovarian hormones had no effect on MAO-B mRNA expression in the DRN. However, there was a significant decrease in MAO-B optical density in the hypothalamic POA, LH and VMN with E, P or E+P treatment. Pixel area generally reflected optical density. Ovarian steroids decreased MAO-A, but not B, in the raphe nucleus. However, both MAO-A and B were decreased in discrete hypothalamic nuclei by hormone replacement. These data suggest that the transcriptional regulation of

  18. Concurrent decrease of vasopressin and protein kinase C-alpha immunoreactivity during the light phase in the vole suprachiasmatic nucleus

    NARCIS (Netherlands)

    Jansen, K; Van der Zee, EA; Gerkema, MP

    1998-01-01

    Vasopressin (AVP) is a major neuropeptide in the suprachiasmatic nucleus, the mammalian hypothalamic circadian pacemaker. Protein kinase C alpha is a putatively coupled intracellular messenger. Mean numbers of AVP- and protein kinase C alpha- immunoreactive neurons were determined in the

  19. Continuous illumination through larval development suppresses dopamine synthesis in the suprachiasmatic nucleus, causing activation of α-MSH synthesis in the pituitary and abnormal metamorphic skin pigmentation in flounder.

    Science.gov (United States)

    Itoh, Kae; Washio, Youhei; Fujinami, Yuichiro; Shimizu, Daisuke; Uji, Susumu; Yokoi, Hayato; Suzuki, Tohru

    2012-04-01

    In order to better understand the endocrine aberrations related to abnormal metamorphic pigmentation that appear in flounder larvae reared in tanks, this study examined the effects of continuous 24-h illumination (LL) through larval development on the expression of tyrosine hydroxylase-1 (th1), proopiomelanocortin (pomc), α-melanophore-stimulating hormone (α-MSH) and melanin concentrating hormone (MCH), which are known to participate in the control of background adaptation of body color. We observed two conspicuous deviations in the endocrine system under LL when compared with natural light conditions (LD). First, LL severely suppressed th1 expression in the dopaminergic neurons in the anterior diencephalon, including the suprachiasmatic nucleus (SCN). Second, pomc and α-MSH expression in the pars intermedia melanotrophs was enhanced by LL. Skin color was paler under LL than LD before metamorphic pigmentation, and abnormal metamorphic pigmentation occurred at a higher ratio in LL. We therefore hypothesize that continuous LL inhibited dopamine synthesis in the SCN, which resulted in up-regulation of pomc mRNA expression in the melanotrophs. In spite of the up-regulation of pomc in the melanotrophs, larval skin was adjusted to be pale by MCH which was not affected by LL. Accumulation of α-MSH in the melanotrophs is caused by uncoupling of α-MSH synthesis and secretion due to inhibitory role of MCH on α-MSH secretion, which results in abnormal metamorphic pigmentation by affecting differentiation of adult-type melanophores. Our data demonstrate that continuous illumination at the post-embryonic stage has negative effects on the neuroendocrine system and pituitary in flounder. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Remarkable Phenytoin Sensitivity in 4 Children with SCN8A-related Epilepsy : A Molecular Neuropharmacological Approach

    NARCIS (Netherlands)

    Boerma, Ragna S.; Braun, Kees P.; van de Broek, Maarten P. H.; van Berkestijn, Frederique M. C.; Swinkels, Marielle E.; Hagebeuk, Eveline O.; Lindhout, Dick; van Kempen, Marjan; Boon, Maartje; Nicolai, Joost; de Kovel, Carolien G.; Brilstra, Eva H.; Koeleman, Bobby P. C.

    Mutations in SCN8A are associated with epilepsy and intellectual disability. SCN8A encodes for sodium channel Nav1.6, which is located in the brain. Gain-of-function missense mutations in SCN8A are thought to lead to increased firing of excitatory neurons containing Nav1.6, and therefore to lead to

  1. The bidirectional phase-shifting effects of melatonin on the arginine vasopressin secretion rhythm in rat suprachiasmatic nuclei in vitro

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Irena; Vaněček, Jiří; Zemková, Hana

    2003-01-01

    Roč. 116, 1-2 (2003), s. 80-85 ISSN 0169-328X R&D Projects: GA ČR GA309/02/1519; GA ČR GA309/02/1479; GA AV ČR IAA5011103; GA AV ČR IAA5011105 Institutional research plan: CEZ:AV0Z5011922 Keywords : melatonin * arginine vasopressin * circadian rhythm Subject RIV: ED - Physiology Impact factor: 2.107, year: 2003

  2. Circadian rhythmicity in AVP secretion and GABAergic synaptic transmission in the rat suprachiasmatic nucleus

    Czech Academy of Sciences Publication Activity Database

    Kretschmannová, Karla; Svobodová, Irena; Balík, Aleš; Mazna, Petr; Zemková, Hana

    2005-01-01

    Roč. 1048, - (2005), s. 103-115 ISSN 0077-8923 R&D Projects: GA ČR(CZ) GA309/02/1519; GA AV ČR(CZ) IAA5011103; GA AV ČR(CZ) IAA5011408 Institutional research plan: CEZ:AV0Z5011922 Keywords : circadian rhythms * suprachiasmatic nucleus * melatonin Subject RIV: FH - Neurology Impact factor: 1.971, year: 2005

  3. Photoperiodic modulation of the hepatic clock by the suprachiasmatic nucleus and feeding regime in mice

    Czech Academy of Sciences Publication Activity Database

    Parkanová, Daniela; Nováková, Marta; Sosniyenko, Serhiy; Sumová, Alena

    2012-01-01

    Roč. 35, č. 9 (2012), s. 1446-1457 ISSN 0953-816X R&D Projects: GA ČR(CZ) GA305/09/0321; GA ČR(CZ) GAP303/11/0668 EU Projects: European Commission(XE) 18741 - EUCLOCK Institutional research plan: CEZ:AV0Z50110509 Keywords : suprachiasmatic nucleus * photoperiod * circadian clock * clock gene * mice Subject RIV: FH - Neurology Impact factor: 3.753, year: 2012

  4. Differential regulation of fos family genes in the ventrolateral and dorsomedial subdivisions of the rat suprachiasmatic nucleus.

    Science.gov (United States)

    Schwartz, W J; Carpino, A; de la Iglesia, H O; Baler, R; Klein, D C; Nakabeppu, Y; Aronin, N

    2000-01-01

    Extensive studies have established that light regulates c-fos gene expression in the suprachiasmatic nucleus, the site of an endogenous circadian clock, but relatively little is known about the expression of genes structurally related to c-fos, including fra-1, fra-2 and fosB. We analysed the photic and temporal regulation of these genes at the messenger RNA and immunoreactive protein levels in rat suprachiasmatic nucleus, and we found different expression patterns after photic stimulation and depending on location in the ventrolateral or dorsomedial subdivisions. In the ventrolateral suprachiasmatic nucleus, c-fos, fra-2 and fosB expression was stimulated after a subjective-night (but not subjective-day) light pulse. Expression of the fra-2 gene was prolonged following photic stimulation, with elevated messenger RNA and protein levels that appeared unchanged for at least a few hours beyond the c-fos peak. Unlike c-fos and fra-2, the fosB gene appeared to be expressed constitutively in the ventrolateral suprachiasmatic nucleus throughout the circadian cycle; immunohistochemical analysis suggested that delta FosB was the protein product accounting for this constitutive expression, while FosB was induced by the subjective-night light pulse. In the dorsomedial suprachiasmatic nucleus, c-fos and fra-2 expression exhibited an endogenous circadian rhythm, with higher levels during the early subjective day, although the relative abundance was much lower than that measured after light pulses in the ventrolateral suprachiasmatic nucleus. Double-label immunohistochemistry suggested that some of the dorsomedial cells responsible for the circadian expression of c-Fos also synthesized arginine vasopressin. No evidence of suprachiasmatic nucleus fra-1 expression was found. In summary, fos family genes exhibit differences in their specific expression patterns in the suprachiasmatic nucleus, including their photic and circadian regulation in separate cell populations in the

  5. Distinctive electro-clinical features of epilepsy in severe early onset SCN8A encephalopathy

    DEFF Research Database (Denmark)

    Gardella, E.; Larsen, Jan; Wolff, M.

    2015-01-01

    Rationale: SCN8A mutations have been recently associated with early infantile epileptic encephalopathy with a broad phenotypic spectrum. We aim to further delineate the interictal and ictal video-EEG features of a peculiar clinical subgroup of patients affected by early onset SCN8A-related enceph......Rationale: SCN8A mutations have been recently associated with early infantile epileptic encephalopathy with a broad phenotypic spectrum. We aim to further delineate the interictal and ictal video-EEG features of a peculiar clinical subgroup of patients affected by early onset SCN8A....../9 patients (follow-up 10-25 months); all seizure types have been documented. Patients had both focal and generalized seizures (FS,GS), the latter consisting of GTCS, pseudo-absences, spasms and myoclonus. FS were usually prolonged (3-5 min), with prominent hypomotor and vegetative semiology, evolving...

  6. An R1632C variant in the SCN5A gene causing Brugada syndrome.

    Science.gov (United States)

    García-Molina, Esperanza; Sabater-Molina, María; Muñoz, Carmen; Ruiz-Espejo, Francisco; Gimeno, Juan R

    2016-06-01

    Brugada syndrome (BS) is an electrical disease, inherited in an autosomal dominant manner. BS is caused by mutations in up to 13 different genes. SCN5A is the gene most frequently mutated in BS, although this presents an incomplete penetrance. The present case study investigated the SCN5A gene in a family exhibiting BS. Direct sequencing of the SCN5A gene was performed to identify mutations and a familial investigation was performed. A novel variant was identified in the voltage‑sensing domain of the SCN5A protein. This familial investigation revealed one novel asymptomatic carrier in the family. Genetic investigations are useful to classify individuals who require more frequent clinical monitoring and to stratify the risk of developing the disease.

  7. Epidural Analgesia with Ropivacaine during Labour in a Patient with a SCN5A Gene Mutation

    Directory of Open Access Journals (Sweden)

    A. L. M. J. van der Knijff-van Dortmont

    2016-01-01

    Full Text Available SCN5A gene mutations can lead to ion channel defects which can cause cardiac conduction disturbances. In the presence of specific ECG characteristics, this mutation is called Brugada syndrome. Many drugs are associated with adverse events, making anesthesia in patients with SCN5A gene mutations or Brugada syndrome challenging. In this case report, we describe a pregnant patient with this mutation who received epidural analgesia using low dose ropivacaine and sufentanil during labour.

  8. Multiple arrhythmic syndromes in a newborn, owing to a novel mutation in SCN5A

    DEFF Research Database (Denmark)

    Calloe, Kirstine; Schmitt, Nicole; Grubb, Søren

    2011-01-01

    Mutations in the SCN5A gene have been linked to Brugada syndrome (BrS), conduction disease, Long QT syndrome (LQT3), atrial fibrillation (AF), and to pre- and neonatal ventricular arrhythmias.......Mutations in the SCN5A gene have been linked to Brugada syndrome (BrS), conduction disease, Long QT syndrome (LQT3), atrial fibrillation (AF), and to pre- and neonatal ventricular arrhythmias....

  9. Nuclei and quantum worlds

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    2000-01-01

    This document gathers the slides and their commentaries that have been presented at the conference 'physics and fundamental questions' by P. Chomaz. The author reviews the different quantum aspects of nuclei: tunnel effect, symmetries, magic numbers, wave functions, size, shapes and deformations. The author shows that nuclei are quantum objects of great complexity, their structures are not yet well understood and the study of exotic nuclei will continue bringing valuable information

  10. Ab initio investigation of the SCN{sup -} chemisorption of single-walled boron nitride nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, Alireza, E-mail: alireza.soltani46@yahoo.com [Young Researchers Club, Gorgan Branch, Islamic Azad University, Gorgan (Iran, Islamic Republic of); Ahmadian, Nasim [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Kanani, Yaser [Department of Chemistry, Gorgan Branch, Islamic Azad University, Gorgan (Iran, Islamic Republic of); Dehnokhalaji, Aliakbar; Mighani, Hossein [Department of Chemistry, Faculty of Science, Golestan University, Gorgan (Iran, Islamic Republic of)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer We explored the adsorption behavior of the SCN{sup -} on outer surface BNNTs via DFT. Black-Right-Pointing-Pointer We reported the NBO charge distribution of SCN{sup -} on BNNTs surface. Black-Right-Pointing-Pointer Chemisorptions are observed for SCN{sup -} on Al- and Ga-doped BNNTs. Black-Right-Pointing-Pointer Notable changes are observed in the electronic properties of BNNT after doping. - Abstract: The thiocyanate anion (SCN{sup -}) adsorption capacity of zigzag single-walled boron nitride nanotubes (SWBNNTs) is studied via first-principles theory. Binding energy corresponding to the most stable configuration of SCN{sup -}/BNNT is found to be -148.42 kJ mol{sup -1}, which is typical for the chemisorptions. Our results indicate that both aluminum and gallium doping can significantly enhance the adsorption energy of SCN{sup -}/BNNTs complexes. Our electronic results reveal that there is a significant orbital hybridization between two species in adsorption process being an evidence of strong interaction. Thus, we arrive at the prediction that the BNNTs nanocage can be implemented as suitable sensor for practical applications.

  11. Mutation analysis of CACNA1S and SCN4A in patients with hypokalemic periodic paralysis.

    Science.gov (United States)

    Wang, Xiao-Ying; Ren, Bing-Wen; Yong, Zeng-Hua; Xu, Hong-Yan; Fu, Qiu-Xia; Yao, He-Bin

    2015-10-01

    Mutations in CACNA1S (calcium channel, voltage‑dependent, L type, alpha 1S subunit) and SCN4A (sodium channel, voltage‑gated, type IV, alpha subunit) are associated with hypokalemic periodic paralysis (HPP). The aim of the current study was to investigate CACNA1S and SCN4A mutations in patients with HPP. Mutations in CACNA1S and SCN4A were detected in three familial hypokalemic periodic paralysis (FHPP) pedigrees and in two thyrotoxic hypokalemic periodic paralysis (THPP) pedigrees using polymerase chain reaction, DNA sequencing and sequence alignment with GenBank data. A single base mutation from cytosine to guanine at site 1582 was identified in exon 11 of CACNA1S in one FHPP pedigree, resulting in an arginine to glycine (R528G) substitution. A single base mutation from thymine to cytosine at site 2012 was identified in exon 12 of SCN4A in one THPP pedigree, resulting in a phenylalanine to serine (F671S) substitution. No mutations in CACNA1S or SCN4A were identified in the remaining three pedigrees. The present study indicated that CACNA1S and SCN4A mutations are relatively rare in patients with HPP, and further studies are required to determine whether these mutation‑associated substitutions are representative of patients with HPP.

  12. Reduction of the thermal conductivity of the thermoelectric material ScN by Nb alloying

    DEFF Research Database (Denmark)

    Tureson, Nina; Van Nong, Ngo; Fournier, Daniele

    2017-01-01

    ) orientation. The crystal structure, morphology, thermal conductivity, and thermoelectric and electrical properties were investigated. The ScN reference film exhibited a Seebeck coefficient of −45 μV/K and a power factor of 6 × 10−4 W/m K2 at 750 K. Estimated from room temperature Hall measurements, all...... samples exhibit a high carrier density of the order of 1021 cm−3. Inclusion of heavy transition metals into ScN enables the reduction in thermal conductivity by an increase in phonon scattering. The Nb inserted ScN thin films exhibited a thermal conductivity lower than the value of the ScN reference (10.......5 W m−1 K−1) down to a minimum value of 2.2 Wm−1 K−1. Insertion of Nb into ScN thus resulted in a reduction in thermal conductivity by a factor of ∼5 due to the mass contrast in ScN, which increases the phonon scattering in the material....

  13. Influence of annealing on microstructural and photoelectrochemical characteristics of CuSCN thin films via electrochemical process

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Mao-Chia [Institute of Materials Science and Engineering, National Central University, Jhongli 32001, Taiwan (China); Wang, TsingHai [Department of Biomedical Engineering and Environment Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Tseng, Yao-Tien [Institute of Materials Science and Engineering, National Central University, Jhongli 32001, Taiwan (China); Wu, Ching-Chen [Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan (China); Lin, Jing-Chie, E-mail: jclin4046@gmail.com [Institute of Materials Science and Engineering, National Central University, Jhongli 32001, Taiwan (China); Department of Mechanical Engineering, National Central University, Jhongli 32001, Taiwan (China); Hsu, Wan-Yi [Department of Mechanical Engineering, National Central University, Jhongli 32001, Taiwan (China); Chang, Wen-Sheng [Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan (China); Chen, I-Chen [Institute of Materials Science and Engineering, National Central University, Jhongli 32001, Taiwan (China); Peng, Kun-Cheng [Department of Materials Engineering, Mingchi University of Technology, New Taipei City 24301, Taiwan (China)

    2015-02-15

    Highlights: • CuSCN films were synthesized by electrochemical process. • The parameter of CuSCN films was annealing temperature. • The photoelectrochemical characteristics of CuSCN films were investigated. - Abstract: Thin films of p-type β-CuSCN were deposited on indium-tin oxide glass substrates via electrochemical process. Various annealing temperatures (200, 300 and 400 °C) were taken into consideration. The influence of annealing temperature on structural, optical, electrical and photoelectrochemical characteristics of β-CuSCN thin films were investigated. Results from X-ray diffraction indicated as-obtained β-CuSCN thin film was in a hexagonal close pack crystal structure. We found that the crystallographic orientation changed and the optical energy band gap slightly increased with increasing annealing temperatures. These properties made CuSCN films annealed at 400 °C a better photoelectrochemical performance with photocurrent density of about −0.39 mA/cm{sup 2} at −0.5 V vs. SCE. This value is about 5 times higher than the as-deposited CuSCN film. Observed higher photocurrent density is likely due to the intrinsic of a higher charge carrier concentration, and a lower resistance within CuSCN crystal and at CuSCN/electrolyte interface.

  14. Identification of novel light-induced genes in the suprachiasmatic nucleus

    Directory of Open Access Journals (Sweden)

    Piontkivska Helen

    2007-11-01

    Full Text Available Abstract Background The transmission of information about the photic environment to the circadian clock involves a complex array of neurotransmitters, receptors, and second messenger systems. Exposure of an animal to light during the subjective night initiates rapid transcription of a number of immediate-early genes in the suprachiasmatic nucleus of the hypothalamus. Some of these genes have known roles in entraining the circadian clock, while others have unknown functions. Using laser capture microscopy, microarray analysis, and quantitative real-time PCR, we performed a comprehensive screen for changes in gene expression immediately following a 30 minute light pulse in suprachiasmatic nucleus of mice. Results The results of the microarray screen successfully identified previously known light-induced genes as well as several novel genes that may be important in the circadian clock. Newly identified light-induced genes include early growth response 2, proviral integration site 3, growth-arrest and DNA-damage-inducible 45 beta, and TCDD-inducible poly(ADP-ribose polymerase. Comparative analysis of promoter sequences revealed the presence of evolutionarily conserved CRE and associated TATA box elements in most of the light-induced genes, while other core clock genes generally lack this combination of promoter elements. Conclusion The photic signalling cascade in the suprachiasmatic nucleus activates an array of immediate-early genes, most of which have unknown functions in the circadian clock. Detected evolutionary conservation of CRE and TATA box elements in promoters of light-induced genes suggest that the functional role of these elements has likely remained the same over evolutionary time across mammalian orders.

  15. Neurons of the rat suprachiasmatic nucleus show a circadian rhythm in membrane properties that is lost during prolonged whole-cell recording

    NARCIS (Netherlands)

    Schaap, J.; Bos, N. P.; de Jeu, M. T.; Geurtsen, A. M.; Meijer, J. H.; Pennartz, C. M.

    1999-01-01

    The suprachiasmatic nucleus is commonly considered to contain the main pacemaker of behavioral and hormonal circadian rhythms. Using whole-cell patch-clamp recordings, the membrane properties of suprachiasmatic nucleus neurons were investigated in order to get more insight in membrane physiological

  16. Isobars in nuclei

    International Nuclear Information System (INIS)

    Beurtey, R.

    1975-01-01

    The present situation of the theoretical studies and experimental material concerning the potential presence of virtual nucleon excited states (isobars) in nuclei is reported. Three particular aspects are examined: the theoretical work devoted to the isobar content of nuclei (especially deuteron), the experimental material concerning isobar exchange and the attempts to obtain a direct evidence for such objects in the deuteron (spectator method) [fr

  17. Neutron rich nuclei

    International Nuclear Information System (INIS)

    Foucher, R.

    1979-01-01

    If some β - emitters are particularly interesting to study in light, medium, and heavy nuclei, another (and also) difficult problem is to know systematically the properties of these neutron rich nuclei far from the stability line. A review of some of their characteristics is presented. How far is it possible to be objective in the interpretation of data is questioned and implications are discussed

  18. Nuclei in high forms

    International Nuclear Information System (INIS)

    Szymanski, Z.; Berger, J.F.; Heenen, P.H.; Heyde, K.; Haas, B.; Janssens, R.; Paya, D.; Gogny, D.; Huber, G.; Bjoernholm, S.; Brack, M.

    1991-01-01

    The purpose of 1991 Joliot-Curie Summer School is to review the most advances in the understanding of the nuclei physics after the considerable progress in gamma spectroscopy. It covers the following topics: Highly and super-deformed nuclei, nuclear structures, mean-field approach and beyond, fission isomers, nuclear excitations with long lifetime and metal clusters

  19. Eta mesons in nuclei

    International Nuclear Information System (INIS)

    Liu, L.C.

    1987-01-01

    The possibility of producing eta-mesic nuclei by the use of pions is discussed. If these nuclei are observed experimentally, then the binding energies of the eta in this new nuclear matter can be used to extract accurately the eta-N-N* coupling constant in a nucleus. The framework for these calculations is the coupled channel isobar model

  20. Association between SCN1A polymorphism and carbamazepine-resistant epilepsy

    Science.gov (United States)

    Abe, Tomohide; Seo, Takayuki; Ishitsu, Takateru; Nakagawa, Takehiro; Hori, Masaharu; Nakagawa, Kazuko

    2008-01-01

    WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT The SCN1Agene encodes the α subunit of the neuronal voltage-gated sodium channel, which is a target for carbamazepine and other antiepileptic drugs (AEDs). Recent studies have demonstrated that a common polymorphism of SCN1A IVS5-91 G > A was associated with carbamazepine and phenytoin use in daily practice. However, it has not been determined whether the polymorphism affects carbamazepine or other AED responsiveness. WHAT THIS STUDY ADDS This study demonstrated a significant association between the SCN1A IVS5-91 AA genotype and carbamazepine-resistant epilepsy, while the AA genotype did not affect carbamazepine use. AIMS To establish whether the SCN1A IVS5-91 G > A polymorphism of the SCN1A gene, which encodes the neuronal sodium channel α subunit, affects responsivenss to the antiepileptic drugs (AEDS) carbamazepine and/or phenytoin. METHODS SCN1A IVS5-91 G > A polymorphism was genotyped in 228 Japanese epileptic patients treated with AEDs. The association between AED responsiveness and the polymorphism was estimated by logistic regression analysis, adjusting for clinical factors affecting the outcome of AED therapy. RESULTS The frequency of the AA genotype was significantly higher in carbamazepine-resistant patients (odds ratio, 2.7; 95% confidence interval (CI), 1.1, 7.1) and was insignificantly higher in AED-resistant patients. CONCLUSIONS This is the first report demonstrating an association between the SCN1A polymorphism and carbamazepine-resistant epilepsy. PMID:18489610

  1. A network of (autonomic) clock outputs

    NARCIS (Netherlands)

    Kalsbeek, A.; Perreau-Lenz, S.; Buijs, R. M.

    2006-01-01

    The circadian clock in the suprachiasmatic nuclei (SCN) is composed of thousands of oscillator neurons, each of which is dependent on the cell-autonomous action of a defined set of circadian clock genes. A major question is still how these individual oscillators are organized into a biological clock

  2. A network of (autonomic) clock outputs

    NARCIS (Netherlands)

    Kalsbeek, A.; Perreau-Lenz, S.; Buijs, R. M.

    2006-01-01

    The circadian clock in the suprachiasmatic nuclei (SCN) is composed of thousands of oscillator neurons, each dependent on the cell-autonomous action of a defined set of circadian clock genes. A major question is still how these individual oscillators are organized into a biological clock that

  3. The diurnal modulation of hormonal responses in the rat varies with different stimuli

    NARCIS (Netherlands)

    Kalsbeek, A.; Ruiter, M.; La Fleur, S. E.; van Heijningen, C.; Buijs, R. M.

    2003-01-01

    The circadian clock, located in the suprachiasmatic nuclei (SCN) of the hypothalamus not only controls the basal daily temporal organization of many neuroendocrine functions, but also its responsiveness. We studied the time-of-day influence on plasma changes in adrenocorticotropic hormone (ACTH),

  4. Sleep deprivation and caffeine treatment potentiate photic resetting of the master circadian clock in a diurnal rodent

    NARCIS (Netherlands)

    Kumar Jha, Pawan; Bouâouda, Hanan; Gourmelen, Sylviane; Dumont, Stephanie; Fuchs, Fanny; Goumon, Yannick; Bourgin, Patrice; Kalsbeek, A.; Challet, Etienne

    Circadian rhythms in nocturnal and diurnal mammals are primarily synchronized to local time by the light-dark cycle. However, non-photic factors, such as behavioural arousal and metabolic cues, can also phase-shift the master clock in the suprachiasmatic nuclei (SCN) and/or reduce the synchronizing

  5. Mutations in sodium channel {beta}-subunit SCN3B are associated with early-onset lone atrial fibrillation

    DEFF Research Database (Denmark)

    Olesen, Morten Salling; Jespersen, Thomas; Nielsen, Jonas Bille

    2011-01-01

    AIMS: Atrial fibrillation (AF) is the most frequent arrhythmia. Screening of SCN5A-the gene encoding the a-subunit of the cardiac sodium channel-has indicated that disturbances of the sodium current may play a central role in the mechanism of lone AF. We tested the hypothesis that lone AF in young...... across species. Electrophysiological studies on the SCN3B mutation were carried out and all three SCN3B mutations caused a functionally reduced sodium channel current. One synonymous variant was found in SCN4B. CONCLUSION: In 192 young lone AF patients, we found three patients with suspected disease...

  6. SCN8A mutations in Chinese patients with early onset epileptic encephalopathy and benign infantile seizures.

    Science.gov (United States)

    Wang, Jiaping; Gao, Hua; Bao, Xinhua; Zhang, Qingping; Li, Jiarui; Wei, Liping; Wu, Xiru; Chen, Yan; Yu, Shujie

    2017-09-18

    SCN8A mutations have recently been associated with epilepsy and neurodevelopmental disorders. This study aimed to broaden the phenotypic-spectrum of disease related with SCN8A mutations. To identify the pathogenic gene of a Chinese family, in which six members suffered from epilepsy, whole-exome sequencing was performed. In addition, target next-generation sequencing (NGS) was performed on 178 sporadic patients, who had epilepsy of unknown etiology within 6 months after birth. A detailed clinical history was obtained. A heterozygous missense mutation of SCN8A was identified in the Chinese family. Six de novo mutations of SCN8A were detected in 6 sporadic patients with epilepsy. In the family, six members developed seizures within a few years after birth. Five of them had milder clinical performance, that they had normal cognition and developmental milestones, and seizure-free was achieved by mono-therapy. The other one affected member presented with refractory epilepsy and developmental regression. She died from sudden unexpected death in epilepsy (SUDEP) at 17-year-old. Clinical features of six sporadic patients with SCN8A mutations were diverse, ranging from severe epileptic encephalopathy to benign epilepsy with normal cognition. Seizures started at the mean age of 3.9 months (from 2 months to 6 months). Seizure-free was achieved in four of them by mono- or multi-antiepileptic drugs. Five of them demonstrated mild or severe psychomotor retardation, whereas the other one was normal in development and intelligence. Our findings extend the spectrum of SCN8A mutations and the clinical features of patients with SCN8A mutations. The majority of SCN8A mutations were de novo, inherited mutations from the heterozygous parents can also occur. The phenotypic spectrum of SCN8A mutation varied largely. Most affected patients manifested as refractory epilepsy and severe intellectual disability, only a small number of patients presented with milder clinical patterns

  7. Fine Mapping of the SCN Resistance Locus rhg1-b from PI 88788

    Directory of Open Access Journals (Sweden)

    Myungsik Kim

    2010-09-01

    Full Text Available Soybean cyst nematode (SCN ( Ichinohe is the most economically damaging soybean [ (L. Merr.] pest in the USA and genetic resistance is a key component for its control. Although SCN resistance is quantitative, the locus on chromosome 18 (formerly known as Linkage Group G confers a high level of resistance. The objective of this study was to fine-map the allele that is derived from plant introduction (PI 88788. F and F plants and F lines from crosses between SCN resistant and susceptible genotypes were tested with genetic markers to identify recombination events close to . Lines developed from these recombinant plants were then tested for resistance to the SCN isolate PA3, which originally had an HG type 0 phenotype, and with genetic markers. Analysis of lines carrying key recombination events positioned between the simple sequence repeat (SSR markers BARCSOYSSR_18_0090 and BARCSOYSSR_18_0094. This places to a 67-kb region of the ‘Williams 82’ genome sequence. The receptor-like kinase gene that has been previously identified as a candidate for the ‘Peking’-derived SCN resistant gene is adjacent to, but outside of, the interval defined in the present study.

  8. Perovskite solar cells with CuSCN hole extraction layers yield stabilized efficiencies greater than 20%

    Science.gov (United States)

    Arora, Neha; Dar, M. Ibrahim; Hinderhofer, Alexander; Pellet, Norman; Schreiber, Frank; Zakeeruddin, Shaik Mohammed; Grätzel, Michael

    2017-11-01

    Perovskite solar cells (PSCs) with efficiencies greater than 20% have been realized only with expensive organic hole-transporting materials. We demonstrate PSCs that achieve stabilized efficiencies exceeding 20% with copper(I) thiocyanate (CuSCN) as the hole extraction layer. A fast solvent removal method enabled the creation of compact, highly conformal CuSCN layers that facilitate rapid carrier extraction and collection. The PSCs showed high thermal stability under long-term heating, although their operational stability was poor. This instability originated from potential-induced degradation of the CuSCN/Au contact. The addition of a conductive reduced graphene oxide spacer layer between CuSCN and gold allowed PSCs to retain >95% of their initial efficiency after aging at a maximum power point for 1000 hours under full solar intensity at 60°C. Under both continuous full-sun illumination and thermal stress, CuSCN-based devices surpassed the stability of spiro-OMeTAD-based PSCs.

  9. Cloning and expression of a zebrafish SCN1B ortholog and identification of a species-specific splice variant

    Directory of Open Access Journals (Sweden)

    Slat Emily A

    2007-07-01

    Full Text Available Abstract Background Voltage-gated Na+ channel β1 (Scn1b subunits are multi-functional proteins that play roles in current modulation, channel cell surface expression, cell adhesion, cell migration, and neurite outgrowth. We have shown previously that β1 modulates electrical excitability in vivo using a mouse model. Scn1b null mice exhibit spontaneous seizures and ataxia, slowed action potential conduction, decreased numbers of nodes of Ranvier in myelinated axons, alterations in nodal architecture, and differences in Na+ channel α subunit localization. The early death of these mice at postnatal day 19, however, make them a challenging model system to study. As a first step toward development of an alternative model to investigate the physiological roles of β1 subunits in vivo we cloned two β1-like subunit cDNAs from D. rerio. Results Two β1-like subunit mRNAs from zebrafish, scn1ba_tv1 and scn1ba_tv2, arise from alternative splicing of scn1ba. The deduced amino acid sequences of Scn1ba_tv1 and Scn1ba_tv2 are identical except for their C-terminal domains. The C-terminus of Scn1ba_tv1 contains a tyrosine residue similar to that found to be critical for ankyrin association and Na+ channel modulation in mammalian β1. In contrast, Scn1ba_tv2 contains a unique, species-specific C-terminal domain that does not contain a tyrosine. Immunohistochemical analysis shows that, while the expression patterns of Scn1ba_tv1 and Scn1ba_tv2 overlap in some areas of the brain, retina, spinal cord, and skeletal muscle, only Scn1ba_tv1 is expressed in optic nerve where its staining pattern suggests nodal expression. Both scn1ba splice forms modulate Na+ currents expressed by zebrafish scn8aa, resulting in shifts in channel gating mode, increased current amplitude, negative shifts in the voltage dependence of current activation and inactivation, and increases in the rate of recovery from inactivation, similar to the function of mammalian β1 subunits. In

  10. Coexistence of CLCN1 and SCN4A mutations in one family suffering from myotonia.

    Science.gov (United States)

    Maggi, Lorenzo; Ravaglia, Sabrina; Farinato, Alessandro; Brugnoni, Raffaella; Altamura, Concetta; Imbrici, Paola; Camerino, Diana Conte; Padovani, Alessandro; Mantegazza, Renato; Bernasconi, Pia; Desaphy, Jean-François; Filosto, Massimiliano

    2017-12-01

    Non-dystrophic myotonias are characterized by clinical overlap making it challenging to establish genotype-phenotype correlations. We report clinical and electrophysiological findings in a girl and her father concomitantly harbouring single heterozygous mutations in SCN4A and CLCN1 genes. Functional characterization of N1297S hNav1.4 mutant was performed by patch clamp. The patients displayed a mild phenotype, mostly resembling a sodium channel myotonia. The CLCN1 c.501C>G (p.F167L) mutation has been already described in recessive pedigrees, whereas the SCN4A c.3890A>G (p.N1297S) variation is novel. Patch clamp experiments showed impairment of fast and slow inactivation of the mutated Nav1.4 sodium channel. The present findings suggest that analysis of both SCN4A and CLCN1 genes should be considered in myotonic patients with atypical clinical and neurophysiological features.

  11. Measurement and correlation of vapour pressures of pyridine and thiophene with [EMIM][SCN] ionic liquid

    International Nuclear Information System (INIS)

    Khelassi-Sefaoui, Asma; Mutelet, Fabrice; Mokbel, Ilham; Jose, Jacques; Negadi, Latifa

    2014-01-01

    Highlights: • VLE of (pyridine + [EMIM][SCN]), or (thiophene + [EMIM][SCN]) binary mixtures were measured. • The investigated temperatures are 273 K to 363 K. • The PC-SAFT equation of state has been used to correlate the vapour pressures of the binary systems. - Abstract: In this work (vapour + liquid) equilibrium (VLE) measurements were performed on binary systems of the ionic liquid 1-ethyl-3-methylimidazolium thiocynate [EMIM][SCN] with thiophene or pyridine at pressures close to the atmospheric pressure using a static device at temperatures between 273 K and 363 K. Experimental data were correlated by the PC-SAFT EoS. The binary interaction parameters k ij were optimised on experimental VLE data. The results obtained for the two binary mixtures studied in this paper indicate that the PC-SAFT EoS can be used to represent systems containing ionic liquids

  12. Infantile Epileptic Encephalopathy Associated With SCN2A Mutation Responsive to Oral Mexiletine.

    Science.gov (United States)

    Foster, Laura A; Johnson, Maria R; MacDonald, John T; Karachunski, Peter I; Henry, Thomas R; Nascene, David R; Moran, Brian P; Raymond, Gerald V

    2017-01-01

    Genetic alterations are significant causes of epilepsy syndromes; especially early-onset epileptic encephalopathies and voltage-gated sodium channelopathies are among the best described. Mutations in the SCN2A subunit of voltage-gated sodium channels have been associated with benign familial neonatal-infantile seizures, generalized epilepsy febrile seizures plus, and an early-onset infantile epileptic encephalopathy. We describe two infants with medically refractory seizures due to a de novo SCN2A mutation. The first child responded to intravenous lidocaine with significant reduction in seizure frequency and was successfully transitioned to enteral mexiletine. Mexiletine was subsequently used in a second infant with reduction in seizure frequency. Class 1b antiarrhythmic agents, lidocaine and mexiletine, may be useful in infants with medically refractory early infantile epileptic encephalopathy secondary to mutations in SCN2A. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The phenotypic spectrum of SCN8A encephalopathy

    DEFF Research Database (Denmark)

    Larsen, Jan; Carvill, Gemma L; Gardella, Elena

    2015-01-01

    of the SCN8A gene in 683 patients with a range of epileptic encephalopathies. In addition, we ascertained cases with SCN8A mutations from other centers. A detailed clinical history was obtained together with a review of EEG and imaging data. RESULTS: Seventeen patients with de novo heterozygous mutations...... refractory to antiepileptic therapy. Development was normal in 12 patients and slowed after seizure onset, often with regression; 5 patients had delayed development from birth. All patients developed intellectual disability, ranging from mild to severe. Motor manifestations were prominent including hypotonia...

  14. How atomic nuclei cluster.

    Science.gov (United States)

    Ebran, J-P; Khan, E; Nikšić, T; Vretenar, D

    2012-07-18

    Nucleonic matter displays a quantum-liquid structure, but in some cases finite nuclei behave like molecules composed of clusters of protons and neutrons. Clustering is a recurrent feature in light nuclei, from beryllium to nickel. Cluster structures are typically observed as excited states close to the corresponding decay threshold; the origin of this phenomenon lies in the effective nuclear interaction, but the detailed mechanism of clustering in nuclei has not yet been fully understood. Here we use the theoretical framework of energy-density functionals, encompassing both cluster and quantum liquid-drop aspects of nuclei, to show that conditions for cluster formation can in part be traced back to the depth of the confining nuclear potential. For the illustrative example of neon-20, we show that the depth of the potential determines the energy spacings between single-nucleon orbitals in deformed nuclei, the localization of the corresponding wavefunctions and, therefore, the degree of nucleonic density clustering. Relativistic functionals, in particular, are characterized by deep single-nucleon potentials. When compared to non-relativistic functionals that yield similar ground-state properties (binding energy, deformation, radii), they predict the occurrence of much more pronounced cluster structures. More generally, clustering is considered as a transitional phenomenon between crystalline and quantum-liquid phases of fermionic systems.

  15. H558R, a common SCN5A polymorphism, modifies the clinical phenotype of Brugada syndrome by modulating DNA methylation of SCN5A promoters.

    Science.gov (United States)

    Matsumura, Hiroya; Nakano, Yukiko; Ochi, Hidenori; Onohara, Yuko; Sairaku, Akinori; Tokuyama, Takehito; Tomomori, Shunsuke; Motoda, Chikaaki; Amioka, Michitaka; Hironobe, Naoya; Toshishige, Masaaki; Takahashi, Shinya; Imai, Katsuhiko; Sueda, Taijiro; Chayama, Kazuaki; Kihara, Yasuki

    2017-12-04

    A common SCN5A polymorphism H558R (c.1673 A > G, rs1805124) improves sodium channel activity in mutated channels and known to be a genetic modifier of Brugada syndrome patients (BrS). We investigated clinical manifestations and underlying mechanisms of H558R in BrS. We genotyped H558R in 100 BrS (mean age 45 ± 14 years; 91 men) and 1875 controls (mean age 54 ± 18 years; 1546 men). We compared clinical parameters in BrS with and without H558R (H558R+ vs. H558R- group, N = 9 vs. 91). We also obtained right atrial sections from 30 patients during aortic aneurysm operations and compared SCN5A expression and methylation with or without H558R. H558R was less frequent in BrS than controls (9.0% vs. 19.2%, P = 0.028). The VF occurrence ratio was significantly lower (0% vs. 29.7%, P = 0.03) and spontaneous type 1 ECG was less observed in H558R+ than H558R- group (33.3% vs. 74.7%, P = 0.01). The SCN5A expression level was significantly higher and the methylation rate was significantly lower in sections with H558R (N = 10) than those without (0.98 ± 0.14 vs. 0.83 ± 0.19, P = 0.04; 0.7 ± 0.2% vs. 1.6 ± 0.1%, P = 0.004, respectively). In BrS with heterozygous H558R, the A allele mRNA expression was 1.38 fold higher than G allele expression. The SCN5A polymorphism H558R may be a modifier that protects against VF occurrence in BrS. The H558R decreased the SCN5A promoter methylation and increased the expression level in cardiac tissue. An allelic expression imbalance in BrS with a heterozygous H558R may also contribute to the protective effects in heterozygous mutations.

  16. Embryonic type Na+ channel β-subunit, SCN3B masks the disease phenotype of Brugada syndrome.

    Science.gov (United States)

    Okata, Shinichiro; Yuasa, Shinsuke; Suzuki, Tomoyuki; Ito, Shogo; Makita, Naomasa; Yoshida, Tetsu; Li, Min; Kurokawa, Junko; Seki, Tomohisa; Egashira, Toru; Aizawa, Yoshiyasu; Kodaira, Masaki; Motoda, Chikaaki; Yozu, Gakuto; Shimojima, Masaya; Hayashiji, Nozomi; Hashimoto, Hisayuki; Kuroda, Yusuke; Tanaka, Atsushi; Murata, Mitsushige; Aiba, Takeshi; Shimizu, Wataru; Horie, Minoru; Kamiya, Kaichiro; Furukawa, Tetsushi; Fukuda, Keiichi

    2016-09-28

    SCN5A is abundant in heart and has a major role in I Na . Loss-of-function mutation in SCN5A results in Brugada syndrome (BrS), which causes sudden death in adults. It remains unclear why disease phenotype does not manifest in the young even though mutated SCN5A is expressed in the young. The aim of the present study is to elucidate the timing of the disease manifestation in BrS. A gain-of-function mutation in SCN5A also results in Long QT syndrome type 3 (LQTS3), leading to sudden death in the young. Induced pluripotent stem cells (iPSCs) were generated from a patient with a mixed phenotype of LQTS3 and BrS with the E1784K SCN5A mutation. Here we show that electrophysiological analysis revealed that LQTS3/BrS iPSC-derived cardiomyocytes recapitulate the phenotype of LQTS3 but not BrS. Each β-subunit of the sodium channel is differentially expressed in embryonic and adult hearts. SCN3B is highly expressed in embryonic hearts and iPSC-derived cardiomyocytes. A heterologous expression system revealed that I Na of mutated SCN5A is decreased and SCN3B augmented I Na of mutated SCN5A. Knockdown of SCN3B in LQTS3/BrS iPSC-derived cardiomyocytes successfully unmasked the phenotype of BrS. Isogenic control of LQTS3/BrS (corrected-LQTS3/BrS) iPSC-derived cardiomyocytes gained the normal electrophysiological properties.

  17. Differences in sino-atrial and atrio-ventricular function with age and sex attributable to the Scn5a+/- mutation in a murine cardiac model.

    Science.gov (United States)

    Jeevaratnam, K; Zhang, Y; Guzadhur, L; Duehmke, R M; Lei, M; Grace, A A; Huang, C L-H

    2010-09-01

    To investigate the interacting effects of age and sex on electrocardiographic (ECG) features of Scn5a(+/-) mice modelling Brugada syndrome. Recordings were performed on anaesthetized wild-type (WT) and Scn5a(+/-) mice and differences attributable to these risk factors statistically stratified. Scn5a(+/-) exerted sex-dependent effects upon sino-atrial function that only became apparent with age. RR intervals were greater in old male than in old female Scn5a(+/-). Atrio-ventricular (AV) conduction was slower in young female mice, whether WT and Scn5a(+/-), than the corresponding young male WT and Scn5a(+/-). However, PR intervals lengthened with age in male but not in female Scn5a(+/-) giving the greatest PR intervals in old male Scn5a(+/-) compared with either old male WT or young male Scn5a(+/-) mice. In contrast, PR intervals were similar in old female Scn5a(+/-) and in old female WT. QTc was prolonged in Scn5a(+/-) compared with WT, and female Scn5a(+/-) compared with female WT. Age-dependent alterations in durations of ventricular repolarization relative to WT affected male but not female Scn5a(+/-). Thus, T-wave durations were greater in old male Scn5a(+/-) compared with old male WT, but indistinguishable between old female Scn5a(+/-) and old female WT. Finally, analysis for combined interactions of genotype, age and sex demonstrated no effects on P wave and QRS durations and QTc intervals. We demonstrate for the first time that age, sex and genotype exert both independent and interacting ECG effects. The latter suggest alterations in cardiac pacemaker function, atrio-ventricular conduction and ventricular repolarization greatest in ageing male Scn5a(+/-).

  18. Structure of tellurium nuclei

    International Nuclear Information System (INIS)

    Cizewski, J.A.; Henry, R.G.; Lee, C.S.

    1991-01-01

    The tellurium nuclei with two protons outside of the Z = 50 shell closure exhibit a complicated structure with signatures of collective vibrational, two-quasiparticle, possibly moderately deformed intruder configurations. To study further the structure of the tellurium nuclei the authors made extensive measurements of the (α,xnγ) reactions on even Sn targets, populating excitations in even- and odd-mass Te nuclei up to moderate angular momenta. By examining limits on possible intraband transitions, results suggest that a possible rotational band structure is not supported by the data, since intraband transitions are of comparable E2 strength to interband transitions. In the odd-A isotopes they concentrated on identifying the higher angular momentum negative-parity states (which probe the role of the h 11/2 neutron in the core), and the search for non-yrast negative-parity states, which are a sensitive measure of the shape of the collective excitations

  19. Vibrations in deformed nuclei

    International Nuclear Information System (INIS)

    Aprahamian, A.

    1992-01-01

    Quadrupole oscillations around a deformed shape give rise to vibrations in deformed nuclei. Single phonon vibrations of K = 0 (β) and K = 2 (γ) are a systematic feature in deformed nuclei, but the existence of multi-phonon vibrations had remained an open question until the recently reported results in 168 Er. In this nucleus, a two-phonon K = 4(γγ) band was observed at approximately 2.5 times the energy of the single γ vibration. The authors have studied several deformed rare-earth nuclei using the ( 4 He,2n) reaction in order to map out the systematic behavior of these multi-phonon vibrations. Recently, they have identified a similar K = 4 band in 154 Gd

  20. Novel SCN5A mutation associated with idiopathic ventricular fibrillation due to subclinical Brugada syndrome

    Directory of Open Access Journals (Sweden)

    Juan Jiménez-Jáimez

    2011-12-01

    Full Text Available Idiopathic ventricular fibrillation can be caused by subclinical channelopathies such as Brugada syndrome. Our objective is to study the clinical behaviour of a new SCN5A mutation found in a woman with idiopathic ventricular fibrillation. A 53-year-old woman presented with multiple episodes of ventricular fibrillation, a structurally normal heart and normal baseline electrocardiogram. Genetic testing included KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2 and KCNJ2 and identified a mutation in SCN5A (D1816fs/g98747-98748insT. We studied 15 immediate family members by means of electrocardiogram, echocardiogram, flecainide challenge test and genetic study. Eight subjects had the mutation. The flecainide challenge test was positive for Brugada syndrome in two subjects in the case group and none in the control group. The PR and QRS intervals on the baseline electrocardiogram were longer in the case group. The left atrial volume indexed to body surface was higher in the case group, likely due to the fact that two patients with the mutation had atrial fibrillation and none had it in the control group. The D1816fs/g98747-98748insT mutation in SCN5A may be associated with idiopathic ventricular fibrillation and Brugada syndrome with a broad phenotypic spectrum and incomplete penetrance. Genetic testing may be useful to identify the etiology of idiopathic ventricular fibrillation in patients with a negative thorough clinical evaluation.

  1. Novel mutations in human and mouse SCN4A implicate AMPK in myotonia and periodic paralysis

    Science.gov (United States)

    Corrochano, Silvia; Männikkö, Roope; Joyce, Peter I.; McGoldrick, Philip; Lassi, Glenda; Raja Rayan, Dipa L.; Blanco, Gonzalo; Quinn, Colin; Liavas, Andrianos; Lionikas, Arimantas; Amior, Neta; Dick, James; Healy, Estelle G.; Stewart, Michelle; Carter, Sarah; Hutchinson, Marie; Bentley, Liz; Fratta, Pietro; Cortese, Andrea; Cox, Roger; Brown, Steve D. M.; Tucci, Valter; Wackerhage, Henning; Amato, Anthony A.; Greensmith, Linda; Koltzenburg, Martin; Hanna, Michael G.; Acevedo-Arozena, Abraham

    2014-01-01

    Mutations in the skeletal muscle channel (SCN4A), encoding the Nav1.4 voltage-gated sodium channel, are causative of a variety of muscle channelopathies, including non-dystrophic myotonias and periodic paralysis. The effects of many of these mutations on channel function have been characterized both in vitro and in vivo. However, little is known about the consequences of SCN4A mutations downstream from their impact on the electrophysiology of the Nav1.4 channel. Here we report the discovery of a novel SCN4A mutation (c.1762A>G; p.I588V) in a patient with myotonia and periodic paralysis, located within the S1 segment of the second domain of the Nav1.4 channel. Using N-ethyl-N-nitrosourea mutagenesis, we generated and characterized a mouse model (named draggen), carrying the equivalent point mutation (c.1744A>G; p.I582V) to that found in the patient with periodic paralysis and myotonia. Draggen mice have myotonia and suffer from intermittent hind-limb immobility attacks. In-depth characterization of draggen mice uncovered novel systemic metabolic abnormalities in Scn4a mouse models and provided novel insights into disease mechanisms. We discovered metabolic alterations leading to lean mice, as well as abnormal AMP-activated protein kinase activation, which were associated with the immobility attacks and may provide a novel potential therapeutic target. PMID:25348630

  2. The SCN9A channel and plasma membrane depolarization promote cellular senescence through Rb pathway.

    Science.gov (United States)

    Warnier, Marine; Flaman, Jean-Michel; Chouabe, Christophe; Wiel, Clotilde; Gras, Baptiste; Griveau, Audrey; Blanc, Elena; Foy, Jean-Philippe; Mathot, Pauline; Saintigny, Pierre; Van Coppenolle, Fabien; Vindrieux, David; Martin, Nadine; Bernard, David

    2018-02-15

    Oncogenic signals lead to premature senescence in normal human cells causing a proliferation arrest and the elimination of these defective cells by immune cells. Oncogene-induced senescence (OIS) prevents aberrant cell division and tumor initiation. In order to identify new regulators of OIS, we performed a loss-of-function genetic screen and identified that the loss of SCN9A allowed cells to escape from OIS. The expression of this sodium channel increased in senescent cells during OIS. This upregulation was mediated by NF-κB transcription factors, which are well-known regulators of senescence. Importantly, the induction of SCN9A by an oncogenic signal or by p53 activation led to plasma membrane depolarization, which in turn, was able to induce premature senescence. Computational and experimental analyses revealed that SCN9A and plasma membrane depolarization mediated the repression of mitotic genes through a calcium/Rb/E2F pathway to promote senescence. Taken together, our work delineates a new pathway, which involves the NF-κB transcription factor, SCN9A expression, plasma membrane depolarization, increased calcium, the Rb/E2F pathway and mitotic gene repression in the regulation of senescence. This work thus provides new insight into the involvement of ion channels and plasma membrane potential in the control of senescence. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  3. Genetic and phenotypic heterogeneity suggest therapeutic implications in SCN2A-related disorders

    NARCIS (Netherlands)

    Wolff, Markus; Johannesen, Katrine M; Hedrich, Ulrike B S; Masnada, Silvia; Rubboli, Guido; Gardella, Elena; Lesca, Gaetan; Ville, Dorothée; Milh, Mathieu; Villard, Laurent; Afenjar, Alexandra; Chantot-Bastaraud, Sandra; Mignot, Cyril; Lardennois, Caroline; Nava, Caroline; Schwarz, Niklas; Gérard, Marion; Perrin, Laurence; Doummar, Diane; Auvin, Stéphane; Miranda, Maria J; Hempel, Maja; Brilstra, Eva; Knoers, Nine; Verbeek, Nienke; van Kempen, Marjan; Braun, Kees P; Mancini, Grazia; Biskup, Saskia; Hörtnagel, Konstanze; Döcker, Miriam; Bast, Thomas; Loddenkemper, Tobias; Wong-Kisiel, Lily; Baumeister, Friedrich M; Fazeli, Walid; Striano, Pasquale; Dilena, Robertino; Fontana, Elena; Zara, Federico; Kurlemann, Gerhard; Klepper, Joerg; Thoene, Jess G; Arndt, Daniel H; Deconinck, Nicolas; Schmitt-Mechelke, Thomas; Maier, Oliver; Muhle, Hiltrud; Wical, Beverly; Finetti, Claudio; Brückner, Reinhard; Pietz, Joachim; Golla, Günther; Jillella, Dinesh; Linnet, Karen M; Charles, Perrine; Moog, Ute; Õiglane-Shlik, Eve; Mantovani, John F; Park, Kristen; Deprez, Marie; Lederer, Damien; Mary, Sandrine; Scalais, Emmanuel; Selim, Laila; Van Coster, Rudy; Lagae, Lieven; Nikanorova, Marina; Hjalgrim, Helle; Korenke, G Christoph; Trivisano, Marina; Specchio, Nicola; Ceulemans, Berten; Dorn, Thomas; Helbig, Katherine L; Hardies, Katia; Stamberger, Hannah; de Jonghe, Peter; Weckhuysen, Sarah; Lemke, Johannes R; Krägeloh-Mann, Ingeborg; Helbig, Ingo; Kluger, Gerhard; Lerche, Holger; Møller, Rikke S

    2017-01-01

    Mutations in SCN2A, a gene encoding the voltage-gated sodium channel Nav1.2, have been associated with a spectrum of epilepsies and neurodevelopmental disorders. Here, we report the phenotypes of 71 patients and review 130 previously reported patients. We found that (i) encephalopathies with

  4. Multifocal Ectopic Purkinje-Related Premature Contractions A New SCN5A-Related Cardiac Channelopathy

    NARCIS (Netherlands)

    Laurent, Gabriel; Saal, Samuel; Amarouch, Mohamed Yassine; Béziau, Delphine M.; Marsman, Roos F. J.; Faivre, Laurence; Barc, Julien; Dina, Christian; Bertaux, Geraldine; Barthez, Olivier; Thauvin-Robinet, Christel; Charron, Philippe; Fressart, Véronique; Maltret, Alice; Villain, Elisabeth; Baron, Estelle; Mérot, Jean; Turpault, Rodolphe; Coudière, Yves; Charpentier, Flavien; Schott, Jean-Jacques; Loussouarn, Gildas; Wilde, Arthur A. M.; Wolf, Jean-Eric; Baró, Isabelle; Kyndt, Florence; Probst, Vincent

    2012-01-01

    Objectives The aim of this study was to describe a new familial cardiac phenotype and to elucidate the electrophysiological mechanism responsible for the disease. Background Mutations in several genes encoding ion channels, especially SCN5A, have emerged as the basis for a variety of inherited

  5. Common and rare variants in SCN10A> modulate the risk of atrial fibrillation

    DEFF Research Database (Denmark)

    Jabbari, Javad; Olesen, Morten S.; Yuan, Lei

    2015-01-01

    Background: Genome-wide assocn. studies have shown that the common single nucleotide polymorphism rs6800541 located in SCN10A, encoding the voltage-gated Nav1.8 sodium channel, is assocd. with PR-interval prolongation and atrial fibrillation (AF). Single nucleotide polymorphism rs6800541 is in hi...

  6. SCN2A mutation in a Chinese boy with infantile spasm - response to Modified Atkins Diet.

    Science.gov (United States)

    Wong, Virginia C N; Fung, C W; Kwong, Anna K Y

    2015-08-01

    Mutation of SCN2A, encoding for voltage-gated sodium channel type II alpha subunit, has been demonstrated in various epilepsy phenotypes, ranging from benign to severe epileptic disorders and recently this had been reported for cases with infantile spasm (IS). We study a 6 years-old Chinese boy with severe developmental delay who had infantile spasm since 15 months. He later had severe intellectual disability and autistic features. He failed to respond to most anticonvulsants. Modified Atkins Diet was introduced at 4 years of age and he showed a seizure remission for 12 months with only 1 anticonvulsants. To clarify the unknown etiology, mutations were screened for genes associated with brain development or synaptic function. A heterozygous mutation (c.3631G>A; p.E1211K) was identified in exon 21 of SCN2A gene. This mutation has been reported previously only in a Japanese patient with IS. This is the first case of SCN2A mutation identified in Chinese. Similarity of our case and one Japanese case of infantile spasm indicated that this E1211K mutation is important as possible etiology of IS. Trial of Modified Atkins Diet for other cases of infantile spasm with similar SCN2A mutations is worthwhile pursuing. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  7. Unusual association of SCN2A epileptic encephalopathy with severe cortical dysplasia detected by prenatal MRI.

    Science.gov (United States)

    Bernardo, Silvia; Marchionni, Enrica; Prudente, Sabrina; De Liso, Paola; Spalice, Alberto; Giancotti, Antonella; Manganaro, Lucia; Pizzuti, Antonio

    2017-05-01

    We present an atypical association of SCN2A epileptic encephalopathy with severe cortical dysplasia. SCN2A mutations are associated with epileptic syndromes from benign to extremely severe in absence of such macroscopic brain findings. Prenatal MRI (Magnetic Resonance Imaging) in a 32 weeks fetus, with US (Ultrasonography) diagnosis of isolated ventriculomegaly showed CNS (Central Nervous System) dysplasia characterized by lack of differentiation between cortical and subcortical layers, pachygyria and corpus callosum dysgenesis. Postnatal MRI confirmed the prenatal findings. On day 6 the baby presented a focal status epilepticus, partially controlled by phenobarbital, phenytoin, and levetiracetam. After three weeks a moderate improvement in seizure control has been achieved with carbamazepine. Exome sequencing detected a de novo heterozygous mutation in the SCN2A gene, encoding the α II -subunit of a sodium channel. The patient findings expand the phenotype spectrum of SCN2A mutations to epileptic encephalopathies with macroscopic brain developmental features. Copyright © 2017 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  8. Weak interactions with nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1983-01-01

    Nuclei provide systems where the strong, electomagnetic, and weak interactions are all present. The current picture of the strong interactions is based on quarks and quantum chromodynamics (QCD). The symmetry structure of this theory is SU(3)/sub C/ x SU(2)/sub W/ x U(1)/sub W/. The electroweak interactions in nuclei can be used to probe this structure. Semileptonic weak interactions are considered. The processes under consideration include beta decay, neutrino scattering and weak neutral-current interactions. The starting point in the analysis is the effective Lagrangian of the Standard Model

  9. Disintegration of comet nuclei

    Science.gov (United States)

    Ksanfomality, Leonid V.

    2012-02-01

    The breaking up of comets into separate pieces, each with its own tail, was seen many times by astronomers of the past. The phenomenon was in sharp contrast to the idea of the eternal and unchangeable celestial firmament and was commonly believed to be an omen of impending disaster, especially for comets with tails stretching across half the sky. It is only now that we have efficient enough space exploration tools to see comet nuclei and even - in the particular case of small comet Hartley-2 in 2010 - to watch their disintegration stage. There are also other suspected candidates for disintegration in the vast family of comet nuclei and other Solar System bodies.

  10. SCN2A encephalopathy: A major cause of epilepsy of infancy with migrating focal seizures.

    Science.gov (United States)

    Howell, Katherine B; McMahon, Jacinta M; Carvill, Gemma L; Tambunan, Dimira; Mackay, Mark T; Rodriguez-Casero, Victoria; Webster, Richard; Clark, Damian; Freeman, Jeremy L; Calvert, Sophie; Olson, Heather E; Mandelstam, Simone; Poduri, Annapurna; Mefford, Heather C; Harvey, A Simon; Scheffer, Ingrid E

    2015-09-15

    De novo SCN2A mutations have recently been associated with severe infantile-onset epilepsies. Herein, we define the phenotypic spectrum of SCN2A encephalopathy. Twelve patients with an SCN2A epileptic encephalopathy underwent electroclinical phenotyping. Patients were aged 0.7 to 22 years; 3 were deceased. Seizures commenced on day 1-4 in 8, week 2-6 in 2, and after 1 year in 2. Characteristic features included clusters of brief focal seizures with multiple hourly (9 patients), multiple daily (2), or multiple weekly (1) seizures, peaking at maximal frequency within 3 months of onset. Multifocal interictal epileptiform discharges were seen in all. Three of 12 patients had infantile spasms. The epileptic syndrome at presentation was epilepsy of infancy with migrating focal seizures (EIMFS) in 7 and Ohtahara syndrome in 2. Nine patients had improved seizure control with sodium channel blockers including supratherapeutic or high therapeutic phenytoin levels in 5. Eight had severe to profound developmental impairment. Other features included movement disorders (10), axial hypotonia (11) with intermittent or persistent appendicular spasticity, early handedness, and severe gastrointestinal symptoms. Mutations arose de novo in 11 patients; paternal DNA was unavailable in one. Review of our 12 and 34 other reported cases of SCN2A encephalopathy suggests 3 phenotypes: neonatal-infantile-onset groups with severe and intermediate outcomes, and a childhood-onset group. Here, we show that SCN2A is the second most common cause of EIMFS and, importantly, does not always have a poor developmental outcome. Sodium channel blockers, particularly phenytoin, may improve seizure control. © 2015 American Academy of Neurology.

  11. Electromagnetic structure of nuclei

    International Nuclear Information System (INIS)

    Arnold, R.G.

    1986-07-01

    A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs

  12. Mesons and light nuclei

    International Nuclear Information System (INIS)

    Truhlik, E.; Mach, R.

    1992-01-01

    62 papers and one summary talk were presented at the conference, on subject matters in between nuclear physics (mainly light nuclei) and elementary particle physics, as indicated by the session headings (1) Electroweak nuclear interaction (2) Nuclear physics with pions and antiprotons (3) Nuclear physics with strange particles (4) Relativistic nuclear physics (5) Quark degrees of freedom. (Quittner)

  13. Nucleons in nuclei (II)

    International Nuclear Information System (INIS)

    Laget, J.M.

    1988-01-01

    This summary is a review of our understanding of nuclei in terms of hadrons exchanging mesons. The open problems are: the determination of the high momentum components of nuclear systems, the role of the three-body forces and the nature of the short range correlations. The ways of studying these problems are discussed

  14. Physics of Unstable Nuclei

    Science.gov (United States)

    Khoa, Dao Tien; Egelhof, Peter; Gales, Sydney; Giai, Nguyen Van; Motobayashi, Tohru

    2008-04-01

    Studies at the RIKEN RI beam factory / T. Motobayashi -- Dilute nuclear states / M. Freer -- Studies of exotic systems using transfer reactions at GANIL / D. Beaumel et al. -- First results from the Magnex large-acceptance spectrometer / A. Cunsolo et al. -- The ICHOR project and spin-isospin physics with unstable beams / H. Sakai -- Structure and low-lying states of the [symbol]He exotic nucleus via direct reactions on proton / V. Lapoux et al. -- Shell gap below [symbol]Sn based on the excited states in [symbol]Cd and [symbol]In / M. Górska -- Heavy neutron-rich nuclei produced in the fragmentation of a [symbol]Pb beam / Zs. Podolyák et al. -- Breakup and incomplete fusion in reactions of weakly-bound nuclei / D.J. Hinde et al. -- Excited states of [symbol]B and [symbol]He and their cluster aspect / Y. Kanada-En'yo et al. -- Nuclear reactions with weakly-bound systems: the treatment of the continuum / C. H. Dasso, A. Vitturi -- Dynamic evolution of three-body decaying resonances / A. S. Jensen et al. -- Prerainbow oscillations in [symbol]He scattering from the Hoyle state of [symbol]C and alpha particle condensation / S. Ohkubo, Y. Hirabayashi -- Angular dispersion behavior in heavy ion elastic scattering / Q. Wang et al. -- Microscopic optical potential in relativistic approach / Z.Yu. Ma et al. -- Exotic nuclei studied in direct reactions at low momentum transfer - recent results and future perspectives at fair / P. Egelhof -- Isotopic temperatures and symmetry energy in spectator fragmentation / M. De Napoli et al. -- Multi-channel algebraic scattering theory and the structure of exotic compound nuclei / K. Amos et al. -- Results for the first feasibility study for the EXL project at the experimental storage ring at GSI / N. Kalantar-Nayestanaki et al. -- Coulomb excitation of ISOLDE neutron-rich beams along the Z = 28 chain / P. Van Duppen -- The gamma decay of the pygmy resonance far from stability and the GDR at finite temperature / G. Benzoni et al

  15. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  16. Shape Deformations in Atomic Nuclei

    OpenAIRE

    Hamamoto, Ikuko; Mottelson, Ben R.

    2011-01-01

    The ground states of some nuclei are described by densities and mean fields that are spherical, while others are deformed. The existence of non-spherical shape in nuclei represents a spontaneous symmetry breaking.

  17. Sick sinus syndrome, progressive cardiac conduction disease, atrial flutter and ventricular tachycardia caused by a novel SCN5A mutation

    DEFF Research Database (Denmark)

    Holst, Anders G; Liang, Bo; Jespersen, Thomas

    2010-01-01

    Mutations in the cardiac sodium channel encoded by the gene SCN5A can result in a wide array of phenotypes. We report a case of a young male with a novel SCN5A mutation (R121W) afflicted by sick sinus syndrome, progressive cardiac conduction disorder, atrial flutter and ventricular tachycardia. His...... father carried the same mutation, but had a milder phenotype, presenting with progressive cardiac conduction later in life. The mutation was found to result in a loss-of-function in the sodium current. In conclusion, the same SCN5A mutation can result in a wide array of clinical phenotypes and perhaps...

  18. Nuclei in Astrophysics

    Science.gov (United States)

    Penionzhkevich, Yu. E.

    2016-06-01

    This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclearphysics methods for studying cosmic objects and properties of the Universe. The results of investigations in nuclear reactions, induced by radioactive nuclear beams, make it possible to analyze the nucleosynthesis scenario in the region of light elements in a new manner.

  19. Pion coupling to nuclei

    International Nuclear Information System (INIS)

    Dumbrajs, O.

    1981-01-01

    The concept of the pion-nucleus coupling constants is discussed. Methods of their determination are reviewed. These include: forward dispersion relations, extrapolation of differential cross sections to the poles in the angular variable, analysis of data on electromagnetic form factors with the use of the PCAC and CVC hypotheses, pion photoproduction at threshold and low-energy theorems. Our present knowledge of the pion coupling to the He, Li, Be, C, N and O nuclei is summarized. (author)

  20. Chaotic behavior in nuclei

    International Nuclear Information System (INIS)

    Mitchel, G.; Shriner, J.

    2005-01-01

    Although the predictions of Random Matrix Theory (RMT) were available by the early 1960s, data of sufficiently high quality to adequately test the theory were only obtained a decade later by Rainwater. It was another decade later that Bohigas, Haq and Pandey combined the best available nuclear resonance data - the Columbia neutron resonances in heavy nuclei and the TUNL proton resonances in lighter nuclei - to form the Nuclear Data Ensemble. They obtained excellent agreement for the level statistics with the RMT predictions. The expected Porter-Thomas (PT) distribution was considered very early. However, since the widths (amplitudes squared) are measured, the predicted Gaussian distribution for the amplitudes was only qualitatively confirmed. A much more sensitive test was performed by measuring two widths and the relative phase between the two amplitudes. By comparison of the width and amplitude correlations, the Gaussian distribution was confirmed at the 1% level. Following the Bohigas conjecture - that quantum analogs of classically chaotic systems obey RMT - there was an explosion of activity utilizing level statistics in many different quantum systems. In nuclei the focus was verifying the range of applicability of RMT. Of particular interest was the effect of collectivity and of excitation energy on statistical properties. The effect of symmetry breaking on level statistics was examined and early predictions by Dyson were confirmed. The effect of symmetry breaking on the width distribution was also measured for the first time. Although heuristic arguments predicted no change from the PT distribution, experimentally there was a large deviation from the PT prediction. Later theoretical efforts were consistent with this result. The stringent conditions placed on the experiments - for eigenvalue tests the data need to be essentially perfect (few or no missing levels or mis assigned quantum numbers) - has limited the amount of suitable experimental data. The

  1. Anomalously high thermoelectric power factor in epitaxial ScN thin films

    International Nuclear Information System (INIS)

    Kerdsongpanya, Sit; Zukauskaite, Agne; Jensen, Jens; Birch, Jens; Lu Jun; Hultman, Lars; Wingqvist, Gunilla; Eklund, Per; Van Nong, Ngo; Pryds, Nini

    2011-01-01

    Thermoelectric properties of ScN thin films grown by reactive magnetron sputtering on Al 2 O 3 (0001) wafers are reported. X-ray diffraction and elastic recoil detection analyses show that the composition of the films is close to stoichiometry with trace amounts (∼1 at. % in total) of C, O, and F. We found that the ScN thin-film exhibits a rather low electrical resistivity of ∼2.94 μΩm, while its Seebeck coefficient is approximately ∼-86 μV/K at 800 K, yielding a power factor of ∼2.5 x 10 -3 W/mK 2 . This value is anomalously high for common transition-metal nitrides.

  2. Recurrent and non-recurrent mutations of SCN8A in epileptic encephalopathy

    Directory of Open Access Journals (Sweden)

    Jacy L Wagnon

    2015-05-01

    Full Text Available Mutations of the voltage-gated sodium channel SCN8A have been identified in approximately 1% of nearly 1,000 children with early-infantile epileptic encephalopathies (EIEE who have been tested by DNA sequencing. EIEE caused by mutation of SCN8A is designated EIEE13 (OMIM #614558. Affected children have seizure onset before 18 months of age as well as developmental and cognitive disabilities, movement disorders, and a high incidence of sudden death (SUDEP. EIEE13 is caused by de novo missense mutations of evolutionarily conserved residues in the Nav1.6 channel protein. One-third of the mutations are recurrent, and many occur at CpG dinucleotides. In this review we discuss the effect of pathogenic mutations on the structure of the channel protein, the rate of recurrent mutation, and changes in channel function underlying this devastating disorder.

  3. Evaluation of Presumably Disease Causing SCN1A Variants in a Cohort of Common Epilepsy Syndromes.

    Science.gov (United States)

    Lal, Dennis; Reinthaler, Eva M; Dejanovic, Borislav; May, Patrick; Thiele, Holger; Lehesjoki, Anna-Elina; Schwarz, Günter; Riesch, Erik; Ikram, M Arfan; van Duijn, Cornelia M; Uitterlinden, Andre G; Hofman, Albert; Steinböck, Hannelore; Gruber-Sedlmayr, Ursula; Neophytou, Birgit; Zara, Federico; Hahn, Andreas; Gormley, Padhraig; Becker, Felicitas; Weber, Yvonne G; Cilio, Maria Roberta; Kunz, Wolfram S; Krause, Roland; Zimprich, Fritz; Lemke, Johannes R; Nürnberg, Peter; Sander, Thomas; Lerche, Holger; Neubauer, Bernd A

    2016-01-01

    The SCN1A gene, coding for the voltage-gated Na+ channel alpha subunit NaV1.1, is the clinically most relevant epilepsy gene. With the advent of high-throughput next-generation sequencing, clinical laboratories are generating an ever-increasing catalogue of SCN1A variants. Variants are more likely to be classified as pathogenic if they have already been identified previously in a patient with epilepsy. Here, we critically re-evaluate the pathogenicity of this class of variants in a cohort of patients with common epilepsy syndromes and subsequently ask whether a significant fraction of benign variants have been misclassified as pathogenic. We screened a discovery cohort of 448 patients with a broad range of common genetic epilepsies and 734 controls for previously reported SCN1A mutations that were assumed to be disease causing. We re-evaluated the evidence for pathogenicity of the identified variants using in silico predictions, segregation, original reports, available functional data and assessment of allele frequencies in healthy individuals as well as in a follow up cohort of 777 patients. We identified 8 known missense mutations, previously reported as pathogenic, in a total of 17 unrelated epilepsy patients (17/448; 3.80%). Our re-evaluation indicates that 7 out of these 8 variants (p.R27T; p.R28C; p.R542Q; p.R604H; p.T1250M; p.E1308D; p.R1928G; NP_001159435.1) are not pathogenic. Only the p.T1174S mutation may be considered as a genetic risk factor for epilepsy of small effect size based on the enrichment in patients (P = 6.60 x 10-4; OR = 0.32, fishers exact test), previous functional studies but incomplete penetrance. Thus, incorporation of previous studies in genetic counseling of SCN1A sequencing results is challenging and may produce incorrect conclusions.

  4. Novel mutations in human and mouse SCN4A implicate AMPK in myotonia and periodic paralysis.

    Science.gov (United States)

    Corrochano, Silvia; Männikkö, Roope; Joyce, Peter I; McGoldrick, Philip; Wettstein, Jessica; Lassi, Glenda; Raja Rayan, Dipa L; Blanco, Gonzalo; Quinn, Colin; Liavas, Andrianos; Lionikas, Arimantas; Amior, Neta; Dick, James; Healy, Estelle G; Stewart, Michelle; Carter, Sarah; Hutchinson, Marie; Bentley, Liz; Fratta, Pietro; Cortese, Andrea; Cox, Roger; Brown, Steve D M; Tucci, Valter; Wackerhage, Henning; Amato, Anthony A; Greensmith, Linda; Koltzenburg, Martin; Hanna, Michael G; Acevedo-Arozena, Abraham

    2014-12-01

    Mutations in the skeletal muscle channel (SCN4A), encoding the Nav1.4 voltage-gated sodium channel, are causative of a variety of muscle channelopathies, including non-dystrophic myotonias and periodic paralysis. The effects of many of these mutations on channel function have been characterized both in vitro and in vivo. However, little is known about the consequences of SCN4A mutations downstream from their impact on the electrophysiology of the Nav1.4 channel. Here we report the discovery of a novel SCN4A mutation (c.1762A>G; p.I588V) in a patient with myotonia and periodic paralysis, located within the S1 segment of the second domain of the Nav1.4 channel. Using N-ethyl-N-nitrosourea mutagenesis, we generated and characterized a mouse model (named draggen), carrying the equivalent point mutation (c.1744A>G; p.I582V) to that found in the patient with periodic paralysis and myotonia. Draggen mice have myotonia and suffer from intermittent hind-limb immobility attacks. In-depth characterization of draggen mice uncovered novel systemic metabolic abnormalities in Scn4a mouse models and provided novel insights into disease mechanisms. We discovered metabolic alterations leading to lean mice, as well as abnormal AMP-activated protein kinase activation, which were associated with the immobility attacks and may provide a novel potential therapeutic target. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain.

  5. A comprehensive approach to identifying repurposed drugs to treat SCN8A epilepsy.

    Science.gov (United States)

    Atkin, Talia A; Maher, Chani M; Gerlach, Aaron C; Gay, Bryant C; Antonio, Brett M; Santos, Sonia C; Padilla, Karen M; Rader, JulieAnn; Krafte, Douglas S; Fox, Matthew A; Stewart, Gregory R; Petrovski, Slavé; Devinsky, Orrin; Might, Matthew; Petrou, Steven; Goldstein, David B

    2018-04-01

    Many previous studies of drug repurposing have relied on literature review followed by evaluation of a limited number of candidate compounds. Here, we demonstrate the feasibility of a more comprehensive approach using high-throughput screening to identify inhibitors of a gain-of-function mutation in the SCN8A gene associated with severe pediatric epilepsy. We developed cellular models expressing wild-type or an R1872Q mutation in the Na v 1.6 sodium channel encoded by SCN8A. Voltage clamp experiments in HEK-293 cells expressing the SCN8A R1872Q mutation demonstrated a leftward shift in sodium channel activation as well as delayed inactivation; both changes are consistent with a gain-of-function mutation. We next developed a fluorescence-based, sodium flux assay and used it to assess an extensive library of approved drugs, including a panel of antiepileptic drugs, for inhibitory activity in the mutated cell line. Lead candidates were evaluated in follow-on studies to generate concentration-response curves for inhibiting sodium influx. Select compounds of clinical interest were evaluated by electrophysiology to further characterize drug effects on wild-type and mutant sodium channel functions. The screen identified 90 drugs that significantly inhibited sodium influx in the R1872Q cell line. Four drugs of potential clinical interest-amitriptyline, carvedilol, nilvadipine, and carbamazepine-were further investigated and demonstrated concentration-dependent inhibition of sodium channel currents. A comprehensive drug repurposing screen identified potential new candidates for the treatment of epilepsy caused by the R1872Q mutation in the SCN8A gene. Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.

  6. SCN5A mutations and polymorphisms in patients with ventricular fibrillation during acute myocardial infarction.

    Science.gov (United States)

    Boehringer, Tim; Bugert, Peter; Borggrefe, Martin; Elmas, Elif

    2014-10-01

    Mutations in the SCN5A gene encoding the Nav1.5 channel α-subunit are known to be risk factors of arrhythmia, including Brugada Syndrome and Long QT syndrome subtype 3. The present study focused on the role of SCN5A variants in the development of ventricular fibrillation (VF) during acute myocardial infarction (AMI). Since VF during AMI is the major cause of sudden death in the Western world, SCN5A mutations represent genetic risk factors for sudden death. By exon re-sequencing, the entire coding region and flanking intron regions were sequenced in 46 AMI/VF+ patients. In total, nine single nucleotide variants were identified of which four represented common single nucleotide polymorphisms (SNPs; 87G>A, 1673A>G, IVS16‑6C>T and 5457T>A). Only five rare variants were identified, each in only one patient. Only two of the rare variants represented missense mutations (3578G>A and 4786T>A). The common SNPs and the missense mutations were also genotyped using polymerase chain reaction methods in 79 AMI/VF‑ patients and 480 healthy controls. The SNPs did not demonstrate significant differences in allele and genotype frequencies between the study groups. The 3578G>A mutation was identified in one out of the 480 controls, whereas the 4786T>A mutation was not present in AMI/VF- patients and controls. In conclusion, the majority of AMI/VF+ patients demonstrated a wild type sequence or common SNPs in SCN5A. Only two out of 46 (4.3%) AMI/VF+ patients revealed mutations that may be involved in Nav1.5 dysfunction and VF. However, this requires further functional validation.

  7. Anomalously high thermoelectric power factor in epitaxial ScN thin films

    DEFF Research Database (Denmark)

    Kerdsongpanya, Sit; Van Nong, Ngo; Pryds, Nini

    2011-01-01

    found that the ScN thin-film exhibits a rather low electrical resistivity of ∼2.94 μΩm, while its Seebeck coefficient is approximately ∼−86 μV/K at 800 K, yielding a power factor of ∼2.5 × 10−3 W/mK2. This value is anomalously high for common transition-metal nitrides. © 2011 American Institute...

  8. SCN2A mutation is associated with infantile spasms and bitemporal glucose hypometabolism.

    Science.gov (United States)

    Sundaram, Senthil K; Chugani, Harry T; Tiwari, Vijay N; Huq, A H M M

    2013-07-01

    Genetic mutations play a crucial role in the etiology of cryptogenic infantile spasms, but the cause is still unknown in a significant proportion of patients. Whole exome sequencing technology shows great promise in identifying genetic causes of infantile spasms. In this study whole exome sequencing was performed with 2-deoxy-2-((18)F)fluoro-d-glucose positron emission tomography scan of an infant boy with infantile spasms. Exome sequencing was also performed in the parents to identify any de novo mutations. The positron emission tomography scan showed a pattern of bilateral symmetric temporal lobe glucose hypometabolism. A total of 8171 nonsynonymous variants were identified in the child. Despite the large number of nonsynonymous variants, there was only a single de novo missense mutation in SCN2A in the child (NCBI hg19 assembly, position: Chr2:166234116, K1422E). Subsequent Sanger sequencing confirmed the de novo status of this variant. This mutation has never been reported in 6500 individuals of the exome variant server database. Similarly, this variant is not reported in the Online Mendelian Inheritance in Man Database or the Human Gene Mutation Database. It has previously been shown that SCN2A mutations are associated with hippocampal hyperexcitability. Therefore, this study indicates that infantile spasms and bitemporal hypometabolism in this patient might have been caused by hippocampal hyperexcitability due to SCN2A mutation. The simultaneous presence of an SCN2A mutation and bitemporal hypometabolism in this patient with infantile spasms suggests a plausible hippocampal origin. However, additional mechanistic and clinical studies are required to validate this link. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Characterization of a de novo SCN8A mutation in a patient with epileptic encephalopathy.

    Science.gov (United States)

    de Kovel, Carolien G F; Meisler, Miriam H; Brilstra, Eva H; van Berkestijn, Frederique M C; van 't Slot, Ruben; van Lieshout, Stef; Nijman, Isaac J; O'Brien, Janelle E; Hammer, Michael F; Estacion, Mark; Waxman, Stephen G; Dib-Hajj, Sulayman D; Koeleman, Bobby P C

    2014-11-01

    Recently, de novo SCN8A missense mutations have been identified as a rare dominant cause of epileptic encephalopathies (EIEE13). Functional studies on the first described case demonstrated gain-of-function effects of the mutation. We describe a novel de novo mutation of SCN8A in a patient with epileptic encephalopathy, and functional characterization of the mutant protein. Whole exome sequencing was used to discover the variant. We generated a mutant cDNA, transfected HEK293 cells, and performed Western blotting to assess protein stability. To study channel functional properties, patch-clamp experiments were carried out in transfected neuronal ND7/23 cells. The proband exhibited seizure onset at 6 months of age, diffuse brain atrophy, and more profound developmental impairment than the original case. The mutation p.Arg233Gly in the voltage sensing transmembrane segment D1S4 was present in the proband and absent in both parents. This mutation results in a temperature-sensitive reduction in protein expression as well as reduced sodium current amplitude and density and a relative increased response to a slow ramp stimulus, though this did not result in an absolute increased current at physiological temperatures. The new de novo SCN8A mutation is clearly deleterious, resulting in an unstable protein with reduced channel activity. This differs from the gain-of-function attributes of the first SCN8A mutation in epileptic encephalopathy, pointing to heterogeneity of mechanisms. Since Nav1.6 is expressed in both excitatory and inhibitory neurons, a differential effect of a loss-of-function of Nav1.6 Arg223Gly on inhibitory interneurons may underlie the epilepsy phenotype in this patient. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Multiple arrhythmic syndromes in a newborn, owing to a novel mutation in SCN5A

    Science.gov (United States)

    Calloe, Kirstine; Schmitt, Nicole; Grubb, Soren; Pfeiffer, Ryan; David, Jens-Peter; Kanter, Ronald; Cordeiro, Jonathan M.; Antzelevitch, Charles

    2011-01-01

    Background Mutations in the SCN5A gene have been linked to Brugada syndrome (BrS), conduction disease, Long QT syndrome (LQT3), atrial fibrillation (AF), and to pre- and neonatal ventricular arrhythmias. Objective The objective of this study is to characterize a novel mutation in Nav1.5 found in a newborn with fetal chaotic atrial tachycardia, postpartum intraventricular conduction delay, and QT interval prolongation. Methods Genomic DNA was isolated and all exons and intron borders of 15 ion-channel genes were sequenced, revealing a novel missense mutation (Q270K) in SCN5A. Nav1.5 wild type (WT) and Q270K were expressed in CHO-K1 with and without the Navβ1 subunit. Results Patch-clamp analysis showed ~40% reduction in peak sodium channel current (INa) density for Q270K compared with WT. Fast and slow decay of INa were significantly slower in Q270K. Steady-state activation and inactivation of Q270K channels were shifted to positive potentials, and window current was increased. The tetrodotoxin-sensitive late INa was increased almost 3-fold compared with WT channels. Ranolazine reduced late INa in WT and Q270K channels, while exerting minimal effects on peak INa. Conclusion The Q270K mutation in SCN5A reduces peak INa while augmenting late INa, and may thus underlie the development of atrial tachycardia, intraventricular conduction delay, and QT interval prolongation in an infant. PMID:21895525

  11. Copper(I) thiocyanate (CuSCN) as a hole-transport material for large-area opto/electronics

    Science.gov (United States)

    Wijeyasinghe, Nilushi; Anthopoulos, Thomas D.

    2015-10-01

    Recent advances in large-area optoelectronics research have demonstrated the tremendous potential of copper(I) thiocyanate (CuSCN) as a universal hole-transport interlayer material for numerous applications, including transparent thin-film transistors, high-efficiency organic and hybrid organic-inorganic photovoltaic cells, and organic light-emitting diodes. CuSCN combines intrinsic hole-transport (p-type) characteristics with a large bandgap (>3.5 eV) which facilitates optical transparency across the visible to near infrared part of the electromagnetic spectrum. Furthermore, CuSCN is readily available from commercial sources while it is inexpensive and can be processed at low-temperatures using solution-based techniques. This unique combination of desirable characteristics makes CuSCN a promising material for application in emerging large-area optoelectronics. In this review article, we outline some important properties of CuSCN and examine its use in the fabrication of potentially low-cost optoelectronic devices. The merits of using CuSCN in numerous emerging applications as an alternative to conventional hole-transport materials are also discussed.

  12. Universality and Halo Nuclei

    Directory of Open Access Journals (Sweden)

    Tomio L.

    2010-04-01

    Full Text Available Universal aspects of few-body systems will be reviewed motivated by recent interest in atomic and nuclear physics. The critical conditions for the existence of excited states in three-body systems with two-identical particles will be explored. In particular, we consider halo nuclei that can be modeled as three-body nuclear systems, with two halo neutrons and a core. In this context, we also discuss the low-energy neutron−19C elastic scattering, near the conditions for the app earance of an Efimov state.

  13. Anomalous carbon nuclei

    International Nuclear Information System (INIS)

    Gasparian, A.P.

    1984-01-01

    Results are presented from a bubble chamber experiment to search for anomalous mean free path (MFP) phenomena for secondary multicharged fragments (Zsub(f)=5 and 6) of the beam carbon nucleus at 4.2 GeV/c per nucleon. A total of 50000 primary interactions of carbon with propane (C 3 H 8 ) were created. Approximately 6000 beam tragments with charges Zsub(f)=5 and 6 were analyzed in detail to find out an anomalous decrease of MFP. The anomaly is observed only for secondary 12 C nuclei

  14. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    2001-01-01

    The present collection of letters from JINR, Dubna, contains eight separate records on the interaction of high energy Λ 6 He hypernuclear beams with atomic nuclei, the position-sensitive detector of a high spatial resolution on the basis of a multiwire gas electron multiplier, pseudorapidity hadron density at the LHC energy, high precision laser control of the ATLAS tile-calorimeter module mass production at JINR, a new approach to ECG's features recognition involving neural network, subcriticity of a uranium target enriched in 235 U, beam space charge effects in high-current cyclotron injector CI-5, a homogeneous static gravitational field and the principle of equivalence

  15. Active galactic nuclei

    CERN Document Server

    Blandford, RD; Woltjer, L

    1990-01-01

    Starting with this volume, the Lecture Notes of the renowned Advanced Courses of the Swiss Society for Astrophysics and Astronomy will be published annually. In each course, three extensive lectures given by leading experts in their respective fields cover different and essential aspects of the subject. The 20th course, held at Les Diablerets in April 1990, dealt with current research on active galactic nuclei; it represents the most up-to-date views on the subject, presented with particular regard for clarity. The previous courses considered a wide variety of subjects, beginning with ""Theory

  16. Active galactic nuclei

    CERN Document Server

    Beckmann, Volker

    2012-01-01

    This AGN textbook includes phenomena based on new results in the X-Ray domain from new telescopes such as Chandra and XMM Newton not mentioned in any other book. Furthermore, it considers also the Fermi Gamma Ray Space Telescope with its revolutionary advances of unprecedented sensitivity, field of view and all-sky monitoring. Those and other new developments as well as simulations of AGN merging events and formations, enabled through latest super-computing capabilities. The book gives an overview on the current knowledge of the Active Galacitc Nuclei phenomenon. The spectral energy d

  17. Stability of superheavy nuclei

    Science.gov (United States)

    Pomorski, K.; Nerlo-Pomorska, B.; Bartel, J.; Schmitt, C.

    2018-03-01

    The potential-energy surfaces of an extended set of heavy and superheavy even-even nuclei with 92 ≤Z ≤126 and isospins 40 ≤N -Z ≤74 are evaluated within the recently developed Fourier shape parametrization. Ground-state and decay properties are studied for 324 different even-even isotopes in a four-dimensional deformation space, defined by nonaxiality, quadrupole, octupole, and hexadecapole degrees of freedom. Nuclear deformation energies are evaluated in the framework of the macroscopic-microscopic approach, with the Lublin-Strasbourg drop model and a Yukawa-folded mean-field potential. The evolution of the ground-state equilibrium shape (and possible isomeric, metastable states) is studied as a function of Z and N . α -decay Q values and half-lives, as well as fission-barrier heights, are deduced. In order to understand the transition from asymmetric to symmetric fission along the Fm isotopic chain, the properties of all identified fission paths are investigated. Good agreement is found with experimental data wherever available. New interesting features about the population of different fission modes for nuclei beyond Fm are predicted.

  18. Rotating clusters in nuclei

    International Nuclear Information System (INIS)

    Pauling, L.; Robinson, A.B.

    1975-01-01

    Values of R, the radius of rotation of the rotating cluster, are calculated from the energy of the lowest 2 + level of even-even nuclei with the assumption that the cluster consists of p 2 or n 2 respectively, for N or P magic, and of a helion (α) for N or P differing from a magic number by +-2. The values as a function of A show a zigzag course, which is correlated with the polyspheron structure of the nuclei. If the mantle is not overcrowded the cluster glides over the surface of the mantle and the value of R increases by one spheron diameter, about 3.2 fm. At certain values of N a change in structure of the nucleus occurs, with increase in radius of the core by half a spheron diameter, permitting the cluster to drop back into the mantle, with decrease in R by half a spheron diameter. In the lanthanon region of permanent prolate deformation the rotating cluster is a polyhelion, containing the number of helions permitted by the difference between Z or N and the nearest magic number, and in the actinon region it contains all the nucleons beyond 208 Pb, with maximum p 10 n 16 . An explanation is given of the difference between these regions. (author)

  19. Theory of magic nuclei

    International Nuclear Information System (INIS)

    Nosov, V.G.; Kamchatnov, A.M.

    A consistent theory of the shell and magic oscillations of the masses of spherical nuclei is developed on the basis of the Fermi liquid concept of the energy spectrum of nuclear matter. A ''magic'' relationship between the system's dimensions and the limiting momentum of the quasi-particle distribution is derived; an integer number of the de Broglie half-waves falls on the nuclear diameter. An expression for the discontinuity in the nucleon binding energy in the vicinity of a magic nucleus is obtained. The role of the residual interaction is analyzed. It is shown that the width of the Fermi-surface diffuseness due to the residual interaction is proportional to the squared vector of the quasi-particle orbital angular momentum. The values of the corresponding proportionality factors (the coupling constant for quasi particles) are determined from the experimental data for 52 magic nuclei. The rapid drop of the residual interaction with increasing nuclear size is demonstrated. (7 figures, 3 tables) (U.S.)

  20. Neuropeptide Y-mediated long-term depression of excitatory activity in suprachiasmatic nucleus neurons.

    Science.gov (United States)

    van den Pol, A N; Obrietan, K; Chen, G; Belousov, A B

    1996-09-15

    A brief exposure to light can shift the phase of mammalian circadian rhythms by 1 hr or more. Neuropeptide Y (NPY) administration to the hypothalamic suprachiasmatic nucleus, the circadian clock in the brain, also causes a phase shift in circadian rhythms. After a phase shift, the neural clock responds differently to light, suggesting that learning has occurred in neural circuits related to clock function. Thus, certain stimuli can produce effects that last for an extended period, but possible mechanisms of this long-term effect have not been previously examined at the cellular level. Here, we report that NPY caused a long-term depression in both electrical activity and intracellular calcium levels of neurons, as studied with whole-cell patch-clamp recording and Fura-2 digital imaging. In contrast to the immediate (1 sec) recovery after relief from glutamate receptor blockade, a brief single application of NPY (100 nM) depressed cytosolic Ca2+ for > 1 hr. The mechanism of this long-term calcium depression, a form of cellular learning, is dependent on the simultaneous release of glutamate and activation of NPY receptors, because both the extended response to NPY and any aftereffect were blocked by coapplication of glutamate receptor antagonists. Postsynaptic actions of NPY, mediated by both Y1- and Y2-like receptors, were short term and recovered rapidly. The primary site of long-term NPY actions may be on presynaptic glutamatergic axons, because the frequency of miniature excitatory postsynaptic currents in the presence of tetrodotoxin was reduced by transient exposure to NPY in both cultures and slices.

  1. Exotic nuclei and radioactive beams

    International Nuclear Information System (INIS)

    Chomaz, P.

    1996-01-01

    The Nuclei called exotic are all the nuclei that it is necessary to recreate in laboratory to study them. Their life time is too short -in relation to earth age- for it remains enough on earth. The researchers are going to have at their s disposal at GANIL (Caen) with the S.P.I.R.A.L. project, exotic nuclei beams and will study new kinds of nuclear reactions to better understand the atom nucleus. (N.C.). 2 refs., 9 figs

  2. SCN4A variants and Brugada syndrome: phenotypic and genotypic overlap between cardiac and skeletal muscle sodium channelopathies.

    Science.gov (United States)

    Bissay, Véronique; Van Malderen, Sophie C H; Keymolen, Kathelijn; Lissens, Willy; Peeters, Uschi; Daneels, Dorien; Jansen, Anna C; Pappaert, Gudrun; Brugada, Pedro; De Keyser, Jacques; Van Dooren, Sonia

    2016-03-01

    SCN5A mutations involving the α-subunit of the cardiac voltage-gated muscle sodium channel (NaV1.5) result in different cardiac channelopathies with an autosomal-dominant inheritance such as Brugada syndrome. On the other hand, mutations in SCN4A encoding the α-subunit of the skeletal voltage-gated sodium channel (NaV1.4) cause non-dystrophic myotonia and/or periodic paralysis. In this study, we investigated whether cardiac arrhythmias or channelopathies such as Brugada syndrome can be part of the clinical phenotype associated with SCN4A variants and whether patients with Brugada syndrome present with non-dystrophic myotonia or periodic paralysis and related gene mutations. We therefore screened seven families with different SCN4A variants and non-dystrophic myotonia phenotypes for Brugada syndrome and performed a neurological, neurophysiological and genetic work-up in 107 Brugada families. In the families with an SCN4A-associated non-dystrophic myotonia, three patients had a clinical diagnosis of Brugada syndrome, whereas we found a remarkably high prevalence of myotonic features involving different genes in the families with Brugada syndrome. One Brugada family carried an SCN4A variant that is predicted to probably affect function, one family suffered from a not genetically confirmed non-dystrophic myotonia, one family was diagnosed with myotonic dystrophy (DMPK gene) and one family had a Thomsen disease myotonia congenita (CLCN1 variant that affects function). Our findings and data suggest a possible involvement of SCN4A variants in the pathophysiological mechanism underlying the development of a spontaneous or drug-induced type 1 electrocardiographic pattern and the occurrence of malignant arrhythmias in some patients with Brugada syndrome.

  3. Restricted feeding regime affects clock gene expression profiles in the suprachiasmatic nucleus of rats exposed to constant light

    Czech Academy of Sciences Publication Activity Database

    Nováková, Marta; Polidarová, Lenka; Sládek, Martin; Sumová, Alena

    2011-01-01

    Roč. 197, - (2011), s. 65-71 ISSN 0306-4522 R&D Projects: GA ČR(CZ) GA305/09/0321; GA ČR(CZ) GAP303/11/0668; GA MŠk(CZ) LC554 Grant - others:GA ČR(CZ) GD309/08/H079 Institutional research plan: CEZ:AV0Z50110509 Keywords : circadian system * suprachiasmatic nucleus * restricted feeding * constant light Subject RIV: FH - Neurology Impact factor: 3.380, year: 2011

  4. Neutrino interactions with nuclei

    International Nuclear Information System (INIS)

    Walecka, J.D.

    1983-01-01

    We examine tests of the Glashow-Weinberg-Salam (GWS) Standard Theory of Electroweak Interactions. The tests are model-independent in the sense that they are relations between experimental quantities that are direct consequences of the GWS theory, but they are independent of the detailed structure of the nucleus. Such relationships were anticipated by Weinberg. Neutrino reactions with nuclei are considered, focusing largely on charged-lepton production, and it is demonstrated that intermediate-energy neutrino reactions have a central and unique role to play in our understanding of semileptonic weak interactions. This point is illustrated by discussing a complete kinematic experiment on the nucleon. A discussion of what neutrino reactions could teach us about nuclear structure is also given

  5. Electron scattering off nuclei

    International Nuclear Information System (INIS)

    Gattone, A.O.

    1989-01-01

    Two recently developed aspects related to the scattering of electrons off nuclei are presented. On the one hand, a model is introduced which emphasizes the relativistic aspects of the problem in the impulse approximation, by demanding strict maintenance of the algebra of the Poincare group. On the other hand, the second model aims at a more sophisticated description of the nuclear response in the case of collective excitations. Basically, it utilizes the RPA formalism with a new development which enables a more careful treatment of the states in the continuum as is the case for the giant resonances. Applications of both models to the description of elastic scattering, inelastic scattering to discrete levels, giant resonances and the quasi-elastic region are discussed. (Author) [es

  6. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    2000-01-01

    The present collection of letters from JINR, Dubna, contains eight separate records on liquid argon pollution tests of the ATLAS detector materials at IBR-2 reactor in Dubna, irradiation tests of readout chain components of the ATLAS liquid argon calorimeters, study of neutron induced outgassing from tungsten alloy for ATLAS FCAL, yields of nuclear reaction products from a thick beryllium target bombarded by beams of 7 Li, 11 B and 15 N ions as well as on the mass surface and the properties of nuclides close to hypothetic doubly magic lead-164, the Web-site of information-diagnostic system of IBR-2 pulsed neutron source state, discovery of η-mesic nuclei and calculation of the ion angular distributions after the ionization in ion-atom collisions

  7. Clusters in nuclei

    CERN Document Server

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This third volume follows the successful Lect. Notes Phys. 818 (Vol. 1) and 848 (Vol. 2), and comprises six extensive lectures covering the following topics:  - Gamma Rays and Molecular Structure - Faddeev Equation Approach for Three Cluster Nuclear Reactions - Tomography of the Cluster Structure of Light Nuclei Via Relativistic Dissociation - Clustering Effects Within the Dinuclear Model : From Light to Hyper-heavy Molecules in Dynamical Mean-field Approach - Clusterization in Ternary Fission - Clusters in Light N...

  8. Pion production in nuclei

    International Nuclear Information System (INIS)

    Afnan, I.R.; Thomas, A.W.

    1976-01-01

    A method has been suggested for relating μ-capture in nuclei to pion absorption through partially conserved axial vector current hypothesis. The success of the method relies heavily on the knowledge of the pion absorption amplitude at a momentum transfer equal to the μ-meson mass. That is we need to know the pion absorption amplitude off the mass-shell. The simplest nucleus for which this suggestion can be examined is μ-capture in deuterium. The Koltum-Reitan model is used to determine the pion absorption amplitude off the mass shell. In particular the senstivity of this off-mass-shell extrapolution to details of the N-N interaction is studied. (author)

  9. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors) 304 refs., 53 figs., 5 tabs.

  10. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1998-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors)

  11. Evaluation of Presumably Disease Causing SCN1A Variants in a Cohort of Common Epilepsy Syndromes.

    Directory of Open Access Journals (Sweden)

    Dennis Lal

    Full Text Available The SCN1A gene, coding for the voltage-gated Na+ channel alpha subunit NaV1.1, is the clinically most relevant epilepsy gene. With the advent of high-throughput next-generation sequencing, clinical laboratories are generating an ever-increasing catalogue of SCN1A variants. Variants are more likely to be classified as pathogenic if they have already been identified previously in a patient with epilepsy. Here, we critically re-evaluate the pathogenicity of this class of variants in a cohort of patients with common epilepsy syndromes and subsequently ask whether a significant fraction of benign variants have been misclassified as pathogenic.We screened a discovery cohort of 448 patients with a broad range of common genetic epilepsies and 734 controls for previously reported SCN1A mutations that were assumed to be disease causing. We re-evaluated the evidence for pathogenicity of the identified variants using in silico predictions, segregation, original reports, available functional data and assessment of allele frequencies in healthy individuals as well as in a follow up cohort of 777 patients.We identified 8 known missense mutations, previously reported as pathogenic, in a total of 17 unrelated epilepsy patients (17/448; 3.80%. Our re-evaluation indicates that 7 out of these 8 variants (p.R27T; p.R28C; p.R542Q; p.R604H; p.T1250M; p.E1308D; p.R1928G; NP_001159435.1 are not pathogenic. Only the p.T1174S mutation may be considered as a genetic risk factor for epilepsy of small effect size based on the enrichment in patients (P = 6.60 x 10-4; OR = 0.32, fishers exact test, previous functional studies but incomplete penetrance. Thus, incorporation of previous studies in genetic counseling of SCN1A sequencing results is challenging and may produce incorrect conclusions.

  12. Stress and strain effects on the electronic structure and optical properties of ScN monolayer

    Science.gov (United States)

    Tamleh, Shirin; Rezaei, Ghasem; Jalilian, Jaafar

    2018-02-01

    Based on the density functional theory, electronic and optical properties of a monolayer scandium nitride structure have been studied under different strain conditions. Our results indicate that both biaxial compressive and tensile strain effects lead to change the band gap of this structure with different rates. Also, optical absorption spectrum peaks experience an obvious red and blue shifts with the exerting of tensile and compressive strains, respectively. Our results express that ScN monolayer can be the promising candidate for the future nano-base electrical and optical devices.

  13. Ventricular tachycardia in a Brugada syndrome patient caused by a novel deletion in SCN5A

    DEFF Research Database (Denmark)

    Tfelt-Hansen, J; Jespersen, T; Hofman-Bang, J

    2009-01-01

    -cell patch clamp experiments using human embryonic kidney 293 cells transfected with the mutated SCN5A, no current could be recorded. Hence, the results suggest that the patient suffered from haploinsufficiency of Na(v)1.5, and that this mutation was the cause of his Brugada syndrome.......The aim of the present study was to identify the molecular mechanism behind ventricular tachycardia in a patient with Brugada syndrome. Arrhythmias in patients with Brugada syndrome often occur during sleep. However, a 28-year-old man with no previously documented arrhythmia or syncope who...

  14. SCN1Bb R214Q found in 3 patients: 1 with Brugada syndrome and 2 with lone atrial fibrillation

    DEFF Research Database (Denmark)

    Olesen, Morten S; Holst, Anders G; Haunsø, Stig

    2012-01-01

    BACKGROUND: SCN1Bb encodes the ß-subunit of the sodium channel. A mutation in SCN1Bb R214Q has recently been shown both to increase the Kv4.3 current and to decrease the sodium current. The variant was suggested to increase the susceptibility to Brugada syndrome (BrS). OBJECTIVE: To sequence...... a population of BrS and early-onset lone atrial fibrillation (AF) patients for the R214Q mutation in the SCN1Bb gene. METHODS: The coding sequence and splice junctions of SCN1Bb were bidirectionally sequenced by using Big Dye chemistry in 192 early-onset lone AF patients and 22 BrS patients. RESULTS: Three......) and has not previously been reported in conjunction to AF. CONCLUSION: Three patients of 192 young lone AF and 22 BrS patients carried the nonsynonymous R214Q mutations in SCN1Bb, thereby indicating that this variant increases the susceptibility to both BrS and AF....

  15. Quarks in Few Body Nuclei

    Directory of Open Access Journals (Sweden)

    Holt Roy J.

    2016-01-01

    Full Text Available Electron scattering at very high Bjorken x from hadrons provides an excellent test of models, has an important role in high energy physics, and from nuclei, provides a window into short range correlations. Light nuclei have a key role because of the relatively well-known nuclear structure. The development of a novel tritium target for Jefferson Lab has led to renewed interest in the mass three system. For example, deep inelastic scattering experiments in the light nuclei provide a powerful means to determine the neutron structure function. The isospin dependence of electron scattering from mass-3 nuclei provide information on short range correlations in nuclei. The program using the new tritium target will be presented along with a summary of other experiments aimed at revealing the large-x structure of the nucleon.

  16. DIFFERENCES IN THE NUMBER OF ARGININE-VASOPRESSIN-IMMUNOREACTIVE NEURONS EXIST IN THE SUPRACHIASMATIC NUCLEI OF HOUSE MICE SELECTED FOR DIFFERENCES IN NEST-BUILDING BEHAVIOR

    NARCIS (Netherlands)

    VANDERZEE, EA; COMPAAN, JC; LYNCH, CB; Compaan, Josje C.; Lynch, Carol B.

    1992-01-01

    Arginine-vasopressin (AVP) is a homeostatic modulator of body temperature during fever and may also be involved in normal body temperature control. In the present study the hypothalamus of mice bi-directionally selected for thermoregulatory nest-building behavior was immunocytochemically labeled for

  17. The cochlear nuclei of snakes.

    Science.gov (United States)

    Miller, M R

    1980-08-15

    The cochlear nuclei of three burrowing snakes (Xenopeltis unicolor, Cylindrophis rufus, and Eryx johni) and three non-burrowing snakes (Epicrates cenchris, Natrix sipedon, and Pituophis catenifer) were studied. The posterior branch of the statoacoustic nerve and its posterior ganglion were destroyed and the degenerated nerve fibers and terminals traced to primary cochlear nuclei in 13 specimens of Pituophis catenifer. All these snake species possess three primary and one secondary cochlear nuclei. The primary cochlear nuclei consist of a small nucleus angularis located at the cerebello-medullary junction and a fairly large nucleus magnocellularis forming a dorsal cap over the cephalic end of the alar eminence. Nucleus magnocellularis may be subdivided into a medially placed group of rounder cells, nucleus magnocellularis medialis, and a laterally placed group of more ovate and paler-staining cells, nucleus magnocellularis lateralis. A small but well-defined secondary nucleus which showed no degenerated nerve terminals after nerve root section, nucleus laminaris, underlies the cephalic part of both nucleus magnocellularis medialis and nucleus magnocellularis lateralis. Larger and better-developed cochlear nuclei were found in burrowing species than in non-burrowing species of snakes. Of the three burrowing species studied, Xenopeltis showed the greatest development of cochlear nuclei; Eryx cochlear nuclei were not quite as large but were better differentiated than in Xenopeltis; and Cylindrophis cochlear nuclei were fairly large but not as well developed nor as well differentiated as in either Xenopeltis or Eryx. The cochlear nuclei of the three non-burrowing snakes, Epicrates, Natrix, and Pituophis, were not as large nor as well developed as those of the burrowing snakes. There is some, but not complete, correlation between cochlear development and papilla basilaris length and number of hair cells. Thus, Xenopeltis and Eryx, with well-developed cochlear nuclei

  18. Heterobimetallic thiocyanato-bridged coordination polymers based on [Hg(SCN)4]2-: Synthesis, crystal structure, magnetic properties and ESR studies

    International Nuclear Information System (INIS)

    Jian Fangfang; Xiao Hailian; Liu Faqian

    2006-01-01

    Three new M/Hg bimetallic thiocyanato-bridged coordination polymers; [Hg(SCN) 4 Ni(Im) 3 ] ∞ 1, [Hg(SCN) 4 Mn(Im) 2 ] ∞ 2, and [Hg(SCN) 4 Cu(Me-Im) 2 Hg(SCN) 4 Cu(Me-Im) 4 ] ∞ 3, (Im=imidazole, Me-Im=N-methyl-imidazole), have been synthesized and characterized by means of elemental analysis, ESR, and single-crystal X-ray. X-ray diffraction analysis reveals that these three complexes all form 3D network structure, and their structures all contain a thiocyanato-bridged Hg...Hg chain (M=Mn, Ni, Cu) in which the metal and mercury centers exhibit different coordination environments. In complex 1, the [Hg(SCN) 4 ] 2- anion connects three [Ni(Im) 3 ] 2+ using three SCN ligands giving rise to a 3D structure, and in complex 2, four SCN ligands bridge [Hg(SCN) 4 ] 2- and [Mn(Im) 2 ] 2+ to form a 3D structure. The structure of 3 contains two copper atoms with distinct coordination environment; one is coordinated by four N-methyl-imidazole ligands and two axially elongated SCN groups, and another by four SCN groups (two elongated) and two N-methyl-imidazole ligands. The magnetic property of complex 1 has been investigated. The spin state structure in hetermetallic NiHgNi systems of complex 1 is irregular. The ESR spectra results of complex 3 demonstrate Cu 2+ ion lie on octahedral environment. -- Graphical abstract: Three new M/Hg bimetallic thiocyanato-bridged coordination polymers; [Hg(SCN) 4 Ni(Im) 3 ] ∞ 1, [Hg(SCN) 4 Mn(Im) 2 ] ∞ 2, and [Hg(SCN) 4 Cu(Me-Im) 2 Hg(SCN) 4 Cu(Me-Im) 4 ] ∞ 3, (Im=imidazole, Me-Im=N-methyl-imidazole), have been synthesized and characterized by single-crystal X-ray. All coordination polymers possess 3-D structures, and consist of organic base neutral ligands (imidazole and N-methyl-imidazole) and SCN -1 anions. Their structural difference is mainly caused by the role of the organic base and metal ions. The complex 1 shows the irregular spin state structure

  19. Efficacy of sodium channel blockers in SCN2A early infantile epileptic encephalopathy.

    Science.gov (United States)

    Dilena, Robertino; Striano, Pasquale; Gennaro, Elena; Bassi, Laura; Olivotto, Sara; Tadini, Laura; Mosca, Fabio; Barbieri, Sergio; Zara, Federico; Fumagalli, Monica

    2017-04-01

    Recent clinical evidence supports a targeted therapeutic approach for genetic epileptic encephalopathies based on the molecular dysfunction. A 2-day-old male infant presented with epileptic encephalopathy characterized by burst-suppression EEG background and tonic-clonic migrating partial seizures. The condition was refractory to phenobarbital, pyridoxine, pyridoxal phosphate and levetiracetam, but a dramatic response to an intravenous loading dose of phenytoin was documented by video-EEG monitoring. Over weeks phenytoin was successfully switched to carbamazepine to prevent seizure relapses associated with difficulty in maintaining proper blood levels of phenytoin. Genetic analysis identified a novel de novo heterozygous mutation (c.[4633A>G]p.[Met1545Val]) in SCN2A. At two years and three months of age the patient is still seizure-free on carbamazepine, although a developmental delay is evident. Sodium channel blockers represent the first-line treatment for confirmed or suspected SCN2A-related epileptic encephalopathies. In severe cases with compatible electro-clinical features we propose a treatment algorithm based on a test trial with high dose intravenous phenytoin followed in case of a positive response by carbamazepine, more suitable for long-term maintenance treatment. Because of their rarity, collaborative studies are needed to delineate shared therapeutic protocols for EIEE based on the electro-clinical features and the presumed underlying genetic substrate. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  20. Altered gene expression profile in a mouse model of SCN8A encephalopathy.

    Science.gov (United States)

    Sprissler, Ryan S; Wagnon, Jacy L; Bunton-Stasyshyn, Rosie K; Meisler, Miriam H; Hammer, Michael F

    2017-02-01

    SCN8A encephalopathy is a severe, early-onset epilepsy disorder resulting from de novo gain-of-function mutations in the voltage-gated sodium channel Na v 1.6. To identify the effects of this disorder on mRNA expression, RNA-seq was performed on brain tissue from a knock-in mouse expressing the patient mutation p.Asn1768Asp (N1768D). RNA was isolated from forebrain, cerebellum, and brainstem both before and after seizure onset, and from age-matched wildtype littermates. Altered transcript profiles were observed only in forebrain and only after seizures. The abundance of 50 transcripts increased more than 3-fold and 15 transcripts decreased more than 3-fold after seizures. The elevated transcripts included two anti-convulsant neuropeptides and more than a dozen genes involved in reactive astrocytosis and response to neuronal damage. There was no change in the level of transcripts encoding other voltage-gated sodium, potassium or calcium channels. Reactive astrocytosis was observed in the hippocampus of mutant mice after seizures. There is considerable overlap between the genes affected in this genetic model of epilepsy and those altered by chemically induced seizures, traumatic brain injury, ischemia, and inflammation. The data support the view that gain-of-function mutations of SCN8A lead to pathogenic alterations in brain function contributing to encephalopathy. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. SCN8A Epileptic Encephalopathy: Detection of Fetal Seizures Guides Multidisciplinary Approach to Diagnosis and Treatment.

    Science.gov (United States)

    McNally, Melanie A; Johnson, Julia; Huisman, Thierry A; Poretti, Andrea; Baranano, Kristin W; Baschat, Ahmet A; Stafstrom, Carl E

    2016-11-01

    SCN8A mutations are rare and cause a phenotypically heterogeneous early onset epilepsy known as early infantile epileptic encephalopathy type 13 (EIEE13, OMIM #614558). There are currently no clear genotype-phenotype correlations to help guide patient counseling and management. We describe a patient with EIEE13 (de novo heterozygous pathogenic mutation in SCN8A - p.Ile240Val (ATT>GTT)) who presented prenatally with maternally reported intermittent, rhythmic movements that, when observed on ultrasound, were concerning for fetal seizures. Ultrasound also revealed abnormal developmental states. With maternal administration of levetiracetam, the rhythmic fetal movements stopped. After birth, the patient developed treatment-refractory multi-focal epilepsy confirmed by electroencephalogram. Neuroimaging revealed restricted diffusion in the superior cerebellar peduncles, a finding not reported previously in EIEE13. This is the first report of EIEE13 associated with clinical prenatal-onset seizures. Ultrasonography can be useful for identifying fetal seizures, which may be treatable in utero. Ideally, the clinical approach to fetal seizures should involve a multidisciplinary team spanning the pre- and postnatal course to expedite early diagnosis and optimize management, as illustrated by this patient. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Development of Field-Controlled Smart Optic Materials (ScN, AlN) with Rare Earth Dopants

    Science.gov (United States)

    Kim, Hyun-Jung; Park, Yeonjoon; King, Glen C.; Choi, Sang H.

    2012-01-01

    The purpose of this investigation is to develop the fundamental materials and fabrication technology for field-controlled spectrally active optics that are essential for industry, NASA, and DOD applications such as: membrane optics, filters for LIDARs, windows for sensors, telescopes, spectroscopes, cameras, flat-panel displays, etc. ScN and AlN thin films were fabricated on c-axis Sapphire (0001) or quartz substrate with the RF and DC magnetron sputtering. The crystal structure of AlN in fcc (rocksalt) and hcp (wurtzite) were controlled. Advanced electrical characterizations were performed, including I-V and Hall Effect Measurement. ScN film has a free carrier density of 5.8 x 10(exp 20)/per cubic centimeter and a conductivity of 1.1 x 10(exp 3) per centimeter. The background ntype conductivity of as-grown ScN has enough free electrons that can readily interact with the photons. The high density of free electrons and relatively low mobility indicate that these films contain a high level of shallow donors as well as deep levels. Also, the UV-Vis spectrum of ScN and AlN thin films with rare earth elements (Er or Ho) were measured at room temperature. Their optical band gaps were estimated to be about 2.33eV and 2.24eV, respectively, which are obviously smaller than that of undoped thin film ScN (2.4eV). The red-shifted absorption onset gives direct evidence for the decrease of band gap (Eg) and the energy broadening of valence band states are attributable to the doping. As the doped elements enter the ScN crystal lattices, the localized band edge states form at the doped sites with a reduction of Eg. Using a variable angle spectroscopic ellipsometer, the decrease in refractive index with applied field is observed with a smaller shift in absorption coefficient.

  3. Thermoelectric properties of epitaxial ScN films deposited by reactive magnetron sputtering onto MgO(001) substrates

    Science.gov (United States)

    Burmistrova, Polina V.; Maassen, Jesse; Favaloro, Tela; Saha, Bivas; Salamat, Shuaib; Rui Koh, Yee; Lundstrom, Mark S.; Shakouri, Ali; Sands, Timothy D.

    2013-04-01

    Epitaxial ScN(001) thin films were grown on MgO(001) substrates by dc reactive magnetron sputtering. The deposition was performed in an Ar/N2 atmosphere at 2 × 10-3 Torr at a substrate temperature of 850 °C in a high vacuum chamber with a base pressure of 10-8 Torr. In spite of oxygen contamination of 1.6 ± 1 at. %, the electrical resistivity, electron mobility, and carrier concentration obtained from a typical film grown under these conditions by room temperature Hall measurements are 0.22 mΩ cm, 106 cm2 V-1 s-1, and 2.5 × 1020 cm-3, respectively. These films exhibit remarkable thermoelectric power factors of 3.3-3.5 × 10-3 W/mK2 in the temperature range of 600 K to 840 K. The cross-plane thermal conductivity is 8.3 W/mK at 800 K yielding an estimated ZT of 0.3. Theoretical modeling of the thermoelectric properties of ScN calculated using a mean-free-path of 23 nm at 300 K is in very good agreement with the experiment. These results also demonstrate that further optimization of the power factor of ScN is possible. First-principles density functional theory combined with the site occupancy disorder technique was used to investigate the effect of oxygen contamination on the electronic structure and thermoelectric properties of ScN. The computational results suggest that oxygen atoms in ScN mix uniformly on the N site forming a homogeneous solid solution alloy. Behaving as an n-type donor, oxygen causes a shift of the Fermi level in ScN into the conduction band without altering the band structure and the density of states.

  4. Mutation status of gene CACNA1S and SCN4A in the hypokalemic periodic paralysis pedigree in Chinese population

    Directory of Open Access Journals (Sweden)

    Kun WU

    2013-04-01

    Full Text Available Objective  To investigate the mutation status of gene CACNA1S and SCN4A in hypokalemic periodic paralysis (HPP pedigree of Chinese population, and compare the status with that in Caucasian populations as reported in previous literature. Methods  To define the gene mutation status, the genes CACNA1S and SCN4A were sequenced by PCR and DNA sequencing technology in two familial HPP pedigrees, one hyperthyroid HPP pedigree and four sporadic HPP patients, the findings were then compared with the reference sequences in gene library. A total of nine relevant reports concerning the gene CACNA1S and SCN4A mutation of HPP pedigree published from Jan. 1999 to Dec. 2012 were retrieved from PubMed database. Results  All the probands were suffering from paroxysmal muscle weakness with hypokalemia. As a typical symptom of HPP, muscle weakness often involved the extremities. Auxiliary examination confirmed serum hypopotassemia, electrocardiogram (ECG showed hypokalemic change, and electromyography (EMG showed shortened motor potential duration and low amplitude. All the findings mentioned above were in accordance with clinical diagnosis of HPP. Gene analysis indicated that no mutation of CACNA1S and SCN4A was found in the probands, the family members of the three HPP pedigrees and the four patients of sporadic HPP. The previous literature presented that mutation rate of gene CACN1AS and SCN4A was much higher in Caucasian HPP patients than in Chinese population. Conclusion  The mutation rate of gene CACN1AS and SCN4A is lower in Chinese HPP patients than in Caucasian patients with significant difference.

  5. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    1997-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author) 270 refs.

  6. Photon interactions with nuclei

    International Nuclear Information System (INIS)

    Thornton, S.T.; Sealock, R.M.

    1989-01-01

    This document is a progress report for DOE Grant No. FG05-89ER40501, A000. The grant began March, 1989. Our primary research effort has been expended at the LEGS project at Brookhaven National Laboratory. This report will summarize our present research effort at LEGS as well as data analysis and publications from previous experiments performed at SLAC. In addition the principal investigators are heavily involved in the CLAS collaboration in Hall B at CEBAF. We have submitted several letters of intent and proposals and have made commitments to construct experimental equipment for CEBAF. We expect our primary experimental effort to continue at LEGS until CEBAF becomes operational. This report will be divided into separate sections describing our progress at LEGS, SLAC, and CEBAF. We will also discuss our significant efforts in the education and training of both undergraduate and graduate students. Photon detectors are described as well as experiments on delta deformation in nuclei of quasielastic scattering and excitation of the delta by 4 He(e,e')

  7. Supersymmetry in nuclei

    CERN Document Server

    Jolie, J

    2002-01-01

    All the elementary particles that make up matter (as do quarks, electrons, neutrinos....) are fermions, the particles that convey the fundamental interactions (as do photons, gluons, W, Z...) are bosons. Composite particles are either bosons, or fermions according to the number of fermions they contain: if this number is even the particle is a boson, otherwise it is a fermion. According to this rule a proton is a fermion and the He sup 4 atom is a boson. Symmetry plays an important role in the standard model, a symmetry is a transformation that connect bosons with other bosons or fermions with other fermions. Supersymmetry associates a boson with a fermion or a fermion with a boson, in fact supersymmetry connects nuclei that are not generally considered as akin. Supersymmetry has just been observed in low energy levels of Gold sup 1 sup 9 sup 5 sup - sup 1 sup 9 sup 6 and Platinum sup 1 sup 9 sup 4 - sup 1 sup 9 sup 5 , it means that the description of these energy levels is simplified and can be made by a co...

  8. Collective excitations in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    1997-01-01

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author)

  9. Gluon density in nuclei

    International Nuclear Information System (INIS)

    Ayala, A.L.

    1996-01-01

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab

  10. A Switchable Molecular Dielectric with Two Sequential Reversible Phase Transitions: [(CH3)4P]4[Mn(SCN)6].

    Science.gov (United States)

    Li, Qiang; Shi, Ping-Ping; Ye, Qiong; Wang, Hui-Ting; Wu, De-Hong; Ye, Heng-Yun; Fu, Da-Wei; Zhang, Yi

    2015-11-16

    A new organic-inorganic hybrid switchable and tunable dielectric compound, [(CH3)4P]4[Mn(SCN)6] (1), exhibits three distinct dielectric states above room temperature and undergoes two reversible solid-state phase transitions, including a structural phase transition at 330 K and a ferroelastic phase transition with the Aizu notation of mmmF2/m at 352 K. The variable-temperature structural analyses disclose that the origin of the phase transitions and dielectric anomalies can be ascribed to the reorientation or motion of both the [(CH3)4P](+) cations and [Mn(SCN)6](4-) anions in solid-state crystals.

  11. Electron scattering for exotic nuclei

    International Nuclear Information System (INIS)

    Suda, T.

    2013-01-01

    An electron scattering facility is under construction in RIKEN RI Beam Factory, Japan, which is dedicated to the structure studies of short-lived nuclei. This is the world's first and currently only facility of its type. The construction is nearly completed, and the first electron scattering experiment off short-lived nuclei will be carried out in the beginning of next year. The charge density distributions of short-lived nuclei will be precisely determined by elastic electron scattering for the first time. Physics pursued at this facility including future perspectives are explained

  12. Monopole transitions in hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Sujkowski, Z. [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland)

    1994-12-31

    Monopole transitions can be a signature of shape changing in a hot, pulsating nucleus (the low energy E0 mode) and/or a measure of the compressibility of finite nuclei (GMR, the breathing mode). Experimental information pertaining to GMR is reviewed. Recipes for deducing the incompressibility modules for infinite nuclear matter from data on GMR are discussed. Astrophysical implications are outlined. The first attempts at locating the GMR strength in moderately hot nuclei are described. Prospects for improving the experimental techniques to make an observation of this strength in selected nuclei unambiguous are discussed. (author). 46 refs, 8 figs.

  13. Circadian rhythm and photic induction of the C-terminal splice variant of NMDAR1 subunit in the rat suprachiasmatic nucleus

    Czech Academy of Sciences Publication Activity Database

    Bendová, Zdeňka; Janoušková, Hana; Svobodová, Irena

    2014-01-01

    Roč. 68, č. 2 (2014), s. 85-88 ISSN 0887-4476 R&D Projects: GA ČR(CZ) GAP303/10/1227 Institutional support: RVO:67985823 Keywords : circadian clock * NMDA receptor * NR1 subunit * rat * suprachiasmatic nucleus Subject RIV: FH - Neurology Impact factor: 2.127, year: 2014

  14. Cavitation inception from bubble nuclei

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2015-01-01

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years....... The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model...... and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes....

  15. The delta in nuclei. Experiments

    International Nuclear Information System (INIS)

    Roy-Stephan, M.

    1989-01-01

    Experimental aspects of the Δ excitation will be presented. The Δ excitation in nuclei will be compared to the free Δ excitation. Various probes will be reviewed and their specific features will be underlined [fr

  16. Nuclei Isolation from Nematode Ascaris

    Science.gov (United States)

    Kang, Yuanyuan; Wang, Jianbin; Davis, Richard E.

    2017-01-01

    Preparing nuclei is necessary in a variety of experimental paradigms to study nuclear processes. In this protocol, we describe a method for rapid preparation of large number of relatively pure nuclei from Ascaris embryos or tissues that are ready to be used for further experiments such as chromatin isolation and ChIP-seq, nuclear RNA analyses, or preparation of nuclear extracts (Kang et al., 2016; Wang et al., 2016). PMID:29082294

  17. Genotype-Phenotype Correlation of SCN5A Mutation for the Clinical and Electrocardiographic Characteristics of Probands With Brugada Syndrome: A Japanese Multicenter Registry.

    Science.gov (United States)

    Yamagata, Kenichiro; Horie, Minoru; Aiba, Takeshi; Ogawa, Satoshi; Aizawa, Yoshifusa; Ohe, Tohru; Yamagishi, Masakazu; Makita, Naomasa; Sakurada, Harumizu; Tanaka, Toshihiro; Shimizu, Akihiko; Hagiwara, Nobuhisa; Kishi, Ryoji; Nakano, Yukiko; Takagi, Masahiko; Makiyama, Takeru; Ohno, Seiko; Fukuda, Keiichi; Watanabe, Hiroshi; Morita, Hiroshi; Hayashi, Kenshi; Kusano, Kengo; Kamakura, Shiro; Yasuda, Satoshi; Ogawa, Hisao; Miyamoto, Yoshihiro; Kapplinger, Jamie D; Ackerman, Michael J; Shimizu, Wataru

    2017-06-06

    The genotype-phenotype correlation of SCN5A mutations as a predictor of cardiac events in Brugada syndrome remains controversial. We aimed to establish a registry limited to probands, with a long follow-up period, so that the genotype-phenotype correlation of SCN5A mutations in Brugada syndrome can be examined without patient selection bias. This multicenter registry enrolled 415 probands (n=403; men, 97%; age, 46±14 years) diagnosed with Brugada syndrome whose SCN5A gene was analyzed for mutations. During a mean follow-up period of 72 months, the overall cardiac event rate was 2.5%/y. In comparison with probands without mutations ( SCN5A (-), n=355), probands with SCN5A mutations ( SCN5A (+), n=60) experienced their first cardiac event at a younger age (34 versus 42 years, P =0.013), had a higher positive rate of late potentials (89% versus 73%, P =0.016), exhibited longer P-wave, PQ, and QRS durations, and had a higher rate of cardiac events ( P =0.017 by log-rank). Multivariate analysis indicated that only SCN5A mutation and history of aborted cardiac arrest were significant predictors of cardiac events ( SCN5A (+) versus SCN5A (-): hazard ratio, 2.0 and P =0.045; history of aborted cardiac arrest versus no such history: hazard ratio, 6.5 and P syndrome patients with SCN5A mutations exhibit more conduction abnormalities on ECG and have higher risk for cardiac events. © 2017 American Heart Association, Inc.

  18. Turning dilemmas into opportunities: a UNU/SCN capacity development network in public nutrition in Central and Eastern Europe

    NARCIS (Netherlands)

    Pavlovic, M.; Pepping, F.; Demes, M.; Biro, L.; Szabolcs, P.; Dimitrovska, Z.; Duleva, V.; Parvan, C.; Hadziomeragic, A.F.; Glibetic, M.; Oshaug, A.

    2009-01-01

    Capacity development in nutrition is a process whereby individuals, groups, institutions, organizations and societies enhance their abilities to identify and meet challenges in a sustainable manner. To address these issues, in 2001 the UN System Standing Committee on Nutrition (SCN) established a

  19. The incidence of SCN1A-related Dravet syndrome in Denmark is 1:22,000

    DEFF Research Database (Denmark)

    Bayat, Allan; Hjalgrim, Helle; Møller, Rikke S.

    2015-01-01

    Dravet syndrome is a severe infantile-onset epileptic encephalopathy associated with mutations in the sodium channel alpha-1 subunit gene SCN1A. We aimed to describe the incidence of Dravet syndrome in the Danish population. Based on a 6-year birth cohort from 2004 to 2009, we propose an incidenc...

  20. Hydride vapor phase epitaxy growth of GaN, InGaN, ScN, and ScAIN

    NARCIS (Netherlands)

    Bohnen, T.

    2010-01-01

    Chemical vapor deposition (CVD); hydride vapor phase epitaxy (HVPE); gallium nitride (GaN); indium gallium nitride (InGaN); scandium nitride (ScN); scandium aluminum nitride (ScAlN); semiconductors; thin films; nanowires; III nitrides; crystal growth - We studied the HVPE growth of different III

  1. Mutation Analysis of KCNQ1, KCNH2 and SCN5A Genes in Taiwanese Long QT Syndrome Patients.

    Science.gov (United States)

    Chang, Ya-Sian; Yang, Yi-Wen; Lin, Yen-Nien; Lin, Kuo-Hung; Chang, Kuan-Cheng; Chang, Jan-Gowth

    2015-01-01

    Long QT syndrome (LQTS) is a genetic cardiac disease. Gene mutation affects the structure or function of ion channels that are associated with a high risk of sudden death. The goal of this study was to determine the frequency of KCNQ1, KCNH2, and SCN5A mutations in LQTS in a Taiwanese population. Genomic DNA was extracted from peripheral blood samples obtained from 5 patients with LQTS and the family members of 3 LQTS patients. High resolution melting (HRM) analysis and direct DNA sequencing were used to characterize the KCNQ1, KCNH2, and SCN5A genetic variations. HRM analysis was successfully optimized for 14 of the 16 exons of the KCNQ1, 5 of the 15 exons of the KCNH2, and 23 of the 27 exons of the SCN5A. HRM and direct DNA sequencing was applied to the cohort of 5 cases and some of their family. The genetic testing revealed two pathogenic mutations (p.T309I in KCNQ1 and p.R744fs in KCNH2) and all of the mutational frequencies in KCNQ1 and KCNH2 were 20%. In the two patients who carry the pathogenic mutation presenting with recurrent syncope due to ventricular fibrillation, an implantable cardioverter defibrillator was implanted. We also discovered 11 polymorphisms in KCNQ1, 3 in KCNH2, and 5 in SCN5A. Two-fifths of cases (40%) presented with one of the three major LQTS-causing gene mutations.

  2. Redetermination of the crystal structure of K2Hg(SCN4

    Directory of Open Access Journals (Sweden)

    Jascha Bandemehr

    2017-07-01

    Full Text Available Single crystals of K2Hg(SCN4 [dipotassium tetrathiocyanatomercurate(II] were grown from aqueous solutions of potassium thiocyanate and mercury(II thiocyanate and studied by single-crystal X-ray diffraction. In comparison with the previously reported structure model [Zvonkova (1952. Zh. Fiz. Khim. 26, 1798–1803], all atoms in the crystal structure were located, with lattice parameters and fractional coordinates determined to a much higher precision. In the (crystal structure, the HgII atom is located on a twofold rotation axis and is coordinated in the form of a distorted tetrahedron by four S atoms of the thiocyanate anions. The K+ cation shows a coordination number of eight.

  3. Cholecystokinin (CCK)-expressing neurons in the suprachiasmatic nucleus: innervation, light responsiveness and entrainment in CCK-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hundahl, Christian; Fahrenkrug, Jan

    2010-01-01

    , CCK-containing processes make synaptic contacts with both groups of neurons and some CCK cell bodies were innervated by VIPergic neurons. The CCK neurons received no direct input from the three major pathways to the SCN, and the CCK neurons were not light-responsive as evaluated by induction of c......FOS, and did not express the core clock protein PER1. Accordingly, CCK-deficient mice showed normal entrainment and had similar t, light-induced phase shift and negative masking behaviour as wild-type animals. In conclusion, CCK signalling seems not to be involved directly in light-induced resetting...

  4. Formation of scandium nitride (ScN) layer on gallium arsenide (GaAs) substrate using a combined technique of e-beam evaporator and ammonia annealing treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yong Shee Meng, Alvin [Institute of Nano Optoelectronics Research and Technology (INOR), sains@usm, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang (Malaysia); Zainal, Norzaini, E-mail: norzaini@usm.my [Nano Optoelectronics Research and Laboratory, Universiti Sains Malaysia, sains@usm, Persiaran Bukit Jambul, 11900, Bayan Lepas, Penang (Malaysia); Hassan, Zainuriah; Ibrahim, Kamarulazizi [Institute of Nano Optoelectronics Research and Technology (INOR), sains@usm, Persiaran Bukit Jambul, 11900 Bayan Lepas, Penang (Malaysia)

    2015-12-30

    Graphical abstract: - Highlights: • Forming ScN layer using electron e-beam evaporator with successive NH{sub 3} annealing thermal has been successfully demonstrated. • NH{sub 3} annealing played the role in changing the grain structure of the ScN layer. • The existence of Sc−N bonds was confirmed by XPS measurement. • The 900 °C annealed ScN layer showed the best structural and optical characteristics. • ScN layer annealed at 980 °C exhibited poor structural and optical characteristics. - Abstract: A demonstration on a new technique of growing ScN using electron beam (e-beam) evaporator, coupled with successive ammonia (NH{sub 3}) annealing treatment is presented in this paper. The annealing temperature was varied at 750, 800, 850, 900 and 980 °C in order to obtain the best ScN layer. It was found that as the annealing temperature increased, the surface morphology of the ScN layer changed and ScN grains formed abundantly on the surface. The best surface of ScN layer was found in the 900 °C annealed sample. However, the roughness of the ScN increased with temperature. The photoluminescence (PL) peak of the near-to-band-edge (NBE) of ScN was observable in all samples and its intensity was the highest in the 900 °C annealed sample. Note that when the annealing treatment was conducted at 980 °C, the GaN PL peak is observable. Raman peaks of TO(X) of ScN were much evident at the annealing temperature above 900 °C. The formation of Sc−N bonds was confirmed by X-ray spectroscopy (XPS) measurement. In the end of this work, we propose that the formation of ScN using the above techniques was successful, with thermal annealing at the temperature of 900 °C.

  5. Mutations in the sodium channel gene SCN2A cause neonatal epilepsy with late-onset episodic ataxia.

    Science.gov (United States)

    Schwarz, N; Hahn, A; Bast, T; Müller, S; Löffler, H; Maljevic, S; Gaily, E; Prehl, I; Biskup, S; Joensuu, T; Lehesjoki, A-E; Neubauer, B A; Lerche, H; Hedrich, U B S

    2016-02-01

    Mutations in SCN2A cause epilepsy syndromes of variable severity including neonatal-infantile seizures. In one case, we previously described additional childhood-onset episodic ataxia. Here, we corroborate and detail the latter phenotype in three further cases. We describe the clinical characteristics, identify the causative SCN2A mutations and determine their functional consequences using whole-cell patch-clamping in mammalian cells. In total, four probands presented with neonatal-onset seizures remitting after five to 13 months. In early childhood, they started to experience repeated episodes of ataxia, accompanied in part by headache or back pain lasting minutes to several hours. In two of the new cases, we detected the novel mutation p.Arg1882Gly. While this mutation occurred de novo in both patients, one of them carries an additional known variant on the same SCN2A allele, inherited from the unaffected father (p.Gly1522Ala). Whereas p.Arg1882Gly alone shifted the activation curve by -4 mV, the combination of both variants did not affect activation, but caused a depolarizing shift of voltage-dependent inactivation, and a significant increase in Na(+) current density and protein production. p.Gly1522Ala alone did not change channel gating. The third new proband carries the same de novo SCN2A gain-of-function mutation as our first published case (p.Ala263Val). Our findings broaden the clinical spectrum observed with SCN2A gain-of-function mutations, showing that fairly different biophysical mechanisms can cause a convergent clinical phenotype of neonatal seizures and later onset episodic ataxia.

  6. From heavy nuclei to super-heavy nuclei

    International Nuclear Information System (INIS)

    Theisen, Ch.

    2003-01-01

    The existence of super-heavy nuclei has been predicted nearly fifty years ago. Due to the strong coulomb repulsion, the stabilisation of these nuclei is possible only through shell effects. The reasons for this fragile stability, as well as the theoretical predictions concerning the position of the island of stability are presented in the first part of this lecture. In the second part, experiments and experimental techniques which have been used to synthesize or search for super-heavy elements are described. Spectroscopic studies performed in very heavy elements are presented in the following section. We close this lecture with techniques that are currently being developed in order to reach the superheavy island and to study the structure of very-heavy nuclei. (author)

  7. Nuclei in a neutron star

    International Nuclear Information System (INIS)

    Oyamatsu, K.; Yamada, M.

    1994-01-01

    We report on the recent progress in understanding the matter in the crust of a neutron star. For nuclides in the outer crust, recently measured masses of neutron-rich nuclei enable us to determine more accurately the stable nuclide as a function of the matter density. In the inner crust, the compressible liquid-drop model predicts successive change of the nuclear shape, from sphere to cylinder, slab, cylindrical hole and spherical hole at densities just before the transition to uniform matter. In order to go beyond the liquiddrop model, we performed the Thomas-Fermi calculation paying special attention to the surface diffuseness, and have recently calculated the shell energies of the non-spherical nuclei. We have found from these studies that all these non-spherical nuclei exist stably in the above order even if we include the surface diffuseness and shell energies. (author)

  8. Spinodal decomposition of atomic nuclei

    International Nuclear Information System (INIS)

    Chomaz, P.; Colonna, M.; Guarnera, A.

    1996-01-01

    Multifragmentation of atomic nuclei is discussed. It is shown that this description of the dynamics of first order phase transitions in infinite and finite system is now partially achieved. An important conclusion is that in some specific cases well-defined collective motions were initiating the self-organisation of the unstable matter in fragments. In the case of finite systems the possible signals kept from this early fragmentation stage can inform on the possible occurrence of a liquid-gas phase transition in nuclei. (K.A.)

  9. Hole-transporting transistors and circuits based on the transparent inorganic semiconductor copper(I) thiocyanate (CuSCN) processed from solution at room temperature

    KAUST Repository

    Pattanasattayavong, Pichaya

    2012-12-27

    The wide bandgap and highly transparent inorganic compound copper(I) thiocyanate (CuSCN) is used for the first time to fabricate p-type thin-film transistors processed from solution at room temperature. By combining CuSCN with the high-k relaxor ferroelectric polymeric dielectric P(VDF-TrFE-CFE), we demonstrate low-voltage transistors with hole mobilities on the order of 0.1 cm2 V-1 s-1. By integrating two CuSCN transistors, unipolar logic NOT gates are also demonstrated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world's first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density ...

  11. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    collaborators [1,2]. The importance of deformed valleys in the potential energy surfaces. (PES) is that they provide the most favoured fission channels for the decay of superheavy nuclei. For the dynamics study, one has to introduce the influence of mass tensor. We use the results from pairing calculations for the occupation ...

  12. Cavitation Nuclei: Experiments and Theory

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2009-01-01

    us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character....

  13. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    Abstract. The charged current pion production induced by neutrinos in 12C, 16O and 56Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of in ...

  14. Percolation and multifragmentation of nuclei

    International Nuclear Information System (INIS)

    Shmakov, S.Yu.; Uzhinskij, V.V.

    1989-01-01

    A method to build the 'cold' nuclei as percolation clusters is suggested. Within the framework of definite assumptions of the character of nucleon-nucleon couplings breaking resulting from the nuclear reactions as description of the multifragmentation process in the hadron-nucleus and nucleus-nucleus reactions at high energies is obtained. 19 refs.; 6 figs

  15. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    2015-08-02

    Aug 2, 2015 ... ... nuclear configurations typical for fission processes. The deformed two-centre shell model is used to obtain single-particle energy levels for the transition region of two partially overlapped daughter and emitted fragment nuclei. The macroscopic part is obtained using the Yukawa-plus-exponential potential.

  16. Proton scattering from unstable nuclei

    Indian Academy of Sciences (India)

    Abstract. Recent improvements in the intensities and optical qualities of radioactive beams have made possible the study of elastic and inelastic proton scattering on unstable nuclei. The design and performances of an innovative silicon strip detector array devoted to such experiments are described. The quality of the data ...

  17. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

    A review of nuclear astrophysics of light nuclei using radioactive beams or techniques developed for radioactive beams is given. We discuss Big Bang nucleosynthesis, with special focus on the lithium problem, aspects of neutrino-physics, helium-burning and finally selected examples of studies...

  18. Unintegrated parton distributions in nuclei

    Science.gov (United States)

    de Oliveira, E. G.; Martin, A. D.; Navarra, F. S.; Ryskin, M. G.

    2013-09-01

    We study how unintegrated parton distributions in nuclei can be calculated from the corresponding integrated partons using the EPS09 parametrization. The role of nuclear effects is presented in terms of the ratio R A = uPDF A / A·PDF N for both large and small x domains.

  19. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    The pion production processes from nucleons and nuclei at intermediate energies are important tools to study the hadronic structure. The dynamic models of the hadronic structure are used to calculate the various nucleon and transition form factors which are tested by using the experimental data on photo, electro and.

  20. Influence of photoperiod duration and light–dark transitions on entrainment of Per1 and Per2 gene and protein expression in subdivisions of the mouse suprachiasmatic nucleus

    Czech Academy of Sciences Publication Activity Database

    Sosniyenko, Serhiy; Hut, R.A.; Daan, S.; Sumová, Alena

    2009-01-01

    Roč. 30, č. 9 (2009), s. 1802-1814 ISSN 0953-816X R&D Projects: GA MŠk(CZ) LC554; GA ČR(CZ) GA309/08/0503 Grant - others:EC(XE) LSH-2004115-4-018741 Institutional research plan: CEZ:AV0Z50110509 Keywords : clock gene * suprachiasmatic nucleus * photoperiod Subject RIV: FH - Neuro logy Impact factor: 3.418, year: 2009

  1. Red light emission from ZnO:Eu{sup 3+}|CuSCN hetero-junction under cathodic polarization

    Energy Technology Data Exchange (ETDEWEB)

    Sirimanne, P.M., E-mail: psirimane@hotmail.com [Department of Science and Technology, Uwa Wellassa University, Badulla (Sri Lanka); Minoura, H. [Environmental and Renewable Energy Systems Division, Graduate School of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193 (Japan)

    2015-09-15

    Eu{sup 3+} ions were bonded to ZnO ceramic via organic ligand. Surface bonded Eu{sup 3+} ions were exhibited specific luminescence bands due to electron transitions between f–f intra-configurationally transitions. Further enhancement of luminescence bands was observed by attaching selected oligomers to Eu{sup 3+} ions. A hetero-junction was prepared by depositing copper-thiocyanate on Eu{sup 3+} ions bonded ZnO ceramic. Red light emission was observed from surface bonded Eu{sup 3+} ions in ZnO:Eu{sup 3+}|CuSCN hetero-junction under reverse bias. - Highlights: • Europium doped ZnO ceramic exhibits photo-luminescence. • Semiconductor hetro-junction was prepared. • ZnO:Eu{sup 3+}|CuSCN hetero-junction emits red light under reverse bias.

  2. Reduced Penetrance and Variable Expression of SCN5A Mutations and the Importance of Co-inherited Genetic Variants: Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    T. Robyns, MD.

    2014-05-01

    Full Text Available Mutations in the SCN5A gene are responsible for multiple phenotypical presentations including Brugada syndrome, long QT syndrome, progressive familial heart block, sick sinus syndrome, dilated cardiomyopathy, lone atrial fibrillation and multiple overlap syndromes. These different phenotypic expressions of a mutation in a single gene can be explained by variable expression and reduced penetrance. One of the possible explanations of these phenomena is the co-inheritance of genetic variants. We describe a family where the individuals exhibit a compound heterozygosity in the SCN5A gene including a mutation (R1632H and a new variant (M858L. Individuals with both the mutation and new variant present with a more severe phenotype including spontaneous atrial tachyarrhythmia at young age. We give an overview of the different phenotypes of "SCN5A disease" and discuss the importance of co-inherited genetic variants in the expression of SCN5A disease.

  3. Sodium channel SCN8A (Nav1.6: properties and de novo mutations in epileptic encephalopathy and intellectual disability

    Directory of Open Access Journals (Sweden)

    Janelle Elizabeth O'Brien

    2013-10-01

    Full Text Available The sodium channel Nav1.6, encoded by the gene SCN8A, is one of the major voltage-gated channels in human brain. The sequences of sodium channels have been highly conserved during evolution, and minor changes in biophysical properties can have a major impact in vivo. Insight into the role of Nav1.6 has come from analysis of spontaneous and induced mutations of mouse Scn8a during the past 18 years. Only within the past year has the role of SCN8A in human disease become apparent from whole exome and genome sequences of patients with sporadic disease. Unique features of Nav1.6 include its contribution to persistent current, resurgent current, repetitive neuronal firing, and subcellular localization at the axon initial segment and nodes of Ranvier. Loss of Nav1.6 activity results in reduced neuronal excitability, while gain-of-function mutations can increase neuronal excitability. Mouse Scn8a (med mutants exhibit movement disorders including ataxia, tremor and dystonia. Thus far, more than ten human de novo mutations have been identified in patients with two types of disorders, epileptic encephalopathy and intellectual disability. We review these human mutations as well as the unique features of Nav1.6 that contribute to its role in determining neuronal excitability in vivo. A supplemental figure illustrating the positions of amino acid residues within the 4 domains and 24 transmembrane segments of Nav1.6 is provided to facilitate the location of novel mutations within the channel protein.

  4. Crystal structure of K[Hg(SCN3] – a redetermination

    Directory of Open Access Journals (Sweden)

    Matthias Weil

    2014-09-01

    Full Text Available The crystal structure of the room-temperature modification of K[Hg(SCN3], potassium trithiocyanatomercurate(II, was redetermined based on modern CCD data. In comparison with the previous report [Zhdanov & Sanadze (1952. Zh. Fiz. Khim. 26, 469–478], reliability factors, standard deviations of lattice parameters and atomic coordinates, as well as anisotropic displacement parameters, were revealed for all atoms. The higher precision and accuracy of the model is, for example, reflected by the Hg—S bond lengths of 2.3954 (11, 2.4481 (8 and 2.7653 (6 Å in comparison with values of 2.24, 2.43 and 2.77 Å. All atoms in the crystal structure are located on mirror planes. The Hg2+ cation is surrounded by four S atoms in a seesaw shape [S—Hg—S angles range from 94.65 (2 to 154.06 (3°]. The HgS4 polyhedra share a common S atom, building up chains extending parallel to [010]. All S atoms of the resulting 1∞[HgS2/1S2/2] chains are also part of SCN− anions that link these chains with the K+ cations into a three-dimensional network. The K—N bond lengths of the distorted KN7 polyhedra lie between 2.926 (2 and 3.051 (3 Å.

  5. Ab-initio studies of the Sc adsorption and the ScN thin film formation on the GaN(000-1)-(2 × 2) surface

    International Nuclear Information System (INIS)

    Guerrero-Sánchez, J.; Sánchez-Ochoa, F.; Cocoletzi, Gregorio H.; Rivas-Silva, J.F.; Takeuchi, Noboru

    2013-01-01

    First principles total energy calculations have been performed to investigate the initial stages of the Sc adsorption and ScN thin film formation on the GaN(000-1)-(2 × 2) surface. Studies are done within the periodic density functional theory as implemented in the PWscf code of the Quantum ESPRESSO package. The Sc adsorption at high symmetry sites results in the bridge site as the most stable structure. When a Sc monolayer is deposited above the surface the T4 site results as the most stable geometry. The Sc migration into the first Ga monolayer induces the Ga displaced ad-atom to be adsorbed at the T4-2 site. A ScN bilayer may be obtained under the Ga monolayer. Finally a ScN bilayer may be formed in the wurtzite phase above the surface. The formation energy plots show that in the moderate Ga-rich conditions we obtain the formation of a ScN bilayer under the gallium monolayer. However at N-rich conditions the formation of ScN bilayer above the surface is the most favorable structure. We report the density of states to explain the electronic structure of the most favorable geometries. - Highlights: • Studies of the initial stages in the formation of Sc and ScN structures on GaN • In the adsorption of Sc on the GaN the Br site is the most favorable geometry. • When a Sc replaces a Ga of the first monolayer the displaced Ga occupies a T4-2 site. • For Ga-rich conditions there is formation of ScN under the Ga monolayer. • In N-rich conditions there is formation of ScN in the wurtzite phase

  6. The first pseudo-ternary thiocyanate containing two alkali metals. Synthesis and single-crystal structure of LiK2[SCN]3

    International Nuclear Information System (INIS)

    Reckeweg, Olaf; DiSalvo, Francis J.

    2016-01-01

    A procedure was empirically developed to prepare the compound LiK 2 [SCN] 3 , which forms colorless, transparent, very fragile, and extremely hygroscopic thin rectangular plates. Its unique crystal structure was determined by single-crystal X-ray diffraction. LiK 2 [SCN] 3 adopts the orthorhombic space group Pna2 1 (no. 33, Z = 4) with the cell parameters a = 1209.32(9), b = 950.85(9), and c = 849.95(6) pm.

  7. Dysfunction of the Scn8a Voltage-gated Sodium Channel Alters Sleep Architecture, Reduces Diurnal Corticosterone Levels, and Enhances Spatial Memory

    OpenAIRE

    Papale, Ligia Assumpção [UNIFESP; Paul, Ketema N.; Sawyer, Nikki T.; Manns, Joseph R.; Tufik, Sergio [UNIFESP; Escayg, Andrew

    2010-01-01

    Voltage-gated sodium channels (VGSCs) are responsible for the initiation and propagation of transient depolarizing currents and play a critical role in the electrical signaling between neurons. A null mutation in the VGSC gene SCN8A, which encodes the transmembrane protein Na(v)1.6, was identified previously in a human family. Heterozygous mutation carriers displayed a range of phenotypes, including ataxia, cognitive deficits, and emotional instability. A possible role for SCN8A was also prop...

  8. Electric field-induced hole transport in copper(i) thiocyanate (CuSCN) thin-films processed from solution at room temperature

    KAUST Repository

    Pattanasattayavong, Pichaya

    2013-01-01

    The optical, structural and charge transport properties of solution-processed films of copper(i) thiocyanate (CuSCN) are investigated in this work. As-processed CuSCN films of ∼20 nm in thickness are found to be nano-crystalline, highly transparent and exhibit intrinsic hole transporting characteristics with a maximum field-effect mobility in the range of 0.01-0.1 cm2 V-1 s-1. © 2013 The Royal Society of Chemistry.

  9. High-Efficiency Fullerene Solar Cells Enabled by a Spontaneously Formed Mesostructured CuSCN-Nanowire Heterointerface

    KAUST Repository

    Sit, Wai-Yu

    2018-02-02

    Fullerenes and their derivatives are widely used as electron acceptors in bulk-heterojunction organic solar cells as they combine high electron mobility with good solubility and miscibility with relevant semiconducting polymers. However, studies on the use of fullerenes as the sole photogeneration and charge-carrier material are scarce. Here, a new type of solution-processed small-molecule solar cell based on the two most commonly used methanofullerenes, namely [6,6]-phenyl-C61-butyric acid methyl ester (PC60BM) and [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM), as the light absorbing materials, is reported. First, it is shown that both fullerene derivatives exhibit excellent ambipolar charge transport with balanced hole and electron mobilities. When the two derivatives are spin-coated over the wide bandgap p-type semiconductor copper (I) thiocyanate (CuSCN), cells with power conversion efficiency (PCE) of ≈1%, are obtained. Blending the CuSCN with PC70BM is shown to increase the performance further yielding cells with an open-circuit voltage of ≈0.93 V and a PCE of 5.4%. Microstructural analysis reveals that the key to this success is the spontaneous formation of a unique mesostructured p–n-like heterointerface between CuSCN and PC70BM. The findings pave the way to an exciting new class of single photoactive material based solar cells.

  10. Fabrication and characterization of ZnO nano wires/Cd Se/CuSCN eta-solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Tena-Zaera, R.; Ryan, M.A.; Abou, Katty; Hodes, G.; Bastide, St.; Levy-Clement, C. [LCMTR, Institut des sciences chimiques Seine-Amont, CNRS, 94 - Thiais (France); Tena-Zaera, R. [Valancia Univ., Dept. Fisica Aplicada i Electromagnetisme (Spain); Ryan, M.A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States); Hodes, G. [Weizmann Institute of Science, Dept. of Materials and Interfaces, Rehovot (Israel)

    2006-05-15

    ZnO/CdSe/CuSCN extremely thin absorber (eta)-solar cells based on ZnO nano-wires have been successfully realized using easily accessible electrochemical and solution deposition techniques. An n-type ZnO film consisting of free-standing single crystal nano-wires several microns high and 100-200 nm in diameter was-deposited on a conducting glass (SnO{sub 2}:F) substrate covered by a thin spray pyrolysis ZnO electronic blocking layer. A 30-40-nm-thin layer of CdSe absorber was electrodeposited, coating the ZnO nano-wires. The voids between the ZnO/CdSe nano-wires were filled with p-type CuSCN; the entire assembly formed a p-i-n junction. The ZnO/CdSe nano-wire layer exhibited a high light-trapping effect, with an effective absorbance of {approx}89% and effective reflectance of {approx}8% in the 400-800 nm region of the solar spectrum (AM1.5). The effects of an annealing process on the CdSe grain size and on the energy conversion efficiency of the eta-solar cell have been analyzed. The obtained efficiencies, for cells with annealed CdSe (1.5-2.3%) show that the ZnO/CdSe/CuSCN nano-heterostructure is an interesting option for developing new solar cell devices. (authors)

  11. Fabrication and characterization of ZnO nano wires/Cd Se/CuSCN eta-solar cell

    International Nuclear Information System (INIS)

    Tena-Zaera, R.; Ryan, M.A.; Abou, Katty; Hodes, G.; Bastide, St.; Levy-Clement, C.; Tena-Zaera, R.; Ryan, M.A.; Hodes, G.

    2006-01-01

    ZnO/CdSe/CuSCN extremely thin absorber (eta)-solar cells based on ZnO nano-wires have been successfully realized using easily accessible electrochemical and solution deposition techniques. An n-type ZnO film consisting of free-standing single crystal nano-wires several microns high and 100-200 nm in diameter was-deposited on a conducting glass (SnO 2 :F) substrate covered by a thin spray pyrolysis ZnO electronic blocking layer. A 30-40-nm-thin layer of CdSe absorber was electrodeposited, coating the ZnO nano-wires. The voids between the ZnO/CdSe nano-wires were filled with p-type CuSCN; the entire assembly formed a p-i-n junction. The ZnO/CdSe nano-wire layer exhibited a high light-trapping effect, with an effective absorbance of ∼89% and effective reflectance of ∼8% in the 400-800 nm region of the solar spectrum (AM1.5). The effects of an annealing process on the CdSe grain size and on the energy conversion efficiency of the eta-solar cell have been analyzed. The obtained efficiencies, for cells with annealed CdSe (1.5-2.3%) show that the ZnO/CdSe/CuSCN nano-heterostructure is an interesting option for developing new solar cell devices. (authors)

  12. Efficient and stable CH3NH3PbI3-x(SCN)x planar perovskite solar cells fabricated in ambient air with low-temperature process

    Science.gov (United States)

    Zhang, Zongbao; Zhou, Yang; Cai, Yangyang; Liu, Hui; Qin, Qiqi; Lu, Xubing; Gao, Xingsen; Shui, Lingling; Wu, Sujuan; Liu, Jun-Ming

    2018-02-01

    Planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x (SCN: thiocyanate) active layer and low-temperature processed TiO2 films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN)2 precursor to improve the microstructure of CH3NH3PbI3-x(SCN)x perovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport, reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.

  13. Nuclear treasure island [superheavy nuclei

    CERN Document Server

    CERN. Geneva

    1999-01-01

    Summary form only given. Soon after the experiments at Dubna, which synthesized element 114 and made the first footprints on the beach of the "island of nuclear stability", two new superheavy elements have been discovered at the Lawrence Berkeley National Laboratory. Element 118 and its immediate decay product, element 116, were manufactured at Berkeley's 88 inch cyclotron by fusing targets of lead-208 with an intense beam of 449 MeV krypton-86 ions. Although both new nuclei almost instantly decay into lighter ones, the decay sequence is consistent with theories that have long predicted the island of stability for nuclei with approximately 114 protons and 184 neutrons. Theorist Robert Smolanczuk, visiting from the Soltan Institute for Nuclear Studies in Poland, had calculated that this reaction should have particularly favourable production rates. Now that this route has been signposted, similar reactions could be possible: new elements and isotopes, tests of nuclear stability and mass models, and a new under...

  14. Cooper pairs in atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, 19716 Delaware (United States); Dussel, G. G. [Departamento de Fisica J.J. Giambiagi, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Dukelsky, J.; Sarriguren, P. [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2008-12-15

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  15. Relativistic description of deformed nuclei

    International Nuclear Information System (INIS)

    Price, C.E.

    1988-01-01

    The author has shown that relativistic Hartree calculations using parameters that have been fit to the properties of nuclear matter can provide a good description of both spherical and axially deformed nuclei. The quantitative agreement with experiment is equivalent to that which was obtained in non-relativistic calculations using Skyrme interactions. The equilibrium deformation is strongly correlated with the size of the spin-orbit splitting, and that parameter sets which give roughly the correct value for this splitting provide the best agreement with the quadrupole moments in the s-d shell. Finally, for closed shell +/- 1 nuclei, it was shown that the self-consistent calculations are able to reproduce the experimental magnetic moments. This was not possible in relativistic calculations which include only the effects of the valence orbital

  16. Multiple phonon excitation in nuclei

    International Nuclear Information System (INIS)

    Chomaz, Ph.; Frascaria, N.

    1994-01-01

    The studies of multiphonon excitations in nuclei are reviewed both from the theoretical and experimental points of view. The presence of giant resonances in nuclei is described in the framework of macroscopic and microscopic models and the relative merits of different probes to excite such states are illustrated. The existence of giant resonances built on excited states is stressed. An exhaustive description of the theoretical estimates of the properties of the multiphonon states is presented. The theory predicts that such multiple collective excitations should closely follow a harmonic pattern. Recent experimental results on the double giant dipole resonance using the (π + π - ) double charge exchange reaction are shown. The status of the search for isoscalar multiphonon excitations by means of the strong nuclear potential produced by heavy ions is presented. Conclusions are drawn and new prospects are discussed. (authors) 293 refs., 67 figs., 8 tabs

  17. A SCN9A gene-encoded dorsal root ganglia sodium channel polymorphism associated with severe fibromyalgia

    Directory of Open Access Journals (Sweden)

    Vargas-Alarcon Gilberto

    2012-02-01

    Full Text Available Abstract Background A consistent line of investigation suggests that autonomic nervous system dysfunction may explain the multi-system features of fibromyalgia (FM; and that FM is a sympathetically maintained neuropathic pain syndrome. Dorsal root ganglia (DRG are key sympathetic-nociceptive short-circuit sites. Sodium channels located in DRG (particularly Nav1.7 act as molecular gatekeepers for pain detection. Nav1.7 is encoded in gene SCN9A of chromosome 2q24.3 and is predominantly expressed in the DRG pain-sensing neurons and sympathetic ganglia neurons. Several SCN9A sodium channelopathies have been recognized as the cause of rare painful dysautonomic syndromes such as paroxysmal extreme pain disorder and primary erythromelalgia. The aim of this study was to search for an association between fibromyalgia and several SCN9A sodium channels gene polymorphisms. Methods We studied 73 Mexican women suffering from FM and 48 age-matched women who considered themselves healthy. All participants filled out the Fibromyalgia Impact Questionnaire (FIQ. Genomic DNA from whole blood containing EDTA was extracted by standard techniques. The following SCN9A single-nucleotide polymorphisms (SNP were determined by 5' exonuclease TaqMan assays: rs4371369; rs4387806; rs4453709; rs4597545; rs6746030; rs6754031; rs7607967; rs12620053; rs12994338; and rs13017637. Results The frequency of the rs6754031 polymorphism was significantly different in both groups (P = 0.036 mostly due to an absence of the GG genotype in controls. Interestingly; patients with this rs6754031 GG genotype had higher FIQ scores (median = 80; percentile 25/75 = 69/88 than patients with the GT genotype (median = 63; percentile 25/75 = 58/73; P = 0.002 and the TT genotype (median = 71; percentile 25/75 = 64/77; P = 0.001. Conclusion In this ethnic group; a disabling form of FM is associated to a particular SCN9A sodium channel gene variant. These preliminary results raise the possibility that

  18. Spectroscopy of heavy fissionable nuclei

    Indian Academy of Sciences (India)

    2015-08-05

    Aug 5, 2015 ... A comparison of aligned angular momentum in these nuclei over the range of observed frequencies (up to ¯hω ≈ 0.25 MeV) reveals a possible, small but signifi- cant contribution from j15/2 neutrons in 249Cm, as evidenced from the higher degree of alignment compared to 247Cm over the observed range ...

  19. Density functional theory of nuclei

    International Nuclear Information System (INIS)

    Terasaki, Jun

    2008-01-01

    The density functional theory of nuclei has come to draw attention of scientists in the field of nuclear structure because the theory is expected to provide reliable numerical data in wide range on the nuclear chart. This article is organized to present an overview of the theory to the people engaged in the theory of other fields as well as those people in the nuclear physics experiments. At first, the outline of the density functional theory widely used in the electronic systems (condensed matter, atoms, and molecules) was described starting from the Kohn-Sham equation derived on the variational principle. Then the theory used in the field of nuclear physics was presented. Hartree-Fock and Hartree-Fock-Bogolyubov approximation by using Skyrme interaction was explained. Comparison of the results of calculations and experiments of binding energies and ground state mean square charge radii of some magic number nuclei were shown. The similarity and dissimilarity between the two streams were summarized. Finally the activities of the international project of Universal Nuclear Energy Density Functional (UNEDF) which was started recently lead by US scientist was reported. This project is programmed for five years. One of the applications of the project is the calculation of the neutron capture cross section of nuclei on the r-process, which is absolutely necessary for the nucleosynthesis research. (S. Funahashi)

  20. Thermodynamical description of excited nuclei

    International Nuclear Information System (INIS)

    Bonche, P.

    1989-01-01

    In heavy ion collisions it has been possible to obtain composite systems at rather high excitation energies corresponding to temperatures of several MeV. The theoretical studies of these systems are based on concepts borrowed from thermodynamics or statistical physics, such as the temperature. In these lectures, we present the concepts of statistical physics which are involved in the physics of heavy ion as they are produced nowadays in the laboratory and also during the final stage of a supernova collapse. We do not attempt to describe the reaction mechanisms which yield such nuclear systems nor their decay by evaporation or fragmentation. We shall only study their static properties. The content of these lectures is organized in four main sections. The first one gives the basic features of statistical physics and thermodynamics necessary to understand quantum mechanics at finite temperature. In the second one, we present a study of the liquid-gas phase transition in nuclear physics. A phenomenological approach of the stability of hot nuclei follows. The microscopic point of view is proposed in the third part. Starting from the basic concepts derived in the first part, it provides a description of excited or hot nuclei which confirms the qualitative results of the second part. Furthermore it gives a full description of most properties of these nuclei as a function of temperature. Finally in the last part, a microscopic derivation of the equation of state of nuclear matter is proposed to study the collapse of a supernova core

  1. Genetic and phenotypic heterogeneity suggest therapeutic implications in SCN2A-related disorders.

    Science.gov (United States)

    Wolff, Markus; Johannesen, Katrine M; Hedrich, Ulrike B S; Masnada, Silvia; Rubboli, Guido; Gardella, Elena; Lesca, Gaetan; Ville, Dorothée; Milh, Mathieu; Villard, Laurent; Afenjar, Alexandra; Chantot-Bastaraud, Sandra; Mignot, Cyril; Lardennois, Caroline; Nava, Caroline; Schwarz, Niklas; Gérard, Marion; Perrin, Laurence; Doummar, Diane; Auvin, Stéphane; Miranda, Maria J; Hempel, Maja; Brilstra, Eva; Knoers, Nine; Verbeek, Nienke; van Kempen, Marjan; Braun, Kees P; Mancini, Grazia; Biskup, Saskia; Hörtnagel, Konstanze; Döcker, Miriam; Bast, Thomas; Loddenkemper, Tobias; Wong-Kisiel, Lily; Baumeister, Friedrich M; Fazeli, Walid; Striano, Pasquale; Dilena, Robertino; Fontana, Elena; Zara, Federico; Kurlemann, Gerhard; Klepper, Joerg; Thoene, Jess G; Arndt, Daniel H; Deconinck, Nicolas; Schmitt-Mechelke, Thomas; Maier, Oliver; Muhle, Hiltrud; Wical, Beverly; Finetti, Claudio; Brückner, Reinhard; Pietz, Joachim; Golla, Günther; Jillella, Dinesh; Linnet, Karen M; Charles, Perrine; Moog, Ute; Õiglane-Shlik, Eve; Mantovani, John F; Park, Kristen; Deprez, Marie; Lederer, Damien; Mary, Sandrine; Scalais, Emmanuel; Selim, Laila; Van Coster, Rudy; Lagae, Lieven; Nikanorova, Marina; Hjalgrim, Helle; Korenke, G Christoph; Trivisano, Marina; Specchio, Nicola; Ceulemans, Berten; Dorn, Thomas; Helbig, Katherine L; Hardies, Katia; Stamberger, Hannah; de Jonghe, Peter; Weckhuysen, Sarah; Lemke, Johannes R; Krägeloh-Mann, Ingeborg; Helbig, Ingo; Kluger, Gerhard; Lerche, Holger; Møller, Rikke S

    2017-05-01

    Mutations in SCN2A, a gene encoding the voltage-gated sodium channel Nav1.2, have been associated with a spectrum of epilepsies and neurodevelopmental disorders. Here, we report the phenotypes of 71 patients and review 130 previously reported patients. We found that (i) encephalopathies with infantile/childhood onset epilepsies (≥3 months of age) occur almost as often as those with an early infantile onset (<3 months), and are thus more frequent than previously reported; (ii) distinct phenotypes can be seen within the late onset group, including myoclonic-atonic epilepsy (two patients), Lennox-Gastaut not emerging from West syndrome (two patients), and focal epilepsies with an electrical status epilepticus during slow sleep-like EEG pattern (six patients); and (iii) West syndrome constitutes a common phenotype with a major recurring mutation (p.Arg853Gln: two new and four previously reported children). Other known phenotypes include Ohtahara syndrome, epilepsy of infancy with migrating focal seizures, and intellectual disability or autism without epilepsy. To assess the response to antiepileptic therapy, we retrospectively reviewed the treatment regimen and the course of the epilepsy in 66 patients for which well-documented medical information was available. We find that the use of sodium channel blockers was often associated with clinically relevant seizure reduction or seizure freedom in children with early infantile epilepsies (<3 months), whereas other antiepileptic drugs were less effective. In contrast, sodium channel blockers were rarely effective in epilepsies with later onset (≥3 months) and sometimes induced seizure worsening. Regarding the genetic findings, truncating mutations were exclusively seen in patients with late onset epilepsies and lack of response to sodium channel blockers. Functional characterization of four selected missense mutations using whole cell patch-clamping in tsA201 cells-together with data from the literature-suggest that

  2. Exotic light nuclei and nuclei in the lead region

    International Nuclear Information System (INIS)

    Poppelier, N.A.F.M.

    1989-01-01

    Three methods are discussed for modifying, or renormalizing, a truncated nuclear hamiltonian such that the wave functions obtained by diagonalizing this modified or effective hamiltoniandescribe the nucleus as well as possible: deriving the hamiltonian directly from a realistic nucleon-nucleon interaction between free nucleons; parametrizing the hamiltonian in terms of a number of parameters and determining these parameters from a least-squares fit of calculated properties to experimental data; approximating the nucleon-nucleon (NN) interaction between two nucleons in a nucleus by a simple analytic expression. An effective hamiltonian derived following the second method is applied in a theoretical study of exotic nuclei in the region of Z=2-9 and A=4-30 and the problem of the neutron halo in 11 Li is discussed. Results of shell-model calculations of 20i Pb and nuclei in its neighbourhood are presented in which an effective hamiltonian was employed derived with the last method. The quenching of M1 strength in 208 Pb, and the spectroscopic factors measured in proton knock-out reactions could be described quite satisfactory. Finally, a method is presented for deriving the effective hamiltonian directly from the realistic NN interaction with algebraic techniques. (H.W.). 114 refs.; 34 figs.; 12 tabs.; schemes

  3. Microscopic structure for light nuclei

    International Nuclear Information System (INIS)

    Sharma, V.K.

    1995-01-01

    The microscopic structure for light nuclei e.g. 4 He, 7 Li and 8 Be is considered in the frame work of the generator coordinate method (GCM). The physical interpretation of our GCM is also discussed. The GC amplitudes are used to calculate the various properties like charge and magnetic RMS radii, form factors, electromagnetic moments, astrophysical S-factor, Bremsstrahlung weighted cross sections, relative wavefunctions and vertex functions etc. All the calculated quantities agree well with the values determined experimentally. (author). 30 refs., 10 figs., 2 tabs

  4. Nucleon transfer between heavy nuclei

    International Nuclear Information System (INIS)

    Von Oertzen, W.

    1984-02-01

    Nucleon transfer reactions between heavy nuclei are characterized by the classical behaviour of the scattering orbits. Thus semiclassical concepts are well suited for the description of these reactions. In the present contribution the characteristics of single and multinucleon transfer reactions at energies below and above the Coulomb barrier are shown for systems like Sn+Sn, Xe+U and Ni+Pb. The role of the pairing interaction in the transfer of nucleon pairs is illustrated. For strong transitions the coupling of channels and the absorption into more complicated channels is taken into account in a coupled channels calculation

  5. Quarks in hadrons and nuclei

    International Nuclear Information System (INIS)

    Close, F.E.

    1988-01-01

    The paper concerns some of the ideas underlying quarks and their interactions, the way that quarks build up hadrons, and the extent to which the QCD theory can be applied to phenomena involving nuclei. The article is part of the Proceedings of the International School of Nuclear Physics, Erice, 1987. A description is given of quarks and multiplets. Colour is discussed with respect to: evidence for colour, a non abelian Su(3) theory, the pauli principle at work in hadrons, and spin flavour correlations and magnetic moments. Colour, gluons and the inter quark potential are also examined. (UK)

  6. Microscopic properties of superdeformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Lennart B

    1999-04-01

    Many high spin rotational bands in superdeformed nuclei have been found in the A 140 - 150 region, but so far no linking transitions to known normal-deformed states have been found in these nuclei. Therefore, configuration and spin assignments have to be based on indirect spectroscopic information. Identical bands were first discovered in this region of superdeformed states. At present, some identical bands have also been found at normal deformation, but such bands are more common at superdeformation. Recently lifetime measurements have given relative quadrupole moments with high accuracy. Spectroscopic quantities are calculated using the configuration constrained cranked Nilsson-Strutinsky model with the modified oscillator potential. In a statistical study the occurrence of identical bands is tested. Comparing superdeformed and normal deformed nuclei, the higher possibility for identical bands at superdeformation is understood from calculated reduced widths of the E{sub {gamma}} and J{sup (2)} distributions. The importance of high-N orbitals for identical bands is also discussed. Additivity of electric quadrupole moment contributions in the superdeformed A - 150 region is discussed with the nucleus {sup 152}Dy as a `core`. In analytic harmonic oscillator calculations, the effective electric quadrupole moment q{sub eff}, i.e. the change in the total quadrupole moment caused by the added particle, is expressed as a simple function of the single-particle mass, quadrupole moment q{sub {nu}}. Also in realistic calculations, simple relations between q{sub eff} and q{sub {nu}} can be used to estimate the total electric quadrupole moment, e.g. for the nucleus {sup 142}Sm, by adding the effect of 10 holes, to the total electric quadrupole moment of {sup 152}Dy. Furthermore, tools are given for estimating the quadrupole moment for possible configurations in the superdeformed A - 150 region. For the superdeformed region around {sup 143}Eu, configuration and spin assignments

  7. Aberrant Sodium Channel Currents and Hyperexcitability of Medial Entorhinal Cortex Neurons in a Mouse Model of SCN8A Encephalopathy.

    Science.gov (United States)

    Ottolini, Matteo; Barker, Bryan S; Gaykema, Ronald P; Meisler, Miriam H; Patel, Manoj K

    2017-08-09

    SCN8A encephalopathy, or early infantile epileptic encephalopathy 13 (EIEE13), is caused predominantly by de novo gain-of-function mutations in the voltage-gated Na channel Na v 1.6. Affected individuals suffer from refractory seizures, developmental delay, cognitive disability, and elevated risk of sudden unexpected death in epilepsy (SUDEP). A knock-in mouse model carrying the patient mutation p.Asn1768Asp (N1768D) reproduces many features of the disorder, including spontaneous seizures and SUDEP. We used the mouse model to examine the effects of the mutation on layer II stellate neurons of the medial entorhinal cortex (mEC), which transmit excitatory input to the hippocampus. Heterozygous ( Scn8a D/+ ), homozygous ( Scn8a D/D) ), and WT ( Scn8a +/+ ) littermates were compared at 3 weeks of age, the time of seizure onset for homozygous mice. Heterozygotes remain seizure free for another month. mEC layer II neurons of heterozygous and homozygous mice were hyperexcitable and generated long-lasting depolarizing potentials with bursts of action potentials after synaptic stimulation. Recording of Na currents revealed proexcitatory increases in persistent and resurgent currents and rightward shifts in inactivation parameters, leading to significant increases in the magnitude of window currents. The proexcitatory changes were more pronounced in homozygous mice than in heterozygotes, consistent with the earlier age of seizure onset in homozygotes. These studies demonstrate that the N1768D mutation increases the excitability of mEC layer II neurons by increasing persistent and resurgent Na currents and disrupting channel inactivation. The aberrant activities of mEC layer II neurons would provide excessive excitatory input to the hippocampus and contribute to hyperexcitability of hippocampal neurons in this model of SCN8A encephalopathy. SIGNIFICANCE STATEMENT SCN8A encephalopathy is a devastating neurological disorder that results from de novo mutations in the Na channel

  8. Barriers in the energy of deformed nuclei

    Directory of Open Access Journals (Sweden)

    V. Yu. Denisov

    2014-06-01

    Full Text Available Interaction energy between two nuclei considering to their deformations is studied. Coulomb and nuclear in-teraction energies, as well as the deformation energies of both nuclei, are taken into account at evaluation of the interaction energy. It is shown that the barrier related to the interaction energy of two nuclei depends on the de-formations and the height of the minimal barrier is evaluated. It is obtained that the heavier nucleus-nucleus sys-tems have large deformation values at the lowest barrier. The difference between the barrier between spherical nuclei and the lowest barrier between deformed nuclei increases with the mass and the charge of the interacting nuclei.

  9. Exotic nuclei: another aspect of nuclear structure

    International Nuclear Information System (INIS)

    Dobaczewski, J.; Blumenfeld, Y.; Flocard, H.; Garcia Borge, M.J.; Nowacki, F.; Rombouts, S.; Theisen, Ch.; Marques, F.M.; Lacroix, D.; Dessagne, P.; Gaeggeler, H.

    2002-01-01

    This document gathers the lectures made at the Joliot Curie international summer school in 2002 whose theme that year was exotic nuclei. There were 11 contributions whose titles are: 1) interactions, symmetry breaking and effective fields from quarks to nuclei; 2) status and perspectives for the study of exotic nuclei: experimental aspects; 3) the pairing interaction and the N = Z nuclei; 4) borders of stability region and exotic decays; 5) shell structure of nuclei: from stability to decay; 6) variational approach of system with a few nucleons; 7) from heavy to super-heavy nuclei; 8) halos, molecules and multi-neutrons; 9) macroscopic approaches for fusion reactions; 10) beta decay: a tool for spectroscopy; 11) the gas phase chemistry of super-heavy elements

  10. Brugada syndrome with a novel missense mutation in SCN5A gene: A case report from Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Zahidus Sayeed

    2014-01-01

    Full Text Available Brugada syndrome is an inherited cardiac arrhythmia that follows autosomal dominant transmission and can cause sudden death. We report a case of Brugada syndrome in a 55-year-old male patient presented with recurrent palpitation, atypical chest pain and presyncope. ECG changes were consistent with type 1 Brugada. Gene analysis revealed a novel missense mutation in SCN5A gene with a genetic variation of D785N and a nucleotide change at 2353G-A. One of his children also had the same mutation. To our knowledge this is the first genetically proved case of Brugada syndrome in Bangladesh.

  11. Effect of Rare Earth Elements (Er, Ho) on Semi-Metallic Materials (ScN) in an Applied Electric Field

    Science.gov (United States)

    Kim, Hyunjung; Park, Yeonjoon; King, Glen C.; Lee, Kunik; Choi, Sang H.

    2012-01-01

    The development of materials and fabrication technology for field-controlled spectrally active optics is essential for applications such as membrane optics, filters for LIDARs, windows for sensors, telescopes, spectroscopes, cameras and flat-panel displays. The dopants of rare earth elements, in a host of optical systems, create a number of absorption and emission band structures and can easily be incorporated into many high quality crystalline and amorphous hosts. In wide band-gap semiconductors like ScN, the existing deep levels can capture or emit the mobile charges, and can be ionized with the loss or capture of the carriers which are the fundamental basis of concept for smart optic materials. The band gap shrinkage or splitting with dopants supports the possibility of this concept. In the present work, a semi-metallic material (ScN) was doped with rare earth elements (Er, Ho) and tested under an applied electric field to characterize spectral and refractive index shifts by either Stark or Zeeman Effect. These effects can be verified using the UV-Vis spectroscopy, the Hall Effect measurement and the ellipsometric spectroscopy. The optical band gaps of ScN doped with Er and doped with Ho were experimentally estimated as 2.33eV and 2.24eV ( 0.2eV) respectively. This is less than that of undoped ScN (2.5 0.2eV). The red-shifted absorption onset is a direct evidence for the decrease of band gap energy (Eg), and the broadening of valence band states is attributable to the doping cases. A decrease in refractive index with an applied field was observed as a small shift in absorption coefficient using a variable angle spectroscopic ellipsometer. In the presence of an electric field, mobile carriers are redistributed within the space charge region (SCR) to produce this electro-refractive effect. The shift in refractive index is also affected by the density and location of deep potential wells within the SCR. In addition, the microstructure change was observed by a TEM

  12. Solution-processed inorganic copper(I) thiocyanate (CuSCN) hole transporting layers for efficient p–i–n perovskite solar cells

    KAUST Repository

    Zhao, Kui

    2015-08-27

    CuSCN is a highly transparent, highly stable, low cost and easy to solution process HTL that is proposed as a low cost replacement to existing organic and inorganic metal oxide hole transporting materials. Here, we demonstrate hybrid organic-inorganic perovskite-based p-i-n planar heterojunction solar cells using a solution-processed copper(I) thiocyanate (CuSCN) bottom hole transporting layer (HTL). CuSCN, with its high workfunction, increases the open circuit voltage (Voc) by 0.23 V to 1.06 V as compared with devices based on the well-known poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (0.83 V), resulting in a superior power conversion efficiency (PCE) of 10.8% without any notable hysteresis. Photoluminescence measurements suggest a similar efficiency of charge transfer at HTL/perovskite interface as PEDOT:PSS. However, we observe more efficient light harvesting in the presence of CuSCN at shorter wavelengths despite PEDOT:PSS being more transparent. Further investigation of the microstructure and morphology reveals differences in the crystallographic texture of the polycrystalline perovskite film, suggesting somewhat modified perovskite growth on the surface of CuSCN. The successful demonstration of the solution-processed inorganic HTL using simple and low temperature processing routes bodes well for the development of reliable and efficient flexible p-i-n perovskite modules or for integration as a front cell in hybrid tandem solar cells.

  13. Laser method of free atom nuclei orientation

    International Nuclear Information System (INIS)

    Barabanov, A.L.

    1987-01-01

    Orientation process of free atom (atoms in beams) nuclei, scattering quanta of circularly polarized laser radiation is considered. A method for the evaluation of nuclei orientation parameters is developed. It is shown that in the process of pumping between the ground and first excited atomic states with electron shell spins J 1 and J 2 , so that J 2 = J 1 + 1, a complete orientation of nuclei can be attained

  14. Are there multiquark bags in nuclei

    International Nuclear Information System (INIS)

    Kondratyuk, L.A.; Scmatkov, M.Zh.

    1983-01-01

    Arguments are presented favouring the idea that multiquark bags do eXist in nuclei. Such hypothesis makes possible to reveal the relationship among three different scopes of phenomena: deep inelastic scattering of leptons by nUclei, large q 2 (where q 2 is a square of momentum transfer) behaviour of the form factors of light nuclei and yield of cumulative proton.s

  15. Nuclei quadrupole coupling constants in diatomic molecule

    International Nuclear Information System (INIS)

    Ivanov, A.I.; Rebane, T.K.

    1993-01-01

    An approximate relationship between the constants of quadrupole interaction of nuclei in a two-atom molecule is found. It enabled to establish proportionality of oscillatory-rotation corrections to these constants for both nuclei in the molecule. Similar results were obtained for the factors of electrical dipole-quadrupole screening of nuclei. Applicability of these relationships is proven by the example of lithium deuteride molecule. 4 refs., 1 tab

  16. Circadian ATP Release in Organotypic Cultures of the Rat Suprachiasmatic Nucleus Is Dependent on P2X7 and P2Y Receptors

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Irena; Bhattacharya, Anirban; Ivetic, Milorad; Bendová, Z.; Zemková, Hana

    2018-01-01

    Roč. 9, Mar 6 (2018), č. článku 192. ISSN 1663-9812 R&D Projects: GA ČR(CZ) GA16-12695S; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : suprachiasmatic nucleus * organotypic cultures * astrocytes * P2X7 receptor * P2Y1 receptor * P2Y2 receptor * pannexin-1 hemichannel * ATP release Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 4.400, year: 2016

  17. Hypothalamic neurosecretory and circadian vasopressinergic neuronal systems in the blind cone-rod homeobox knock out mouse (Crx(-/-) ) and the 129sv wild type mouse

    DEFF Research Database (Denmark)

    Rovsing, Louise; Rath, Martin Fredensborg; Møller, Morten

    2013-01-01

    magnocellular and parvocellular vasopressinergic systems in both genotypes. We here present a detailed mapping of all classical hypothalamo-pituitary and accessory magnocellular nuclei and neurons in the hypothalamus by use of immunohistochemistry and in situ hybridization in both genotypes. Semiquantitative...... in situ hybridization revealed a very high expression of Avp-mRNA in all the magnocellular nuclei compared to a much lower level in the parvocellular suprachiasmatic nucleus. In a series of mice killed every 4 hours, The Avp-mRNA expression in the SCN showed a significant daily rhythm with a zenith...

  18. Deformation effect on spectral statistics of nuclei

    Science.gov (United States)

    Sabri, H.; Jalili Majarshin, A.

    2018-02-01

    In this study, we tried to get significant relations between the spectral statistics of atomic nuclei and their different degrees of deformations. To this aim, the empirical energy levels of 109 even-even nuclei in the 22 ≤ A ≤ 196 mass region are classified as their experimental and calculated quadrupole, octupole, hexadecapole and hexacontatetrapole deformations values and analyzed by random matrix theory. Our results show an obvious relation between the regularity of nuclei and strong quadrupole, hexadecapole and hexacontatetrapole deformations and but for nuclei that their octupole deformations are nonzero, we have observed a GOE-like statistics.

  19. The asymptotic hadron spectrum, anti-nuclei, hyper-nuclei and quark phase

    International Nuclear Information System (INIS)

    Glendenning, N.K.

    1978-01-01

    The only hope of determining the hadronic spectrum in the high mass region is through a study of matter produced in very high energy nuclear collisions. Along the way, exotic nuclei, i.e., anti-nuclei and hyper-nuclei may be produced in appreciable numbers, and the detection of a quark phase may be possible. (orig.) [de

  20. Temperature-dependent changes in neuronal dynamics in a patient with an SCN1A mutation and hyperthermia induced seizures

    Science.gov (United States)

    Peters, C.; Rosch, R. E.; Hughes, E.; Ruben, P. C.

    2016-09-01

    Dravet syndrome is the prototype of SCN1A-mutation associated epilepsies. It is characterised by prolonged seizures, typically provoked by fever. We describe the evaluation of an SCN1A mutation in a child with early-onset temperature-sensitive seizures. The patient carries a heterozygous missense variant (c3818C > T pAla1273Val) in the NaV1.1 brain sodium channel. We compared the functional effects of the variant vs. wild type NaV1.1 using patch clamp recordings from channels expressed in Chinese Hamster Ovary Cells at different temperatures (32, 37, and 40 °C). The variant channels produced a temperature-dependent destabilization of activation and fast inactivation. Implementing these empirical abnormalities in a computational model predicts a higher threshold for depolarization block in the variant, particularly at 40 °C, suggesting a failure to autoregulate at high-input states. These results reveal direct effects of abnormalities in NaV1.1 biophysical properties on neuronal dynamics. They illustrate the value of combining cellular measurements with computational models to integrate different observational scales (gene/channel to patient).

  1. Deep Ultraviolet Copper(I) Thiocyanate (CuSCN) Photodetectors Based on Coplanar Nanogap Electrodes Fabricated via Adhesion Lithography

    KAUST Repository

    Wyatt-Moon, Gwenhivir

    2017-11-28

    Adhesion lithography (a-Lith) is a versatile fabrication technique used to produce asymmetric coplanar electrodes separated by a <15 nm nanogap. Here, we use a-Lith to fabricate deep ultraviolet (DUV) photodetectors by combining coplanar asymmetric nanogap electrode architectures (Au/Al) with solution-processable wide-band-gap (3.5–3.9 eV) p-type semiconductor copper(I) thiocyanate (CuSCN). Because of the device’s unique architecture, the detectors exhibit high responsivity (≈79 A W–1) and photosensitivity (≈720) when illuminated with a DUV-range (λpeak = 280 nm) light-emitting diode at 220 μW cm–2. Interestingly, the photosensitivity of the photodetectors remains fairly high (≈7) even at illuminating intensities down to 0.2 μW cm–2. The scalability of the a-Lith process combined with the unique properties of CuSCN paves the way to new forms of inexpensive, yet high-performance, photodetectors that can be manufactured on arbitrary substrate materials including plastic.

  2. Neutron halo in deformed nuclei

    International Nuclear Information System (INIS)

    Zhou Shangui; Meng Jie; Ring, P.; Zhao Enguang

    2010-01-01

    Halo phenomena in deformed nuclei are investigated within a deformed relativistic Hartree Bogoliubov (DRHB) theory. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Contributions of the halo, deformation effects, and large spatial extensions of these systems are described in a fully self-consistent way by the DRHB equations in a spherical Woods-Saxon basis with the proper asymptotic behavior at a large distance from the nuclear center. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nucleus 44 Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the occurrence of this decoupling effects are discussed.

  3. Loss-of-function mutations in SCN4A cause severe foetal hypokinesia or ‘classical’ congenital myopathy

    Science.gov (United States)

    Zaharieva, Irina T.; Thor, Michael G.; Oates, Emily C.; van Karnebeek, Clara; Hendson, Glenda; Blom, Eveline; Witting, Nanna; Rasmussen, Magnhild; Gabbett, Michael T.; Ravenscroft, Gianina; Sframeli, Maria; Suetterlin, Karen; Sarkozy, Anna; D’Argenzio, Luigi; Hartley, Louise; Matthews, Emma; Pitt, Matthew; Vissing, John; Ballegaard, Martin; Krarup, Christian; Slørdahl, Andreas; Halvorsen, Hanne; Ye, Xin Cynthia; Zhang, Lin-Hua; Løkken, Nicoline; Werlauff, Ulla; Abdelsayed, Mena; Davis, Mark R.; Feng, Lucy; Phadke, Rahul; Sewry, Caroline A.; Morgan, Jennifer E.; Laing, Nigel G.; Vallance, Hilary; Ruben, Peter; Hanna, Michael G.; Lewis, Suzanne; Kamsteeg, Erik-Jan; Männikkö, Roope

    2016-01-01

    See Cannon (doi:10.1093/brain/awv400) for a scientific commentary on this article. Congenital myopathies are a clinically and genetically heterogeneous group of muscle disorders characterized by congenital or early-onset hypotonia and muscle weakness, and specific pathological features on muscle biopsy. The phenotype ranges from foetal akinesia resulting in in utero or neonatal mortality, to milder disorders that are not life-limiting. Over the past decade, more than 20 new congenital myopathy genes have been identified. Most encode proteins involved in muscle contraction; however, mutations in ion channel-encoding genes are increasingly being recognized as a cause of this group of disorders. SCN4A encodes the α-subunit of the skeletal muscle voltage-gated sodium channel (Nav1.4). This channel is essential for the generation and propagation of the muscle action potential crucial to muscle contraction. Dominant SCN4A gain-of-function mutations are a well-established cause of myotonia and periodic paralysis. Using whole exome sequencing, we identified homozygous or compound heterozygous SCN4A mutations in a cohort of 11 individuals from six unrelated kindreds with congenital myopathy. Affected members developed in utero- or neonatal-onset muscle weakness of variable severity. In seven cases, severe muscle weakness resulted in death during the third trimester or shortly after birth. The remaining four cases had marked congenital or neonatal-onset hypotonia and weakness associated with mild-to-moderate facial and neck weakness, significant neonatal-onset respiratory and swallowing difficulties and childhood-onset spinal deformities. All four surviving cohort members experienced clinical improvement in the first decade of life. Muscle biopsies showed myopathic features including fibre size variability, presence of fibrofatty tissue of varying severity, without specific structural abnormalities. Electrophysiology suggested a myopathic process, without myotonia. In vitro

  4. Loss-of-function mutations in SCN4A cause severe foetal hypokinesia or 'classical' congenital myopathy.

    Science.gov (United States)

    Zaharieva, Irina T; Thor, Michael G; Oates, Emily C; van Karnebeek, Clara; Hendson, Glenda; Blom, Eveline; Witting, Nanna; Rasmussen, Magnhild; Gabbett, Michael T; Ravenscroft, Gianina; Sframeli, Maria; Suetterlin, Karen; Sarkozy, Anna; D'Argenzio, Luigi; Hartley, Louise; Matthews, Emma; Pitt, Matthew; Vissing, John; Ballegaard, Martin; Krarup, Christian; Slørdahl, Andreas; Halvorsen, Hanne; Ye, Xin Cynthia; Zhang, Lin-Hua; Løkken, Nicoline; Werlauff, Ulla; Abdelsayed, Mena; Davis, Mark R; Feng, Lucy; Phadke, Rahul; Sewry, Caroline A; Morgan, Jennifer E; Laing, Nigel G; Vallance, Hilary; Ruben, Peter; Hanna, Michael G; Lewis, Suzanne; Kamsteeg, Erik-Jan; Männikkö, Roope; Muntoni, Francesco

    2016-03-01

    Congenital myopathies are a clinically and genetically heterogeneous group of muscle disorders characterized by congenital or early-onset hypotonia and muscle weakness, and specific pathological features on muscle biopsy. The phenotype ranges from foetal akinesia resulting in in utero or neonatal mortality, to milder disorders that are not life-limiting. Over the past decade, more than 20 new congenital myopathy genes have been identified. Most encode proteins involved in muscle contraction; however, mutations in ion channel-encoding genes are increasingly being recognized as a cause of this group of disorders. SCN4A encodes the α-subunit of the skeletal muscle voltage-gated sodium channel (Nav1.4). This channel is essential for the generation and propagation of the muscle action potential crucial to muscle contraction. Dominant SCN4A gain-of-function mutations are a well-established cause of myotonia and periodic paralysis. Using whole exome sequencing, we identified homozygous or compound heterozygous SCN4A mutations in a cohort of 11 individuals from six unrelated kindreds with congenital myopathy. Affected members developed in utero- or neonatal-onset muscle weakness of variable severity. In seven cases, severe muscle weakness resulted in death during the third trimester or shortly after birth. The remaining four cases had marked congenital or neonatal-onset hypotonia and weakness associated with mild-to-moderate facial and neck weakness, significant neonatal-onset respiratory and swallowing difficulties and childhood-onset spinal deformities. All four surviving cohort members experienced clinical improvement in the first decade of life. Muscle biopsies showed myopathic features including fibre size variability, presence of fibrofatty tissue of varying severity, without specific structural abnormalities. Electrophysiology suggested a myopathic process, without myotonia. In vitro functional assessment in HEK293 cells of the impact of the identified SCN4A

  5. Photic stimulation of the suprachiasmatic nucleus via the non-visual optic system. A gene expression study in the blind Crx (-/-) mouse

    DEFF Research Database (Denmark)

    Rovsing, Louise; Møller, Morten

    2014-01-01

    photoreceptors. At zeitgeber time 16, the Crx (-/-) and wild-type mice were exposed to 1 h of light. This resulted in a strong up-regulation of the immediate early genes Nr4a1, Erg, and Rrad in the SCN of both genotypes. Light stimulation during the subjective night resulted in a strong up-regulation of c...... to light during the subjective night is an immediate expression of several early response genes in the SCN. We show, by quantitative real-time polymerase chain reaction, that the amount of melanopsin mRNA in the retinal ganglion cells is preserved in the blind Crx (-/-) mouse with degenerated classic......-fos in both genotypes with a significantly higher up-regulation in the blind Crx (-/-) mouse. Expression of Grp and Vip, the genes for two classic peptides located in the SCN, was not influenced by light stimulation. The data strongly indicate the involvement of the melanopsin-based non-visual optic system...

  6. High-spin excitations of atomic nuclei

    International Nuclear Information System (INIS)

    Xu Furong; National Laboratory of Heavy Ion Physics, Lanzhou; Chinese Academy of Sciences, Beijing

    2004-01-01

    The authors used the cranking shell model to investigate the high-spin motions and structures of atomic nuclei. The authors focus the collective rotations of the A∼50, 80 and 110 nuclei. The A∼50 calculations show complicated g spectroscopy, which can have significant vibration effects. The A≅80 N≅Z nuclei show rich shape coexistence with prolate and oblate rotational bands. The A≅110 nuclei near the r-process path can have well-deformed oblate shapes that become yrast and more stable with increasing rotational frequency. As another important investigation, the authors used the configuration-constrained adiabatic method to calculate the multi-quasiparticle high-K states in the A∼130, 180 and superheavy regions. The calculations show significant shape polarizations due to quasi-particle excitations for soft nuclei, which should be considered in the investigations of high-K states. The authors predicted some important high-K isomers, e.g., the 8 - isomers in the unstable nuclei of 140 Dy and 188 Pb, which have been confirmed in experiments. In superheavy nuclei, our calculations show systematic existence of high-K states. The high-K excitations can increase the productions of synthesis and the survival probabilities of superheavy nuclei. (authors)

  7. Mean-field models and exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Buervenich, T.; Maruhn, J.A.; Greiner, W. [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); Rutz, K. [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany)]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Reinhard, P.G. [Inst. fuer Theoretische Physik, Univ. Erlangen (Germany)

    1998-06-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  8. Thermodynamics of pairing phase transition in nuclei

    International Nuclear Information System (INIS)

    Karim, Afaque; Ahmad, Shakeb

    2014-01-01

    The pairing gaps, pairing energy, heat capacity and entropy are calculated within BCS (Bardeen- Cooper-Schrieffer) based quasi particle approach, including thermal fluctuations on pairing field within pairing model for all nuclei (light, medium, heavy and super heavy nuclei). Quasi particles approach in BCS theory was introduced and reformulated to study various properties. For thermodynamic behavior of nuclei at finite temperatures, the anomalous averages of creation and annihilation operators are introduced. It is solved self consistently at finite temperatures to obtain BCS Hamiltonian. After doing unitary transformation, we obtained the Hamiltonian in the diagonal form. Thus, one gets temperature dependence gap parameter and pairing energy for nuclei. Moreover, the energy at finite temperatures is the sum of the condensation energy and the thermal energy of fermionic quasi particles. With the help of BCS Hamiltonian, specific heat, entropy and free energy are calculated for different nuclei. In this paper the gap parameter occupation number and pairing energy as a function of temperature which is important for all the light, medium, heavy and super heavy nuclei is calculated. Moreover, the various thermo dynamical quantities like specific heat, entropy and free energy is also obtained for different nuclei. Thus, the thermodynamics of pairing phase transition in nuclei is studied

  9. Structure of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Ploszajczak, M.

    2003-01-01

    Structure of exotic radioactive nuclei having extreme neutron-to-proton ratios is different from that around the stability line. This short review discusses the progress in modeling of exotic nuclei in the nuclear ''Terra Incognita''. The consistent theoretical description of weakly bound systems requires a synergy between nuclear structure and nuclear reaction methods. (orig.)

  10. RFP for the Comet Nuclei Tour (CONTOUR)

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Madsen, Peter Buch; Betto, Maurizio

    1999-01-01

    This document describes the ASC Star Tracker (performance, functionality, requirements etc.) to The Johns Hopkins University - Applied Physics Laboratory for their Comet Nuclei TOUR (CONTOUR) Program.......This document describes the ASC Star Tracker (performance, functionality, requirements etc.) to The Johns Hopkins University - Applied Physics Laboratory for their Comet Nuclei TOUR (CONTOUR) Program....

  11. Mean-field models and exotic nuclei

    International Nuclear Information System (INIS)

    Bender, M.; Buervenich, T.; Maruhn, J.A.; Greiner, W.; Rutz, K.; Reinhard, P.G.

    1998-01-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  12. Partial Dynamical Symmetry in Deformed Nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    1996-01-01

    We discuss the notion of partial dynamical symmetry in relation to nuclear spectroscopy. Explicit forms of Hamiltonians with partial SU(3) symmetry are presented in the framework of the interacting boson model of nuclei. An analysis of the resulting spectrum and electromagnetic transitions demonstrates the relevance of such partial symmetry to the spectroscopy of axially deformed nuclei. copyright 1996 The American Physical Society

  13. Partial Dynamical Symmetry in Deformed Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)

    1996-07-01

    We discuss the notion of partial dynamical symmetry in relation to nuclear spectroscopy. Explicit forms of Hamiltonians with partial SU(3) symmetry are presented in the framework of the interacting boson model of nuclei. An analysis of the resulting spectrum and electromagnetic transitions demonstrates the relevance of such partial symmetry to the spectroscopy of axially deformed nuclei. {copyright} {ital 1996 The American Physical Society.}

  14. Single Particle Entropy in Heated Nuclei

    International Nuclear Information System (INIS)

    Guttormsen, M.; Chankova, R.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.; Sunde, A. C.; Syed, N. U. H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.

    2006-01-01

    The thermal motion of single particles represents the largest contribution to level density (or entropy) in atomic nuclei. The concept of single particle entropy is presented and shown to be an approximate extensive (additive) quantity for mid-shell nuclei. A few applications of single particle entropy are demonstrated

  15. The first pseudo-ternary thiocyanate containing two alkali metals. Synthesis and single-crystal structure of LiK{sub 2}[SCN]{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Reckeweg, Olaf; DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States). Baker Lab.

    2016-04-01

    A procedure was empirically developed to prepare the compound LiK{sub 2}[SCN]{sub 3}, which forms colorless, transparent, very fragile, and extremely hygroscopic thin rectangular plates. Its unique crystal structure was determined by single-crystal X-ray diffraction. LiK{sub 2}[SCN]{sub 3} adopts the orthorhombic space group Pna2{sub 1} (no. 33, Z = 4) with the cell parameters a = 1209.32(9), b = 950.85(9), and c = 849.95(6) pm.

  16. A double potential model for neutron halo nuclei

    OpenAIRE

    Abbas, Afsar

    2003-01-01

    It is shown here that loosely bound halo structure of neutron rich nuclei and the ground state spin of single neutron halo nuclei are correlated and are consistently explained if one assumes a double potential shell model for these nuclei.

  17. A new spin on nuclei

    International Nuclear Information System (INIS)

    Clark, R.; Wadsworth, B.

    1998-01-01

    Magnetic rotation is a new phenomenon that is forcing physicists to rethink their understanding of what goes on inside the nucleus The rotation of quantum objects has a long and distinguished history in physics. In 1912 the Danish scientist Niels Bjerrum was the first to recognize that the rotation of molecules is quantized. In 1938 Edward Teller and John Wheeler observed similar features in the spectra of excited nuclei, and suggested that this was caused by the nucleus rotating. But a more complete explanation had to wait until 1951, when Aage Bohr (the son of Niels) pointed out that rotation was a consequence of the nucleus deforming from its spherical shape. We owe much of our current understanding of nuclear rotation to the work of Bohr and Ben Mottelson, who shared the 1975 Nobel Prize for Physics with James Rainwater for developing a model of the nucleus that combined the individual and collective motions of the neutrons and protons inside the nucleus. What makes it possible for a nucleus to rotate? Quantum mechanically, a perfect sphere cannot rotate because it appears the same when viewed from any direction and there is no point of reference against which its change in position can be detected. To see the rotation the spherical symmetry must be broken to allow an orientation in space to be defined. For example, a diatomic molecule, which has a dumbbell shape, can rotate about the two axes perpendicular to its axis of symmetry. A quantum mechanical treatment of a diatomic molecule leads to a very simple relationship between rotational energy, E, and angular momentum. This energy is found to be proportional to J(J + 1), where J is the angular momentum quantum number. The molecule also has a magnetic moment that is proportional to J. These concepts can be applied to the atomic nucleus. If the distribution of mass and/or charge inside the nucleus becomes non-spherical then the nucleus will be able to rotate. The rotation is termed ''collective'' because many

  18. Ice Nuclei from Birch Trees

    Science.gov (United States)

    Felgitsch, Laura; Seifried, Teresa; Winkler, Philipp; Schmale, David, III; Grothe, Hinrich

    2017-04-01

    While the importance of heterogeneous ice nucleation in the atmosphere is known, we still know very little about the substances triggering these freezing events. Recent findings support the theory that biological ice nuclei (IN) exhibit the ability to play an important role in these processes. Huffman et al. (2013) showed a burst of biological IN over woodlands triggered by rain events. Birch pollen are known to release a high number of efficient IN if incubated in water (Pummer et al. 2012). Therefore birches are of interest in our research on this topic. Plants native to the timberline, such as birch trees, have to cope with very cold climatic conditions, rendering freezing avoidance impossible. These plants trigger freezing in their extracellular spaces to control the freezing process and avoid intracellular freezing, which would have lethal consequences. The plants hereby try to freeze at a temperature well above homogeneous freezing temperatures but still at temperatures low enough to not be effected by brief night frosts. To achieve this, IN are an important tool. The specific objective of our work was to study the potential sources and distribution of IN in birch trees. We collected leaves, fruit, bark, and trunk cores from a series of mature birch trees in Tyrol, Austria at different altitudes and sampling sites. We also collected samples from a birch tree in an urban park in Vienna, Austria. Our data show a sampling site dependence and the distribution of IN throughout the tree. Our data suggest that leaves, bark, and wood of birch can function as a source of IN, which are easily extracted with water. The IN are therefore not restricted to pollen. Hence, the amount of IN, which can be released from birch trees, is tremendous and has been underrated so far. Future work aims to elucidate the nature, contribution, and potential ecological roles of IN from birch trees in different habitats. Huffman, J.A., Prenni, A.J., DeMott, P.J., Pöhlker, C., Mason, R

  19. The expression of NR2B subunit of NMDA receptor in the suprachiasmatic nucleus of Wistar rats and its role in glutamate-induced CREB and ERK1/2 phosphorylation

    Czech Academy of Sciences Publication Activity Database

    Bendová, Zdeňka; Sládek, Martin; Svobodová, Irena

    2012-01-01

    Roč. 61, č. 1 (2012), s. 43-47 ISSN 0197-0186 R&D Projects: GA ČR GAP303/10/1227 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : circadian clock * NMDA receptor * NR2B subunit * rat * suprachiasmatic nucleus Subject RIV: FH - Neurology Impact factor: 2.659, year: 2012

  20. Symmetry and Phase Transitions in Nuclei

    International Nuclear Information System (INIS)

    Iachello, F.

    2009-01-01

    Phase transitions in nuclei have received considerable attention in recent years, especially after the discovery that, contrary to expectations, systems at the critical point of a phase transition display a simple structure. In this talk, quantum phase transitions (QPT), i.e. phase transitions that occur as a function of a coupling constant that appears in the quantum Hamiltonian, H, describing the system, will be reviewed and experimental evidence for their occurrence in nuclei will be presented. The phase transitions discussed in the talk will be shape phase transitions. Different shapes have different symmetries, classified by the dynamic symmetries of the Interacting Boson Model, U(5), SU(3) and SO(6). Very recently, the concept of Quantum Phase Transitions has been extended to Excited State Quantum Phase Transitions (ESQPT). This extension will be discussed and some evidence for incipient ESQPT in nuclei will be presented. Systems at the critical point of a phase transition are called 'critical systems'. Approximate analytic formulas for energy spectra and other properties of 'critical nuclei', in particular for nuclei at the critical point of the second order U(5)-SO(6) transition, called E(5), and along the line of first order U(5)-SU(3) transitions, called X(5), will be presented. Experimental evidence for 'critical nuclei' will be also shown. Finally, the microscopic derivation of shape phase transitions in nuclei within the framework of density functional methods will be briefly discussed.(author)

  1. Evolution of planetary nebula nuclei

    International Nuclear Information System (INIS)

    Shaw, R.A.

    1985-01-01

    The evolution of planetary nebula nuclei (PNNs) is examined with the aid of the most recent available stellar evolution calculations and new observations of these objects. Their expected distribution in the log L-log T plane is calculated based upon the stellar evolutionary models of Paczynski, Schoenberner and Iben, the initial mass function derived by Miller and Scalo, and various assumptions concerning mass loss during post-main sequence evolution. The distribution is found to be insensitive both to the assumed range of main-sequence progenitor mass and to reasonable variations in the age and the star forming history of the galactic disk. Rather, the distribution is determined by the strong dependence of the rate of stellar evolution upon core mass, the steepness of the initial mass function, and to a lesser extent the finite lifetime of an observable planetary nebula. The theoretical distributions are rather different than any of those inferred from earlier observations. Possible observational selection effects that may be responsible are examined, as well as the intrinsic uncertainties associated with the theoretical model predictions. An extensive photometric and smaller photographic survey of southern hemisphere planetary nebulae (PNs) is presented

  2. Clusters in Nuclei. Vol. 2

    International Nuclear Information System (INIS)

    Beck, Christian

    2012-01-01

    Following the pioneering discovery of alpha clustering and of molecular resonances, the field of nuclear clustering is today one of those domains of heavy-ion nuclear physics that faces the greatest challenges, yet also contains the greatest opportunities. After many summer schools and workshops, in particular over the last decade, the community of nuclear molecular physicists has decided to collaborate in producing a comprehensive collection of lectures and tutorial reviews covering the field. This second volume follows the successful Lect. Notes Phys. 818 (Vol.1), and comprises six extensive lectures covering the following topics: - Microscopic cluster models - Neutron halo and break-up reactions - Break-up reaction models for two- and three-cluster projectiles - Clustering effects within the di-nuclear model - Nuclear alpha-particle condensates - Clusters in nuclei: experimental perspectives By promoting new ideas and developments while retaining a pedagogical style of presentation throughout, these lectures will serve as both a reference and an advanced teaching manual for future courses and schools in the fields of nuclear physics and nuclear astrophysics. (orig.)

  3. Coupled-cluster computations of atomic nuclei.

    Science.gov (United States)

    Hagen, G; Papenbrock, T; Hjorth-Jensen, M; Dean, D J

    2014-09-01

    In the past decade, coupled-cluster theory has seen a renaissance in nuclear physics, with computations of neutron-rich and medium-mass nuclei. The method is efficient for nuclei with product-state references, and it describes many aspects of weakly bound and unbound nuclei. This report reviews the technical and conceptual developments of this method in nuclear physics, and the results of coupled-cluster calculations for nucleonic matter, and for exotic isotopes of helium, oxygen, calcium, and some of their neighbors.

  4. Hot nuclei: high temperatures, high angular momenta

    International Nuclear Information System (INIS)

    Guerreau, D.

    1991-01-01

    A review is made of the present status concerning the production of hot nuclei above 5 MeV temperature, concentrating mainly on the possible experimental evidences for the attainment of a critical temperature, on the existence of dynamical limitations to the energy deposition and on the experimental signatures for the formation of hot spinning nuclei. The data strongly suggest a nuclear disassembly in collisions involving very heavy ions at moderate incident velocities. Furthermore, hot nuclei seem to be quite stable against rotation on a short time scale. (author) 26 refs.; 12 figs

  5. Pathophysiological mechanisms of sino-atrial dysfunction and ventricular conduction disease associated with SCN5A deficiency: insights from mouse models

    Directory of Open Access Journals (Sweden)

    Christopher L-H Huang

    2012-07-01

    Full Text Available Genetically modified mice provide a number of models for studying cardiac channelopathies related to cardiac Na+ channel (SCN5A abnormalities. We review key pathophysiological features in these murine models that may underlie clinical features observed in sinus node dysfunction and progressive cardiac conduction disease, thereby providing insights into their pathophysiological mechanisms. We describe loss of Na+ channel function and fibrotic changes associated with both loss and gain-of-function Na+ channel mutations. Recent reports further relate the progressive fibrotic changes to upregulation of TGF-β1 production and the transcription factors, Atf3, a stress-inducible gene, and Egr1, to the presence of heterozygous Scn5a inactivation. Both changes are thus directly implicated in the clinically observed disruptions in sino-atrial node pacemaker function, and sino-atrial and ventricular conduction, and their progression with age. Murine systems with genetic modifications in Scn5a thus prove a useful tool to address questions concerning roles of genetic and environmental modifiers on human SCN5A disease phenotypes.

  6. Functional profiles of SCN9A variants in dorsal root ganglion neurons and superior cervical ganglion neurons correlate with autonomic symptoms in small fibre neuropathy

    NARCIS (Netherlands)

    Han, C.; Hoeijmakers, J.G.; Liu, S.; Gerrits, M.M.; te Morsche, R.H.; Lauria, G.; Dib-Hajj, S.D.; Drenth, J.P.H.; Faber, C.G.; Merkies, I.S.; Waxman, S.G.

    2012-01-01

    Patients with small fibre neuropathy typically manifest pain in distal extremities and severe autonomic dysfunction. However, occasionally patients present with minimal autonomic symptoms. The basis for this phenotypic difference is not understood. Sodium channel Na(v)1.7, encoded by the SCN9A gene,

  7. Changes in action potentials and intracellular ionic homeostasis in a ventricular cell model related to a persistent sodium current in SCN5A mutations underlying LQT3

    Czech Academy of Sciences Publication Activity Database

    Christé, G.; Chahine, M.; Chevalier, P.; Pásek, Michal

    2008-01-01

    Roč. 96, - (2008), s. 281-293 ISSN 0079-6107 Institutional research plan: CEZ:AV0Z20760514 Keywords : cardiac cell * SCN5A mutation * Long QT syndrome * quantitative modelling Subject RIV: BO - Biophysics Impact factor: 6.388, year: 2008

  8. De novo SCN8A mutation identified by whole-exome sequencing in a boy with neonatal epileptic encephalopathy, multiple congenital anomalies, and movement disorders.

    Science.gov (United States)

    Vaher, Ulvi; Nõukas, Margit; Nikopensius, Tiit; Kals, Mart; Annilo, Tarmo; Nelis, Mari; Ounap, Katrin; Reimand, Tiia; Talvik, Inga; Ilves, Pilvi; Piirsoo, Andres; Seppet, Enn; Metspalu, Andres; Talvik, Tiina

    2014-12-01

    Epileptic encephalopathies represent a clinically and genetically heterogeneous group of disorders, majority of which are of unknown etiology. We used whole-exome sequencing of a parent-offspring trio to identify the cause of early infantile epileptic encephalopathy in a boy with neonatal seizures, movement disorders, and multiple congenital anomalies who died at the age of 17 months because of respiratory illness and identified a de novo heterozygous missense mutation (c.3979A>G; p.Ile1327Val) in SCN8A (voltage-gated sodium-channel type VIII alpha subunit) gene. The variant was confirmed in the proband with Sanger sequencing. Because the clinical phenotype associated with SCN8A mutations has previously been identified only in a few patients with or without epileptic seizures, these data together with our results suggest that mutations in SCN8A can lead to early infantile epileptic encephalopathy with a broad phenotypic spectrum. Additional investigations will be worthwhile to determine the prevalence and contribution of SCN8A mutations to epileptic encephalopathies. © The Author(s) 2013.

  9. Characterization of proton conducting blend polymer electrolyte using PVA-PAN doped with NH{sub 4}SCN

    Energy Technology Data Exchange (ETDEWEB)

    Premalatha, M. [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Materials Research Center, Coimbatore-641 045 (India); Mathavan, T., E-mail: tjmathavan@gmail.com, E-mail: kingslin.genova20@gmail.com [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Selvasekarapandian, S. [Materials Research Center, Coimbatore-641 045 (India); Genova, F. Kingslin Mary, E-mail: tjmathavan@gmail.com, E-mail: kingslin.genova20@gmail.com; Umamaheswari, R. [Department of physics, S.F.R College for Women, Sivakasi-626 128 (India)

    2016-05-23

    Polymer electrolytes with proton conductivity based on blend polymer using polyvinyl alcohol (PVA) and poly acrylo nitrile (PAN) doped with ammonium thiocyanate have been prepared by solution casting method using DMF as solvent. The complex formation between the blend polymer and the salt has been confirmed by FTIR Spectroscopy. The amorphous nature of the blend polymer electrolytes have been confirmed by XRD analysis. The highest conductivity at 303 K has been found to be 3.25 × 10{sup −3} S cm{sup −1} for 20 mol % NH{sub 4}SCN doped 92.5PVA:7.5PAN system. The increase in conductivity of the doped blend polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy is found to be low (0.066 eV) for the highest conductivity sample.

  10. Multiple loss-of-function mechanisms contribute to SCN5A-related familial sick sinus syndrome.

    Directory of Open Access Journals (Sweden)

    Junhong Gui

    2010-06-01

    Full Text Available To identify molecular mechanisms underlying SCN5A-related sick sinus syndrome (SSS, a rare type of SSS, in parallel experiments we elucidated the electrophysiological properties and the cell surface localization of thirteen human Na(v1.5 (hNa(v1.5 mutant channels previously linked to this disease.Mutant hNa(v1.5 channels expressed by HEK293 cells and Xenopus oocytes were investigated by whole-cell patch clamp and two-microelectrode voltage clamp, respectively. HEK293 cell surface biotinylation experiments quantified the fraction of correctly targeted channel proteins. Our data suggested three distinct mutant channel subtypes: Group 1 mutants (L212P, P1298L, DelF1617, R1632H gave peak current densities and cell surface targeting indistinguishable from wild-type hNa(v1.5. Loss-of-function of these mutants resulted from altered channel kinetics, including a negative shift of steady-state inactivation and a reduced voltage dependency of open-state inactivation. Group 2 mutants (E161K, T220I, D1275N gave significantly reduced whole-cell currents due to impaired cell surface localization (D1275N, altered channel properties at unchanged cell surface localization (T220I, or a combination of both (E161K. Group 3 mutant channels were non-functional, due to an almost complete lack of protein at the plasma membrane (T187I, W1421X, K1578fs/52, R1623X or a probable gating/permeation defect with normal surface localisation (R878C, G1408R.This study indicates that multiple molecular mechanisms, including gating abnormalities, trafficking defects, or a combination of both, are responsible for SCN5A-related familial SSS.

  11. Uniform and pitting corrosion events induced by SCN- anions on Al alloys surfaces and the effect of UV light

    International Nuclear Information System (INIS)

    Amin, Mohammed A.

    2011-01-01

    The influence of the alloying elements on the uniform and pitting corrosion processes of Al-6061, Al-4.5%Cu, Al-7.5%Cu, Al-6%Si and Al-12%Si alloys was studied in 0.50 M KSCN solution at 25 o C. Open-circuit potential, Tafel polarization, linear polarization resistance (LPR) and ICP-AES measurements were used to study the uniform corrosion process on the surfaces of the tested alloys. Cyclic polarization, potentiostatic current-time transients and impedance techniques were employed for pitting corrosion studies. Obtained results were compared with pure Al. Passivation kinetics of the tested Al samples were also studied as a function of applied potential, [SCN - ] and sample composition by means of potentiostatic current transients. The induction time, after which the growth of stable pits occurs, decreased with increasing applied potential and [SCN - ]. Regarding to uniform corrosion, alloyed Cu was found to enhance the corrosion rate, while alloyed Si suppressed it. Alloying elements of the tested samples diminished pitting attack to an extent depending on the percentage of the alloying element in the sample. Among the investigated materials, Al-Si alloys exhibited the highest corrosion resistance towards uniform and pitting corrosion processes in KSCN solutions. The passive and dissolution behaviour of Al was also studied under the conditions of continuous illumination (300-450 nm) based on cyclic polarization and potentiostatic techniques. The incident photons had a little influence on pit initiation and a marked effect on pit growth. These explained in terms of a photo-induced modification of the passive film formed on the anode surface, which render it more resistant to pitting. The effects of UV photons energy and period of illumination on the morphology of the pitted surfaces were also studied.

  12. Parton distributions in nuclei: Quagma or quagmire

    Energy Technology Data Exchange (ETDEWEB)

    Close, F.E.

    1988-01-01

    The emerging information on the way quark, antiquark, and gluon distributions are modified in nuclei relative to free nucleons is reviewed. Particular emphasis is placed on Drell-Yan and /psi/ production on nuclei and caution against premature use of these as signals for quagma in heavy-ion collisions. If we are to identify the formation of quark-gluon plasma in heavy-ion collisions by changes in the production rates for /psi/ relative to Drell-Yan lepton pairs, then it is important that we first understand the ''intrinsic'' changes in parton distributions in nuclei relative to free nucleons. So, emerging knowledge on how quark, antiquark, and gluon distributions are modified in nuclei relative to free nucleons is reviewed, and the emerging theoretical concensus is briefly summarized.

  13. New vistas of exotic heavy nuclei

    International Nuclear Information System (INIS)

    Cocks, J.F.C.; Butler, P.A.

    1997-01-01

    We report studies of examples of reflection-asymmetric nuclei which are difficult to access using compound nucleus reactions. The most octupole deformed nuclei should be uranium isotopes with N ∼ 132; preliminary measurements of these very fissile nuclei suggest that they are within reach of current spectroscopic techniques. The octupole radium isotopes with N > 132 and radon isotopes are not accessible by reactions employing stable targets and beams; we have shown that multinucleon transfer reactions can populate these nuclei with sufficient yield for their structure to be determined. We report high spin studies in 218,220,222 Rn and 222,224,226 Ra which reveal upbending effects in this mass region for the first time and show that the electric dipole moment is constant with spin. (author)

  14. Superheavy nuclei: a relativistic mean field outlook

    International Nuclear Information System (INIS)

    Afanasjev, A.V.

    2006-01-01

    The analysis of quasi-particle spectra in the heaviest A∼250 nuclei with spectroscopic data provides an additional constraint for the choice of effective interaction for the description of superheavy nuclei. It strongly suggests that only the parametrizations which predict Z = 120 and N = 172 as shell closures are reliable for superheavy nuclei within the relativistic mean field theory. The influence of the central depression in the density distribution of spherical superheavy nuclei on the shell structure is studied. A large central depression produces large shell gaps at Z = 120 and N = 172. The shell gaps at Z = 126 and N = 184 are favoured by a flat density distribution in the central part of the nucleus. It is shown that approximate particle number projection (PNP) by means of the Lipkin-Nogami (LN) method removes pairing collapse seen at these gaps in the calculations without PNP

  15. Nuclear Computational Low Energy Initiative (NUCLEI)

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Sanjay K. [University of Washington

    2017-08-14

    This is the final report for University of Washington for the NUCLEI SciDAC-3. The NUCLEI -project, as defined by the scope of work, will develop, implement and run codes for large-scale computations of many topics in low-energy nuclear physics. Physics to be studied include the properties of nuclei and nuclear decays, nuclear structure and reactions, and the properties of nuclear matter. The computational techniques to be used include Quantum Monte Carlo, Configuration Interaction, Coupled Cluster, and Density Functional methods. The research program will emphasize areas of high interest to current and possible future DOE nuclear physics facilities, including ATLAS and FRIB (nuclear structure and reactions, and nuclear astrophysics), TJNAF (neutron distributions in nuclei, few body systems, and electroweak processes), NIF (thermonuclear reactions), MAJORANA and FNPB (neutrino-less double-beta decay and physics beyond the Standard Model), and LANSCE (fission studies).

  16. Observation of spinodal decomposition in nuclei?

    International Nuclear Information System (INIS)

    Guarnera, A.; Colonna, M.; Chomaz, Ph.

    1996-01-01

    Multifragmentation in heavy ion collisions is investigated in the framework of mean-field theory, in order to gain information on the equation of state of nuclear matter. Spinodal decomposition in nuclei is studied. (K.A.)

  17. Infrared Observations of Cometary Dust and Nuclei

    Science.gov (United States)

    Lisse, Carey

    2004-01-01

    This bibliography lists citations for publications published under the grant. Subjects of the publications include cometary dust, instellar and interplanetary dust, comet nuclei and comae, Comet Hale-Bopp, infrared observations of comets, mass loss, and comet break-up.

  18. Critical-Point Structure in Finite Nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    2006-01-01

    Properties of quantum shape-phase transitions in finite nuclei are considered in the framework of the interacting boson model. Special emphasis is paid to the dynamics at the critical-point of a general first-order phase transition

  19. Electro-magnetic properties of heavy nuclei

    International Nuclear Information System (INIS)

    Otsuka, Takaharu

    1989-01-01

    Two topics of electro-magnetic properties of heavy nuclei are discussed. The first topic is the M1 excitation from well-deformed heavy nuclei, and the other is the sudden increase of the isotope shift as a function of N in going away from the closed shell. These problems are considered in terms of the particle-number projected (Nilsson-) BCS calculation. (author)

  20. High energy particle interactions with nuclei

    International Nuclear Information System (INIS)

    Czyz, W.

    1978-01-01

    The recent interest in multiparticle production processes on nuclei was triggered by re-discovering their 'enigmatic simplicity' which has been known to cosmic ray physicists for over 20 years: the mean multiplicity and angular distributions of relativistic secondaries produced on nuclei do not differ markedly from what emerges from p-p collisions. The author considers how such reactions may provide a way of obtaining details of hadron structure. (Auth.)

  1. Nuclei far off the stability line

    International Nuclear Information System (INIS)

    Fenyes, T.

    1978-01-01

    Theoretical and experimental aspects of the formation of some ''exotic'' nuclei far off the stability line were reviewed in addition to the relevant results of research in this field. Results in beta- and gamma-ray spectroscopy, heavy-ion-spectroscopy, achievements in the fields of measuring the atomic mass, the moment, and the radius of the nuclei as well as some astronomical aspects were described. (Z.P.)

  2. Proton radioactivity from proton-rich nuclei

    International Nuclear Information System (INIS)

    Guzman, F.; Goncalves, M.; Tavares, O.A.P.; Duarte, S.B.; Garcia, F.; Rodriguez, O.

    1999-03-01

    Half-lives for proton emission from proton-rich nuclei have been calculated by using the effective liquid drop model of heavy-particle decay of nuclei. It is shown that this model is able to offer results or spontaneous proton-emission half-life-values in excellent agreement with the existing experimental data. Predictions of half-life-values for other possible proton-emission cases are present for null orbital angular momentum. (author)

  3. Oscillations of atomic nuclei in crystals

    OpenAIRE

    Vdovenkov, V. A.

    2002-01-01

    Oscillations of atomic nuclei in crystals are considered in this paper. It is shown that elastic nuclei oscillations relatively electron envelops (inherent, I-oscillations) and waves of such oscillations can exist in crystals at adiabatic condition. The types and energy quantums of I-oscillations for different atoms are determined. In this connection the adiabatic crystal model is offered. Each atom in the adiabatic model is submitted as I-oscillator whose stationary oscillatory terms are sho...

  4. Hot nuclei, limiting temperatures and excitation energies

    International Nuclear Information System (INIS)

    Peter, J.

    1986-09-01

    Hot fusion nuclei are produced in heavy ion collisions at intermediate energies (20-100 MeV/U). Information on the maximum excitation energy per nucleon -and temperatures- indicated by the experimental data is compared to the predictions of static and dynamical calculations. Temperatures around 5-6 MeV are reached and seem to be the limit of formation of thermally equilibrated fusion nuclei

  5. Thomas Fermi model of finite nuclei

    International Nuclear Information System (INIS)

    Boguta, J.; Rafelski, J.

    1977-01-01

    A relativistic Thomas-Fermi model of finite-nuclei is considered. The effective nuclear interaction is mediated by exchanges of isoscalar scalar and vector mesons. The authors include also a self-interaction of the scalar meson field and the Coulomb repulsion of the protons. The parameters of the model are constrained by the average nuclear properties. The Thomas-Fermi equations are solved numerically for finite, stable nuclei. The particular case of 208 82 Pb is considered in more detail. (Auth.)

  6. Parity and time reversal violation in nuclei

    International Nuclear Information System (INIS)

    Adelberger, E.G.; Washington Univ., Seattle

    1987-01-01

    The current status of investigations into parity (P) and time-reversal (T) violation in nuclei is considered. Nuclear P-violation is an expected consequence of the standard model. It has been observed in a wide variety of nuclei (from A=2, to A∼ 200) by using a wide variety of reactions (reactions induced by polarized neutrons and polarized protons, γ-decay, α-decay, and (α, γ) reactions)

  7. Major new sources of biological ice nuclei

    Science.gov (United States)

    Moffett, B. F.; Hill, T.; Henderson-Begg, S. K.

    2009-12-01

    Almost all research on biological ice nucleation has focussed on a limited number of bacteria. Here we characterise several major new sources of biogenic ice nuclei. These include mosses, hornworts, liverworts and cyanobacteria. Ice nucleation in the eukaryotic bryophytes appears to be ubiquitous. The temperature at which these organisms nucleate is that at which the difference in vapour pressure over ice and water is at or close to its maximum. At these temperatures (-8 to -18 degrees C) ice will grow at the expense of supercooled water. These organisms are dependent for their water on occult precipitation - fog, dew and cloudwater which by its nature is not collected in conventional rain gauges. Therefore we suggest that these organism produce ice nuclei as a water harvesting mechanism. Since the same mechanism would also drive the Bergeron-Findeisen process, and as moss is known to become airborne, these nuclei may have a role in the initiation of precipitation. The properties of these ice nuclei are very different from the well characterised bacterial nuclei. We will also present DNA sequence data showing that, although related, the proteins responsible are only very distantly related to the classical bacterial ice nuclei.

  8. Elastic magnetic form factors of exotic nuclei

    International Nuclear Information System (INIS)

    Dong Tiekuang; Guo Yanqing; Ren Zhongzhou

    2007-01-01

    How to identify the orbital of the valence nucleon(s) of exotic nuclei is an important problem. The elastic magnetic electron scattering is an excellent probe to determine the valence structure of odd-A nuclei. The relativistic mean-field theory has been successfully applied to systematic studies of the elastic charge electron scattering from even-even exotic nuclei. The extension of this method to investigate the elastic magnetic electron scattering from odd-A exotic nuclei is a natural generalization. The experimental form factors of 17 O and 41 Ca are reproduced very well with the help of the spectroscopic factors which are introduced into the relativistic treatment of the magnetic electron scattering for the first time. The emphases are put on the magnetic form factors of 15,17,19 C, 23 O, 17 F, and 49,59 Ca calculated in the relativistic impulse approximation. Great differences have been found in the form factors of the same nucleus with different configurations. Therefore, the elastic magnetic electron scattering can be used to determine the orbital of the last nucleon of odd-A exotic nuclei. Our results can provide references for the electron scattering from exotic nuclei in the near future

  9. The anatomy of the vestibular nuclei.

    Science.gov (United States)

    Highstein, Stephen M; Holstein, Gay R

    2006-01-01

    The vestibular portion of the eighth cranial nerve informs the brain about the linear and angular movements of the head in space and the position of the head with respect to gravity. The termination sites of these eighth nerve afferents define the territory of the vestibular nuclei in the brainstem. (There is also a subset of afferents that project directly to the cerebellum.) This chapter reviews the anatomical organization of the vestibular nuclei, and the anatomy of the pathways from the nuclei to various target areas in the brain. The cytoarchitectonics of the vestibular brainstem are discussed, since these features have been used to distinguish the individual nuclei. The neurochemical phenotype of vestibular neurons and pathways are also summarized because the chemical anatomy of the system contributes to its signal-processing capabilities. Similarly, the morphologic features of short-axon local circuit neurons and long-axon cells with extrinsic projections are described in detail, since these structural attributes of the neurons are critical to their functional potential. Finally, the composition and hodology of the afferent and efferent pathways of the vestibular nuclei are discussed. In sum, this chapter reviews the morphology, chemoanatomy, connectivity, and synaptology of the vestibular nuclei.

  10. Structure of light neutron-rich nuclei through Coulomb dissociation

    Indian Academy of Sciences (India)

    The physics of exotic nuclei has attracted much interest during the past decade. The prop- erties of nuclei with large neutron excess have turned out to be very different compared to those of stable nuclei in many respects. One outstanding observation in exotic nuclei is the halo structure. The halo structure arises from the ...

  11. Adipocyte nuclei captured from VAT and SAT.

    Science.gov (United States)

    Ambati, Suresh; Yu, Ping; McKinney, Elizabeth C; Kandasamy, Muthugapatti K; Hartzell, Diane; Baile, Clifton A; Meagher, Richard B

    2016-01-01

    Obesity-related comorbidities are thought to result from the reprogramming of the epigenome in numerous tissues and cell types, and in particular, mature adipocytes within visceral and subcutaneous adipose tissue, VAT and SAT. The cell-type specific chromatin remodeling of mature adipocytes within VAT and SAT is poorly understood, in part, because of the difficulties of isolating and manipulating large fragile mature adipocyte cells from adipose tissues. We constructed MA-INTACT (Mature Adipocyte-Isolation of Nuclei TAgged in specific Cell Types) mice using the adiponectin (ADIPOQ) promoter (ADNp) to tag the surface of mature adipocyte nuclei with a reporter protein. The SUN1mRFP1Flag reporter is comprised of a fragment of the nuclear transmembrane protein SUN1, the fluorescent protein mRFP1, and three copies of the Flag epitope tag. Mature adipocyte nuclei were rapidly and efficiently immuno-captured from VAT and SAT (MVA and MSA nuclei, respectively), of MA-INTACT mice. MVA and MSA nuclei contained 1,000 to 10,000-fold higher levels of adipocyte-specific transcripts, ADIPOQ, PPARg2, EDNRB, and LEP, relative to uncaptured nuclei, while the latter expressed higher levels of leukocyte and endothelial cell markers IKZF1, RETN, SERPINF1, SERPINE1, ILF3, and TNFA. MVA and MSA nuclei differentially expressed several factors linked to adipogenesis or obesity-related health risks including CEBPA, KLF2, RETN, SERPINE1, and TNFA. The various nuclear populations dramatically differentially expressed transcripts encoding chromatin remodeler proteins regulating DNA cytosine methylation and hydroxymethylation (TETs, DNMTs, TDG, GADD45s) and nucleosomal histone modification (ARID1A, KAT2B, KDM4A, PRMT1, PRMT5, PAXIP1). Remarkably, MSA and MVA nuclei expressed 200 to 1000-fold higher levels of thermogenic marker transcripts PRDM16 and UCP1. The MA-INTACT mouse enables a simple way to perform cell-type specific analysis of highly purified mature adipocyte nuclei from VAT and SAT

  12. Prevalence of SCN1A-related dravet syndrome among children reported with seizures following vaccination: a population-based ten-year cohort study.

    Science.gov (United States)

    Verbeek, Nienke E; van der Maas, Nicoline A T; Jansen, Floor E; van Kempen, Marjan J A; Lindhout, Dick; Brilstra, Eva H

    2013-01-01

    To determine the prevalence of Dravet syndrome, an epileptic encephalopathy caused by SCN1A-mutations, often with seizure onset after vaccination, among infants reported with seizures following vaccination. To determine differences in characteristics of reported seizures after vaccination in children with and without SCN1A-related Dravet syndrome. Data were reviewed of 1,269 children with seizures following immunization in the first two years of life, reported to the safety surveillance system of the Dutch national immunization program between 1 January 1997 and 31 December 2006. Selective, prospective follow-up was performed of children with clinical characteristics compatible with a diagnosis of Dravet syndrome. In 21.9% (n = 279) of children, a diagnosis of Dravet syndrome could not be excluded based on available clinical data (median age at follow-up 16 months). Additional follow-up data were obtained in 83.9% (n = 234) of these children (median age 8.5 years). 15 (1.2% of 1,269; 95%CI:0.6 to 1.8%) children were diagnosed with SCN1A-related Dravet syndrome. Of all reported seizures following vaccinations in the first year of life, 2.5% (95%CI:1.3 to 3.6%) were due to SCN1A-related Dravet syndrome, as were 5.9% of reported seizures (95%CI:3.1 to 8.7%) after 2(nd) or 3(rd) DTP-IPV-Hib vaccination. Seizures in children with SCN1A-related Dravet syndrome occurred more often with a body temperature below 38.5°C (57.9% vs. 32.6%, p = 0.020) and reoccurred more often after following vaccinations (26.7% vs. 4.0%, p = 0.003), than in children without a diagnosis of SCN1A-related Dravet Syndrome. Although Dravet syndrome is a rare genetic epilepsy syndrome, 2.5% of reported seizures following vaccinations in the first year of life in our cohort occurred in children with this disorder. Knowledge on the specific characteristics of vaccination-related seizures in this syndrome might promote early diagnosis and indirectly, public faith in vaccination safety.

  13. Prevalence of SCN1A-Related Dravet Syndrome among Children Reported with Seizures following Vaccination: A Population-Based Ten-Year Cohort Study

    Science.gov (United States)

    Verbeek, Nienke E.; van der Maas, Nicoline A. T.; Jansen, Floor E.; van Kempen, Marjan J. A.; Lindhout, Dick; Brilstra, Eva H.

    2013-01-01

    Objectives To determine the prevalence of Dravet syndrome, an epileptic encephalopathy caused by SCN1A-mutations, often with seizure onset after vaccination, among infants reported with seizures following vaccination. To determine differences in characteristics of reported seizures after vaccination in children with and without SCN1A-related Dravet syndrome. Methods Data were reviewed of 1,269 children with seizures following immunization in the first two years of life, reported to the safety surveillance system of the Dutch national immunization program between 1 January 1997 and 31 December 2006. Selective, prospective follow-up was performed of children with clinical characteristics compatible with a diagnosis of Dravet syndrome. Results In 21.9% (n = 279) of children, a diagnosis of Dravet syndrome could not be excluded based on available clinical data (median age at follow-up 16 months). Additional follow-up data were obtained in 83.9% (n = 234) of these children (median age 8.5 years). 15 (1.2% of 1,269; 95%CI:0.6 to 1.8%) children were diagnosed with SCN1A-related Dravet syndrome. Of all reported seizures following vaccinations in the first year of life, 2.5% (95%CI:1.3 to 3.6%) were due to SCN1A-related Dravet syndrome, as were 5.9% of reported seizures (95%CI:3.1 to 8.7%) after 2nd or 3rd DTP-IPV-Hib vaccination. Seizures in children with SCN1A-related Dravet syndrome occurred more often with a body temperature below 38.5°C (57.9% vs. 32.6%, p = 0.020) and reoccurred more often after following vaccinations (26.7% vs. 4.0%, p = 0.003), than in children without a diagnosis of SCN1A-related Dravet Syndrome. Conclusions Although Dravet syndrome is a rare genetic epilepsy syndrome, 2.5% of reported seizures following vaccinations in the first year of life in our cohort occurred in children with this disorder. Knowledge on the specific characteristics of vaccination-related seizures in this syndrome might promote early diagnosis and indirectly

  14. Prevalence of SCN1A-related dravet syndrome among children reported with seizures following vaccination: a population-based ten-year cohort study.

    Directory of Open Access Journals (Sweden)

    Nienke E Verbeek

    Full Text Available OBJECTIVES: To determine the prevalence of Dravet syndrome, an epileptic encephalopathy caused by SCN1A-mutations, often with seizure onset after vaccination, among infants reported with seizures following vaccination. To determine differences in characteristics of reported seizures after vaccination in children with and without SCN1A-related Dravet syndrome. METHODS: Data were reviewed of 1,269 children with seizures following immunization in the first two years of life, reported to the safety surveillance system of the Dutch national immunization program between 1 January 1997 and 31 December 2006. Selective, prospective follow-up was performed of children with clinical characteristics compatible with a diagnosis of Dravet syndrome. RESULTS: In 21.9% (n = 279 of children, a diagnosis of Dravet syndrome could not be excluded based on available clinical data (median age at follow-up 16 months. Additional follow-up data were obtained in 83.9% (n = 234 of these children (median age 8.5 years. 15 (1.2% of 1,269; 95%CI:0.6 to 1.8% children were diagnosed with SCN1A-related Dravet syndrome. Of all reported seizures following vaccinations in the first year of life, 2.5% (95%CI:1.3 to 3.6% were due to SCN1A-related Dravet syndrome, as were 5.9% of reported seizures (95%CI:3.1 to 8.7% after 2(nd or 3(rd DTP-IPV-Hib vaccination. Seizures in children with SCN1A-related Dravet syndrome occurred more often with a body temperature below 38.5°C (57.9% vs. 32.6%, p = 0.020 and reoccurred more often after following vaccinations (26.7% vs. 4.0%, p = 0.003, than in children without a diagnosis of SCN1A-related Dravet Syndrome. CONCLUSIONS: Although Dravet syndrome is a rare genetic epilepsy syndrome, 2.5% of reported seizures following vaccinations in the first year of life in our cohort occurred in children with this disorder. Knowledge on the specific characteristics of vaccination-related seizures in this syndrome might promote early diagnosis

  15. Exposure of Pregnant Rats to Restricted Feeding Schedule Synchronizes the SCN Clocks of Their Fetuses under Constant Light but Not under a Light-Dark Regime

    Czech Academy of Sciences Publication Activity Database

    Nováková, Marta; Sládek, Martin; Sumová, Alena

    2010-01-01

    Roč. 25, č. 5 (2010), s. 350-360 ISSN 0748-7304 R&D Projects: GA ČR(CZ) GA309/08/0503; GA MŠk(CZ) LC554 Grant - others:GA ČR(CZ) GD309/08/H079; EC(XE) LSH-2004-115-4-018741 Institutional research plan: CEZ:AV0Z50110509 Keywords : suprachiasmatic nucleus * restricted food * ontogenesis Subject RIV: FH - Neurology Impact factor: 3.309, year: 2010

  16. Pollen grains are efficient cloud condensation nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pope, F D, E-mail: fdp21@cam.ac.uk [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2010-10-15

    This letter presents a laboratory study investigating the ability of pollen grains to act as cloud condensation nuclei. The hygroscopicity of pollen is measured under subsaturated relative humidities using an electrodynamic balance. It is found, along with other results, that pollen exhibits bulk uptake of water under subsaturated conditions. Through the use of an environmental scanning electron microscope it was observed that the surface of pollen is wettable at high subsaturated humidities. The hygroscopic response of the pollen to subsaturated relative humidities is parametrized using {kappa}-Koehler theory and values of the parameter {kappa} for pollen are between 0.05 and 0.1. It is found that while pollen grains are only moderately hygroscopic, they can activate at critical supersaturations of 0.001% and lower, and thus pollen grains will readily act as cloud condensation nuclei. While the number density of pollen grains is too low for them to represent a significant global source of cloud condensation nuclei, the large sizes of pollen grains suggest that they will be an important source of giant cloud condensation nuclei. Low temperature work using the environmental scanning electron microscope indicated that pollen grains do not act as deposition ice nuclei at temperatures warmer than - 15 deg. C.

  17. Relativistic mean field theory for unstable nuclei

    International Nuclear Information System (INIS)

    Toki, Hiroshi

    2000-01-01

    We discuss the properties of unstable nuclei in the framework of the relativistic mean field (RMF) theory. We take the RMF theory as a phenomenological theory with several parameters, whose form is constrained by the successful microscopic theory (RBHF), and whose values are extracted from the experimental values of unstable nuclei. We find the outcome with the newly obtained parameter sets (TM1 and TMA) is promising in comparison with various experimental data. We calculate systematically the ground state properties of even-even nuclei up to the drip lines; about 2000 nuclei. We find that the neutron magic shells (N=82, 128) at the standard magic numbers stay at the same numbers even far from the stability line and hence provide the feature of the r-process nuclei. However, many proton magic numbers disappear at the neutron numbers far away from the magic numbers due to the deformations. We discuss how to describe giant resonances for the case of the non-linear coupling terms for the sigma and omega mesons in the relativistic RPA. We mention also the importance of the relativistic effect on the spin observables as the Gamow-Teller strength and the longitudinal and transverse spin responses. (author)

  18. Stability and production of superheavy nuclei

    International Nuclear Information System (INIS)

    Moeller, P.; Los Alamos National Lab., NM; Nix, J.R.

    1997-01-01

    Beyond uranium heavy elements rapidly become increasingly unstable with respect to spontaneous fission as the proton number Z increases, because of the disruptive effect of the long-range Coulomb force. However, in the region just beyond Z = 100 magic proton and neutron numbers and the associated shell structure enhances nuclear stability sufficient to allow observation of additional nuclei. Some thirty years ago it was speculated that an island of spherical, relatively stable superheavy nuclei would exist near the next doubly magic proton-neutron combination beyond 208 Pb, that is, at proton number Z 114 and neutron number N = 184. Theory and experiment now show that there also exists a rock of stability in the vicinity of Z = 110 and N = 162 between the actinide region, which previously was the end of the peninsula of known elements, and the predicted island of spherical superheavy nuclei slightly southwest of the magic numbers Z = 114 and N = 184. The authors review here the stability properties of the heavy region of nuclei. Just as the decay properties of nuclei in the heavy region depend strongly on shell structure, this structure also dramatically affects the fusion entrance channel. The six most recently discovered new elements were all formed in cold-fusion reactions. They discuss here the effect of the doubly magic structure of the target in cold-fusion reactions on the fusion barrier and on dissipation

  19. Fast neutron inelastic scattering from nuclei

    International Nuclear Information System (INIS)

    Lachkar, J.

    1978-01-01

    The need for accurate values of inelastic scattering cross sections appears when the requests for neutron data for reactors and other applied purposes are considered. These requests are partly related to values for spherical nuclei, well studied over many years. These studies were extensively considered in two review papers presented, in 1976, at the International Conference on the Interactions of Neutrons with nuclei. Other requests are related to vibrational and rotational nuclei, and relevant studies have been recently performed. The quality of these investigations and the large number of recent results have lead to concentration on them as the topic of the present review. The constant improvements of the experimental techniques permits precise measurements of inelastic scattering cross sections to the first excited levels over a range of incident energies, such that different reactions mechanisms are predominant in different parts of that range of energies. Quadrupole, hexadecapole and octupole deformation parameters of the target nuclei can be deduced from the data using phenomenological models. The successful application of the analysis over the range of energies leads to the conclusion that reliable information on the shape of the nuclei has been derived. The validity of the various models, which include direct interaction and compound nucleus reaction mechanisms, is discussed in connection with analyses of recent experiments. (author) [fr

  20. Training nuclei detection algorithms with simple annotations

    Directory of Open Access Journals (Sweden)

    Henning Kost

    2017-01-01

    Full Text Available Background: Generating good training datasets is essential for machine learning-based nuclei detection methods. However, creating exhaustive nuclei contour annotations, to derive optimal training data from, is often infeasible. Methods: We compared different approaches for training nuclei detection methods solely based on nucleus center markers. Such markers contain less accurate information, especially with regard to nuclear boundaries, but can be produced much easier and in greater quantities. The approaches use different automated sample extraction methods to derive image positions and class labels from nucleus center markers. In addition, the approaches use different automated sample selection methods to improve the detection quality of the classification algorithm and reduce the run time of the training process. We evaluated the approaches based on a previously published generic nuclei detection algorithm and a set of Ki-67-stained breast cancer images. Results: A Voronoi tessellation-based sample extraction method produced the best performing training sets. However, subsampling of the extracted training samples was crucial. Even simple class balancing improved the detection quality considerably. The incorporation of active learning led to a further increase in detection quality. Conclusions: With appropriate sample extraction and selection methods, nuclei detection algorithms trained on the basis of simple center marker annotations can produce comparable quality to algorithms trained on conventionally created training sets.

  1. Electron scattering and reactions from exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karataglidis, S. [University of Johannesburg, Department of Physics, Auckland Park (South Africa); University of Melbourne, School of Physics, Victoria (Australia)

    2017-04-15

    The SCRIT and FAIR/ELISe experiments are the first to attempt to measure directly electron scattering form factors from nuclei far from stability. This will give direct information for the (one-body) charge densities of those systems, about which there is little information available. The SCRIT experiment will be taking data for medium-mass exotic nuclei, while the electron-ion collider at ELISe, when constructed, will be able to measure form factors for a wide range of exotic nuclei, as available from the radioactive ion beams produced by the FAIR experiment. Other facilities are now being proposed, which will also consider electron scattering from exotic nuclei at higher energies, to study short-range correlations in exclusive reactions. This review will consider all available information concerning the current status (largely theoretical) of electron scattering from exotic nuclei and, where possible, complement such information with equivalent information concerning the neutron densities of those exotic systems, as obtained from intermediate energy proton scattering. The issue of long- and short-range correlations will be discussed, and whether extending such studies to the exotic sector will elicit new information. (orig.)

  2. Critical and shape-unstable nuclei

    CERN Document Server

    Cailliau, M; Husson, J P; Letessier, J; Mang, H J

    1973-01-01

    The authors' experimental work on the decay of neutron deficient mercury osmium nuclei, some other studies at ISOLDE (CERN) and their first theoretical analysis show that the nuclei around /sup 186/Pt (Z=78, N=108) are at the limit of spherical, oblate, prolate nuclei, have (the even one) their first 0/sup +/ excited states at very low energy; quasi- rotational bands are associated to these states. The energy of this O/sup +/ state in /sup 186-/Pt deviate from the Kumar value: angular shape instability is not enough to explain this result. The authors look at radial shape and pairing fluctuations. The position of the 4p-4n state must also be known. (0 refs).

  3. Structure and reactions of light exotic nuclei

    International Nuclear Information System (INIS)

    Suzuki, Y.; Yabana, Y.; Lovas, R.G.; Varga, K.

    1998-01-01

    With the advent of radioactive beams, light exotic nuclei have come to the focus of a great number of investigations. The most prominent phenomena found are the neutron halos. A fundamental and yet feasible microscopic approach has been developed to the description of light exotic nuclei. A comprehensive and didactically balanced review of the structure and reaction theory of light exotic nuclei is being developed. This general structure theory has been written up. This is followed by a brief review of cluster models, and that paves the way before introducing the multicluster approximation. That is the apt point to clarify the relationship of the microscopic multicluster approach to other microscopic approaches and to macroscopic models. The structure theory part is then completed with a review of calculations for actual cases. (K.A.)

  4. Reflections on cavitation nuclei in water

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2007-01-01

    to explaining why the tensile strength of water varies so dramatically between the experiments reported. A model for calculation of the critical pressure of skin-covered free gas bubbles as well as that of interfacial gaseous nuclei covered by a skin is presented. This model is able to bridge the apparently......The origin of cavitation bubbles, cavitation nuclei, has been a subject of debate since the early years of cavitation research. This paper presents an analysis of a representative selection of experimental investigations of cavitation inception and the tensile strength of water. At atmospheric...... pressure, the possibility of stabilization of free gas bubbles by a skin has been documented, but only within a range of bubble sizes that makes them responsible for tensile strengths up to about 1.5 bar, and values reaching almost 300 bar have been measured. However, cavitation nuclei can also be harbored...

  5. Superscaling and nucleon momentum distributions in nuclei

    International Nuclear Information System (INIS)

    Antonov, A.

    2005-01-01

    The scaling functions f(ψ ' ) and F(y) from the ψ ' - and y-scaling analyses of inclusive electron scattering from nuclei are constructed within the Coherent Density Fluctuation Model (CDFM) using its two equivalent formulations based on either the local density or the nucleon momentum distribution (NMD). The approach is a natural extension of the relativistic Fermi-gas model to finite realistic nuclear systems. The calculations show that the high-momentum components of NMD in the CDFM and their similarity for different nuclei lead to quantitative description of the super-scaling phenomenon and to a good agreement with the experimental data for y ' ' ' - and y-scaling are informative for NMDs at momenta not larger than 2.0-2.5 fm -1 . The work shows the role of both basic quantities, the momentum and density distributions, for the explanation of super-scaling in inclusive electron scattering from nuclei

  6. Particle-rotation coupling in atomic nuclei

    International Nuclear Information System (INIS)

    Almberger, J.

    1980-01-01

    Recently an increased interest in the rotational nuclei has been spurred by the new experimental high-spin activities and by the possibilities for lower spins to interpret an impressive amount of experimental data by some comparatively simple model calculations. The author discusses the particle modes of excitation for rotational nuclei in the pairing regime where some puzzles in the theoretical description remain to be resolved. A model comparison is made between the particle-rotor and cranking models which have different definitions of the collective rotation. The cranking model is found to imply a smaller value of the quasiparticle spin alignment than the particle-rotor model. Rotational spectra for both even and odd nuclei are investigated with the use of the many-BCS-quasiparticles plus rotor model. This model gives an accurate description of the ground and S-bands in many even-even rare-earth nuclei. However, the discrepancies for odd-A nuclei between theory and experiments point to the importance of additional physical components. Therefore the rotationally induced quadrupole pair field is considered. This field has an effect on the low spin states in odd-A nuclei, but is not sufficient to account for the experimental data. Another topic considered is the interaction matrix element in crossings for given spin between quasiparticle rotational bands. The matrix elements are found to oscillate as a function of the number of particles, thereby influencing the sharpness of the backbending. Finally the low-spin continuation of the S-band is studied and it is shown that such states can be populated selectively by means of one-particle pickup reactions involving high angular momentum transfer. (Auth.)

  7. Fabrication and characterization of a nanostructured TiO2/In2S3-Sb2S3/CuSCN extremely thin absorber (eta) solar cell

    Science.gov (United States)

    Huerta-Flores, Alí M.; García-Gómez, Nora A.; de la Parra-Arciniega, Salomé M.; Sánchez, Eduardo M.

    2016-08-01

    In this work we report the successful assembly and characterization of a TiO2/In2S3-Sb2S3/CuSCN extremely thin absorber solar cell. Nanostructured TiO2 deposited by screen printing on an ITO substrate was used as an n-type electrode. An ∼80 nm extremely thin layer of the system In2S3-Sb2S3 deposited by successive ionic layer adsorption and a reaction (silar) method was used as an absorber. The voids were filled with p-type CuSCN and the entire assembly was completed with a gold contact. The solar cell fabricated with this heterostructure showed an energy conversion efficiency of 4.9%, which is a promising result in the development of low cost and simple fabrication of solar cells.

  8. Flecainide provocation reveals concealed brugada syndrome in a long QT syndrome family with a novel L1786Q mutation in SCN5A

    DEFF Research Database (Denmark)

    Kanters, Jørgen K; Yuan, Lei; Hedley, Paula L

    2014-01-01

    BACKGROUND: Mutations in SCN5A can result in both long QT type 3 (LQT3) and Brugada syndrome (BrS), and a few mutations have been found to have an overlapping phenotype. Long QT syndrome is characterized by prolonged QT interval, and a prerequisite for a BrS diagnosis is ST elevation in the right...... precordial leads of the electrocardiogram. METHODS AND RESULTS: In a Danish family suffering from long QT syndrome, a novel missense mutation in SCN5A, changing a leucine residue into a glutamine residue at position 1786 (L1786Q), was found to be present in heterozygous form co-segregating with prolonged QT......, a negative shift in inactivation properties and a positive shift in activation properties, compatible with BrS. Furthermore, the sustained (I(Na,late)) tetrodotoxin-sensitive sodium current was found to be drastically increased, explaining the association between the mutation and LQT syndrome. CONCLUSIONS...

  9. Medium energy hadron scattering from nuclei

    International Nuclear Information System (INIS)

    Ginocchio, J.N.; Wenes, G.

    1986-01-01

    The Glauber approximation for medium energy scattering of hadronic projectiles from nuclei is combined with the interacting boson model of nuclei to produce a transition matrix for elastic and inelastic scattering in algebraic form which includes coupling to all the intermediate states. We present closed form analytic expresions for the transition matrix elements for the three dynamical symmetries of the interacting boson model; that is for, a spherical quadrupole vibrator, a γ unstable rotor, and both prolate and oblate axially symmetric rotors. We give examples of application of this formalism to proton scattering from 154 Sm and 154 Gd. 27 refs., 5 figs., 1 tab

  10. Virtual photon spectra for finite nuclei

    International Nuclear Information System (INIS)

    Wolynec, E.; Martins, M.N.

    1988-01-01

    The experimental results of an isochromat of the virtual photon spectrum, obtained by measuring the number of ground-state protons emitted by the 16.28 MeV isobaric analogue state in 90 Zr as a function of electron incident energy in the range 17-105 MeV, are compared with the values predicted by a calculation of the E1 DWBA virtual photon spectra for finite nuclei. It is found that the calculations are in excellent agreement with the experimental results. The DWBA virtual photon spectra for finite nuclei for E2 and M1 multipoles are also assessed. (author) [pt

  11. Maris polarization in neutron-rich nuclei

    Science.gov (United States)

    Shubhchintak; Bertulani, C. A.; Aumann, T.

    2018-03-01

    We present a theoretical study of the Maris polarization effect and its application in quasi-free reactions to assess information on the structure of exotic nuclei. In particular, we explore the dependence of the polarization effect on neutron excess and neutron-skin thickness. We discuss the uncertainties in the calculations of triple differential cross sections and of analyzing powers due the choices of various nucleon-nucleon interactions and optical potentials and the limitations of the method. Our study implies that polarization variables in (p, 2p) reactions in inverse kinematics can be an effective probe of single-particle structure of nuclei in radioactive-beam facilities.

  12. MAGIC NUCLEI: Tin-100 turns up

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    In the same way as the Periodic Table of chemical elements reflects the successive filling of orbital electron shells, in nuclear physics the socalled 'magic' numbers correspond to closed shells of 2, 8, 20, 28, 50, 82, 126,... neutrons and/or protons. More tightly bound than other nuclei, these are the nuclear analogues of the inert gases. 'Doubly magic' nuclei have closed shells of both neutrons and protons. Examples in nature are helium-4 (2 protons and 2 neutrons), oxygen-16 (8 and 8), calcium-40 (20 and 20) and calcium-48 (20 and 28). Radioactive tin-132 (50+82) has been widely studied

  13. Dissipation and the population of compound nuclei

    International Nuclear Information System (INIS)

    Thoennessen, M.; Beene, J.R.

    1992-01-01

    The importance of nuclear dissipative efforts on the formation of compound nuclei is studied with the γ-ray decay of the giant dipole resonance (GDR) built on highly excited states. The compound nuclei 164 Yb, 160 Er, and 110 Sn were produced with very mass-asymmetric and with more mass-symmetric target/projectile combinations. The large deviation from statistical model prediction observed in the γ-ray spectra from the more symmetrically formed 160 Er and 164 Yb can be qualitatively explained within the particle exchange model

  14. Monte Carlo approaches to light nuclei

    International Nuclear Information System (INIS)

    Carlson, J.

    1990-01-01

    Significant progress has been made recently in the application of Monte Carlo methods to the study of light nuclei. We review new Green's function Monte Carlo results for the alpha particle, Variational Monte Carlo studies of 16 O, and methods for low-energy scattering and transitions. Through these calculations, a coherent picture of the structure and electromagnetic properties of light nuclei has arisen. In particular, we examine the effect of the three-nucleon interaction and the importance of exchange currents in a variety of experimentally measured properties, including form factors and capture cross sections. 29 refs., 7 figs

  15. Monte Carlo approaches to light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.

    1990-01-01

    Significant progress has been made recently in the application of Monte Carlo methods to the study of light nuclei. We review new Green's function Monte Carlo results for the alpha particle, Variational Monte Carlo studies of {sup 16}O, and methods for low-energy scattering and transitions. Through these calculations, a coherent picture of the structure and electromagnetic properties of light nuclei has arisen. In particular, we examine the effect of the three-nucleon interaction and the importance of exchange currents in a variety of experimentally measured properties, including form factors and capture cross sections. 29 refs., 7 figs.

  16. Selfconsistent theory of Coulomb mixing in nuclei

    International Nuclear Information System (INIS)

    Pyatov, N.I.

    1978-01-01

    The theory of isobaric states is considered according to the Coulomb mixing in nuclei. For a given form of the isovestor potential the separable residual interactions are constructed by means of the isotopic invariance principle. The strength parameter of the force is found from a selfconsistency condition. The charge dependent force is represented by the Coulomb effective potential. The theory of the isobaric states is developed using the random phase approximation. The Coulomb mixing effects in the ground and isobaric 0 + states of even-mass nuclei are investigated

  17. Computer Model Of Fragmentation Of Atomic Nuclei

    Science.gov (United States)

    Wilson, John W.; Townsend, Lawrence W.; Tripathi, Ram K.; Norbury, John W.; KHAN FERDOUS; Badavi, Francis F.

    1995-01-01

    High Charge and Energy Semiempirical Nuclear Fragmentation Model (HZEFRG1) computer program developed to be computationally efficient, user-friendly, physics-based program for generating data bases on fragmentation of atomic nuclei. Data bases generated used in calculations pertaining to such radiation-transport applications as shielding against radiation in outer space, radiation dosimetry in outer space, cancer therapy in laboratories with beams of heavy ions, and simulation studies for designing detectors for experiments in nuclear physics. Provides cross sections for production of individual elements and isotopes in breakups of high-energy heavy ions by combined nuclear and Coulomb fields of interacting nuclei. Written in ANSI FORTRAN 77.

  18. Weak and electromagnetic interactions in nuclei

    International Nuclear Information System (INIS)

    Klapdor, H.V.

    1986-01-01

    The International Symposium W.E.I.N. 1986 brought together leading experts in the fields of nuclear and elementary particle physics, astrophysics and cosmology. In addition to current problems in nuclear physics (weak and electromagnetic nuclear properties, electroweak interactions in nuclei, exotic nuclei) this book presents fascinating contributions that arise from the interaction among these fields: lepton number violation and neutrino mass; muon physics; weak interactions and fundamental symmetries; fundamental decays; basic experiments for GUTs; weak interactions and astrophysics; GUTs, SUSYs and the early Universe. The book demonstrates that in this context nuclear physics promises exciting future developments. (orig.)

  19. Structure of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics]|[Oak Ridge National Lab., TN (United States). Physics Div.]|[Warsaw Univ. (Poland). Inst. of Theoretical Physics

    1997-11-01

    One of the frontiers of today`s nuclear science is the ``journey to the limits``: of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The new data on exotic nuclei are expected to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this talk, current developments in nuclear structure of neutron-rich nuclei are discussed from a theoretical perspective.

  20. Structure of neutron-rich nuclei

    International Nuclear Information System (INIS)

    Nazarewicz, W.; Oak Ridge National Lab., TN; Warsaw Univ.

    1997-11-01

    One of the frontiers of today's nuclear science is the ''journey to the limits'': of atomic charge and nuclear mass, of neutron-to-proton ratio, and of angular momentum. The new data on exotic nuclei are expected to bring qualitatively new information about the fundamental properties of the nucleonic many-body system, the nature of the nuclear interaction, and nucleonic correlations at various energy-distance scales. In this talk, current developments in nuclear structure of neutron-rich nuclei are discussed from a theoretical perspective

  1. The Novel SCN''- Ion-selective Electrode Based on the 1-Benzyl-3-(4-nitrophenyl) thio-urea Ionophore

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Mi; Kang, Dong Hyeon; Choe, Ju Eun; You, Jung Min; Go, Min Jeong; Lee, Jung Seong; Jeon, Seung Won [Chungnam National University, Daejeon (Korea, Republic of)

    2014-09-15

    A potentiometric sensor based on the 1-benzyl-3-(4-nitrophenyl) thio-urea was synthesized and tested as an ionophore in PVC based membrane sensor towards SCN - ions. This membrane exhibits a linear stable response over a wide concentration range (1.0 × 10''-5 to 1.0 × 10''-2 M) with a slope of -59.2 mV/dec., a detection limit of log[SCN''- ] = -5.05, and a selectivity coefficient for thiocyanate against perchlorate anion of logK{sub s}cn''pot = -0.133. The selectivity series of the membrane is as follows: SCN''- > ClO{sub 4}''- > I''- >NO{sub 3}''- >HSO{sub 3}''- > Cl''-HSO{sub '}'-''4 > F''- > CH{sub 3}COO''- > HCO''-''3 > Br''- > H{sub 2}PO{sub 4}''- > SO{sub 3}''-''2 > SO{sub 4}''-''2 > CO{sub 3}''-''2. The proposed electrode showed good selectivity and a good response for the SCN''- ion over a wide variety of other anions in pH 6.0 buffer solutions and has a fast response time of about < 5s.. The influences of the membrane by pH, ionophore, and plasticizer were studied.

  2. De novo gain-of-function and loss-of-function mutations of SCN8A in patients with intellectual disabilities and epilepsy.

    Science.gov (United States)

    Blanchard, Maxime G; Willemsen, Marjolein H; Walker, Jaclyn B; Dib-Hajj, Sulayman D; Waxman, Stephen G; Jongmans, Marjolijn C J; Kleefstra, Tjitske; van de Warrenburg, Bart P; Praamstra, Peter; Nicolai, Joost; Yntema, Helger G; Bindels, René J M; Meisler, Miriam H; Kamsteeg, Erik-Jan

    2015-05-01

    Mutations of SCN8A encoding the neuronal voltage-gated sodium channel NaV1.6 are associated with early-infantile epileptic encephalopathy type 13 (EIEE13) and intellectual disability. Using clinical exome sequencing, we have detected three novel de novo SCN8A mutations in patients with intellectual disabilities, and variable clinical features including seizures in two patients. To determine the causality of these SCN8A mutations in the disease of those three patients, we aimed to study the (dys)function of the mutant sodium channels. The functional consequences of the three SCN8A mutations were assessed using electrophysiological analyses in transfected cells. Genotype-phenotype correlations of these and other cases were related to the functional analyses. The first mutant displayed a 10 mV hyperpolarising shift in voltage dependence of activation (gain of function), the second did not form functional channels (loss of function), while the third mutation was functionally indistinguishable from the wildtype channel. Comparison of the clinical features of these patients with those in the literature suggests that gain-of-function mutations are associated with severe EIEE, while heterozygous loss-of-function mutations cause intellectual disability with or without seizures. These data demonstrate that functional analysis of missense mutations detected by clinical exome sequencing, both inherited and de novo, is valuable for clinical interpretation in the age of massive parallel sequencing. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Adult siblings with homozygous G6PC3 mutations expand our understanding of the severe congenital neutropenia type 4 (SCN4 phenotype

    Directory of Open Access Journals (Sweden)

    Fernandez Bridget A

    2012-11-01

    Full Text Available Abstract Background Severe congenital neutropenia type 4 (SCN4 is an autosomal recessive disorder caused by mutations in the third subunit of the enzyme glucose-6-phosphatase (G6PC3. Its core features are congenital neutropenia and a prominent venous skin pattern, and affected individuals have variable birth defects. Oculocutaneous albinism type 4 (OCA4 is caused by autosomal recessive mutations in SLC45A2. Methods We report a sister and brother from Newfoundland, Canada with complex phenotypes. The sister was previously reported by Cullinane et al., 2011. We performed homozygosity mapping, next generation sequencing and conventional Sanger sequencing to identify mutations that cause the phenotype in this family. We have also summarized clinical data from 49 previously reported SCN4 cases with overlapping phenotypes and interpret the medical histories of these siblings in the context of the literature. Results The siblings’ phenotype is due in part to a homozygous mutation in G6PC3, [c.829C > T, p.Gln277X]. Their ages are 38 and 37 years respectively and they are the oldest SCN4 patients published to date. Both presented with congenital neutropenia and later developed Crohn disease. We suggest that the latter is a previously unrecognized SCN4 manifestation and that not all affected individuals have an intellectual disability. The sister also has a homozygous mutation in SLC45A2, which explains her severe oculocutaneous hypopigmentation. Her brother carried one SLC45A2 mutation and was diagnosed with “partial OCA” in childhood. Conclusions This family highlights that apparently novel syndromes can in fact be caused by two known autosomal recessive disorders.

  4. Turning dilemmas into opportunities: a UNU/SCN capacity development network in public nutrition in Central and Eastern Europe.

    Science.gov (United States)

    Pavlovic, Mirjana; Pepping, Fré; Demes, Michal; Biro, Lajos; Szabolcs, Peter; Dimitrovska, Zlatka; Duleva, Vesselka; Parvan, Camelia; Hadziomeragic, Aida Filipovic; Glibetic, Maria; Oshaug, Arne

    2009-08-01

    Capacity development in nutrition is a process whereby individuals, groups, institutions, organizations and societies enhance their abilities to identify and meet challenges in a sustainable manner. To address these issues, in 2001 the UN System Standing Committee on Nutrition (SCN) established a Working Group on Capacity Development under the joint coordination of the United Nations University (UNU) and the International Union of Nutritional Sciences. Several regional professional networks have developed under this working group, the latest for the Central and Eastern Europe (CEE) countries. Ten CEE countries formed a network in 2006 and identified major nutritional challenges in the region, which included: irregular meal patterns; low consumption of fruits/vegetables, milk products and fish; low intake of some micronutrients; and high intakes of fat, sugar and salt. Public policies in nutrition were either weak or absent. Some countries had recently developed nutrition plans. Higher education in nutrition was seen as very important for public nutrition work by professionals in the region, who considered it a prerequisite for reversing the negative trend of the nutrition transition. The network will continue to work on issues that are still not covered adequately. Its activities to date and prospects for the future are assessed against ten principles for good capacity development suggested by the United Nations Development Programme.

  5. The temperature dependence of the reflection intensities of the modulated composite structure Hg0.776(BEDT-TTF)SCN

    International Nuclear Information System (INIS)

    Pressprich, M.R.; Beek, C. van; Coppens, P.

    1994-01-01

    The temperature dependence between 30 and 300 K of the intensities of 24 reflections of the column-composite structure Hg 0.776 (BEDT-TTF)SCN [Wang, Beno, Carlson, Thorup, Murray, Porter, Williams, Maly, Bu, Petricek, Cisarova, Coppens, Jung, Whangbo, Shirber and Overmyer (1991). Chem. Mater. 3, 508-513; BEDT-TTF=3,4,3',4'-bis(ethylenedithio)-2,2',5,5'-tetrathiafulvalene] has been analyzed in terms of a model including phason temperature factors. The temperature dependence of the main and first-order satellite reflections is reasonably well reproduced in a refinement with 236 observations and four variables. The results are interpreted in terms of a temperature independence of the static displacement amplitudes. The room-temperature r.m.s. phason fluctuations of the mercury sublattice are 50(2) . This value implies that the mean mercury displacement amplitude will increase by ∝60% on lowering of the temperature to within the liquid-helium range. The thermal contraction on cooling is the same for the two sublattices. (orig.)

  6. Luminescence studies of Sm(III) and Cm(III) complexes in NaSCN/DHDECMP extraction systems

    CERN Document Server

    Chung, D Y; Kimura, T

    1999-01-01

    Laser-induced fluorescence (LIF) studies of Sm(III) and Cm(III) complexes in the NaSCN/DHDECMP solvent extraction system were carried out. Luminescence lifetimes were measured to determine the number of water molecules coordinated to Sm(III), Tb(III), Dy(III), and Cm(III) in the sodium thiocyanate solution and in the DHDECMP phase. The hydration number of Sm(III), Tb(III), Dy(III), and Cm(III) in the sodium thiocyanate solution decreased linearly with increasing sodium thiocyanate concentration. The hydration numbers of Sm(III), Dy(III), and Cm(III) in the DHDECMP phase decreased with increasing sodium thiocyanate concentration. The water molecules in the inner coordination sphere of Sm(III) and Dy(III) extracted into the DHDECMP were not completely removed at low sodium thiocyanate concentration but decreased with increasing sodium thiocyanate concentration. However, in the case of Cm(III) extracted into the DHDECMP phase from the sodium thiocyanate solution, there was no water in the inner coordination sphe...

  7. Copper(I) Thiocyanate (CuSCN) Hole-Transport Layers Processed from Aqueous Precursor Solutions and Their Application in Thin-Film Transistors and Highly Efficient Organic and Organometal Halide Perovskite Solar Cells

    KAUST Repository

    Wijeyasinghe, Nilushi

    2017-07-28

    This study reports the development of copper(I) thiocyanate (CuSCN) hole-transport layers (HTLs) processed from aqueous ammonia as a novel alternative to conventional n-alkyl sulfide solvents. Wide bandgap (3.4–3.9 eV) and ultrathin (3–5 nm) layers of CuSCN are formed when the aqueous CuSCN–ammine complex solution is spin-cast in air and annealed at 100 °C. X-ray photoelectron spectroscopy confirms the high compositional purity of the formed CuSCN layers, while the high-resolution valence band spectra agree with first-principles calculations. Study of the hole-transport properties using field-effect transistor measurements reveals that the aqueous-processed CuSCN layers exhibit a fivefold higher hole mobility than films processed from diethyl sulfide solutions with the maximum values approaching 0.1 cm2 V−1 s−1. A further interesting characteristic is the low surface roughness of the resulting CuSCN layers, which in the case of solar cells helps to planarize the indium tin oxide anode. Organic bulk heterojunction and planar organometal halide perovskite solar cells based on aqueous-processed CuSCN HTLs yield power conversion efficiency of 10.7% and 17.5%, respectively. Importantly, aqueous-processed CuSCN-based cells consistently outperform devices based on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate HTLs. This is the first report on CuSCN films and devices processed via an aqueous-based synthetic route that is compatible with high-throughput manufacturing and paves the way for further developments.

  8. How Anion Chaotrope Changes the Local Structure of Water. Insights from Photoelectron Spectroscopy and Theoretical Modeling of SCN- Water Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Valiev, Marat [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deng, Shihu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Xue B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-09

    The behavior of charged solute molecules in aqueous solutions is often classified using the concept of kosmotropes (“structure makers”) and chaotropes (“structure breakers”). There is a growing consensus that the key to kosmotropic/chaotropic behaviors lies in the local solvent region, but the exact microscopic basis for such differentiation is not well understood. This issue is examined in this work by analyzing size selective solvation of a well-known chaotrope, negatively charged SCN- molecule. Combining experimental photoelectron spectroscopy measurements with theoretical modeling we examine evolution of solvation structure up to eight waters. We observe that SCN- indeed fits the description of weakly hydrated ion and its solvation is heavily driven by stabilization of water-water interaction network. However, the impact on water structure is more subtle than that associated with “structure breaker”. In particular, we observe that the solvation structure of SCN- preserves the “packing” structure of the water network but changes local directionality of hydrogen bonds in the local solvent region. The resulting effect closer to that of “structure weakener”, where solute can be readily accommodated into the native water network, at the cost of compromising its stability due to constraints on hydrogen bonding.

  9. Quadruple or quintuple conversion of hlb, sak, sea (or sep), scn, and chp genes by bacteriophages in non-beta-hemolysin-producing bovine isolates of Staphylococcus aureus.

    Science.gov (United States)

    Kumagai, Rina; Nakatani, Kazue; Ikeya, Nanami; Kito, Yukiko; Kaidoh, Toshio; Takeuchi, Shotaro

    2007-05-16

    In 13 of 43 non-beta-hemolysin-producing bovine isolates of Staphylococcus aureus, two truncated beta-hemolysin (hlb) genes were demonstrated by PCR and sequencing, and one truncated hlb gene was located beside the integrase (int) gene of phage origin. The staphylokinase (sak) gene was detected in all 13 isolates in which the truncated hlb genes were detected by PCR. Enterotoxin A (sea) and enterotoxin P (sep) genes were also detected in 5 and 2 of the 13 isolates, respectively. Moreover, the scn and chp genes encoding staphylococcal complement inhibitor (SCIN) and chemotaxis inhibitory protein of S. aureus (CHIPS) were detected in 13 and 4 of the 13 isolates, respectively. The bacteriophage induced by mitomycin C treatment was able to lysogenize one beta-hemolysin-producing isolate of S. aureus, and the sak and scn genes were detected from the lysogenized isolate. These results suggest quadruple or quintuple conversion of hlb, sak, sea (or sep), scn, and chp genes by bacteriophages among non-beta-hemolysin-producing bovine isolates of S. aureus.

  10. LPG sensor based on complete inorganic n-Bi2S3-p-CuSCN heterojunction synthesized by a simple chemical route

    Science.gov (United States)

    Ladhe, R. D.; Baviskar, P. K.; Tan, W. W.; Zhang, J. B.; Lokhande, C. D.; Sankapal, B. R.

    2010-06-01

    An effective and versatile room temperature soft chemical route was employed to deposit n-Bi2S3 films followed by p-CuSCN films onto fluorine doped tin oxide (FTO) coated glass substrates. Well optimized preparative parameters led to the formation of a good heterojunction between the n-Bi2S3 and p-CuSCN films without any post-annealing treatment. An interconnected microflake of CuSCN on to the nanocrystalline Bi2S3 film enables a high porous structure in the top layer. The device was completed by ensuring silver as a front and FTO as a back ohmic contact, and exposed to sense the liquefied petroleum gas (LPG) at room temperature (27 °C). The upper porous structure allowed enough room for the gas species to adsorb and de-adsorb easily at the interface. The device exhibited more than 70% response at 1370 ppm of LPG, and the process suggests the possibility to develop a room temperature LPG sensing device with a low cost chemical method.

  11. The prevalence of mutations in KCNQ1, KCNH2, and SCN5A in an unselected national cohort of young sudden unexplained death cases

    DEFF Research Database (Denmark)

    Winkel, Bo Gregers; Larsen, Maiken Kudahl; Berge, Knut Erik

    2012-01-01

    on novel mutations. RESULTS: In total, 5 of 44 cases (11%) carried a mutation in 1 of the 3 genes corresponding to 11% of all investigated cases (R190W KCNQ1, F29L KCNH2 (2 cases), P297S KCNH2 and P1177L SCN5A). P1177L SCN5A has not been reported before. In vitro electrophysiological studies of P1177L SCN5......INTRODUCTION: Sudden unexplained death account for one-third of all sudden natural deaths in the young (1-35 years). Hitherto, the prevalence of genopositive cases has primarily been based on deceased persons referred for postmortem genetic testing. These deaths potentially may represent the worst...... of cases, thus possibly overestimating the prevalence of potentially disease causing mutations in the 3 major long-QT syndrome (LQTS) genes in the general population. We therefore wanted to investigate the prevalence of mutations in an unselected population of sudden unexplained deaths in a nationwide...

  12. DNA Measurement of Overlapping Cell Nuclei in Thick Tissue Sections

    Directory of Open Access Journals (Sweden)

    Liang Ji

    1997-01-01

    Full Text Available The paper describes an improved image analysis procedure for measuring the DNA content of cell nuclei in thick sections of liver tissue by absorption densitometry. Whereas previous methods only permitted the analysis of isolated nuclei, the new technique enables both isolated and overlapping nuclei to be measured. A 3D segmentation procedure determines whether each object is an isolated nucleus or a pair of overlapping nuclei; in the latter case the combined optical density is redistributed to the individual nuclei. A selection procedure ensures that only complete nuclei are measured.

  13. Enlargement of thalamic nuclei in Tourette syndrome

    DEFF Research Database (Denmark)

    Miller, Ann M; Bansal, Ravi; Hao, Xuejun

    2010-01-01

    : Morphological abnormalities in the thalamus, together with the disturbances reported in the sensorimotor cortex, striatum, and globus pallidus, support the hypothesis of a circuitwide disorder within motor pathways in TS. The connectivity and function of the numerous and diverse thalamic nuclei within cortical...... in motor circuits to attenuate the severity of tics....

  14. High energy spin isospin modes in nuclei

    International Nuclear Information System (INIS)

    Chanfray, G.; Ericson, M.

    1984-01-01

    The high energy response of nuclei to a spin-isospin excitation is investigated. We show the existence of a strong contrast between the spin transverse and spin longitudinal responses. The second one undergoes a shadow effect in the Δ region and displays the occurrence of the pionic branch

  15. Decay of heavy and superheavy nuclei

    Indian Academy of Sciences (India)

    2014-03-27

    Mar 27, 2014 ... Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 4. Decay of heavy and superheavy nuclei. K P Santhosh. Volume 82 Issue 4 April 2014 ... Author Affiliations. K P Santhosh1. School of Pure and Applied Physics, Kannur University, Swami Anandatheertha Campus, Payyanur 670 327, India ...

  16. Test of Pseudospin Symmetry in Deformed Nuclei

    OpenAIRE

    Ginocchio, J. N.; Leviatan, A.; Meng, J.; Zhou, Shan-Gui

    2003-01-01

    Pseudospin symmetry is a relativistic symmetry of the Dirac Hamiltonian with scalar and vector mean fields equal and opposite in sign. This symmetry imposes constraints on the Dirac eigenfunctions. We examine extensively the Dirac eigenfunctions of realistic relativistic mean field calculations of deformed nuclei to determine if these eigenfunctions satisfy these pseudospin symmetry constraints.

  17. Cloud condensation nuclei from biomass burning

    International Nuclear Information System (INIS)

    Rogers, C.F.; Hudson, J.G.; Zielinska, B.; Tanner, R.L.; Hallett, J.; Watson, J.G.

    1991-01-01

    In this work, the authors have analyzed biomass and crude oil smoke samples for ionic and organic species. The cloud condensation nuclei activities of the smoke particles are discussed in terms of the measured chemical compositions of the smoke samples. The implications of biomass burning to global climatic change are discussed

  18. Spectroscopic Studies of Exotic Nuclei at ISOLDE

    CERN Multimedia

    2002-01-01

    Experiment IS50 is designed to: a) Investigate the full range of the @b strength function of heavy (A~$>$~48)~K nuclei b)~Study the decay of isomeric states in n-deficient bromine nuclei (A~=~72 and 70). The heavy K isotopes appeared to have complex decay schemes, including feeding by the @b-decay of levels having open neutron channels (Beta decay energy Q(@b) exceeds neutron binding energy S^n); in addition, a large fraction of the delayed transitions populate excited levels in the daughter nuclei. The allowed @b-decay selects states in the daughter nucleus with wave functions having a large overlap with the initial state. Hence, the @b strength functions, deduced from these deca reveal simple structures correlated to the particle-hole excitation energies in the Ca nuclei. These results are valuable for the application of the shell-model calculations far from stability. The delayed neutron spectra are measured with a large area curved scintillator in coincidence either with high resolution Ge(Li) detectors, ...

  19. Physics of the continuum of borromean nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Vaagen, J.S.; Rogde, T. [Dept. of Physics, Univ. of Bergen (Norway); Danilin, B.V. [RRC The Kurchatov Inst., Kurchatov, Moscow (Russian Federation); Ershov, S.N. [JINR, Dubna, Moscow (Russian Federation); Thompson, I.J. [Dept. of Physics, Univ. of Surrey, Guildford (United Kingdom); Zhukov, M.V. [Chalmers Univ. of Technology and Goeteborg Univ., Goeteborg (Sweden); RNBT Collaboration

    1998-06-01

    The continuum states of two-neutron halo nuclei are calculated in the method of hyperspherical harmonics. Using DWIA theory appropriate for dilute halo matter we have probed the structure of the low-lying {sup 6}He continuum via calculations of charge-exchange and inelastic scattering. (orig.)

  20. Fisica degli atomi e dei nuclei

    CERN Document Server

    Bernardini, Carlo

    1965-01-01

    Evidenza della struttura atomica della materia ; le proprietà degli atomi e la meccanica atomica ; gli atomi e le radiazioni elettromagnetiche ; struttura microscopica dello stato gassoso ; struttura microscopica dello stato liquido ; struttura microscopica della stato solido ; proprietà elettriche e magnetiche delle sostanze ; proprietà dei nuclei degli atomi ; le particelle elementari.

  1. Quasars: Active nuclei of young galaxies

    Science.gov (United States)

    Komberg, B. V.

    1980-01-01

    The hypothetical properties of 'young' galaxies and possible methods of observing them are discussed. It is proposed that star formation first takes place in the central regions of protogalaxies which may appear as quasar-like objects. An evolutionary scheme is outlined in which the radio quasars are transformed in time into the nuclei of radio galaxies.

  2. Parity non-conservation in nuclei

    International Nuclear Information System (INIS)

    Tadic, D.

    1980-01-01

    Since parity non-conservation in nuclei is an inescapable consequence of weak interactions this review starts with derivation of the effective weak Hamiltonian which then acts as a perturbation mixing states of the opposite parity in nuclei. The connection between the effective weak Hamiltonian and various models of weak interactions (or quantum flavour dynamics, QFD) and the strong quantum chromodynamics (QCD) is briefly reviewed. The effective weak Hamiltonian serves as an input for determining the weak parity-violating potential. This weak potential is the main tool for connecting elementary particles with nuclear physics. Its derivation is discussed with special attention to one-boson-exchange (rho meson, pion, etc) contributions. Examples of theoretical and semi-empirical weak parity-violating potentials are given. Nuclear physics aspects of parity non-conservation in nuclei are discussed including, the gauge invariance of electromagnetic effects and the parity-violating nucleon-nucleon-photon vertex, two-body problems, processes involving α-particles, photon decays of complex nuclei, parity non-conservation in nuclear scattering, and similar effects. 329 references. (U.K.)

  3. Stability of the spherical form of nuclei

    International Nuclear Information System (INIS)

    Sabry, A.A.

    1976-08-01

    An extension of the mass formula for a spherical nucleus in the drop model to include a largely deformed nucleus of different forms is investigated. It is found that although the spherical form is stable under small deformations from equilibrium, there exists for heavier nuclei another more favourable stable form, which can be approximated by two, or three touching prolate ellipsoids of revolution

  4. Properties of semi-infinite nuclei

    International Nuclear Information System (INIS)

    El-Jaick, L.J.; Kodama, T.

    1976-04-01

    Several relations among density distributions and energies of semi-infinite and infinite nuclei are iventigated in the framework of Wilets's statistical model. The model is shown to be consistent with the theorem of surface tension given by Myers and Swiatecki. Some numerical results are shown by using an appropriate nuclear matter equation of state

  5. Thomas-Fermi model of warm nuclei

    International Nuclear Information System (INIS)

    Buchler, J.R.; Epstein, R.I.

    1980-01-01

    The average nuclear level density of spherical nuclei is computed with a finite temperature Thomas-Fermi model. More than 80% of the low energy nuclear excitations can be accounted for in terms of this statistical model. The relevance for stellar collapse is discussed

  6. Viscosity: From air to hot nuclei

    Indian Academy of Sciences (India)

    November 2014 physics pp. 683–693. Viscosity: From air to hot nuclei. NGUYEN DINH DANG1,2. 1RIKEN Nishina Center for Accelerator-Based Science, RIKEN 2-1 Hirosawa, Wako City,. 351-0198 Saitama, Japan. 2Institute for Nuclear Science and Technique, 179 Hoang Quoc Viet, Nghia Do,. Cau Giay Hanoi, Vietnam.

  7. Test of pseudospin symmetry in deformed nuclei

    International Nuclear Information System (INIS)

    Ginocchio, J.N.; Leviatan, A.; Meng, J.; Zhou Shangui

    2004-01-01

    Pseudospin symmetry is a relativistic symmetry of the Dirac Hamiltonian with scalar and vector mean fields equal and opposite in sign. This symmetry imposes constraints on the Dirac eigenfunctions. We examine extensively the Dirac eigenfunctions of realistic relativistic mean field calculations of deformed nuclei to determine if these eigenfunctions satisfy these pseudospin symmetry constraints

  8. Growth and Interaction of Colloid Nuclei

    Science.gov (United States)

    Lam, Michael-Angelo; Khusid, Boris; Meyer, William; Kondic, Lou

    2017-11-01

    We study evolution of colloid systems under zero-gravity conditions. In particular, we focus on the regime where there is a coexistence between a liquid and a solid state. Under zero gravity, the dominating process in the bulk of the fluid phase and the solid phase is diffusion. At the moving solid/liquid interface, osmotic pressure is balanced by surface tension, as well as balancing fluxes (conservation of mass) with the kinematics of nuclei growth (Wilson-Frenkel law). Due to the highly nonlinear boundary condition at the moving boundary, care has to be taken when performing numerical simulations. In this work, we present a nonlinear model for colloid nuclei growth. Numerical simulations using a finite volume method are compared with asymptotic analysis of the governing equation and experimental results for nuclei growth. Novel component in our numerical simulations is the inclusion of nonlinear (collective) diffusion terms that depend on the chemical potentials of the colloid in the solid and fluid phase. The results include growth and dissolution of a single colloidal nucleus, as well as evolution of multiple interacting nuclei. Supported by NASA Grant No. NNX16AQ79G.

  9. Electronuclear sum rules for the lightest nuclei

    International Nuclear Information System (INIS)

    Efros, V.D.

    1992-01-01

    It is shown that the model-independent longitudinal electronuclear sum rules for nuclei with A = 3 and A = 4 have an accuracy on the order of a percent in the traditional single-nucleon approximation with free nucleons for the nuclear charge-density operator. This makes it possible to test this approximation by using these sum rules. The longitudinal sum rules for A = 3 and A = 4 are calculated using the wave functions of these nuclei corresponding to a large set of realistic NN interactions. The values of the model-independent sum rules lie in the range of values calculated by this method. Model-independent expressions are obtained for the transverse sum rules for nuclei with A = 3 and A = 4. These sum rules are calculated using a large set of realistic wave functions of these nuclei. The contribution of the convection current and the changes in the results for different versions of realistic NN forces are given. 29 refs., 4 tabs

  10. Radiative muon capture on nuclei and protons

    International Nuclear Information System (INIS)

    Azuelos, G.; Gorringe, T.P.; Henderson, R.; Macdonald, J.A.; Poutissou, J.M.; Azuelos, G.; Depommier, P.; Poutissou, R.; Ahmad, S.; Burnham, A.; Hasinoff, M.D.; Larabee, A.J.; Waltham, C.E.; Wright, D.H.; Armstrong, D.S.; Blecher, M.; Serna-Angel, A.; Bertl, W.; Chen, C.Q.; Zhang, N.S.; McDonald, S.C.; Taylor, G.N.; Robertson, B.C.

    1990-01-01

    A brief review is made of the study of gp, the induced pseudoscalar coupling constant, in radiative muon capture on light nuclei, and of motivations for a measurement on hydrogen, with particular emphasis on recent and ongoing experiments at TRIUMF [fr

  11. Superheavy nuclei – cold synthesis and structure

    Indian Academy of Sciences (India)

    120 and Ж = 172 or 184, for superheavy nuclei. This result is discussed in ... 1980 [7] on the basis of the QMFT, once again prior to its observation in 1984. Thus, cold ... On the other hand, based on a rather complete deformed relativistic mean field (DRMF) calculation, using the NL1 parameter set, we [16] predicted. = 120.

  12. Efimov effect in 2-neutron halo nuclei

    Indian Academy of Sciences (India)

    This paper presents an overview of our theoretical investigations in search of Efimov states in light 2-neutron halo nuclei. The calculations have been carried out within a three-body formalism, assuming a compact core and two valence neutrons forming the halo. The calculations provide strong evidence for the occurrence ...

  13. Nuclear moments of nuclei near sphericity

    International Nuclear Information System (INIS)

    El Hajjaji, O.

    1987-05-01

    Magnetic and electric hyperfine interactions are studied by means of low temperature nuclear orientation. The magnetic moment of the 149 Gd isotope and that of 151 Gd are determined. The values follow the same trend as literature values of neighbouring nuclei. The calculated moments of the 7/2 - states using the Mottelson-Nilsson model without configuration mixing are nearly independent of deformation. Thus we assign the decrease of the magnetic moment versus neutron number to many particle coupling in the f shell. The Moessbauer effect detection of nuclear orientation is discussed. Two series of experiences are performed with different finalities. In the first one we determined the electric quadrupole moments of 125m Te and 129 Te. The quadrupole moments confirm the nearly spherical shape of these nuclei. In the second series we describe the Moessbauer effect of the radiation emitted by the daigleter nucleus of 125 I, implanted in two semiconductor matrices, locally oriented at low temperature by the electric field gradient of impurity-vacancy coupling. Despite the difficulty of the cooling down of Te nuclei to lattice temperature, we have shown the existence of the electric field gradient of implanted I into Si and α-Sn and determined their signs. The level mixing resonance is applied on oriented nuclei technique to determine the weak prolate deformation of silver nuclei. Studying the Δm = 3 resonance of 107 Ag m , we etablished the quadrupole moment of this state, which is in good agreement with the theoretical estimations of Moeller and Nix [fr

  14. Ice Nuclei Production in Volcanic Clouds

    Science.gov (United States)

    Few, A. A.

    2012-12-01

    The paper [Durant et al., 2008] includes a review of research on ice nucleation in explosive volcanic clouds in addition to reporting their own research on laboratory measurements focused on single-particle ice nucleation. Their research as well as the research they reviewed were concerned with the freezing of supercooled water drops (250 to 260 K) by volcanic ash particles acting as ice freezing nuclei. Among their conclusions are: Fine volcanic ash particles are very efficient ice freezing nuclei. Volcanic clouds likely contain fine ash concentrations 104 to 105 times greater than found in meteorological clouds. This overabundance of ice nuclei will produce a cloud with many small ice crystals that will not grow larger as they do in meteorological clouds because the cloud water content is widely distributed among the numerous small ice crystals. The small ice crystals have a small fall velocity, thus volcanic clouds are very stable. The small ice crystals are easily lofted into the stratosphere transporting water and adsorbed trace gasses. In this paper we examine the mechanism for the production of the small ice nuclei and develop a simple model for calculating the size of the ice nuclei based upon the distribution of magma around imbedded bubbles. We also have acquired a volcanic bomb that exhibits bubble remnants on its entire surface. The naturally occurring fragments from the volcanic bomb reveal a size distribution consistent with that predicted by the simple model. Durant, A. J., R. A. Shaw, W. I. Rose, Y. Mi, and G. G. J. Ernst (2008), Ice nucleation and overseeding of ice in volcanic clouds, J. Geophys. Res., 113, D09206, doi:10.1029/2007JD009064.

  15. Nuclear Shell Structure and Beta Decay I. Odd A Nuclei II. Even A Nuclei

    Science.gov (United States)

    Mayer, M.G.; Moszkowski, S.A.; Nordheim, L.W.

    1951-05-01

    In Part I a systematics is given of all transitions for odd A nuclei for which sufficiently reliable data are available. The allowed or forbidden characters of the transitions are correlated with the positions of the initial and final odd nucleon groups in the nuclear shell scheme. The nuclear shells show definite characteristics with respect to parity of the ground states. The latter is the same as the one obtained from known spins and magnetic moments in a one-particle interpretation. In Part II a systematics of the beta transitions of even-A nuclei is given. An interpretation of the character of the transitions in terms of nuclear shell structure is achieved on the hypothesis that the odd nucleon groups have the same structure as in odd-A nuclei, together with a simple coupling rule between the neutron and proton groups in odd-odd nuclei.

  16. scnRCA: a novel method to detect consistent patterns of translational selection in mutationally-biased genomes.

    Directory of Open Access Journals (Sweden)

    Patrick K O'Neill

    Full Text Available Codon usage bias (CUB results from the complex interplay between translational selection and mutational biases. Current methods for CUB analysis apply heuristics to integrate both components, limiting the depth and scope of CUB analysis as a technique to probe into the evolution and optimization of protein-coding genes. Here we introduce a self-consistent CUB index (scnRCA that incorporates implicit correction for mutational biases, facilitating exploration of the translational selection component of CUB. We validate this technique using gene expression data and we apply it to a detailed analysis of CUB in the Pseudomonadales. Our results illustrate how the selective enrichment of specific codons among highly expressed genes is preserved in the context of genome-wide shifts in codon frequencies, and how the balance between mutational and translational biases leads to varying definitions of codon optimality. We extend this analysis to other moderate and fast growing bacteria and we provide unified support for the hypothesis that C- and A-ending codons of two-box amino acids, and the U-ending codons of four-box amino acids, are systematically enriched among highly expressed genes across bacteria. The use of an unbiased estimator of CUB allows us to report for the first time that the signature of translational selection is strongly conserved in the Pseudomonadales in spite of drastic changes in genome composition, and extends well beyond the core set of highly optimized genes in each genome. We generalize these results to other moderate and fast growing bacteria, hinting at selection for a universal pattern of gene expression that is conserved and detectable in conserved patterns of codon usage bias.

  17. Probing the density tail of radioactive nuclei with antiprotons

    CERN Document Server

    Obertelli, Alexandre; Uesaka, Tomohiro; Corsi, Anna; Pollacco, Emmanuel; Flavigny, Freddy

    2017-01-01

    We propose an experiment to determine the proton and neutron content of the radial density tail in short-lived nuclei. The objectives are to (i) to evidence new proton and neutron halos, (ii) to understand the development of neutron skins in medium-mass nuclei, (iii) to provide a new observable that characterises the density tail of short-lived nuclei.

  18. The Role of Broken Cooper Pairs in Warm Nuclei

    International Nuclear Information System (INIS)

    Guttormsen, M.; Chankova, R.; Larsen, A.C.; Rekstad, J.; Siem, S.; Syed, N.U.H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.

    2007-01-01

    In order to understand warm nuclei and describe the underlying microscopic structure, entropy is measured for several even-even and odd-mass nuclei. Mid-shell nuclei show significant odd-even entropy differences interpreted as the single-particle entropy introduced by the valence nucleon. A method to extract critical temperatures for the pair breaking process is demonstrated. (author)

  19. Kinetics of photocurrent generation and an efficient charge separation of a dye-sensitized n-Cu2O/p-CuSCN junction photoelectrode in a solid-state photovoltaic cell

    International Nuclear Information System (INIS)

    Fernando, C A N; Kumara, N T R N; Gamage, T N

    2010-01-01

    A Cu/n-Cu 2 O/dye/p-CuSCN junction photoelectrode is fabricated to produce a solid-state dye-sensitized photovoltaic cell. Samples are characterized by XRD, SEM and surface resistivity measurements. Photocurrent generation is found due to light absorption of n-Cu 2 O thin film and dye sensitization between p-CuSCN and the dye. Kinetics of the photocurrent generation of the dye sensitization is studied solving the rate equations by the iteration method obtaining a relationship for the photocurrent quantum efficiency (Φ) depending on the surface concentration (D o ) of the dye and the rate constants of the reactions with connection to the dye sensitization process. The solution obtained in the steady state by iteration is found to be of the form Φ = AD o −BD o 2 (A and B are constants related to the reaction rates of the photocurrent generation process and the concentration of the n-Cu 2 O film). The variation of the n-Cu 2 O concentration with photocurrent is presented. A photocurrent enhancement is observed for the Cu/n-Cu 2 O/dye/p-CuSCN photovoltaic cell compared to that of Cu/n-Cu 2 O, Cu/p-CuSCN/dye and Cu/n-Cu 2 O/p-CuSCN photovoltaic cells. Good rectification characteristics are observed for the Cu/n-Cu 2 O/p-CuSCN photoelectrode compared to that of Cu/n-Cu 2 O and Cu/p-CuSCN photoelectrodes. Photocurrent enhancement is found due to the efficient charge separation process at the n–p junction. Energy band structures of the n–p junction are proposed according to the onset potentials which are used to discuss the mechanism of the efficient charge separation suppressing the recombination process

  20. Isospin Mixing In N $\\approx$ Z Nuclei

    CERN Multimedia

    Srnka, D; Versyck, S; Zakoucky, D

    2002-01-01

    Isospin mixing in N $\\approx$ Z nuclei region of the nuclear chart is an important phenomenon in nuclear physics which has recently gained theoretical and experimental interest. It also forms an important nuclear physics correction in the precise determination of the $ft$-values of superallowed 0$^+ \\rightarrow 0^+ \\beta$- transitions. The latter are used in precision tests of the weak interaction from nuclear $\\beta$- decay. We propose to experimentally measure isospin mixing into nuclear ground states in the N $\\approx$ Z region by determining the isospin forbidden Fermi-component in the Gamow-Teller dominated $J^{\\pi} \\rightarrow J^{\\pi} \\beta$- transitions through the observation of anisotropic positron emission from oriented nuclei. First measurements were carried out with $^{71}$As and are being analyzed now.

  1. Electron interactions with nuclei: Progress report

    International Nuclear Information System (INIS)

    McCarthy, J.S.

    1987-08-01

    High energy is being conducted at the Stanford Linear Accelerator Center. This includes inclusive electron scattering, electroexcitation of the delta in nuclei, longitudinal and transverse response in the quasi-elastic region, the q 2 dependence of 4 He(e,e'p), deep inelastic scattering from nuclei, transverse and longitudinal response in the resonance region, nuclear physics at PEP and 1.6 GeV spectrometer properties. Additional high energy research on electron scattering on 3 H and 3 He and the nuclear structure of 205 Tl and 206 Pb are being conducted at MIT-Bates. Other activities are being carried out at Saclay and research and development for Monte Carlo studies of Hall A spectrometers for CEBAF is being conducted

  2. Monopole Strength Function of Deformed Superfluid Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Stoitsov, M. V. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Kortelainen, E. M. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Nakatsukasa, T. [RIKEN, Japan; Losa, C. [International School for Advanced Studies (SISSA), Trieste, Italy; Nazarewicz, Witold [ORNL

    2011-01-01

    We present an efficient method for calculating strength functions using the finite amplitude method (FAM) for deformed superfluid heavy nuclei within the framework of the nuclear density functional theory. We demonstrate that FAM reproduces strength functions obtained with the fully self-consistent quasi-particle random-phase approximation (QRPA) at a fraction of computational cost. As a demonstration, we compute the isoscalar and isovector monopole strength for strongly deformed configurations in ^{240}Pu by considering huge quasi-particle QRPA spaces. Our approach to FAM, based on Broyden's iterative procedure, opens the possibility for large-scale calculations of strength distributions in well-bound and weakly bound nuclei across the nuclear landscape.

  3. Tensor coupling and pseudospin symmetry in nuclei

    International Nuclear Information System (INIS)

    Alberto, P.; Castro, A.S. de; Lisboa, R.; Malheiro, M.

    2005-01-01

    In this work we study the contribution of the isoscalar tensor coupling to the realization of pseudospin symmetry in nuclei. Using realistic values for the tensor coupling strength, we show that this coupling reduces noticeably the pseudospin splittings, especially for single-particle levels near the Fermi surface. By using an energy decomposition of the pseudospin energy splittings, we show that the changes in these splittings come mainly through the changes induced in the lower radial wave function for the low-lying pseudospin partners and through changes in the expectation value of the pseudospin-orbit coupling term for surface partners. This allows us to confirm the conclusion already reached in previous studies, namely that the pseudospin symmetry in nuclei is of a dynamical nature

  4. Electron interactions with nuclei. Progress report

    International Nuclear Information System (INIS)

    1986-07-01

    Research includes work at SLAC, Bates, and Saclay research facilities. The high energy program at SLAC concerns inclusive electron scattering from nuclei, electroexcitation of the delta in nuclei, and the design of an electron detection system for the SLAC 1.6 GeV/c magnetic spectrometer. The high energy program at Bates includes quasielastic electron scattering from 1 H, 2 H, 3 He, and 4 He, and electron scattering from 3 H and 3 He. Nuclear structure studies are based on high resolution inelastic electron scattering and include electron scattering from 208 Pb and mercury isotopes, charge densities from low lying states in 86 Sr, and magnetization densities of 205 Tl and 207 Pb. (DWL) 72 refs., 29 figs., 1 tab

  5. SP (4,R) symmetry in light nuclei

    International Nuclear Information System (INIS)

    Peterson, D.R.

    1979-01-01

    A classification of nuclear states according to the noncompact sympletic Lie algebras sp(2n,R), n = 1, 2, 3, is investigated. Such a classification has recently been shown to be physically meaningful. This classification scheme is the appropriate generalization fo Elliott's SU 3 model of rotational states in deformed light nuclei to include core excitations. A restricted classification according to the Lie algebra, sp(4,R), is motivated. Truncation of the model space to a single sp(4,R) irreducible representation allows the inclusion of states possessing very high excitation energy. An sp(4,R) model study is performed on S = T = 0 positive-parity rotational bands in the deformed light nuclei 16 O and 24 Mg. States are included in the model space that possess up to 10h ω in excitation energy. Results for the B(E2) transition rates compare favorable with experiment, without resort to effective charges

  6. Nuclear structure investigations on spherical nuclei

    International Nuclear Information System (INIS)

    Heisenberg, J.; Calarco, J.; Dawson, J.; Hersman, F.W.

    1989-09-01

    This report discusses the following topics: electron scattering studies on spherical nuclei; electron scattering from collective states in deformed nuclei; proton and pion scattering studies; 12 C(e,e'p) and 16 O(e,e'p); 12 C(e,e'α) and 16 O(e,e'α); studies at high q at Bates; measurements with rvec e at Bates; 12 C(γ,p); future directions in giant resonance studies; proton knockout from 16 O; quasielastic studies at Bates; triple coincidence studies of nuclear correlations; contributions to (e,e'2p) at KIKHEF; contributions to instrumentation at CEBAF; instrumentation development at UNH; the Bates large acceptance spectrometer toroid; shell model and core polarization calculations; and the relativistic nuclear model

  7. Nuclei at HERA and heavy ion physics

    International Nuclear Information System (INIS)

    Gavin, S.; Strikman, M.

    1995-01-01

    Copies of 16 viewgraph sets from a workshop held at Brookhaven National Laboratory, 17-18 November, 1995. Titles of talks: HERA: The Present; HERA: Potential with Nuclei; Review of Hadron-Lepton Nucleus Data; Fermilab E665: results in muon scattering; Interactions of Quarks and Gluons with Nuclear Matter; Rescattering in Nuclear Targets for Photoproduction and DIS; Structure Functions and Nuclear Effect at PHENIX; Probing Spin-Averaged and Spin-Dependent Parton Distributions Using the Solenoidal Tracker at RHIC (STAR); Jet Quenching in eA, pA, AA; Nuclear Gluon Shadowing via Continuum Lepton Pairs; What can we learn from HERA with a colliding heavy ion beam? The limiting curve of leading particles at infinite A; Coherent Production of Vector Mesons off Light Nuclei in DIS; A Model of High Parton Densities in PQCD; Gluon Production for Weizaecker-Williams Field in Nucleus-Nucleus Collisions; Summary Talk

  8. Disappearance of collective motion in hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Santonocito, D.; Piattelli, P.; Agodi, C.; Alba, R.; Bellia, G.; Coniglione, R.; Del Zoppo, A.; Finocchiaro, P.; Hongmei, F.; Maiolino, C.; Migneco, E.; Sapienza, P. [INFN-LNS, Laboratori Nazionali del Sud, Catania (Italy); Blumenfeld, Y.; Delaunay, F.; Frascaria, N.; Lima, V.; Scarpaci, J. [Institut de Physique Nucleaire, IN2P3-CNRS, 91 - Orsay (France); Migneco, E. [Catania Univ., Dipartimento di Fisica (Italy)

    2003-07-01

    The evolution of the GDR {gamma} yield for excitation energies between 160 and 300 MeV has been investigated in nuclei of mass A {approx} 126 through the reactions {sup 116}Sn + {sup 12}C and {sup 24}Mg at 17 and 23 A*MeV. Gamma-rays were detected with MEDEA array in coincidence with residues detected in MACISTE. The evolution of the GDR parameters has been investigated as a function of the linear momentum transferred to the fused system. This procedure allowed us to select hot nuclei produced in incomplete fusion reactions with different excitation energies. The analysis of the {gamma} spectra and their comparison with CASCADE calculations is presented. Results suggest a saturation of the GDR yield between 200 and 300 MeV excitation energy. (authors)

  9. Antiproton Induced Fission and Fragmentation of Nuclei

    CERN Multimedia

    2002-01-01

    The annihilation of slow antiprotons with nuclei results in a large highly localized energy deposition primarily on the nuclear surface. \\\\ \\\\ The study of antiproton induced fission and fragmentation processes is expected to yield new information on special nuclear matter states, unexplored fission modes, multifragmentation of nuclei, and intranuclear cascades.\\\\ \\\\ In order to investigate the antiproton-nucleus interaction and the processes following the antiproton annihilation at the nucleus, we propose the following experiments: \\item A)~Measurement of several fragments from fission and from multifragmentation in coincidence with particle spectra, especially neutrons and kaons. \\item B)~Precise spectra of $\\pi$, K, n, p, d and t with time-of-flight techniques. \\item C)~Installation of the Berlin 4$\\pi$ neutron detector with a 4$\\pi$ Si detector placed inside for fragments and charged particles. This yields neutron multiplicity distributions and consequently distributions of thermal excitation energies and...

  10. EMC effect and multiquark bags in nuclei

    International Nuclear Information System (INIS)

    Kondratyuk, L.; Shmatikov, M.

    1984-01-01

    Assuming existence of 9q- and 12q bags in niclei the form factors of light nuclei at large momentum transfers and structure functions of deep inelastic scattering of leptons on nuclei are described. It is shown that the existing experimental data can be described in a unified way provided the momentum distribution of quarks in multiquark bags at k 0 has the exponential form PSIsub(q)sup(2)(k) approximately esup(-k/k 0 ) with the parameter k 0 approximately 50-60 MeV. Theoretical results agree well the EMC experimental data on the ratio of the iron and deuteron structure functions with the 20% admixture of 12q-bags in the Fe nucleus

  11. Light-Nuclei Spectra from Chiral Dynamics

    Science.gov (United States)

    Piarulli, M.; Baroni, A.; Girlanda, L.; Kievsky, A.; Lovato, A.; Lusk, Ewing; Marcucci, L. E.; Pieper, Steven C.; Schiavilla, R.; Viviani, M.; Wiringa, R. B.

    2018-02-01

    In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels and level ordering of nuclei in the mass range A =4 - 12 , accurate to ≤2 % of the binding energy, in very satisfactory agreement with experimental data.

  12. The structure of nuclei far from stability

    International Nuclear Information System (INIS)

    Zganjar, E.F.

    1993-01-01

    Studies on nuclei near Z=82 contributed to the establishment of a new region of nuclear deformation and a new class of nuclear structure at closed shells. A important aspect of this work is the establishment of the connection between low-lying 0 + states in even endash even nuclei and the occurrence of shape coexistence in the odd-mass neighbors (E0 transitions in 185 Pt, shape coexistence in 184 Pt and 187 Au). A new type of picosecond lifetime measurement system capable of measuring the lifetime of states that decay only by internal conversion was developed and applied to the 186,188 Tl decay to determine the lifetime of the 0 2 + and 2 2 + deformed states in 186,188 Hg. A search for the population of superdeformed states in 192 Hg by the radioactive decay of 192 Tl was accomplished by using a prototype internal pair formation spectrometer

  13. Decay and fission of the oriented nuclei

    CERN Document Server

    Kadmenskij, S G

    2002-01-01

    The fragment angular distributions for binary decay of oriented spherical and deformed nuclei with taking into account the correct transformational properties of wave functions under time inversion have been investigated. It has been shown that for description of fragment angular distributions the adiabatic approximation for collective rotational nuclear degrees of freedom is not correct. It has been demonstrated that this approximation is valid for description of spontaneous and induced low-energy nuclear fission. The dependence of partial fission widths on the orientation of the internal axes spins, projections of spins, and relative angular moments of fission fragments has been analyzed. It has been shown that the adiabatic approximation results in coherent interference of wave functions of fragments relative movement. This interference forms fragments the universal angular distributions of fission fragments for oriented nuclei. For these distributions the deviations from A. Bohr's formula have been invest...

  14. Realistic microscopic level densities for spherical nuclei

    International Nuclear Information System (INIS)

    Cerf, N.

    1994-01-01

    Nuclear level densities play an important role in nuclear reactions such as the formation of the compound nucleus. We develop a microscopic calculation of the level density based on a combinatorial evaluation from a realistic single-particle level scheme. This calculation makes use of a fast Monte Carlo algorithm allowing us to consider large shell model spaces which could not be treated previously in combinatorial approaches. Since our model relies on a microscopic basis, it can be applied to exotic nuclei with more confidence than the commonly used semiphenomenological formuals. An exhaustive comparison of our predicted neutron s-wave resonance spacings with experimental data for a wide range of nuclei is presented

  15. Deeply virtual Compton scattering off nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Voutier, Eric

    2009-01-01

    Deeply virtual Compton scattering (DVCS) is the golden exclusive channel for the study of the partonic structure of hadrons, within the universal framework of generalized parton distributions (GPDs). This paper presents the aim and general ideas of the DVCS experimental program off nuclei at the Jefferson Laboratory. The benefits of the study of the coherent and incoherent channels to the understanding of the EMC (European Muon Collaboration) effect are discussed, along with the case of nuclear targets to access neutron GPDs.

  16. AMS with light nuclei at small accelerators

    Science.gov (United States)

    Stan-Sion, C.; Enachescu, M.

    2017-06-01

    AMS applications with lighter nuclei are presented. It will be shown how Carbon-14, Boron-10, Beryllium-10, and Tritium-3 can be used to provide valuable information in forensic science, environmental physics, nuclear pollution, in material science and for diagnose of the plasma confinement in fusion reactors. Small accelerators are reliable, efficient and possess the highest ion beam transmissions that confer high precision in measurements.

  17. Production and identification of very exotic nuclei

    International Nuclear Information System (INIS)

    Pougheon, F.

    1986-01-01

    New very exotic nuclei have been produced by fragmentation of the projectile at intermediate energy at GANIL. They have been identified through time of flight and ΔE-E measurements after a magnetic separation with the 0 0 LISE spectrometer. New neutron rich isotopes have been identified up to Z = 26 and evidence for the stability of the new series Tz = -5/2 has been shown. These results improve the knowledge of the neutron and proton drip lines

  18. Fission of nuclei far from stability

    International Nuclear Information System (INIS)

    Schmidt, K.H.; Benlliure, J.; Junghans, A.R.

    2000-11-01

    The secondary-beam facility of GSI provided the technical equipment for a new kind of fission experiment. Fission properties of short-lived neutron-deficient nuclei have been investigated in inverse kinematics. The measured element distributions reveal new kinds of systematics on shell structure and even-odd effects and lead to an improved understanding of structure effects in nuclear fission. Prospects for further experimental studies are discussed. (orig.)

  19. Electromagnetic interactions with nuclei and nucleons

    International Nuclear Information System (INIS)

    Thornton, S.T.; Sealock, R.M.

    1990-01-01

    This report discusses the following topics: general LEGS work; photodisintegration of the deuteron; progress towards other experiments; LEGS instrumentation; major LEGS software projects; NaI detector system; nucleon detector system; waveshifting fibers; EGN prototype detector for CEBAF; photon beam facility at CEBAF; delta electroproduction in nuclei; quasielastic scattering and excitation of the Delta by 4 He(e,e'); and quasielastic scattering at high Q 2

  20. Order and chaos in atomic nuclei

    International Nuclear Information System (INIS)

    Rotter, I.

    1991-01-01

    The interplay between regular and chaotic motion in nuclei is investigated in the framework of an open quantum mechanical system. The effect of avoided resonance overlapping (trapping) leads to long-lived traps which correspond to the formation of quantum chaos. They are hidden by short-lived states which correspond to the formation of a new order with less degrees of freedom. The quantum chaos in the nuclear system may be investigated by means of rare decays. (author)

  1. Some Aspects of Collective Properties of Nuclei

    International Nuclear Information System (INIS)

    Belyaev, S.T.

    1963-01-01

    Certain questions connected with the collective properties of nuclei will be considered in this paper. There are two different complementary approaches in the consideration of collective motions. One method - we shall call it the phenomenological one - consists of directly introducing collective degrees of freedom and the corresponding collective Hamiltonian, H coll , with some phenomenological parameters. The aim of such a theory is, first, to solve the Schrodinger equation with the Hamiltonian H coll , and secondly to calculate the parameters in Hcoil under certain assumptions or using certain models. The Davydov-Filippov model can serve as an example of such an approach to the investigation of collective properties of nuclei. There it is supposed that Hc0udescribes a non-axial rotator and the parameters of the Hamiltonian are then chosen so as to obtain the best fit to experimental data. The second possible method of investigating collective excitations of nuclei - let us call it the microscopic one - works right from the beginning with a many-body Hamiltonian H = H o + H int . Then such excitations in a system of nucleons, the nature of which is collective, are studied. In this method no additional collective degrees of freedom, and hence no additional phenomenological parameters, are introduced a priori. In principle, everything is determined by the nucleon-nucleon interaction H int . As a matter of fact, the interaction H int must practically be introduced phenomenologically, since it has not been possible to derive it from first principles so far. The actual difference is in the ''degree of phenomenologicality'', i.e . in the number of parameters introduced into the theory. One needs only one or two parameters, which in principle determine the various properties of all nuclei, to determine H int . whereas in the above-mentioned example of a non-axial rotator, two parameters are introduced for each nucleus (the value of the first 2 + level and the degree of

  2. Shell effects and nucleosynthesis of heavy nuclei

    International Nuclear Information System (INIS)

    Farhan, A.R.; Sharma, M.M.

    2005-01-01

    The nuclear shell effects across the magic numbers N = 50, 82 and 126 near the r-process path are crucial to understanding the nucleosynthesis of heavy nuclei. Since nuclei near the r-process path are extremely neutron rich and are not accessible in the laboratory, the current understanding of the nuclear abundances is based much upon extrapolations of various mass formulae. In this talk, we will discuss as to how the shell effects evolve in going from the stability line to the r-process path and towards drip line in the heavy mass region. Within the framework of to the relativistic Hartree-Bogoliubov (RHB) theory with the vector self-coupling of omega meson, it will be shown that the shell effects across N = 82 show a significant decline in going from the r-process path to the drip line, whereas those at N = 126 remain resilient to the change in isospin in going from the r-process path to the neutron drip line. This behaviour of the microscopic RHB calculations is consistent with the recent r-process calculations suggesting that a shell quenching at N = 82 would be useful, however, a quenching is not necessary for reproducing r-process abundances near the peak at A ∼ 190. We will also show that due to an onset of deformation for nuclei above N = 126, an additional stability in some nuclei beyond the neutron drip line is provided. Consequently, this would contribute to r-process nuclear abundances in the third peak. A comparative analysis of shell effects with the microscopic RMF theory and with the macroscopic-microscopic mass formulae shows that the microscopic RMF theory possesses the potential of describing nuclear abundances in the peaks about A ∼ 130 and A ∼ 190. (author)

  3. The Skyrmions and quarks in nuclei

    International Nuclear Information System (INIS)

    Rho, M.

    1984-08-01

    It is proposed that the quark-bag description and the Skyrmion description of baryons are related to each other by quantized parameters. Topology (through a chiral anomaly) plays an important role in bridging the fundamental theory of the strong interactions (QCD) to effective theories. Some consequences on the efforts to see quark degrees of freedom in nuclear matter are discussed. It is suggested that at low energies there will be no ''smoking gun'' evidences for quark presence in nuclei

  4. Dynamical timescales in hot rotating nuclei

    International Nuclear Information System (INIS)

    Thoennessen, M.; Michigan State Univ., East Lansing, MI

    1996-01-01

    The effects of dissipation in fission of hot nuclei as well as in heavy-ion reactions are still not well understood and quite controversial. The deformation and/or temperature dependence of the dissipation coefficient as well as the influence of the curvatures of the potential energy surface will be discussed. Evidence for particle/γ-ray decay during compound nucleus formation in certain heavy-ion reactions will be compared to other reactions where no effects were observed. (orig.)

  5. Chiral bags, skyrmions and quarks in nuclei

    International Nuclear Information System (INIS)

    Rho, M.

    1984-09-01

    Recent developments on an intriguing connection between the quark-bag description of the baryons (nucleons in particular) and the Skyrmion model are discussed in terms of the constraints coming from chiral anomalies. Topics treated are the leaking baryon charge, axial charge and energy density; the role of chiral anomalies; the role of Skyrme's quartic term and the connection to the meson degrees of freedom; and finally some qualitative implications in nuclei. The presentation is purposely descriptive and intuitive instead of mathematically precise

  6. Decay of heavy and superheavy nuclei

    Indian Academy of Sciences (India)

    study on the feasibility of observing α decay chains from the isotopes of the superheavy nuclei. Z = 115 in the range 271 ≤ A ≤ 294 and the isotopes of Z = 117 in the range 270 ≤ A ≤ 301, within the Coulomb and .... For Ri we use semiempirical formula in terms of mass number Ai as [3]. Ri = 1.28A. 1/3 i. − 0.76 + 0.8A.

  7. ''Identical'' bands in normally-deformed nuclei

    International Nuclear Information System (INIS)

    Garrett, J.D.; Baktash, C.; Yu, C.H.

    1990-01-01

    Gamma-ray transitions energies in neighboring odd- and even-mass nuclei for normally-deformed nuclear configurations are analyzed in a manner similar to recent analyses for superdeformed states. The moment of inertia is shown to depend on pair correlations and the aligned angular momentum of the odd nucleon. The implications of this analysis for ''identical'' super-deformed bands are discussed. 26 refs., 9 figs

  8. Soft radiative strength in warm nuclei

    International Nuclear Information System (INIS)

    Becker, J A; Bernstein, L A; Garrett, P E; Nelson, R O; Schiller, A; Voinov, A; Agvaanluvsan, U; Algin, E; Belgya, T; Chankova, R; Guttormsen, M; Mitchell, G E; Rekstad, J; Siem, S

    2004-01-01

    Unresolved transitions in the nuclear γ-ray cascade produced in the decay of excited nuclei are best described by statistical concepts: a continuous radiative strength function (RSF) and level density yield mean values of transition matrix elements. Data on the soft (E γ < 3-4 MeV) RSF for transitions between warm states (i.e. states several MeV above the yrast line) have, however, remained elusive

  9. Double charge exchange of pions on nuclei

    International Nuclear Information System (INIS)

    Dzhibuti, R.I.; Kezerashvili, R.Y.

    1985-01-01

    An analysis is made of the results of experimental and theoretical studies during the last ten years of a unique process: double charge exchange of pions on nuclei. On the one hand, the commissioning of meson factories and the use of new and more accurate experimental methods have led to the accumulation of rich and reliable material for not only light but also medium and heavy nuclei. On the other hand, the development and application of new microscopic theoretical approaches have led to a deepening of our ideas about the mechanism of these exotic reactions at low, intermediate, and high energies. The currently existing methods of theoretical investigation and all possible reaction mechanisms are considered. Particular attention is devoted to double charge exchange of pions on the lightest nuclei, for the theoretical description of which it is possible to use the well-developed methods for investigating few-particle systems. The experimental investigations of double-isobar analog and nonanalog transitions in the reaction of double charge exchange are systematized

  10. Fusion excitation functions involving transitional nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Rehm, K.E.; Jiang, C.L.; Esbensen, H. [and others

    1995-08-01

    Measurements of fusion excitation functions involving transitional nuclei {sup 78}Kr and {sup 100}Mo showed a different behavior at low energies, if compared to measurements with {sup 86}Kr and {sup 92}Mo. This points to a possible influence of nuclear structure on the fusion process. One way to characterize the structure of vibrational nuclei is via their restoring force parameters C{sub 2} which can be calculated from the energy of the lowest 2{sup +} state and the corresponding B(E2) value. A survey of the even-even nuclei between A = 28-150 shows strong variations in C{sub 2} values spanning two orders of magnitude. The lowest values for C{sub 2} are observed for {sup 78}Kr, {sup 104}Ru and {sup 124}Xe followed by {sup 74,76}Ge, {sup 74,76}Se, {sup 100}Mo and {sup 110}Pd. In order to learn more about the influence of {open_quotes}softness{close_quotes} on the sub-barrier fusion enhancement, we measured cross sections for evaporation residue production for the systems {sup 78}Kr + {sup 104}Ru and {sup 78}Kr + {sup 76}Ge with the gas-filled magnet technique. For both systems, fusion excitation functions involving the closed neutron shell nucleus {sup 86}Kr were measured previously. The data are presently being analyzed.

  11. History of cluster structure in nuclei

    International Nuclear Information System (INIS)

    Brink, D M

    2008-01-01

    This contribution focuses on the history of clustering in nuclei. Elementary alpha models treat light 4-n nuclei as systems of alpha-particles obeying Bose Einstein statistics. These models neglect the internal structure of the alphas and effects of the Pauli principle between the nucleons in the alpha clusters are taken into account by introducing a short range repulsion between the clusters. The orthogonality condition model and excluded state model treat the alphas as elementary particles, but include effects of the Pauli principle in a more microscopic way. Wheeler's resonating group method is a fully microscopic theory for calculating properties of cluster systems. It makes simplifying assumptions about the internal structure of the clusters but takes the Pauli principle explicitly. Hartree-Fock theory can be used for a microscopic theory of nuclear structure but it is not suitable for light nuclei because there is no well defined mean field. Margenau's microscopic cluster model avoids this problem by using trial wave functions which are antisymmetrized products of parametrized single particle wave functions

  12. Toward yrast spectroscopy in soft vibrational nuclei

    International Nuclear Information System (INIS)

    Marumori, Toshio; Kuriyama, Atsushi; Sakata, Fumihiko.

    1979-10-01

    In a formally parallel way with that exciting progress has been recently achieved in understanding the yrast spectra of the rotational nuclei in terms of the quasi-particle motion in the rotating frame, an attempt to understand the yrast spectra of the vibrational nuclei in terms of the quasi-particle motion is proposed. The essential idea is to introduce the quasi-particle motion in a generalized vibrating frame, which can be regarded as a rotating frame in the gauge space of ''physical'' phonons where the number of the physical phonons plays the role of the angular momentum. On the basis of a simple fundamental principle called as the ''invariance principle of the Schroedinger equation'', which leads us to the ''maximal decoupling'' between the physical phonon and the intrinsic modes, it is shown that the vibrational frame as well as the physical-phonon-number operator represented by the quasi-particles can be self-consistently determined. A new scope toward the yrast spectroscopy of the vibrational nuclei in terms of the quasi-particle motion is discussed. (author)

  13. Gamow-Teller Transitions in hot nuclei

    International Nuclear Information System (INIS)

    Vdovin, A.I.; Dzhioev, A.; Ponomarev, V.; Wambach, J.

    2007-01-01

    A temperature dependence of collective nuclear excitations (giant resonances (GR) in particular) is a subject of theoretical and experimental investigations for many years. One of the reasons of this interest is that the GR properties at finite temperatures are quite important in understanding various astrophysical processes. For example, electron or neutrino capture on nuclei plays an essential role in the early presupernova collapse. In that context, it is important to know the dependence of the charge-exchange and/or magnetic resonance strength distribution from stellar media temperature. To study the problem, we apply the formalism based on the quasiparticle phonon model extended to finite temperature using the thermo field dynamics. Following the TFD prescriptions we have constructed a microscopic thermal Hamiltonian which describes collective vibrations in a hot nucleus. In this approach, the fragmentation of the giant vibrations at T≠0 is due to the coupling with thermal two-phonon configurations. The calculations are performed for selected nuclei from the Fe region. The Gamow-Teller strength distributions are calculated within the thermal RPA at different temperatures. Then they are used to study a temperature dependence of -decay rates for these nuclei in stellar media.

  14. Flow cytometry of DNA in mouse sperm and testis nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Meistrich, M.L. (Univ. of Texas, Houston); Lake, S.; Steinmetz, L.L.; Gledhill, B.L.

    1978-01-01

    Mutations that occur in spermatogenic cells may be expressed as changes in DNA content, but developmentally-dependent alteration of its staining properties complicates the quantitation of DNA in individual germ cells. These alterations have been studied with flow cytometric techniques. Nuclei from mouse testis cells and sperm were stained by the acriflavine--Feulgen method. The fluorescence intensity frequency distribution of nuclei of testis cells was characterized by 2 major and 5 minor peaks. Nuclei sorted from the various peaks with a fluorescence-activated cell sorter were identified microscopically. These data were confirmed by generation of peaks with nuclei prepared from cell suspensions enriched in specific cell types. One of the major peaks corresponded to round spermatid nuclei. The other major peak, located at 0.6 of the fluorescence intensity of the round nuclei, corresponded to elongated spermatid nuclei. Purified nuclei of epididymal and vas deferens spermatozoa displayed asymmetric fluorescence distributions. A minor peak at 0.8 the intensity of the round spermatid nuclei was tentatively assigned to elongating spermatids. 2 of the minor peaks, located at 1.7 and 2.0 times the fluorescence intensity of the round nuclei, corresponded to clumps of 2 haploid and diploid nuclei.

  15. Electric monopole transitions from low energy excitations in nuclei

    CERN Document Server

    Wood, J L; De Coster, C; Heyde, Kris L G

    1999-01-01

    Electric monopole (E0) properties are studied across the entire nuclear mass surface. Besides an introductory discussion of various model results (shell model, geometric vibrational and rotational models, algebraic models), we point out that many of the largest E0 transition strengths, $\\rho^2$(E0), are associated with shape mixing. We discuss in detail the manifestation of E0 transitions and present extensive data for~: single-closed shell nuclei, vibrational nuclei, well-deformed nuclei, nuclei that exhibit sudden ground-state changes, and nuclei that exhibit shape coexistence and intruder states. We also give attention to light nuclei, odd-A nuclei, and illustrate a suggested relation between $\\rho^2$(E0) and isotopic shifts.

  16. Conformational behavior of CH3OC(O)SX (X = CN and SCN) pseudohalide congeners. A combined experimental and theoretical study.

    Science.gov (United States)

    Torrico-Vallejos, Sonia; Erben, Mauricio F; Ge, Mao-Fa; Willner, Helge; Della Védova, Carlos O

    2010-03-18

    Pure methoxycarbonylsulfenyl cyanide, CH(3)OC(O)SCN (I), and methoxycarbonylsulfenyl thiocyanate, CH(3)OC(O)SSCN (II), were prepared by reacting liquid CH(3)OC(O)SCl with either AgCN or AgSCN, respectively. Compounds I and II were characterized by (1)H NMR, CG-MS, and vibrational (FTIR and FT-Raman) techniques. The conformational properties have been studied by using vibrational spectroscopy [infrared (gaseous, liquid, and Ar matrix isolated), Raman (liquid) spectroscopy] together with quantum chemical calculations at the B3LYP and MP2 methods with the extended 6-311++G** and aug-cc-pVTZ basis sets. Compound I exhibits a conformational equilibrium at room temperature having the most stable form C(s) symmetry with a synperiplanar (syn) orientation of the carbonyl double bond (C=O) with respect to both the CH(3)O- and -SCN groups (syn-syn). Several bands assigned to a second conformer have been observed in the IR matrix spectra. This rotamer presents an antiperiplanar orientation of the thiocyanate group (syn-anti). Evaluating the equilibrium compositions at different temperatures by quenching the gas phase mixtures as Ar matrices allowed us to determine the conformational enthalpy difference DeltaH(0) = H(0)((syn-anti)) - H(0)((syn-syn)) = 0.80(18) kcal mol(-1). A similar conformational behavior has been determined for compound II. Thermodynamic properties were also computed at the high-level G2MP2 and G3 model chemistry methods. The importance of mesomeric (resonance) and anomeric (hyperconjugation) electronic interaction in the conformational behavior is evaluated by using the NBO approach for both species.

  17. A novel de novo mutation of SCN8A (Nav1.6) with enhanced channel activation in a child with epileptic encephalopathy.

    Science.gov (United States)

    Estacion, Mark; O'Brien, Janelle E; Conravey, Allison; Hammer, Michael F; Waxman, Stephen G; Dib-Hajj, Sulayman D; Meisler, Miriam H

    2014-09-01

    Rare de novo mutations of sodium channels are thought to be an important cause of sporadic epilepsy. The well established role of de novo mutations of sodium channel SCN1A in Dravet Syndrome supports this view, but the etiology of many cases of epileptic encephalopathy remains unknown. We sought to identify the genetic cause in a patient with early onset epileptic encephalopathy by whole exome sequencing of genomic DNA. The heterozygous mutation c. 2003C>T in SCN8A, the gene encoding sodium channel Nav1.6, was detected in the patient but was not present in either parent. The resulting missense substitution, p.Thr767Ile, alters an evolutionarily conserved residue in the first transmembrane segment of channel domain II. The electrophysiological effects of this mutation were assessed in neuronal cells transfected with mutant or wildtype cDNA. The mutation causes enhanced channel activation, with a 10mV depolarizing shift in voltage dependence of activation as well as increased ramp current. In addition, pyramidal hippocampal neurons expressing the mutant channel exhibit increased spontaneous firing with PDS-like complexes as well as increased frequency of evoked action potentials. The identification of this new gain-of-function mutation of Nav1.6 supports the inclusion of SCN8A as a causative gene in infantile epilepsy, demonstrates a novel mechanism for hyperactivity of Nav1.6, and further expands the role of de novo mutations in severe epilepsy. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Open and closed Fermi surface contributions to the anomalous angular magnetoresistance of α-(BEDT-TTF)2RbHg(SCN)4

    International Nuclear Information System (INIS)

    Athas, G.J.; Klepper, S.J.; Brooks, J.S.; Tokumoto, M.; Kinoshita, N.; Tanaka, Y.

    1994-01-01

    Anomalous angular magnetoresistance (AMR) in the quasi-two dimensional organic conductor α-(BEDT-TTF) 2 RbHg(SCN) 4 is reported. The AMR appears as oscillations with sharp minima below the anitiferromagnetic ordering temperature. The period of these oscillations is anisotropic with respect to the plane of rotation cutting through the conducting layers. Above the ordering temperature, the nature of the AMR changes fundamentally. We propose a model for the AMR that incorporates both open and closed Fermi surfaces, and discuss how temperature and field dependent behaviors of the individual FS contribute to the conductivity. (orig.)

  19. Flecainide provocation reveals concealed brugada syndrome in a long QT syndrome family with a novel L1786Q mutation in SCN5A

    DEFF Research Database (Denmark)

    Kanters, Jørgen K.; Yuan, Lei; Hedley, Paula L

    2014-01-01

    precordial leads of the electrocardiogram. METHODS AND RESULTS: In a Danish family suffering from long QT syndrome, a novel missense mutation in SCN5A, changing a leucine residue into a glutamine residue at position 1786 (L1786Q), was found to be present in heterozygous form co-segregating with prolonged QT......: The L1786Q mutation is associated with a combined LQT3 and concealed BrS phenotype explained by gating characteristics of the mutated ion channel protein. Hence, sodium channel blockade should be considered in clinical evaluation of apparent LQT3 patients....

  20. From heavy nuclei to super-heavy nuclei; Des noyaux lourds aux super-lourds

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, Ch

    2003-01-01

    The existence of super-heavy nuclei has been predicted nearly fifty years ago. Due to the strong coulomb repulsion, the stabilisation of these nuclei is possible only through shell effects. The reasons for this fragile stability, as well as the theoretical predictions concerning the position of the island of stability are presented in the first part of this lecture. In the second part, experiments and experimental techniques which have been used to synthesize or search for super-heavy elements are described. Spectroscopic studies performed in very heavy elements are presented in the following section. We close this lecture with techniques that are currently being developed in order to reach the superheavy island and to study the structure of very-heavy nuclei. (author)

  1. Relativistic exotic nuclei as projectile beams. New perspectives of studies on the properties of nuclei

    International Nuclear Information System (INIS)

    Geissel, H.

    1997-03-01

    Examinations of the production cross-sections and the kinematics permitted refinement of model concepts of the peripheral reactions in exotic nuclei at energies from 100 to 1000 A MeV. Due to the strong selectivity and resolution achieved it was possible to discover a large number of novel isotopes at the fragment separator FRS, despite the relatively low projectile beam intensities of the SIS. The two twice magic nuclei found, Ni 78 and Sn 100, are particularly interesting, as they could not be measured so far with other experimental systems. Fission of relativistic uranium ions proved to be a particularly successful process yielding many medium-heavy, neutron-rich nuclei. Insight into the structure of light neutron halos could be improved. The superlarge spatial dimensions of the nuclear halos is discussed. (orig./CB) [de

  2. The dynamics of the nuclei-nuclei interactions at very high energies

    International Nuclear Information System (INIS)

    Blaizot, J.P.

    1988-01-01

    The lectures on the dynamics of nuclei-nuclei interactions at very high energies, presented in the Summer School on Nuclear Physics and Particle Physics (1988), are shown. The equation of state of the hadronic matter is analyzed, by means of simple models, and some orders of magnitude can be asserted. The main characteristics of the high energy hadronic interactions are recalled. The basis of the dynamics of the relativistic fluids are given. Applications of this dynamics in the description of the space-time evolution of a plasma, generated by heavy ions collision, are carried out [fr

  3. Nuclei at extreme conditions. A relativistic study

    Energy Technology Data Exchange (ETDEWEB)

    Afanasjev, Anatoli [Mississippi State Univ., Mississippi State, MS (United States)

    2014-11-14

    The major goals of the current project were further development of covariant density functional theory (CDFT), better understanding of its features, its application to different nuclear structure and nuclear astrophysics phenomena and training of graduate and undergraduate students. The investigations have proceeded in a number of directions which are discussed in detail in the part “Accomplishments” of this report. We have studied the role of isovector and isoscalar proton-neutron pairings in rotating nuclei; based on available experimental data it was concluded that there are no evidences for the existence of isoscalar proton-neutron pairing. Generalized theoretical approach has been developed for pycnonuclear reaction rates in the crust of neutron stars and interior of white dwarfs. Using this approach, extensive database for considerable number of pycnonuclear reactions involving stable and neutron-rich light nuclei has been created; it can be used in future for the study of various nuclear burning phenomena in different environments. Time-odd mean fields and their manifestations in terminating states, non-rotating and rotating nuclei have been studied in the framework of covariant density functional theory. Contrary to non-relativistic density functional theories these fields, which are important for a proper description of nuclear systems with broken time-reversal symmetry, are uniquely defined in the CDFT framework. Hyperdeformed nuclear shapes (with semi-axis ratio 2.5:1 and larger) have been studied in the Z = 40-58 part of nuclear chart. We strongly believe that such shapes could be studied experimentally in the future with full scale GRETA detector.

  4. Signatures for quark clustering in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, C.E. [College of William and Mary, Williamsburg, VA (United States); Lassila, K.E. [Iowa State Univ., Ames, IA (United States)

    1994-04-01

    As a signature for the presence of quark clusters in nuclei, the authors suggest studying backward protons produced by electron scattering off deuterons and suggest a ratio that cancels out much of the detailed properties of deuterons or 6-quark clusters. The test may be viewed as a test that the short range part of the deuteron is still a 2-nucleon system. They make estimates to show how it fails in characteristic and significant ways if the two nucleons at short range coalesce into a kneaded 6-quark cluster.

  5. The Structure of Nuclei Far from Stability

    Energy Technology Data Exchange (ETDEWEB)

    Zganjar, E.F.

    1999-02-25

    From among a number of important nuclear structure results that have emerged from our research program during the past few years, two stand out as being of extra significance. These are: (a) the identification of a diabatic coexisting structure in {sup 187}Au which arises solely from differences in proton occupation of adjacent oscillator shells, and (b) the realization of a method for estimating EO strength in nuclei and the resulting prediction that the de-excitation of superdeformed bands may proceed, in some cases, by strong EO transitions.

  6. Multipole giant resonances in highly excited nuclei

    International Nuclear Information System (INIS)

    Xia Keding; Cai Yanhuang

    1989-01-01

    The isoscalar giant surface resonance and giant dipole resonance in highly excited nuclei are discussed. Excitation energies of the giant modes in 208 Pb are calculated in a simplified model, using the concept of energy wieghted sum rule (EWSR), and the extended Thomas-Fermi approximation at the finite temperature is employed to describe the finite temperature is employed to describe the finite temperature equilibrium state. It is shown that EWSR and the energy of the resonance depend only weakly on temperature in the system. This weak dependence is analysed

  7. Exploring the physics of unstable nuclei

    International Nuclear Information System (INIS)

    Volya, Alexander

    2015-01-01

    In this presentation the Continuum Shell Model (CSM) approach is advertised as a powerful theoretical tool for studying physics of unstable nuclei. The approach is illustrated using 17 O as an example, which is followed by a brief presentation of the general CSM formalism. The successes of the CSM are highlighted and references are provided throughout the text. As an example, the CSM is applied perturbatively to 20 O allowing one to explore the effects of continuum on positions of weakly bound states and low-lying resonances, as well as to discern some effects of threshold discontinuity. (author)

  8. Cluster and alpha decay of superheavy nuclei

    Science.gov (United States)

    Poenaru, D. N.; Stöcker, H.; Gherghescu, R. A.

    2018-02-01

    We investigated cluster radioactivity and alpha decay of some superheavy nuclei with atomic numbers Z = 119, 120 , which may be produced in the future. Two models are used to calculate the half-lives against cluster radioactivity: ASAF (Analytical Super-Asymmetric Fission) and UNIV (Universal Formula). For α decay half-lives we are based on four models: ASAF, UNIV, semFIS (semi-empirical formula based on Fission Theory) and AKRA (first author Akrawy). The Q -values are calculated using the theoretical model of atomic masses WS10, which sometimes is called W4.

  9. Solitonic fullerene structures in light atomic nuclei.

    Science.gov (United States)

    Battye, R A; Sutcliffe, P M

    2001-04-30

    The Skyrme model is a classical field theory which has topological soliton solutions. These solitons are candidates for describing nuclei, with an identification between the numbers of solitons and nucleons. We have computed numerically, using two different minimization algorithms, minimum energy configurations for up to 22 solitons. We find, remarkably, that the solutions for seven or more solitons have nucleon density isosurfaces in the form of polyhedra made of hexagons and pentagons. Precisely these structures arise, though at the much larger molecular scale, in the chemistry of carbon shells, where they are known as fullerenes.

  10. Signatures for quark clustering in nuclei

    International Nuclear Information System (INIS)

    Carlson, C.E.; Lassila, K.E.

    1994-01-01

    As a signature for the presence of quark clusters in nuclei, the authors suggest studying backward protons produced by electron scattering off deuterons and suggest a ratio that cancels out much of the detailed properties of deuterons or 6-quark clusters. The test may be viewed as a test that the short range part of the deuteron is still a 2-nucleon system. They make estimates to show how it fails in characteristic and significant ways if the two nucleons at short range coalesce into a kneaded 6-quark cluster

  11. Shell model calculations for exotic nuclei

    International Nuclear Information System (INIS)

    Brown, B.A.; Wildenthal, B.H.

    1991-01-01

    A review of the shell-model approach to understanding the properties of light exotic nuclei is given. Binding energies including p and p-sd model spaces and sd and sd-pf model spaces; cross-shell excitations around 32 Mg, including weak-coupling aspects and mechanisms for lowering the ntw excitations; beta decay properties of neutron-rich sd model, of p-sd and sd-pf model spaces, of proton-rich sd model space; coulomb break-up cross sections are discussed. (G.P.) 76 refs.; 12 figs

  12. Nuclear Data on Unstable Nuclei for Astrophysics

    International Nuclear Information System (INIS)

    Smith, Michael Scott; Meyer, Richard A; Lingerfelt, Eric; Scott, J.P.; Hix, William Raphael; Ma, Zhanwen; Bardayan, Daniel W.; Blackmon, Jeff C.; Guidry, Mike W.; KOZUB, RAYMOND L.; Chae, Kyung YuK.

    2004-01-01

    Recent measurements with radioactive beams at ORNL's Holifield Radioactive Ion Beam Facility (HRIBF) have prompted the evaluation of a number of reactions involving unstable nuclei needed for stellar explosion studies. We discuss these evaluations, as well as the development of a new computational infrastructure to enable the rapid incorporation of the latest nuclear physics results in astrophysics models. This infrastructure includes programs that simplify the generation of reaction rates, manage rate databases, and visualize reaction rates, all hosted at a new website http://www.nucastrodata.org

  13. Rotating bubble and toroidal nuclei and fragmentation

    International Nuclear Information System (INIS)

    Royer, G.; Haddad, F.; Jouault, B.

    1995-01-01

    The energy of rotating bubble and toroidal nuclei predicted to be formed in central heavy-ion collisions at intermediate energies is calculated within the generalized rotating liquid drop model. The potential barriers standing in these exotic deformation paths are compared with the three dimensional and plane fragmentation barriers. In the toroidal deformation path of the heaviest systems exists a large potential pocket localised below the plane fragmentation barriers. This might allow the temporary survival of heavy nuclear toroids before the final clusterization induced by the surface and proximity tension. (author)

  14. Sub-Coulomb fusion with halo nuclei

    International Nuclear Information System (INIS)

    Fekou-Youmbi, V.; Sida, J.L.; Alamanos, N.; Auger, F.; Bazin, D.; Borcea, C.; Cabot, C.; Cunsolo, A.; Foti, A.; Gillibert, A.; Lepine, A.; Lewitowicz, M.; Liguori-Neto, R.; Mittig, W.; Pollacco, E.; Roussel-Chomaz, P.; Volant, C.; Yong Feng, Y.

    1995-01-01

    The nuclear structure of halo nuclei may have strong influence on the fusion cross section at sub-barrier energies. The actual theoretical debate is briefly reviewed and sub-barrier fusion calculations for the system 11 Be+ 238 U are presented. An experimental program on sub-barrier fusion for the systems 7,9,10,11 Be+ 238 U is underway at GANIL. First results with 9 Be and 11 Be beams were obtained using the F.U.S.ION detector. Relative fission cross sections are presented. ((orig.))

  15. Inclusive charge longitudinal response in finite nuclei

    International Nuclear Information System (INIS)

    Alberico, W.M.; Molinari, A.; Czerski, P.; Czerski, P.; Ericson, M.

    1986-03-01

    The experimental dynamic and static longitudinal structure factors of 12 C, 40 Ca and 56 Fe are investigated with a semiclassical RPA theory. The parameters entering into the nuclear mean field (including the nucleon effective mass) and in the isoscalar and isovector particle-hole forces are set by best fitting procedures. Quite reasonable values of these quantities allow a satisfactory account of the experimental data over a wide range of momentum transfers in all the three nuclei. However, to achieve this result, the proton root mean square radius has to be increased over the conventional value of about 13% in 12 C and 22% in 40 Ca and 56 Fe

  16. Light unstable nuclei in the continuum

    International Nuclear Information System (INIS)

    Kato, Kiyoshi

    2000-01-01

    It is discussed that the complex scaling method is one of the most available frameworks to solve many body resonances. As the recent developments of the complex scaling method, we present several ways to analyse the properties of resonant states; the matrix elements associated with resonant states, the extended completeness relation and partial widths of resonances. We also show the discussions on the binding mechanism and excited resonant structure of the Borromean systems 4 He+n+n and 9 Li+n+n. It is shown that the pairing correlation between valence neutrons and among core neutrons plays an important role in neutron-rich nuclei. (author)

  17. Lectures on geometrical properties of nuclei

    International Nuclear Information System (INIS)

    Myers, W.D.

    1975-11-01

    Material concerning the geometrical properties of nuclei is drawn from a number of different sources. The leptodermous nature of nuclear density distributions and potential wells is used to draw together the various geometrical properties of these systems and to provide a unified means for their description. Extensive use is made of expansions of radial properties in terms of the surface diffuseness. A strong case is made for the use of convolution as a geometrical ansatz for generating diffuse surface distributions because of the number of simplifications that arise which are of practical importance. 7 figures

  18. Modeling a neutron rich nuclei source

    International Nuclear Information System (INIS)

    Mirea, M.; Bajeat, O.; Clapier, F.; Ibrahim, F.; Mueller, A.C.; Pauwels, N.; Proust, J.; Mirea, M.

    2000-01-01

    The deuteron break-up process in a suitable converter gives rise to intense neutron beams. A source of neutron rich nuclei based on the neutron induced fission can be realised using these beams. A theoretical optimization of such a facility as a function of the incident deuteron energy is reported. The model used to determine the fission products takes into account the excitation energy of the target nucleus and the evaporation of prompt neutrons. Results are presented in connection with a converter-target specific geometry. (authors)

  19. Giant dipole resonance in hot nuclei

    International Nuclear Information System (INIS)

    Mau, N.V.

    1993-01-01

    Giant resonances built on an excited state of the nucleus at a finite temperature T are studied. The following questions are investigated: how long such collective effects occur in a nucleus when T increases. How the properties of the giant resonances vary when the temperature increases. How the study of giant resonances in hot nuclei can give information on the structure of the nucleus in a highly excited state. The special case of the giant dipole resonance is studied. Some of the experimental results are reviewed and in their theoretical interpretation is discussed. (K.A.). 56 refs., 20 figs., 4 tabs

  20. Electromagnetic properties of nuclei at high spins

    International Nuclear Information System (INIS)

    Leander, G.A.

    1986-01-01

    A photon emitted by an excited state is likely to carry away, at most, 1 or 2 h-bar of angular momentum. Therefore, a profusion of photons is needed to deexcite the rapidly rotating states of nuclei formed by heavy-ion reactions. The study of electromagnetic properties has become the primary source of information on nuclear structure at high spins and, also, at the warm temperatures present in the initial stage of the electromagnetic cascade process. The purpose of this paper is a review of the E1, M1, and E2 properties of such highly excited states. 42 refs., 5 figs

  1. Algebraic description of intrinsic modes in nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    1989-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. 28 refs., 1 fig

  2. Algebraic description of intrinsic modes in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A.

    1989-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. 28 refs., 1 fig.

  3. Algebraic description of intrinsic modes in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A. (Los Alamos National Lab., NM (USA))

    1990-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intrinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. (author).

  4. Algebraic description of intrinsic modes in nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.

    1990-01-01

    We present a procedure for extracting normal modes in algebraic number-conserving systems of interacting bosons relevant for collective states in even-even nuclei. The Hamiltonian is resolved into intrinsic (bandhead related) and collective (in-band related) parts. Shape parameters are introduced through non-spherical boson bases. Intrinsic modes decoupled from the spurious modes are obtained from the intrinsic part of the Hamiltonian in the limit of large number of bosons. Intrinsic states are constructed and serve to evaluate electromagnetic transition rates. The method is illustrated for systems with one type of boson as well as with proton-neutron bosons. (author)

  5. Multi-quark correlations in nuclei

    International Nuclear Information System (INIS)

    Vary, J.P.; Harindranath, A.

    1986-01-01

    This paper reviews the consequences of multi-quark correlations in nuclei which arise through the particular cluster decomposition of the nuclear ground state specified by the quark cluster model (QCM). The critical radius of a three quark cluster, R c , controls the formation probability of larger clusters. The value of R c = 0.50 fm is fixed by fits to deep inelastic lepton nucleus scattering data. The QCM prediction for the ratio of nuclear structure functions in the x > 1 domain is discussed as a critical test of the model. We also present an extended discussion of the application of the QCM to the nuclear Drell-Yan process. (orig.)

  6. Experimental level densities of atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Guttormsen, M.; Bello Garrote, F.L.; Eriksen, T.K.; Giacoppo, F.; Goergen, A.; Hagen, T.W.; Klintefjord, M.; Larsen, A.C.; Nyhus, H.T.; Renstroem, T.; Rose, S.J.; Sahin, E.; Siem, S.; Tornyi, T.G.; Tveten, G.M. [University of Oslo, Department of Physics, Oslo (Norway); Aiche, M.; Ducasse, Q.; Jurado, B. [University of Bordeaux, CENBG, CNRS/IN2P3, B.P. 120, Gradignan (France); Bernstein, L.A.; Bleuel, D.L. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Byun, Y.; Voinov, A. [Ohio University, Department of Physics and Astronomy, Athens, Ohio (United States); Gunsing, F. [CEA Saclay, DSM/Irfu/SPhN, Cedex (France); Lebois, L.; Leniau, B.; Wilson, J. [Institut de Physique Nucleaire d' Orsay, Orsay Cedex (France); Wiedeking, M. [iThemba LABS, P.O. Box 722, Somerset West (South Africa)

    2015-12-15

    It is almost 80 years since Hans Bethe described the level density as a non-interacting gas of protons and neutrons. In all these years, experimental data were interpreted within this picture of a fermionic gas. However, the renewed interest of measuring level density using various techniques calls for a revision of this description. In particular, the wealth of nuclear level densities measured with the Oslo method favors the constant-temperature level density over the Fermi-gas picture. From the basis of experimental data, we demonstrate that nuclei exhibit a constant-temperature level density behavior for all mass regions and at least up to the neutron threshold. (orig.)

  7. Fusion and reactions of exotic nuclei

    Directory of Open Access Journals (Sweden)

    Sánchez-Benítez A.M.

    2011-10-01

    Full Text Available Close to the drip lines, the scattering cross sections of halo nuclei show a different behaviour as compared to the tightly bound projectiles of the stability line. Several experiments carried out in the last decade have been dedicated to investigate the competition between transfer, breakup and fusion channels at energies around and below the Coulomb barrier. The rather complex scenario gives rise to conflicting conclusions concerning the effect of breakup and transfer on reaction dynamics and the sub-barrier fusion process. In this work we discuss recent experimental findings in fusion and reactions of 6He halo nucleus at energies around the Coulomb barrier.

  8. Crystal structure, EPR spectra and conductivity of the (ET)2[Hg(SCN)2I] organic conductor (ET - bis-ethylenedithiotetrathiafulvalen)

    International Nuclear Information System (INIS)

    Yudanova, E.I.; Makarova, L.N.; Konovalikhin, S.V.; D'yachenko, O.A.; Lyubovskij, R.B.; Lyubovskaya, R.N.

    1996-01-01

    A study was made on structure, conductivity and EPR spectra of a new organic conductor (ET) 2 [Hg(SCN) 2 I] (ET -bis-ethyeleneithiotetrathiafulvalen). It is shown that cation-radicals in organic layers are packed according to k-type, and anions form a polymer chain. THe existence of cation-radical layers, which differ by the number of shortened S...S-contacts and by the way of interaction with anion layer, was revealed; width of EPR line is equal to 9-11 Gs (300 K) for them. This is several times less, than widths of lines, typical for k-type salts. Existence of conducting band of small dimensions was assumed. Analysis of temperature dependences of conductivity anisotropy and EPR spectra parameters enabled to make the assumption about structural rearrangement in the region of 50 K. Correlation of structure and properties of this compound with other salts of (ET) 2 [Hg(SCN) 3-n X n ], X = Cl, Br, n = 1, 2 family was conducted. 21 refs.; 5 figs

  9. Crystal structure, NMR study, dc-conductivity and dielectric relaxation studies of a new compound [C2H10N2]Cd(SCN)2Cl2

    Science.gov (United States)

    Saidi, K.; Kamoun, S.; Ayedi, H. F.; Gargouri, M.

    2012-06-01

    The crystal structure, the solid NMR spectroscopy and the complex impedance study have been carried out on [C2H10N2]CdCl2(SCN)2. Characterization by single crystal X-ray crystallography shows that the cadmium atoms have à 2N2S2Cl hexa-coordination sphere, exhibiting pseudo-octahedral geometry. The cadmium atoms are bridged by two thiocyanate ions generating 1-D polymeric-chains. These chains are themselves interconnected by means of N-H…Cl(NCS) hydrogen bonds originating from the organic cation [(NH3)2(CH2)2]2+. 111Cd isotropic chemical shifts span a range of 268ppm. The cadmium atom exhibits multiplets that result from 111Cd-14N spin-spin coupling. Examination of 111Cd and 13C MAS line shapes shows direct measurement of the indirect spin-spin coupling constant 2J(111Cd, 14N) = 105Hz and the dipolar coupling constant of 1381Hz . Impedance spectroscopy measurements of [C2H10N2]CdCl2(SCN)2 have been studied from 209Hz to 5 MHz over the temperature range 300-370 K. The Cole-Cole (Z" versus Z') plots are fitted to two equivalent circuits models. The formalism of complex permittivity and impedance were employed to analyze the experimental data. The dc conductivity follows the Arrhenius relation with an activation energy Ea = 0.54 (3) eV.

  10. Crystal structure, NMR study, dc-conductivity and dielectric relaxation studies of a new compound [C2H10N2]Cd(SCN2Cl2

    Directory of Open Access Journals (Sweden)

    Gargouri M.

    2012-06-01

    Full Text Available The crystal structure, the solid NMR spectroscopy and the complex impedance study have been carried out on [C2H10N2]CdCl2(SCN2. Characterization by single crystal X-ray crystallography shows that the cadmium atoms have à 2N2S2Cl hexa-coordination sphere, exhibiting pseudo-octahedral geometry. The cadmium atoms are bridged by two thiocyanate ions generating 1-D polymeric-chains. These chains are themselves interconnected by means of N-H…Cl(NCS hydrogen bonds originating from the organic cation [(NH32(CH22]2+. 111Cd isotropic chemical shifts span a range of 268ppm. The cadmium atom exhibits multiplets that result from 111Cd-14N spin-spin coupling. Examination of 111Cd and 13C MAS line shapes shows direct measurement of the indirect spin-spin coupling constant 2J(111Cd, 14N = 105Hz and the dipolar coupling constant of 1381Hz . Impedance spectroscopy measurements of [C2H10N2]CdCl2(SCN2 have been studied from 209Hz to 5 MHz over the temperature range 300-370 K. The Cole-Cole (Z” versus Z’ plots are fitted to two equivalent circuits models. The formalism of complex permittivity and impedance were employed to analyze the experimental data. The dc conductivity follows the Arrhenius relation with an activation energy Ea = 0.54 (3 eV.

  11. Solution-processed p-type copper(I) thiocyanate (CuSCN) for low-voltage flexible thin-film transistors and integrated inverter circuits

    KAUST Repository

    Petti, Luisa

    2017-03-17

    We report on low operating voltage thin-film transistors (TFTs) and integrated inverters based on copper(I) thiocyanate (CuSCN) layers processed from solution at low temperature on free-standing plastic foils. As-fabricated coplanar bottom-gate and staggered top-gate TFTs exhibit hole-transporting characteristics with average mobility values of 0.0016 cm2 V−1 s−1 and 0.013 cm2 V−1 s−1, respectively, current on/off ratio in the range 102–104, and maximum operating voltages between −3.5 and −10 V, depending on the gate dielectric employed. The promising TFT characteristics enable fabrication of unipolar NOT gates on flexible free-standing plastic substrates with voltage gain of 3.4 at voltages as low as −3.5 V. Importantly, discrete CuSCN transistors and integrated logic inverters remain fully functional even when mechanically bent to a tensile radius of 4 mm, demonstrating the potential of the technology for flexible electronics.

  12. High prevalence of the SCN5A E1784K mutation in school children with long QT syndrome living on the Okinawa islands.

    Science.gov (United States)

    Takahashi, Kazuhiro; Shimizu, Wataru; Miyake, Akira; Nabeshima, Taisuke; Nakayashiro, Mami; Ganaha, Hitoshi

    2014-01-01

    Genetic testing for long QT syndrome (LQTS) is now in clinical practice. We conducted molecular genetic analyses to definitively diagnose LQTS and to determine its subtypes for gene-specific treatment. We conducted a retrospective study to determine the characteristics of schoolchildren with LQTS living on the Okinawa Islands. The study population included children identified in a school-based electrocardiographic (ECG) screening program for cardiovascular diseases who were referred to Okinawa Children's Medical Center between 2007 and 2012; 23 children met the diagnostic criteria for LQTS. Of them, 17 were genotype-positive and 14 were found to harbor theSCN5AE1784K mutation exclusively among the LQTS genotype-positive children. The children were divided into genotype-positive and -negative groups. Clinical characteristics and ECG data were analyzed and compared. The median Schwartz score was 3. The median QT interval was 521 ms. The major finding is that the prevalent subtype of LQTS in Okinawa is discordant with other cohorts living in other regions of Japan or overseas. We cannot exclude the possibility of the presence of a specific founder mutation in this geographically clustered population, particularly considering that the hospital is the only tertiary heart center for children in Okinawa. However, this uniquely high prevalence of theSCN5AE1784K mutation serves as a compelling justification to conduct a larger study.

  13. Interactions of 10.6 GeV/n gold nuclei with light and heavy target nuclei in nuclear emulsion

    International Nuclear Information System (INIS)

    Cherry, M.L.; Denes-Jones, P.

    1994-03-01

    We have investigated the particle production and fragmentation of nuclei participating in the interactions of 10.6 GeV/n gold nuclei in nuclear emulsions. A new criteria has been developed to distinguish between the interactions of these gold nuclei with the light (H, C, N, O) and heavy (Ag, Br) target nuclei in the emulsion. This has allowed separate analyzes of the multiplicity and pseudo-rapidity distributions of the singly charged particles emitted in Au-(H, C, N, O) and Au-(Ag, Br) interactions, as well as of the models of breakup of the projectile and target nuclei. The pseudo-rapidity distributions show strong forward asymmetries, particularly for the interactions with the light nuclei. Heavy target nuclei produce a more severe breakup of the projectile gold nucleus than do the lighter targets. A negative correlation between the number of fragments emitted from the target nuclei and the degree of centrality of the collisions has been observed, which can be attributed to the total destruction of the relatively light target nuclei by these very heavy projectile nuclei. (author). 14 refs, 11 figs, 1 tab

  14. Precision measurement of the mass difference between light nuclei and anti-nuclei

    CERN Document Server

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; 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Zyzak, Maksym

    2015-08-17

    The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons ($\\bar{d}$), and $^{3}{\\rm He}$ and $^3\\overline{\\rm He}$ nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirm CPT invariance to an unprecedented precision in the sector of light nuclei. This funda...

  15. Potentials of interaction between medium energy particles and nuclei

    International Nuclear Information System (INIS)

    Berezhnoj, Yu.A.; Molev, A.S.

    1986-01-01

    The potential of interaction between mean-energy particles and atomic nuclei is determined as a solution of an integral equation relating it to the scattering matrix. Potentials involving the central and spin-orbital or isospin parts are reconstructed on the basis of the scattering matrix of the diffraction model. Approximated expressions for central and spin-orbital potentials in the case of weak refraction are obtained. The effect of nuclear parameters on the shape of central potential of interaction between 156 MeV protons and the 208 Pb nuclei is considered. The calculated and phenomenological central and spin-orbital potentials of interaction between 185 MeV protons and the 90 Zr, 208 Pb nuclei are in good agreement only in the surface region of nuclei. The central and isospin potentials of interaction between the 3 He nuclei with 217 MeV energy and the 9 Be nuclei are studied

  16. Copper diffusion in In2S3 and charge separation at In2S3/CuSCN and TiO2/In2S3 interfaces

    International Nuclear Information System (INIS)

    Juma, Albert Owino

    2013-01-01

    The concept of inorganic nanostructured solar cells consists of a very thin absorber layer sandwiched between highly structured electron and hole conductors. When a TiO 2 /In 2 S 3 /CuSCN nanocomposite heterostructure is illuminated with light, photo-generated electrons in In 2 S 3 can be injected into the conduction band of TiO 2 and holes into the valence band of CuSCN. Charge transfer at the interfaces is limited by the deposition parameters, band alignment and diffusion of Cu from CuSCN into In 2 S 3 , which was the focus of this work. TiO 2 nanoparticles were screen printed onto SnO 2 :F (FTO)-coated glass substrates to give a layer of nanoporous (np) TiO 2 . In 2 S 3 layers were deposited by thermal evaporation or ion layer gas reaction (ILGAR) methods producing Cl-free (In(acac) 3 precursor) and Cl-containing (InCl 3 precursor) layers. A spray-spin method was developed for deposition of CuSCN onto In 2 S 3 . Diffusion of Cu into In 2 S 3 layers was investigated by Rutherford backscattering spectrometry (RBS) while charge transport mechanisms were studied with surface photovoltage (SPV) technique in the fixed capacitor configuration. The activation energy (Ea) for Cu diffusion in thermally evaporated and Cl-free ILGAR In 2 S 3 layers was 0.30 and 0.24 eV, respectively but increased to between 0.72 and 0.78 eV for Cl-containing In 2 S 3 with residual Cl concentrations of 7.8 - 13.8 at.%. The diffusion prefactor (D 0 ) was six orders of magnitude higher for Cl-containing compared to Cl-free layers. The relationship between E a and D 0 was described by the Meyer-Neldel rule with a Meyer-Neldel energy of 40 meV. The presence of Cl has no significant influence on the structural properties of In 2 S 3 but resulted in a modified diffusion mechanism for Cu diffusion. The photovoltage of In 2 S 3 /CuSCN samples decreased after annealing for longer than 2 min at 200 C. A defect band was formed near the interface where holes accumulated and electrons tunneled through

  17. Experiments with stored relativistic exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Geissel, H.; Radon, T.; Attallah, F. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)] [and others

    1998-07-01

    Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: (1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10{sup -6}. The achieved mass resolving power of m/{Delta}m = 6.5 . 10{sup 5} (FWHM) in recent measurements represents an improvement by a factor of two compared to our previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54 {<=} Z {<=} 84. The results are compared with mass models and estimated values based on extrapolations of experimental values. (2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/{Delta}m = 1.5 . 10{sup 5} (FWHM) was achieved in this mode of operation. (3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability. (orig.)

  18. Approximate particle number projection in hot nuclei

    International Nuclear Information System (INIS)

    Kosov, D.S.; Vdovin, A.I.

    1995-01-01

    Heated finite systems like, e.g., hot atomic nuclei have to be described by the canonical partition function. But this is a quite difficult technical problem and, as a rule, the grand canonical partition function is used in the studies. As a result, some shortcomings of the theoretical description appear because of the thermal fluctuations of the number of particles. Moreover, in nuclei with pairing correlations the quantum number fluctuations are introduced by some approximate methods (e.g., by the standard BCS method). The exact particle number projection is very cumbersome and an approximate number projection method for T ≠ 0 basing on the formalism of thermo field dynamics is proposed. The idea of the Lipkin-Nogami method to perform any operator as a series in the number operator powers is used. The system of equations for the coefficients of this expansion is written and the solution of the system in the next approximation after the BCS one is obtained. The method which is of the 'projection after variation' type is applied to a degenerate single j-shell model. 14 refs., 1 tab

  19. Studies of nuclei using radioactive beams

    International Nuclear Information System (INIS)

    Piercey, R.B.

    1989-07-01

    The 12 month period from May 1988 to July 1989 represents the first full year of our 18 month pilot program in nuclear structure research. In this period, research was initiated to develop a capability for radioactive secondary beams at Argonne National Laboratory using the Atlas and the new Fragment Mass Analyzer (FMA), which is currently under construction. Two major new detector facilities are currently in the final stages of design and testing. The Large-Area, Scintillator Telescope (LAST) detector is fully operational and will be shipped to Argonne National Laboratory in August for fit-tests and in-beam calibrations. The first segments of a new sixteen-segment neutron multiplicity detector have been built and tested. The remaining segments are currently being constructed. Research was continued in the areas of (1) Coulomb excitation studies of rare earth and actinide nuclei; (2) In-beam, gamma-ray spectroscopy of nuclei in the mass 100 region, and (3) Advanced detector design. Several journal articles and abstracts were published or submitted for publication in the reporting period, and others are currently in preparation. Three graduate students participated in the program, one from the University of Florida and two from the Royal Institute of Technology, Stockholm, Sweden

  20. STELLAR TRANSITS IN ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Béky, Bence; Kocsis, Bence

    2013-01-01

    Supermassive black holes (SMBHs) are typically surrounded by a dense stellar population in galactic nuclei. Stars crossing the line of site in active galactic nuclei (AGNs) produce a characteristic transit light curve, just like extrasolar planets do when they transit their host star. We examine the possibility of finding such AGN transits in deep optical, UV, and X-ray surveys. We calculate transit light curves using the Novikov-Thorne thin accretion disk model, including general relativistic effects. Based on the expected properties of stellar cusps, we find that around 10 6 solar mass SMBHs, transits of red giants are most common for stars on close orbits with transit durations of a few weeks and orbital periods of a few years. We find that detecting AGN transits requires repeated observations of thousands of low-mass AGNs to 1% photometric accuracy in optical, or ∼10% in UV bands or soft X-ray. It may be possible to identify stellar transits in the Pan-STARRS and LSST optical and the eROSITA X-ray surveys. Such observations could be used to constrain black hole mass, spin, inclination, and accretion rate. Transit rates and durations could give valuable information on the circumnuclear stellar clusters as well. Transit light curves could be used to image accretion disks with unprecedented resolution, allowing us to resolve the SMBH silhouette in distant AGNs.